New Engine Tech Information Request
01-03-2006, 02:06 PM
#1
Junior Member
Thread Starter
Join Date: Jul 2004
Posts: 10
First a little background on what I am doing. I race an FC in basically World Challenge trim in the Touring GT Series here in Ontario. We have had some success, but always a bit down on power with a ported stock S4/S5 intake system and stock S4 ECU. Been held back a bit over the last year or so with my bone stock, though new, S5 Mazda Reman motor (total time on the motor would be less than 20 hours). Last spring the engine ate up its bearings due to a combination of too much throttle on really cold oil (less than 150 degrees oil and water) and the fact that it was pulling over a G in cornering loads. Gotta love co-drivers. Anyways the time has come to rebuild this motor and give it more pop.
So this is the new package. The engine will be a half bridge on the outer 5th and 6th ports using the new Mazda Reman S5 irons and housings. All other ports will be a large street port. I will not be using the sleeve inserts, but will be using a larger wedge (like a Pineapple insert) in the Auxillary port holes. The exhaust will be a large Racing Beat Street port. I will be using clipped S5 rotors and FD Bearings. A bit of discussion is taking place on 2 piece or Racing Beat 1 piece carbon seals. The exhaust is a Racing Beat Road Race header with 120 inch primaries merging into a single 3 inch pipe through a Borla muffler.
The intake will be created using Hayabusa throttle bodies (46mm) with 30 mm velocity stacks drawing from a cold airbox drawing from in front of the front fascia. I will be creating the intake from a 1 inch thick motor flange that will be flowed from a 50mm pipe to the motor's port diameter. The intake stubs will be mandrel bent at a 45 degree angle (to clear the shock tower) to allow me to reach a 11 to 13 inch intake runner length. I will be using the stock S4 fuel rails (primary and secondary) and have both the stock 460's and 550's available to run.
Enough background I think. What I am looking for is great throttle response and a minimum of 200 to 210 RWHP. The throttle bodies will add some "WOW" factor, but they do seem to work extremely well in Australia. I am only planning on pulling a max of 8500 rpm with this motor with very very occasional bursts past that (when I miss a shift). Will set up the stand alone to rev limit at 8750 rpm. The motor needs to be reliable and and have some torque above 4000 rpm, so I am concerned about apex seals and port timing. I am of 2 minds on the apex seals. I have heard that the Racing Beat Carbon Seals give up some chamber sealing for high rpm capability and that stock Mazda 2 piece seals work better up to 8500 rpm, but give you no margin for error. Secondly, is the secondary only bridge with a large street port too much port timing for my application. My irons are untouched at this time, but will start cutting shortly and would like some advice and knowledge. I have some existing partial bridge and street port templates so am just looking for some actual experience from people who have done this already. With the ITB I definitely won't be inlet constrained and as I dont have to worry about low rpm response, I need what works best from 4000 to 8500 rpm.
Any other advice on build components would be appreciated, as I want to do this right the first time.
Thanks in advance.
Eric
(hoping to drag Bill Shurvington out of the woods for his advice as well)
So this is the new package. The engine will be a half bridge on the outer 5th and 6th ports using the new Mazda Reman S5 irons and housings. All other ports will be a large street port. I will not be using the sleeve inserts, but will be using a larger wedge (like a Pineapple insert) in the Auxillary port holes. The exhaust will be a large Racing Beat Street port. I will be using clipped S5 rotors and FD Bearings. A bit of discussion is taking place on 2 piece or Racing Beat 1 piece carbon seals. The exhaust is a Racing Beat Road Race header with 120 inch primaries merging into a single 3 inch pipe through a Borla muffler.
The intake will be created using Hayabusa throttle bodies (46mm) with 30 mm velocity stacks drawing from a cold airbox drawing from in front of the front fascia. I will be creating the intake from a 1 inch thick motor flange that will be flowed from a 50mm pipe to the motor's port diameter. The intake stubs will be mandrel bent at a 45 degree angle (to clear the shock tower) to allow me to reach a 11 to 13 inch intake runner length. I will be using the stock S4 fuel rails (primary and secondary) and have both the stock 460's and 550's available to run.
Enough background I think. What I am looking for is great throttle response and a minimum of 200 to 210 RWHP. The throttle bodies will add some "WOW" factor, but they do seem to work extremely well in Australia. I am only planning on pulling a max of 8500 rpm with this motor with very very occasional bursts past that (when I miss a shift). Will set up the stand alone to rev limit at 8750 rpm. The motor needs to be reliable and and have some torque above 4000 rpm, so I am concerned about apex seals and port timing. I am of 2 minds on the apex seals. I have heard that the Racing Beat Carbon Seals give up some chamber sealing for high rpm capability and that stock Mazda 2 piece seals work better up to 8500 rpm, but give you no margin for error. Secondly, is the secondary only bridge with a large street port too much port timing for my application. My irons are untouched at this time, but will start cutting shortly and would like some advice and knowledge. I have some existing partial bridge and street port templates so am just looking for some actual experience from people who have done this already. With the ITB I definitely won't be inlet constrained and as I dont have to worry about low rpm response, I need what works best from 4000 to 8500 rpm.
Any other advice on build components would be appreciated, as I want to do this right the first time.
Thanks in advance.
Eric
(hoping to drag Bill Shurvington out of the woods for his advice as well)
01-03-2006, 05:09 PM
#2
Member
Join Date: Aug 2004
Location: Houston
Posts: 76
You didn't mention what you are going to use for an ecu. Don't try this setup on a stock ecu. It won't work. If this was your intention and aftermarket ecu would actually do more on the stock intake than the other way around. Hopefully you did just forget to mention this option but you definitely need one.
01-04-2006, 08:29 AM
#4
Senior Member
Join Date: Dec 2003
Posts: 162
Well I'm honoured that you think I may be worthy here :-)
I'm currently playing with a set of R1 TBs as they have a pressure operated slide throttle before the butterflies and I'm pretty sure I could make an interesting inlet for a turbo motor with them.
The Busa throttles should be perfect for you. You may want a longer inlet though. My measurements are not on this PC, but I will try and dig them out later. If you PM me your email address then I'll send you back the spreadsheet that shows how length affects the torque curve to give you an idea of where you want to be.
Obviously dependant on the sort of racing you are doing, but you have about 15HP to shift around with intake tuning. You can have it at 8500 or at 5500, whichever makes you faster.
Factoid: MV Augusta bikes have variable length slides on their runners. Rare bike, but If you can wipe one out on the highway, get the TBs off it. You only need about a 2" length change to have your cake and eat it.
I'm currently playing with a set of R1 TBs as they have a pressure operated slide throttle before the butterflies and I'm pretty sure I could make an interesting inlet for a turbo motor with them.
The Busa throttles should be perfect for you. You may want a longer inlet though. My measurements are not on this PC, but I will try and dig them out later. If you PM me your email address then I'll send you back the spreadsheet that shows how length affects the torque curve to give you an idea of where you want to be.
Obviously dependant on the sort of racing you are doing, but you have about 15HP to shift around with intake tuning. You can have it at 8500 or at 5500, whichever makes you faster.
Factoid: MV Augusta bikes have variable length slides on their runners. Rare bike, but If you can wipe one out on the highway, get the TBs off it. You only need about a 2" length change to have your cake and eat it.
01-04-2006, 08:32 AM
#5
Junior Member
Thread Starter
Join Date: Jul 2004
Posts: 10
Sorry, we will be running a Megasquirt to control both ignition and fueling. Just need to work out how we will tune the 'squirt to run ITB's. Thanks as well to Kim for your advice. I am already selecting an eccentric shaft to do the weber jet mod.
I also have the 110 psi Racing Beat regulator, the Racing Beat windage tray, the full Racing Beat pulley set (Crank, Water Pump and Alt.) I am also moving the alternator to increase wrap around the water pump pulley. The car has dual oil coolers as well as a 3 quart Accusump to handle oiling. I do have an S4 Turbo II oil pump that I was planning to use on this motor.
I also have the 110 psi Racing Beat regulator, the Racing Beat windage tray, the full Racing Beat pulley set (Crank, Water Pump and Alt.) I am also moving the alternator to increase wrap around the water pump pulley. The car has dual oil coolers as well as a 3 quart Accusump to handle oiling. I do have an S4 Turbo II oil pump that I was planning to use on this motor.
01-04-2006, 08:41 AM
#6
Junior Member
Thread Starter
Join Date: Jul 2004
Posts: 10
Bill, when you measure inlet lengths are they measured from throttle shaft to housing mounting face or from port opening into the chamber to velocity stack opening into air box. Also does the length of cold air runner from front fascia to airbox have any real life effect? I would think that the tube length should provide some minor pulse charging effect when you combine it with airbox volume, stack length, etc...., however if force to make a choice of maximizing the last 1-2hp with a longer cold air tube versus packaging in the engine compartment being a lazy sort at heart I will choose packaging ease every time.
01-04-2006, 10:16 AM
#7
Senior Member
Join Date: Dec 2003
Posts: 162
I measure from housing mounting face to end of bell. For calculating resonances you need to measure from port to end of bell +0.3d.
Looked up my notes and I reckon that you need closer to 15". If you can make it such that you can put different length stacks on I would. Ideally primaries and secondaries should be tuned slightly differently as opening times change, but you are into the territory where you need a dyno to optimise.
The airbox will have some small resonances, but generally down under 3000RPM and of no consequence compared to the gains from getting cool air into the engine. A 10C drop in inlet temps will get you air that is some 3.5% denser. On a 200HP engine that is worth 7HP.
Looked up my notes and I reckon that you need closer to 15". If you can make it such that you can put different length stacks on I would. Ideally primaries and secondaries should be tuned slightly differently as opening times change, but you are into the territory where you need a dyno to optimise.
The airbox will have some small resonances, but generally down under 3000RPM and of no consequence compared to the gains from getting cool air into the engine. A 10C drop in inlet temps will get you air that is some 3.5% denser. On a 200HP engine that is worth 7HP.
01-04-2006, 01:40 PM
#10
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Thread Starter
Join Date: Jul 2004
Posts: 10
Bill, just need to clear up some terminology you used "+.03d". Does this mean plus .o3 multiplied by the diameter of the intake runner. If so, as I am using a 50mm (just under 2") runner tapering down to intake port length through a 2" aluminum mounting plate, the length of mounting plate, runner, throttle bodies and velocity stack is 15" / 381mm plus 1.5mm = 382mm?
Right now my setup has the 2" plate, 4" throttle body, 2" velocity stack and a 6" runner. All I need to do is add 1" to my runner length and I am there.
Am I right with my calculations?
Right now my setup has the 2" plate, 4" throttle body, 2" velocity stack and a 6" runner. All I need to do is add 1" to my runner length and I am there.
Am I right with my calculations?