20b In A Glc
03-20-2005, 05:04 PM
#954
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Join Date: Nov 2001
Posts: 2,284
Wow, I haven't posted in this thread at all this year. I just have one 13B to rebuild and install in my REPU before I can get back to this project. The Megasquirt bench testing is complete. It has ignition control on all three leading plugs with an extra spark 180° after each initial spark every 120°. In other words, the engine will receive one ignition event every 60°. Is that any less confusing? I also have the option to run it in a more usual way where the leading has only one spark per rotor face with trailing and no split. I'll eventually get to the dyno and compare both ignition options. I can tell you that my carbed 13Bs all benefitted from the 180° leading spark, regardless of trailing, so I assume the 20B will like it too. You've all heard the sound clips I posted last year when my engine was test fired with my modded 12A dizzy and a makeshift carb setup. The 180° spark idea worked and the engine reved quick and started even at slow cranking speeds, but the carb certainly wasn't right for the engine (it wouldn't idle or stay running).
05-12-2005, 03:01 PM
#956
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Join Date: Nov 2001
Posts: 2,284
Cool, they were both probably built in the same week.
'74 thermostat housing on an FC waterpump. The front hub is stock. I don't think any other hub would work with the 20B's nut, but I didn't compare them when I had it off for the front cover swap.
'74 thermostat housing on an FC waterpump. The front hub is stock. I don't think any other hub would work with the 20B's nut, but I didn't compare them when I had it off for the front cover swap.
08-13-2006, 04:09 PM
#957
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Join Date: Nov 2001
Posts: 2,284
Good news and bad news.
Good news: It runs now on the MegaSquirt!!
Bad news: It overheats!
So what can I do? Last year, I got it to fire up and run in warm up mode taking advantage of the warm up enrichments and the BAC valve on the 20B throttle body. Then as soon as it would warm up to the point of closing the BAC valve and ending the enrichments, it would stall and I couldn't keep it running with my foot.
I had spent so awefully much time on the project as a whole that I had a ton of other stuff on hold that needed attention. Plus I invested all my MegaSquirt time on the hardware side of it, and not enough on the software (tuning) side. I couldn't proceed until I understood the concept of tuning better (I still don't to be honest).
I got several vehicles running while the GLC sat there. Then a week ago I took a refresher course on the MegaSquirt and it only took me a few days to get reaquinted with it.
Following some MegaSquirters' advice, I concentrated on learning what needed to be done to get it to idle on its own without the BAC valve or enrichments, and yesterday I put what I had learned to the test. It paid off, but some other problems showed up.
Anyway, it could be driven fairly quickly around the block. The extra torque of a 20B is appearant at low RPM. Interestingly, the higher the RPM would go (up to about 6k I think), the less power it would have. I blame the 2" exhaust system. When the secondary injectors kicked in around 4k, a lot of smoke could be seen in the rear view mirror. It was probably clearing out the oil buildup inside the secondary ports, caused by old oil seals.
It stopped smoking and the idle didn't smell as bad as the white truck. Man, the white truck runs rich with the old carb meant for a thermal reactor. The exhaust system is very loud now. I think I blew out one or more of the glass packs. Oops. It's at least as loud as the white truck, but with a different tone.
It overheats. The radiator is a 3 row core short style for a '79-'82 1st gen. The '79-'82 1st gen oil cooler is sitting out in front of the rad. The oil temp measured in the pan with a compost bin thermometer got up to 195° but the water temp got up a little past 200° just idling. The fan is the 16" you can see in the pics earlier in this thread. It has 2" of overhang top and bottom because the core is only 12" tall. Cool air enters the oil cooler, heats up, then enters the radiator. The rest of the radiator core is sort of blocked by the bumper.
It doesn't matter whether it sits idling or driving forward at part throttle; the temp climbs and climbs.
Full throttle runs are scary (which is honestly what I was hoping for), but they're scary in regards to the temp, which shoots up quickly when I do it. I was only able to 'gun' it a couple times unfortunatley.
The clutch feels too weak. It's just a stock replacement 225mm disc as can be seen on the Mazdatrix website, and I think the pressure plate is stock. The engagement is long and smooth (blah). I've got a brand new RB street strip pressure plate and HD disc in 225mm that could go in. I think they're going to be a requirement; especially when I put this 20B into something else.
That's right. The 20B has to go into something else. I think it's too much engine for this tiny car. I'd have to remove the bumper, get a custom radiator, get a new fan or two, redo the whole exhaust system in 2 1/2", upgrade the rear end, brakes etc. Just about the only thing that was up to snuff was the fuel system (3/8" line, great flow/volume and so on) which can be kept for a carb or transfered to another vehicle pretty easily.
It was an interesting project for me, and I'm sure you guys enjoyed reading about it. I think I'd rather cut my losses and take what I've learned and do a 2 rotor in this car. It'll still be a great little car, just not quite as grand.
The next question is which vehicle should the 20B go into? A tried and true FC? Many have done them. An FB/SA? Well, maybe I could since the engine will stay NA. I was seriously considering my '76 Cosmo but only four things were keeping me from doing it:
1)shifter position
2)heater core
3)time
4)money
I solved the heater core issue when I measured the distance from the stock shifter hole to the e-brake handle and discovered there is slightly more room in the Cosmo. However the center console would get all cut up, which wasn't an issue in the GLC because there was no center console to worry about.
I never solved the heater core issue because it's right next to the tranny tunnel. It would have to be removed in order to make room for the back of the engine and the slave cylinder. Since I wanted to keep the heater core and already went to so much effort to reatain the heater core in the GLC, I decided against it.
Incidentally I discovered the heater core is leaking in the GLC yesterday. It's just a slow drip. Kind of ironic I suppose.
Lastly, the time and money aspect. I expended so many resources getting the 20B to fit and run in the GLC that it didn't feel right (at the time).
It turns out my brother wants the Cosmo now. It's cool because he helped me to get it back in '98. It's an auto and with the 20B coming out of the GLC, I may have a genuine Cosmo 5 speed for it. I already have the pedals, master and slave from a parts car so it seems doable.
So this means no 20B in the Cosmo, for me, for now. 1st gen? 2nd gen? Both good choices if you ask me. The only problems are that I don't have either car, and I have too many other vehicles around here. My brother was originally interested in one of my REPUs but when he learned the Cosmo was running well after a carb swap, he set his sights on it. Minus one vehicle is minus one vehicle, right?
So he is no longer interested in one of the REPUs... The white one is my daily driver, that is to say I can drive it day to day without problems, but it has its fair share. It needs ball joints, front wheel bearings, new rims which are hubcentric because the current aftermarket lugcentric rims tend to vibrate. Also the rear drums are a bit warped giving it a pulsation under braking. Faily easily fixable, but require time and a desire to fix them. The engine is street ported with a stock carb so it's actually slower in the lower revs than when it had stock ports. The upper revs are pretty good, but the carb runs out of breath by 5 or 6k. The exhaust is also quite loud and has a droning resonating sound that, while unique, isn't pleasant over long periods. The steering is tight and it handles as well as could be expected.
The red truck has been sitting since '03. I have a genuine '74 REPU engine nearly ready to go together for it. It's in better shape over all than the white truck with the only problem being sloppy or 'wonder' steering. Otherwise, it would be a nice truck to get running again. I just installed a new 7 pound Carter fuel pump. I'm debating which tranny it should get.
Three ribcase trannies. Two '76 Cosmo 5 speeds and one '78 RX-4 5 speed. The '78 has taller 1st, 2nd and 5th. Its original home had a rearend gearing of 3.636. It totally felt like you were starting off in 2nd gear all the time. I'm thinking if I put that tranny into one or the other REPU, it would probably be an improvement over the Cosmo gearing (which is the same as a stock REPU 4 speed, only without the 5th gear). See for yourself.
Good news: It runs now on the MegaSquirt!!
Bad news: It overheats!
So what can I do? Last year, I got it to fire up and run in warm up mode taking advantage of the warm up enrichments and the BAC valve on the 20B throttle body. Then as soon as it would warm up to the point of closing the BAC valve and ending the enrichments, it would stall and I couldn't keep it running with my foot.
I had spent so awefully much time on the project as a whole that I had a ton of other stuff on hold that needed attention. Plus I invested all my MegaSquirt time on the hardware side of it, and not enough on the software (tuning) side. I couldn't proceed until I understood the concept of tuning better (I still don't to be honest).
I got several vehicles running while the GLC sat there. Then a week ago I took a refresher course on the MegaSquirt and it only took me a few days to get reaquinted with it.
Following some MegaSquirters' advice, I concentrated on learning what needed to be done to get it to idle on its own without the BAC valve or enrichments, and yesterday I put what I had learned to the test. It paid off, but some other problems showed up.
Anyway, it could be driven fairly quickly around the block.
It stopped smoking and the idle didn't smell as bad as the white truck. Man, the white truck runs rich with the old carb meant for a thermal reactor. The exhaust system is very loud now. I think I blew out one or more of the glass packs. Oops. It's at least as loud as the white truck, but with a different tone.
It overheats. The radiator is a 3 row core short style for a '79-'82 1st gen. The '79-'82 1st gen oil cooler is sitting out in front of the rad. The oil temp measured in the pan with a compost bin thermometer got up to 195° but the water temp got up a little past 200° just idling. The fan is the 16" you can see in the pics earlier in this thread. It has 2" of overhang top and bottom because the core is only 12" tall. Cool air enters the oil cooler, heats up, then enters the radiator. The rest of the radiator core is sort of blocked by the bumper.
It doesn't matter whether it sits idling or driving forward at part throttle; the temp climbs and climbs.
Full throttle runs are scary (which is honestly what I was hoping for), but they're scary in regards to the temp, which shoots up quickly when I do it. I was only able to 'gun' it a couple times unfortunatley.
The clutch feels too weak. It's just a stock replacement 225mm disc as can be seen on the Mazdatrix website, and I think the pressure plate is stock. The engagement is long and smooth (blah). I've got a brand new RB street strip pressure plate and HD disc in 225mm that could go in. I think they're going to be a requirement; especially when I put this 20B into something else.
That's right. The 20B has to go into something else. I think it's too much engine for this tiny car. I'd have to remove the bumper, get a custom radiator, get a new fan or two, redo the whole exhaust system in 2 1/2", upgrade the rear end, brakes etc. Just about the only thing that was up to snuff was the fuel system (3/8" line, great flow/volume and so on) which can be kept for a carb or transfered to another vehicle pretty easily.
It was an interesting project for me, and I'm sure you guys enjoyed reading about it. I think I'd rather cut my losses and take what I've learned and do a 2 rotor in this car. It'll still be a great little car, just not quite as grand.
The next question is which vehicle should the 20B go into? A tried and true FC? Many have done them. An FB/SA? Well, maybe I could since the engine will stay NA. I was seriously considering my '76 Cosmo but only four things were keeping me from doing it:
1)shifter position
2)heater core
3)time
4)money
I solved the heater core issue when I measured the distance from the stock shifter hole to the e-brake handle and discovered there is slightly more room in the Cosmo. However the center console would get all cut up, which wasn't an issue in the GLC because there was no center console to worry about.
I never solved the heater core issue because it's right next to the tranny tunnel. It would have to be removed in order to make room for the back of the engine and the slave cylinder. Since I wanted to keep the heater core and already went to so much effort to reatain the heater core in the GLC, I decided against it.
Incidentally I discovered the heater core is leaking in the GLC yesterday.
Lastly, the time and money aspect. I expended so many resources getting the 20B to fit and run in the GLC that it didn't feel right (at the time).
It turns out my brother wants the Cosmo now. It's cool because he helped me to get it back in '98. It's an auto and with the 20B coming out of the GLC, I may have a genuine Cosmo 5 speed for it. I already have the pedals, master and slave from a parts car so it seems doable.
So this means no 20B in the Cosmo, for me, for now. 1st gen? 2nd gen? Both good choices if you ask me. The only problems are that I don't have either car, and I have too many other vehicles around here. My brother was originally interested in one of my REPUs but when he learned the Cosmo was running well after a carb swap, he set his sights on it. Minus one vehicle is minus one vehicle, right?
So he is no longer interested in one of the REPUs... The white one is my daily driver, that is to say I can drive it day to day without problems, but it has its fair share. It needs ball joints, front wheel bearings, new rims which are hubcentric because the current aftermarket lugcentric rims tend to vibrate. Also the rear drums are a bit warped giving it a pulsation under braking. Faily easily fixable, but require time and a desire to fix them. The engine is street ported with a stock carb so it's actually slower in the lower revs than when it had stock ports. The upper revs are pretty good, but the carb runs out of breath by 5 or 6k. The exhaust is also quite loud and has a droning resonating sound that, while unique, isn't pleasant over long periods. The steering is tight and it handles as well as could be expected.
The red truck has been sitting since '03. I have a genuine '74 REPU engine nearly ready to go together for it. It's in better shape over all than the white truck with the only problem being sloppy or 'wonder' steering. Otherwise, it would be a nice truck to get running again. I just installed a new 7 pound Carter fuel pump. I'm debating which tranny it should get.
Three ribcase trannies. Two '76 Cosmo 5 speeds and one '78 RX-4 5 speed. The '78 has taller 1st, 2nd and 5th. Its original home had a rearend gearing of 3.636. It totally felt like you were starting off in 2nd gear all the time. I'm thinking if I put that tranny into one or the other REPU, it would probably be an improvement over the Cosmo gearing (which is the same as a stock REPU 4 speed, only without the 5th gear). See for yourself.
Code:
Vehicle Year 1st 2nd 3rd 4th 5th Axle Final Cosmo 76 3.683 2.263 1.397 1.000 0.862 3.636 3.134 RX-4 77-78 3.380 2.002 1.390 1.000 0.791 3.636 2.877 ----------------------------------------------------------------------- 3.683 2.263 1.397 1.000 0.862 4.625 3.986 '76 Cosmo 3.380 2.002 1.390 1.000 0.791 4.625 3.658 '78 RX-4 0.303 0.261 0.007 .000 0.071 .000 0.328 ----------------------------------------------------------------------- 1st 2nd 3rd 4th 5th '76 Cosmo 5 speed: 3.683 (1.420) 2.263¶(0.866)¶1.397 (0.397) 1.000-(0.138)-0.862 '78 RX-4 5 speed: 3.380-(1.378)-2.002-(0.612)-1.390-(0.390)-1.000¶(0.209)¶0.791 ----------------------------------------------------------------------- Gear multiplication factor comparison REPU Tranny: '76 Cosmo, Axle: 4.625, REPU 1st 2nd 3rd 4th 5th 3.683 2.263 1.397 1.000 0.862 4.625 4.625 4.625 4.625 4.625 -------------------------------------- 17.033 10.466 6.461 4.625 3.986 Tranny: '78 RX-4, Axle: 4.625, REPU 1st 2nd 3rd 4th 5th 3.380 2.002 1.390 1.000 0.791 4.625 4.625 4.625 4.625 4.625 -------------------------------------- 15.632 9.259 6.428 4.625 3.658 Tranny: 1st gen RX-7, Axle: 4.625, REPU 1st 2nd 3rd 4th 5th 3.674 2.218 1.433 1.000 0.825 4.625 4.625 4.625 4.625 4.625 -------------------------------------- 16.992 10.258 6.627 4.625 3.815 ----------------------------------------------------------------------- Final drive ratios in each gear REPU 1st 2nd 3rd 4th 5th 17.033 10.466 6.461 4.625 3.986 '76 Cosmo 15.632 9.259 6.428 4.625 3.658 '78 RX-4 16.992 10.258 6.627 4.625 3.815 1st gen RX-7
08-13-2006, 04:49 PM
#958
Senior Member
Thread Starter
Join Date: Nov 2001
Posts: 2,284
I was all set to install the RX-4 tranny in my red truck but I could never quite get over the possiblity that the torque multiplication may be lacking a little in 1st and 2nd coupled with the stock power of the engine. I feared my towing capabilities may be reduced. The taller 5th was desireable though. I had considered a supercharger in the future, but with so many other projects on my plate I didn't think it would ever happen. Plus I needed to be able to tow stuff in the mean time on stock power.
The possibility of installing the 20B into the white truck solves everything, and here's why.
The front suspension is stiff due to the springs having been cut (by a previous owner) and when hauling lots of weight in the bed, the suspension actually gets a little softer (more comfortable) up front. It's my guess the front end could handle the extra 70-80 pounds of a 20B without complaining too much, if at all, and if anything, the ride quality could potentially improve.
The curent ported R5 4 port 13B has a cast iron waterpump and a heavy stock REPU 30 pound flywheel (that's not including disc or pressure plate). The rotors are the heaviest (1757 part number), and the side plates are heavier than 12A Y castings or S5 T2 castings. The lighter weight of the rotors, rotor housings and side plates along with a light steel flywheel could potentially offset the 36 pound 80mm thick 20B only intermediate plate, if the extra length of the engine goes rearward. This would allow for the use of a stock FC clutch fan, for which I'm sure the 20B has enough power to spare.
The cooling system is quite large and temps never get very high, even under a fair bit of load. The heater core doesn't even blow warm air in the winter,although I think the selector cable popped out of its clamp. The rad is taller and wider, the oil cooler is bigger, and the cross sectional grill area is a lot more than the GLC. superior cooling, even compared to an RX-7 methinks.
The motor mounts are stiff and haven't sagged like the ones in the red truck. Perhaps they were replaced with the 'competition' ones by a previous owner. The tranny mount crossmember thing under the truck was hacked to fit the 5 speed which has its mounts further back. I happen to have an unmolested 4 speed tranny mount sitting here that could be reworked to locate the tranny 160mm further back I suppose.
I'd keep the header I built for the GLC I think. It's not the best, but It would empty into a 2.5" system and the white truck's current 2" exhaust could be transfered to the red truck, which sorely needs something.
The gas tanks on these early REPUs were around 20 gallons. Would I need a 1.5 liter surge tank fed by a carb pump, which the EFI pump could then draw from? Or could I adapt a feed tube at the bottom of the tank and use the original siphon/send line as a return line?
Speaking of fuel lines, could I use the stock 5/16 send and 1/4 return lines that run along the frame or would I need to install a 3/8" send line and use the 5/16" as a return?
The possibility of installing the 20B into the white truck solves everything, and here's why.
The front suspension is stiff due to the springs having been cut (by a previous owner) and when hauling lots of weight in the bed, the suspension actually gets a little softer (more comfortable) up front. It's my guess the front end could handle the extra 70-80 pounds of a 20B without complaining too much, if at all, and if anything, the ride quality could potentially improve.
The curent ported R5 4 port 13B has a cast iron waterpump and a heavy stock REPU 30 pound flywheel (that's not including disc or pressure plate). The rotors are the heaviest (1757 part number), and the side plates are heavier than 12A Y castings or S5 T2 castings. The lighter weight of the rotors, rotor housings and side plates along with a light steel flywheel could potentially offset the 36 pound 80mm thick 20B only intermediate plate, if the extra length of the engine goes rearward. This would allow for the use of a stock FC clutch fan, for which I'm sure the 20B has enough power to spare.
The cooling system is quite large and temps never get very high, even under a fair bit of load. The heater core doesn't even blow warm air in the winter,although I think the selector cable popped out of its clamp.
The motor mounts are stiff and haven't sagged like the ones in the red truck. Perhaps they were replaced with the 'competition' ones by a previous owner. The tranny mount crossmember thing under the truck was hacked to fit the 5 speed which has its mounts further back. I happen to have an unmolested 4 speed tranny mount sitting here that could be reworked to locate the tranny 160mm further back I suppose.
I'd keep the header I built for the GLC I think. It's not the best, but It would empty into a 2.5" system and the white truck's current 2" exhaust could be transfered to the red truck, which sorely needs something.
The gas tanks on these early REPUs were around 20 gallons. Would I need a 1.5 liter surge tank fed by a carb pump, which the EFI pump could then draw from? Or could I adapt a feed tube at the bottom of the tank and use the original siphon/send line as a return line?
Speaking of fuel lines, could I use the stock 5/16 send and 1/4 return lines that run along the frame or would I need to install a 3/8" send line and use the 5/16" as a return?
08-13-2006, 05:24 PM
#959
Senior Member
Thread Starter
Join Date: Nov 2001
Posts: 2,284
Getting back to the tranny, I think it would be fine to install the RX-4 tranny into the REPU if it has more power, and the 20B will certainly fit the bill and cost less than a supercharger.
The RX-4 tranny could actually be considered a close ratio tranny. Just look above and you'll see that although 1st starts at a somewhat lower engine RPM because it's a taller gear requiring more power to get over the lower multiplication factor, it's closer to 2nd than the earlier gearsets of the REPU and Cosmo trannies, and the revs don't go down as much allowing for a narrower power band like with a ported engine, likewise 2nd is closer to 3rd. 3rd and 4th are about the same. 4th is still 1.000 as it has been for a long time across several Mazda trannies. 5th is taller than the earlier trannies and was Mazda's attempt at getting better gas mileage. In the RX-4, 5th was hardly ever used because the owner didn't often travel on the freeway. I use 5th all the time in the REPU at slow speeds because 4th and the 4.625 diff ratio feels like you're in 2nd or 3rd all the time.
The stock shifter is very close to the bench seat in the REPU to begin with. How can I move it back an additional 16CM or 6 3/8" (I think) and expect to be able to use it? Well, I could set up something called a dogbone which is a linkage to connect from the new shifter position (under the seat lol) to the stock position. I imagine it's kinda like a volkswagen bug or something.
That's the shifter position issue solved. What's left are the heater core, time and money. The heater core is actually further away from the firewall than the Cosmo, but its still down on that level. Only the GLC's heater core was up out of the way. This could cause a problem. I'll have to really get into it and take some careful measurements, but from initial observations, it appears difficult but not impossible to retain the heater core. The gas pedal situation should be similar to the GLC as well.
Time and money. Since my brother is no longer interested in the REPU, I'll hang on to it and drive the red one while I convert the white one. The red one will get a Cosmo tranny for the lower geared 1st and 2nd, thus allowing easier towing on stock power, it'll get a real '74 engine (it's a nice touch), and the exhaust from the white one. All that's left are rims and tires and it's done. But will I have enough time to do all of this? I haven't even looked into a budget yet.
Hey j9fd3s, if I actually go through with this, yet another 20B will be in yet another white Mazda vehicle. What's with that? Here's an older pic of the truck. Sleeper, eh? I've got another grill which isn't missing a chunk. I think I'll tranfer the missing headlight to the other side so I can have a cold air intake on the NA side. Maybe.
The RX-4 tranny could actually be considered a close ratio tranny. Just look above and you'll see that although 1st starts at a somewhat lower engine RPM because it's a taller gear requiring more power to get over the lower multiplication factor, it's closer to 2nd than the earlier gearsets of the REPU and Cosmo trannies, and the revs don't go down as much allowing for a narrower power band like with a ported engine, likewise 2nd is closer to 3rd. 3rd and 4th are about the same. 4th is still 1.000 as it has been for a long time across several Mazda trannies. 5th is taller than the earlier trannies and was Mazda's attempt at getting better gas mileage. In the RX-4, 5th was hardly ever used because the owner didn't often travel on the freeway. I use 5th all the time in the REPU at slow speeds because 4th and the 4.625 diff ratio feels like you're in 2nd or 3rd all the time.
The stock shifter is very close to the bench seat in the REPU to begin with. How can I move it back an additional 16CM or 6 3/8" (I think) and expect to be able to use it? Well, I could set up something called a dogbone which is a linkage to connect from the new shifter position (under the seat lol) to the stock position. I imagine it's kinda like a volkswagen bug or something.
That's the shifter position issue solved. What's left are the heater core, time and money. The heater core is actually further away from the firewall than the Cosmo, but its still down on that level. Only the GLC's heater core was up out of the way. This could cause a problem. I'll have to really get into it and take some careful measurements, but from initial observations, it appears difficult but not impossible to retain the heater core. The gas pedal situation should be similar to the GLC as well.
Time and money. Since my brother is no longer interested in the REPU, I'll hang on to it and drive the red one while I convert the white one. The red one will get a Cosmo tranny for the lower geared 1st and 2nd, thus allowing easier towing on stock power, it'll get a real '74 engine (it's a nice touch), and the exhaust from the white one. All that's left are rims and tires and it's done. But will I have enough time to do all of this? I haven't even looked into a budget yet.
Hey j9fd3s, if I actually go through with this, yet another 20B will be in yet another white Mazda vehicle. What's with that? Here's an older pic of the truck. Sleeper, eh? I've got another grill which isn't missing a chunk. I think I'll tranfer the missing headlight to the other side so I can have a cold air intake on the NA side. Maybe.
08-14-2006, 01:23 AM
#960
Senior Member
Thread Starter
Join Date: Nov 2001
Posts: 2,284
So am I crazy for wanting to do this kind of a project? Has anyone ever done an actual REPU? I've seen pics of some B series pickups with 20Bs, which number about as many as 1st gens. Well, maybe I've seen a couple more 20B powered 1st gens than B series, but FCs are by far the most popular, followed by FDs.
What I'm wondering is since the FC is the most popular choice, shouldn't I be working toward that end? Or is it a more personal choice? Or should I consider the right place and the right time along with my budget?
I honestly couldn't afford to do a high HP 20B in an FC. From the pictures and videos I've seen, I couldn't do it justice. Besides I don't even have one. Plus my heart isn't in it. Perhaps if I had one I'd be thinking differently. But then the **** types like EvilAviator suggest to start off with a T2 for the stronger tranny, better this and that and so on. Heh, good luck finding one out of the blue and not having to bend over.
Which brings me to the FB/SA. I had the oppertunity to get an engineless white SA recently, but there were too many cars here. The problem with the SA is the gas tank is too small with the spare tire well is in the way so I couldn't easily install a GSL-SE tank, and the rear end is an open diff with drum brakes. I'd have to change a bunch of stuff to make it viable. I'd probably want to move the tranny back just a little, but it'd be more difficult than if it were an FB with its shifter extension housing, which can easily be shortened 4" (or any other length if you get creative). However an early ribcase 5 speed will bolt right into an SA, so at least I could use a strong tranny with it. Oh the possibilities.
I also have a streetported 4 port R5 13B ready to drop into a 1st gen. It even has a GSL-SE oil pan and a choice between a freshly surfaced GSL-SE flywheel or a counterweight for a future light steel or aluminum flywheel upgrade. The oil pressure is between 80 and 100 psi, probably 95ish, an FC waterpump and would do well with a Camden supercharger. The SC is kinda heavy, but not as heavy as a 20B. I'll have the torque of a 20B without the weight (nor the wait for a turbo to spool). It's got new apex seals and within spec for the other hard seals. It fired up quickly first time and was able to idle all the way down to 600 RPM within 2 minutes of run time. Very little smoke. I was impressed since its ports are quite large. It's sitting in the red truck for break in. Perhaps the heavy REPU flywheel is helping a little.
The truck would suck with an engine like that. I should know because the white truck already has an engine similar to that, and it's slow down low even with the low diff gearing. A friend's truck has an R5 with an automatic which I ported only out to '74 spec (50° if I remember correctly) and it is vastly quicker than my white truck with a 5 speed. The carb is a stock '74 with the proper jets for that year and port size. I'm hoping I can emulate his truck in my red truck, and the '74 engine with my spare '74 carb ought to do the trick.
Aside from the obvious handling and decent brakes of RX-7s being reasons for droping 20Bs into them, should I do something different with mine? This thread is more for my benefit so don't mind my mindless banter. Let's recap.
The GLC overheats with this much HP if cooling capacity has anything to do with engine output (which it does). It's a small car that could get away with a 2 rotor.
I'm not doing an FD because they're money pits and I don't have one. I couldn't afford to get one even if I wanted to.
I've thought about doing an FC but when it comes down to it, I don't have that deep inner drive which would be required in order to do it justice.
I seriously considered doing a 1st gen and I may still do one, except I already have a nice 13B ready to go, which would suck if I kept it in the truck, unless it was boosted, which I can't afford to do at this time, so it makes sense to put it into a fairly small light car such as a 1st gen, in which it would still be driveable and probably pretty fun until I can afford an SC. That's the way my friend did it, and it's a very awesome package (it gave the Iotus car a run for its money out on the highway). The 13B with SC wouldn't hurt the handling as much as a 20B would. Besides RX-7s are awesome in the twisties, and too much power could potentially make them untractable. Did I spell that right? Anyway it's a possibility for now since I don't have one and can't get one until I finish my current run of projects.
The Cosmo ain't gonna happen because my brother wants it, and I'm happy to oblige since it'll reduce the number of cars around here, and I'm not using it for anything at the moment.
The MG could fit the 20B if I worked at it long enough. The intake manifold would fit since it's very close to the engine. The stock oil pan would fit since there are no obstructions. The starter would intrude into the driver's foot area and the rear header pipe would intrude into the passenger's foot area. The UIM is tall enough that it would probably stick out of the hood. The shifter would move back 16cm which would make it rather uncomfortable to shift. Nah, the 13B fits with 1 or 2 mm to spare on either side. It's tight but serviceable except you gotta pull the engine to do a clutch job.
I'm not really considering some other car. What else is there? I've seen pics and vids of a 20B powered Miata, Rene's RX-2, the Pac Performance RX-3, Lance Warren's HB Cosmo, and just today a 350Z doing donuts. Most vehicles have had extensive work done to handle the extra torque. The REPU comes stock with big universal joints and a Mazda version of a Ford 9". The rear brakes have dual wheel cylinders and the bed capacity is 1400lbs. It's a hair under 3/4 ton in what appears to be a 1/4 ton pickup. No wonder the suspension is so stiff.
Should I do this project because it's different? Because of the 20B-friendly color? Because the vehicle already handles half decently and has beefy drivetrain components? And because I already have an engine ready to drop into a 1st gen if and when I get one? Oh, and because nobody has done an actual REPU before to the best of my knowledge?
What's the worst that could happen? Interfere with the gas pedal a little? The heater core? Shifter linkage no workage? I'll think about it.
What I'm wondering is since the FC is the most popular choice, shouldn't I be working toward that end? Or is it a more personal choice? Or should I consider the right place and the right time along with my budget?
I honestly couldn't afford to do a high HP 20B in an FC. From the pictures and videos I've seen, I couldn't do it justice. Besides I don't even have one. Plus my heart isn't in it. Perhaps if I had one I'd be thinking differently. But then the **** types like EvilAviator suggest to start off with a T2 for the stronger tranny, better this and that and so on. Heh, good luck finding one out of the blue and not having to bend over.
Which brings me to the FB/SA. I had the oppertunity to get an engineless white SA recently, but there were too many cars here. The problem with the SA is the gas tank is too small with the spare tire well is in the way so I couldn't easily install a GSL-SE tank, and the rear end is an open diff with drum brakes. I'd have to change a bunch of stuff to make it viable. I'd probably want to move the tranny back just a little, but it'd be more difficult than if it were an FB with its shifter extension housing, which can easily be shortened 4" (or any other length if you get creative). However an early ribcase 5 speed will bolt right into an SA, so at least I could use a strong tranny with it. Oh the possibilities.
I also have a streetported 4 port R5 13B ready to drop into a 1st gen. It even has a GSL-SE oil pan and a choice between a freshly surfaced GSL-SE flywheel or a counterweight for a future light steel or aluminum flywheel upgrade. The oil pressure is between 80 and 100 psi, probably 95ish, an FC waterpump and would do well with a Camden supercharger. The SC is kinda heavy, but not as heavy as a 20B. I'll have the torque of a 20B without the weight (nor the wait for a turbo to spool). It's got new apex seals and within spec for the other hard seals. It fired up quickly first time and was able to idle all the way down to 600 RPM within 2 minutes of run time. Very little smoke. I was impressed since its ports are quite large. It's sitting in the red truck for break in. Perhaps the heavy REPU flywheel is helping a little.
The truck would suck with an engine like that. I should know because the white truck already has an engine similar to that, and it's slow down low even with the low diff gearing. A friend's truck has an R5 with an automatic which I ported only out to '74 spec (50° if I remember correctly) and it is vastly quicker than my white truck with a 5 speed. The carb is a stock '74 with the proper jets for that year and port size. I'm hoping I can emulate his truck in my red truck, and the '74 engine with my spare '74 carb ought to do the trick.
Aside from the obvious handling and decent brakes of RX-7s being reasons for droping 20Bs into them, should I do something different with mine? This thread is more for my benefit so don't mind my mindless banter. Let's recap.
The GLC overheats with this much HP if cooling capacity has anything to do with engine output (which it does). It's a small car that could get away with a 2 rotor.
I'm not doing an FD because they're money pits and I don't have one. I couldn't afford to get one even if I wanted to.
I've thought about doing an FC but when it comes down to it, I don't have that deep inner drive which would be required in order to do it justice.
I seriously considered doing a 1st gen and I may still do one, except I already have a nice 13B ready to go, which would suck if I kept it in the truck, unless it was boosted, which I can't afford to do at this time, so it makes sense to put it into a fairly small light car such as a 1st gen, in which it would still be driveable and probably pretty fun until I can afford an SC. That's the way my friend did it, and it's a very awesome package (it gave the Iotus car a run for its money out on the highway). The 13B with SC wouldn't hurt the handling as much as a 20B would. Besides RX-7s are awesome in the twisties, and too much power could potentially make them untractable. Did I spell that right? Anyway it's a possibility for now since I don't have one and can't get one until I finish my current run of projects.
The Cosmo ain't gonna happen because my brother wants it, and I'm happy to oblige since it'll reduce the number of cars around here, and I'm not using it for anything at the moment.
The MG could fit the 20B if I worked at it long enough. The intake manifold would fit since it's very close to the engine. The stock oil pan would fit since there are no obstructions. The starter would intrude into the driver's foot area and the rear header pipe would intrude into the passenger's foot area. The UIM is tall enough that it would probably stick out of the hood. The shifter would move back 16cm which would make it rather uncomfortable to shift. Nah, the 13B fits with 1 or 2 mm to spare on either side. It's tight but serviceable except you gotta pull the engine to do a clutch job.
I'm not really considering some other car. What else is there? I've seen pics and vids of a 20B powered Miata, Rene's RX-2, the Pac Performance RX-3, Lance Warren's HB Cosmo, and just today a 350Z doing donuts. Most vehicles have had extensive work done to handle the extra torque. The REPU comes stock with big universal joints and a Mazda version of a Ford 9". The rear brakes have dual wheel cylinders and the bed capacity is 1400lbs. It's a hair under 3/4 ton in what appears to be a 1/4 ton pickup.
Should I do this project because it's different? Because of the 20B-friendly color? Because the vehicle already handles half decently and has beefy drivetrain components? And because I already have an engine ready to drop into a 1st gen if and when I get one? Oh, and because nobody has done an actual REPU before to the best of my knowledge?
What's the worst that could happen? Interfere with the gas pedal a little? The heater core? Shifter linkage no workage? I'll think about it.