hey guys whays up?? iv only posted here a couple times and havnt in a while, because i am trying to decide on a car to build up still. but i find my self back to leaning towrds the fd, esspecially since a-spec tuning in a few minutes away and i hear they are real good.



so this is my question, iv decided my goal for the car being that it weighs so little is i would like 400-500hp at the crank. do you think that could be done with a turbo thatll hit full boost around 3000rpm???? i want a straight up bad ass street car, thats why low end is so important.



thanks

well i see that the people that viewed my post are to good to answer it and help me out. iv never owned a turbo car so even though this question might be stupid to you, not everyone is blessed with the knowledge of knowing how a 400-500hp rotary will perform.



if there is anyone that still realises the whole purpose of forums and wants to be cool and help me out, id appreciate it.

I'm also a newb, but I'll throw out a no.

The single to run that kind of power would not spool that fast to full boost.

Talk to Sean, I'm sure he'll give you a ride in his car so you could feel what 500 at the crank feels like and where the boost comes on. You're not gonna see it at 3K, that's not gonna happen, full boost would come up a bit later but would pull till redline from a decent size turbine.

actually to anyone that reads my original post. i said 400-500hp at the crank but i dont even need 500. id just like 400-450hp at the crank.



that bring me to something i forgot about. ignore the original post if you want but a shop i talked to told me this and if you could brake it down that would help.



they said with their turbo 385-395rwhp could be made with full boost(15psi) by 300-3100rpm in third gear. now thats cool, that means boost will be there fast in 3rd gear but could you tell me what kind of response that would have in first????

Quit worring about the numbers so much. You soulnd like someone has been reading the internet to long. Go get a ride in a fd from Aspec. You said they are close. I am sure that they would be more than happy to give you a ride and then you can see for yourself how hard a fd pulls under boost at 3k. I am sure it will be faster than you expect it to be.



Good luck.

yea they are close and that sounds like a good idea. its the best way to know for sure. i really want a turbo car but i always hear, "low end sucks" you always got to keep revs high to get n e power" but your right, those people probly dont know what they are talking about. i need to see for my self





thanks

low end doesnt suck on all turbo car's, slap whoever told you that.. i have enough power down low to spin my tire's for 50 feet before i hook up, i've practicly gotta start out in low boost to get any traction, and my boost comes on almost instantly when i floor it any time above 2.5K. and my turbo spools completely by about 3.1K all the way to 17 PSI.. im pushin about 310 whp on my car and it's my daily driver, you wont really need much more then that imo unless your gonna make it a part or full time drag car.. i've never owned a turbo rotary, but i've owned several piston turbo car's..

like ive read before



"if you have turbo lag, youre in the wrong gear"



That being said how much money you have set aside to build a 400-450hp rotary motor? I'll tell you this much im building a T78 terror, aiming for 550hp at 20psi. Its come down to, basically, em replacing everything just so there is some reliability in the equation. So far im looking at around 13-15k...and thats with me doing all the labor. But hey better to build it right the first time, no?



kevin.

i agree but its so flucking expensive to go through with



im aiming for 400 rwhp eventually, before i pulled my motor i was stuck in 300's



when u say 400-450 at the crank what kind of drivetrain loss are you anticipating. 15% would be 340-382.5 or somtehing like that at the wheels which u can do easily with stock turbos all the bolt ons and maybe a street port.



i was at 320 (368 at the crank if u use the 15% rot) with a stock intercooler at 12lbs, with no turbo lag.



**that being said im still looking to go single down the line and ditch my days of no turbo lag for a bit more power and a lot less vacuum lines

if you dont want lag.... you can easily attain that low end of the crank power range pretty easily. all you need are healthy turbos and motor, intercooler, openned up exhaust, stronger fuel pump, bigger injectors, ecu, and a whole lot ot good tuning. you can even get up to 400hp at the wheels (few have done it).



seriously though.... lag is way overrated

second thing....





for the power range you want, the difference between the lag from your goal of 3000rpm and the lag you're gunna get with a single turbo that will help you get to 400-500hp is about 1000-1500rpm.



when you are flooring the car, the car's rpm's go to 8000 in less than 2 seconds. with that said.... do you really think 1000rpm will bother you?



i used to think a lot like you until i realized that all the faster cars out there use bigger turbos, and lag is inevidable... and yet you dont see people trading in their large turbos with smaller ones right...... usually they just get bigger and bigger and bigger.

Seriously, the lack of low end torque is there but it is made up for by the tremendous top end. The engine is not throwing you back for the first two-three seconds of first gear but once the boost builds you feel like your in an airplane taking off. It's a fun car to drive. Like Kevin mentioned also, you can drive in the correct gear to keep right off the boost. With the fd gears you can drive in 3rd from around 30-90mph. Most of the time in 3rd you only have to give it some gas and your at full boost.



Seriously go get that ride and then you see what we are all talking about. Have fun.

I don't know about you guys, but a 400whp FD is more then enough car for the street and strip. And remember, boost builds up gradualy, it's not like you won't any power until fool boost.



Aim for 400 to the wheels and you can get it reliably too.

thanks for all your help, i really appreciate it. to be honest the idea of a little lag real doesnt bother me. i just would like to be able to get up and go pretty good from down low, like i said its a street car so say im waiting to take a turn , i wanna be able to go when i see gap in traffic. also i just dont want to have to floor the car everytime i want some power.



did you guys read the scc issue with the results for the ultimate street car challenge?? if you did youd know how the rotary did(not good at all) and that kinda worried me.



but like you guys said, the only way to see the truth is to get a ride in one.



oh yea , i figured a 15% drive train lose. so 340whp would be 400 at the crank and i know you can do that with the efini twins but i heard your alot better off going single, for the fact that its simpler and more reliable. so i guess the a-spec gt35r might be a good option.

like i say time and time again..... if you need instant power DOWNSHIFT!!! The stock sequential setup has made people lazy and they expect to just floor the car no matter what gear or RPM they are in and see full boost. Just because you see instant boost still doesn't mean you are in your powerband anyway.......

why not do a set of seq bnr stage III? would get to that neighborhood.

[quote name='pushnlacs' date='Mar 13 2005, 04:26 PM'] did you guys read the scc issue with the results for the ultimate street car challenge?? if you did youd know how the rotary did(not good at all) and that kinda worried me.



oh yea , i figured a 15% drive train lose. so 340whp would be 400 at the crank and i know you can do that with the efini twins but i heard your alot better off going single, for the fact that its simpler and more reliable. so i guess the a-spec gt35r might be a good option.


[/quote]



I saw the results, but every car there was modified in all different ways, I remember scratching my head to a few of the Rx7 owner's mods, but the other half of that battle was the DRIVER, like most situations.



And FWIK, 340rwhp is obtainable with the USDM Stock Twins, you don't need Efini Twins or BNR Twins to accomplish that...

again thanks for all the help. but my concern isnt really how the car will perform when floored, this being a street car im concered how itll perform at partial throttle and street driving, but i guess thats determined by tuning as much as parts. did you see the drivability portion for the rex??? they straight up said it had almost no tourqe and that the turbo didnt give any power at anything less than wot, that sucks,lol.



hey just wondering though, what are the bnr seq twins??? thanks again

Peform at partial throttle and street driving? That would be performance like any other car driven at partial throttle....less than full thottle. You can make 400 crank hp with the stock twins, which spool up in the 2500-3000 range. What turbo gives power when its driven in vacume? Almost no torque? Take the time to look at some dyno curves to see what kinda torque rotaries make. Just cause its an rx7 doesn't mean you have to drive WOT to get it to move. Its still a car.

i understand that it shouldnt have to be floored to move but that was my point the rx7 in the scc:uscc most have been tuned crappy as hell cause it was only making a little over 400whp and had no low end tourqe and the turbo didnt provide any thrust at anything less than wot.

So there was an rx7 in the ultimate street car challenge that ran like ****, so what. I happen to know someone who rode in that car, and it was a full blown race car that was "smelly and uncomforatable as hell". And thats coming from someone who owns a 400+rwhp single turbo FD. Probably thrown together too quickly and obviously they never worked out the problems before hand. I daily drove a 400+rwhp single turbo FD for 3 years, and currently drive a 4 time SCCA championship FD a few days a week. You need to go out and drive one to understand.

i'm planning to daily drive a 650rwhp FD for the rest of the short time my life has left once the car is finished.

lol

Just get a ride in a 3rd gen that is running in correct form and you will not even worry about any numbers at all. I also agree with GTC https://www.nopistons.com/forums/pub...1047683785.gif

People put way too much emphasis on lag. They also put WAY too much emphasis on the low-end torque properties of the rotary. All I know is that when I'm trying to save gas and driving around in 6th with the RPMs around 2-3, yeah, the torque isn't really there, but around 4-5k? You'll notice it's just been a lot of talk. (Even though you're not in the powerband.) This is all from a NA rotary, I've not noticed any sort of low-end torque "issue" with my FD, I punch it, it goes. Edit: But like everyone else has said, go ride with someone or test drive one for yourself.

[quote name='Srce' date='Mar 13 2005, 01:47 PM']I don't know about you guys, but a 400whp FD is more then enough car for the street and strip. And remember, boost builds up gradualy, it's not like you won't any power until fool boost.



Aim for 400 to the wheels and you can get it reliably too.


[/quote]





Just knocking on the door of 400...

Here's my car:

http://www.utc.edu/Students/Heath-Moore/hobbies.htm



My dyno sheet can be found in my sig below, just click on the link.



I tried to build it with reliability in mind. I don't see full boost at 3000 but I see it before 4K. Lag is nothing to worry about! I wouldn't change back for anything!

Looks very nice Speed. 400 is plenty for a car of the FD's weight.

yea 400whp is definitly cool for a street fd. hell id be cool with like 385whp.



i know i made my concern seem like lag was my focus but its not really lag or when i hit full boost when it comes down to it. its tourqe that matters.



i looked at some of the dyno sheet on here but they were all for real high hp cars.(all i saw were 475whp+ dyno sheets) or weak ass cars. so do you think a 385whp-400whp 13b could produce 200lbs-ft at around 3000rpm??? i know its more numbers and actually riding in a fd will tell me alot more but im just wondering.



hell even better, does anyone have a dyno sheet of their fd with around 385-400whp? or is any one running the a-spec gt35r turbo,or apexi rx6, and have a sheet??



thanks, you guys have been real cool and i appreciate it.

[quote name='pushnlacs' date='Mar 15 2005, 11:57 PM'] hell even better, does anyone have a dyno sheet of their fd with around 385-400whp? or is any one running the a-spec gt35r turbo,or apexi rx6, and have a sheet??



thanks, you guys have been real cool and i appreciate it.


[/quote]



Go here: http://dyno.zeroglabs.com/dyno.php



Found that in a thread of an arguement over BNR Twins vs. Single on the other forum. You can edit what PSI and turbo type you want to view at once, its really really cool.



Besides finding out what turbo you want for what power, when....it's a great way to notice how awesomely cool the powerband of a rotary truly is. The lines are great, as far as their angle and the "area under the curve", it's not a swooping bell curve all the time like other turbo'd cars...

Here's my torque to hp ratio on the rx6 turbo. I later upgraded to a much larger turbo but never dynoed it, but it made a whole lot more power than this setup. This dyno was with a street port.

hey man how did you like the rx6?? obviously you wanted more power but what did you think abou t it response wise and street wise????



also to the guy that left the link. that was cool and all but it only show hp and no nothing for tourqe, also it had a rx6 producing 450whp.

I liked the rx6, probably considered one of the best single turbo's for the street. Spools up quick due to its smaller size and ball bearings and provides a little more power over the stock twins.

dayem BB turbo's run out of torque early, no? curve was flat for 500

rpms.

[quote name='DUB' date='Mar 16 2005, 01:32 PM']dayem BB turbo's run out of torque early, no? curve was flat for 500

rpms.


[/quote]



I'm not sure I understand your question. I don't believe ball bearings have anything to do with it, its the size of the turbo that dictates the power. At some point the torque curve crosses the hp curve, typically around 5500 rpms on rotaries. At that point the hp rises as the torque decreases. One way to help keep the torque from dropping off dramatically is by increases the timing after peak torque.

hey 94touring, how tuned was your car when you ran that dyno and how much psi were you at?? iv actually come to a conclusion on what id want out of a fd, i would like a 380whp(450 or so crank hp) street car. can the rx6 produce 380whp at a reasonable psi or no??



also , anyone have anyexperience with a a-spec gt35r powered fd???

I was running around 15psi on that run. The apexi seems to be in the 385rwhp range for most people, some higher some lower.

how would you say the rx6's response stacked up compared to the stock twins? one guy said the rx6 doesnt make 7psi until 3500rpm and i know thats some bs.

I'd say its comparable to non-seq twins. 500rpms or so later then the regular seq setup. Its not something thats noticable. When I ran a 62-1 which was much bigger than the apexi, it made such good low end power the extra lag was no factor.

cool, thanks.