Ok guys I have decided to finally go for the turbo swap on the GTU, I was going to do it right when I got it but the N/A engine on it was a recent rebuilt, I’m not posting this because I want info on the swap (I have done the swap multiple times) but because I’m looking for a setup that would be reliable. I’ve got the engine and I’m about to rebuild it, I was thinking about just going with a street port and just the stock turbo, I don’t want to make a lot of power because is kind of my daily driver. So my question is: what can I do to have the car at around 250whp, keeping my stock turbo and the stock ECU and have a reliable car? I know an exhaust and good down pipe will help and I have those already, but should I go with a SP or a RP or BP, which one will be more reliable. If I get less than the HP goal I have it really doesn’t bother me. Thanks

 

You should ditch the stock ecu route completely. The money spent on gathering stock components adds up quick, especially for s5 t2 stuff. If you go to a bridge port you will need standalone no matter what(not sure what an RP is). However bridge port is wasted on stock turbo.

 

For 250HP you can leave the ports alone.

 

with an exhaust and a aftermarket ecu you will be able to get your 250whp easily. a mate of mine just got 280 from a S4 motor with standard injectors a S5 turbo and a 3" TID and Exhaust

 

OH WERD?

 

Stock ports with 720 secondarys and Rtek 1.7 or 2.0 will do the trick. FMIC will make 250whp easier but it can be done on stock top mount, although it will heatsoak quickly.

Make sure you port your wastegate significantly.

 

wow no one mentioned an upgraded fuel pump?

 

with an aftermarket ECU and 1600cc sec you dont need an upgraded pump. Stock pump is fine for stock turbo power levels.


Doesnt that rtek stuff require all the stock sensors? If so that would be a step in the wrong direction.

 

Id say a reliable t2 would be just a full turbo back exhaust system and maybe a hybrid turbo... simple and nearly stock. good fuel milage and still good performance

 

How's this for reliable......

S5 TII block streetported,built by Mazdatrix.
Turbonetics T04B S5 hybrid.
Supra TT fuel pump.
Stock 550's and 800cc secondaries.
3" exhaust.
FMIC with 60MM piping.
Light flywheel.
14psi max boost.
No AFC's or fuel control trickery,just an FCD to prevent fuel cut.
Stock ECU and all smog controls intact,100% CA smog legal and certified.



Over 5 years and 50,000 daily driven miles on this setup,in my 84GS.It passes smog every year,goes like stink,and gets 20MPG+ on the highway.

 

Nice, thanks guys, yeah I actually will love to not port the engine I forgot to mention that that was my other choice, but I hate to mess with ECU's cause I have no Idea on what to do on that part, that’s why I wanted to go on stock ECU and I don’t have my dad here to help me with that (he knows a lot more about the after market ECU deal than I do).

 

TII in a FB? I love it!

 

 

I guess you missed that part.

 

Yeah, so?

I bet the transition to the secondaries is far from smooth, but if you are under boost then the A/F ratio is probably not all that bad.

People have been swapping secondary injectors LONG before the S-AFC came around...Just turn up the boost until it's not rich! (I'm serious).

 

Exactly.
The only time I ever get any kind of sputter or hesitation is when I hit higher RPMs, without full throttle,but more than just light throttle.....which aint often.

I can go all the way to redline,under vacuum or light boost and the secondaries will never even come online(have my ACVR watching them) and it runs just fine.Under full throttle,it pulls and transitions just fine,no burps or hesitation whatsoever.It amounts to an engine that behaves like stock when Im not playing around,and pulls hard when I want it to.
My current power levels are very entertaining,but its not the fastest thing on the road....Im no fool,....obviously a standalone is far better and would yield much more power,but in CA we have to play by the rules to a degree.I exercise restraint and never push past 14psi,although when its cold out,she pulls even harder at the same boost levels,with no signs of lean out or breaking up.Im satisfied that I found a fun and reliable combination of power and parts, thats within the stock ECU's abilites.