My STi vs. The World

[04wrx4keeps]

Nice race against the BPU Supra! That's pretty much what I would expect. When my friend was driving my STI(Stock though) we had a similar race in my BPU+ Supra and he jumped out pretty good, but once that 2nd turbo came on line and I got out of second. I blew by hard.

With a nice 300awhp and that substantial low-end STI torque I'm sure it would have been a lot closer. Hehe, close to 400 crank ft-lbs for you. Did you get that one on video?

Just a question because you mentioned the 2nd turbo comming on. Dont know if you've heard about this but while researching supras a while ago I came across a simple (and if I remember correctly free) mod that allows both turbos to run constantly instead of sequentially in the TT Supras. It was some sort of wiring mod if I remember (its been a while since I read it), just thought I'd chime in, in case you'd never heard about it, I'm sure it would give a nice little boost in the lower RPM and probably spool the turbos faster, although I think I remember them saying it kills your gas milage, but that would be expected...

[garrettjj]

Yeah I can speak to that. You are referring to TTC or "True Twin Conversion". Actually it decreases low end torque/power beause it causes both turbos to come on at once at about 4500rpm or so. One good thing is that there is no transition from the 1st to 2nd turbo seeing they both work in unison. In sequential mode, there is a split second delay before the second one charges up. You still run the same amount of boost with TTC, so it's really not worth it in my opinion. There is a joke about that setup because you get more lag and the same amount of power. Most people use TTC as a tool when troubleshooting boost problems with the sequential system. TTC is also a little safer than sequential..I've heard of people blowing their second turbo from overboosting if something is wrong with their sequential plumbing.

Personally I really enjoy the low-end response from the sequential system. The first turbo comes on line at 1,800rpm with full effect by 2,500rpm or so. It usually good for .7 bar on a BPU car and by 4500rpm the 1st turbo feeds the second and whoooosh you get the afterburner effect. I run about 16-18 psi on 91 pump. IMO max boost on stock twins should be no more than 18psi. You could run more with higher octane, but you are out of the efficiency range by than and your just pushing hot air.

[04wrx4keeps]

Yeah I can speak to that. You are referring to TTC or "True Twin Conversion". Actually it decreases low end torque/power beause it causes both turbos to come on at once at about 4500rpm or so. One good thing is that there is no transition from the 1st to 2nd turbo seeing they both work in unison. In sequential mode, there is a split second delay before the second one charges up. You still run the same amount of boost with TTC, so it's really not worth it in my opinion. There is a joke about that setup because you get more lag and the same amount of power. Most people use TTC as a tool when troubleshooting boost problems with the sequential system. TTC is also a little safer than sequential..I've heard of people blowing their second turbo from overboosting if something is wrong with their sequential plumbing..

Sounds cool. I remember on the sight I read it on they made a bunch of performance claims...you deffinatly sound like you know what your talking about to they were probably talking it up a bit.

I cant wait to get back in to Supras, I always wanted to turbocharge my 85, and before long I should have the funds to do it. I've seen alot of people online with the 6M turbo swaps, but I dont remember (its been a year or two since I looked up much supra stuff) reading many storys about 2JZ swaps. I thought it might not be a bad Idea as I hear nothing but good things about that motors strength, durrability and potential (SCC has articles about 4 1000hp+ supras in texas this month, which was pretty good). If I remember the Block is fundamentally the same, and I know the 6M is a (reletively) straight forward swap so they would probably be similar. I would imagien the JZ has better heads though and if it is in fact much stronger (correct me if its not...) it could be worthwhile.

[garrettjj]

Nice times for your WRX! You're almost in the 12's. I just got the COBB AP Stage 1 and am really liking the performance increase. I kept telling myself I would not mod the STI, at least for a while, but that didn't last too long. A Helix catted DP is on the way while I choose what exhaust I want to get. Then of course it's time to upload COBB Stage 2.....

STIGuy, my goal is 300awhp for my STI. What mods do you have on yours?? I'm thinking a COBB Stage 2, turbo back exhaust will get me there-or close to it.

[04wrx4keeps]

Thanks, I've got a TMIC on the way, and a walbro and a Pro-tune will soon follow, hopefully after that I will be in the 12's.

Just a suggestion on the exhaust, since you already have a DP and just need a catback check out the Skunk2. I've seen them new on e-bay for a pretty good price (my friend picked one up for like 350) and I've loved mine, it sounds awesome, very deep, not annoyingly or droning highway loud, and I get alot of compliments on the sound. Its not too loud (maybe a little more with the extra 0.5L in the STi) and its, in my oppinion, the best sounding exhaust I've heard (not that on these cars the all sound ALOT different, but some do). I've also had 1 person buy one, and 2 people I met at a meet were really interested in it after hearing mine. I've yet to run into a single other WRX with the Skunk2, other than the store owner I bought mine from (after listening to the one on his shop car) and my friends. Also back in the day I think SCC did a dyno'd camparo and actually got some hp out of it on the stock car, so it must flow pretty well, especially with the DP. They hit 190whp in the test, and for comparisoon they got a little over 180 on the stock car and the Skunk2 was the highest on the list.

[STiguy]

When i dyno'd i had Turboxs RFL-Ti turboback w/ cat, K&N Typhoon intake, Worx BOV, and Utec tuned for 19 psi