Hey, I asked this in the single turbo forum as well, but then thought that people who frequent this section may be of more help due to the application.

I am building a custom car that is basically going to be used for track racing with little street use. Im looking for suggestions on what kind of engine to build (which rotors, housings, porting, etc)...

The turbo I am using:
T04E .70, 1.0, P-trim

Complete engines I can use parts from for the new engine:
S4 TII streetported
S4 N/A
S5 N/A

From those 3 engines, what suggestions for an engine can I build? rebuild the TII sp? s5 n/a rotors in a 4 port engine? streetport? partial bridge? bridgeport?
Thanks

 

Well First thing First...Your turbo sizing is too big; for example the turbo exhaust A/R of 1.0
for the track. For some track and street racing I would go with the .69 or .81 A/R which will allow you to be in your power band due it`s quick spooling. Furthermore, I`ll recommend a old school 4 port because the runners are larger ( the plates that are stamp R5). However, you can use a !3B-REW with 88 GXL internals (higher compression).

fuel management I`ll recommend the Microtec LT8s

 

Sorry Andre, but I totally have to disagree with you on turbine A/R size, 1.00 should bee great for decent spool and awsome top end, maybe go down to a .96. A .69 housing would kill the top end, but it would spool up pretty darn quick.

As far as the engine, I would stick with the S4 TII for all the parts. If I were to build a high compression motor I would always be running race fuel through it.

Give it a decent SP and bevel the edges of the rotor housing to get a little more timing out of them and call it good. Maybe switcht to a custom Intake manifold or a REW/RE intake, for no reason more than I don't like to FC UIM at all.

 

I'm currently running an 88' S4 turbo II in road racing up here in Canada. I'm running a 60-1 HiFi turbo with a .58 A/R hotside. (it is too small, but came with the turbo). I've built a street port with the hardened 1990 stationary gears and the lower compression TII rotors. I'm running the Microtech and so far it seems pretty good. When you put the engine together, ensure you have a high pressure oil regulator and build the eninge without a front cover gasket. I siezed my first engine by blowing the little O-ring out of the front cover. The current motor (90% same parts) isn't using the gasket and it works quite well.

-Trent

 

why no front cover gasket? its too weak and will blow out or something? are you suppose to use anything else in its place or nothing at all? im confused a little one this one lol

 

question can you through on the rew/re intake manifold on an s4 tII without any problems i was looking into this but then i was deciding to go with the s5 tII intake manifold wich would work best

 

The front gasket allows too much space between the front cover and the front housing. You use RTV (silicone) instead of the gasket. You can find more info here: http://www.mazdatrix.com/faq/oring.htm

enjoy.

-Trent

 

My 0.02:
After reading Paul Ko's detailed article on the differences between the various versions of 13Bs, I would never use most NA parts in a boosted application. It makes me want to step all the way up to an REW block.

http://fc3spro.com/TECH/SWAP/FD3S/BTvsBREW.html