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true twin conversion

9209 Views 42 Replies 5 Participants Last post by  Zerosoul
Hey everyone I am wondering about the TTC mod, is it better, has anyone gained horspower on the dyno or are people running faster quarter miles, or also are people racing other supras with the same mods as them but are sequential and are winning. Can I get some help please thanks.

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you dont run faster in 1/4 mile, you will lose boost below 4000rpm. do it to save your #2 turbo and to get use to driving a single turbo.:D once abover 4500rpm, it does not make a differenc between sqeusntial or TTC
it will not gain hp unless your existing sequential operation is having problem and one of the valves is not opening up all the way not not letting you boost.
I have the TTC mod, it may not give more HP, but when racing it does seem to lower 1/4 mile times. When launching the car only first gear has lag, none of the other gears do. The sequentials i've raced, i start pulling on them after 5000 in second, not by alot but like half a car or so, with the same mods but they dont have TTC. Plus, it saves #2 turbo from breaking, and it pulls much nicer like a big single turbo.

TTC does not save your second turbo. I can verify this from personal experience. Also the lag until 4k rpms is to much if you ask me. If it were a single I could understand but for really small twin turbos it should stay in sequential.
I wouldn't know if it saves them, i've heard it does, but i've had no problems yet.. the lag is alot when cruising and then hitting the gas, but not much when launching. How many miles did you have when your turbo went out.
My car had 62k when the turbo took a shit. I converted my turbos back to sequential when this happened. Only my first turbo boosted. I thought to myself why the F* did I ever go to TTC. Why give up low end power if you have it? Plus your still going to have topend power so with stock twins you can have the best of both worlds. I agree with you though that from a dead stop TTC doesn't lag especially if you launch high like me. TTC= To much lag/ ie. it sucks.
The lag was something i got used to, off the line acceleration was spectacular though. It may not give you more HP, i dont know for sure, but do you know if it lowers 1/4 times and increases trap speed?
1/4 mile times....

From what I understand the 1/4 mile times are very similar. So if your sole reason to switching to TTC is to lower your et's its not worth it. My car is currently in the shop to get a new set of twins. I'm going to stay with sequential this time around.
I bought my car used, how can I check/tell if my car has that mod? If I do I would like to know.
Does your car lag under 4k rpms? If so it's in TTC. If the car pulls and then @ 3,500rpms it starts to kick you in the ass again then it's in sequential.:cool:
Chucky Doll said:
Does your car lag under 4k rpms? If so it's in TTC. If the car pulls and then @ 3,500rpms it starts to kick you in the ass again then it's in sequential.:cool:
It starts with lag, then it kicks in. 9I would guess it's in sequential mode) I don't know at what RPM though. Thanks!
As far at running TTC at the track, I have found SEQ a lot eaiser to get consistant 60' times, however I did pull my best 60' in TTC. In TTC you have to luanch at higher rpm's and slip the clutch otherwise you will bog badly, much worse than you would bog in SEQ. After first gear I never saw any differance because both turbo's are online the whole run in wither mode.
Very true, on one of my first races i didn't launch w/enuf RPMs, it bogged down and my RPMs dropped to like 2500, major turbo lag then. Its just a little trickier.
Elejes--- if you dont start boosting untill 3900-4100 RPM its TTC. Mine kicked in right at 4100 RPMs.
TTC eliminate those "accident" kick to #2 turbo. it also makes the car run cooler cruizing cuz #1 is not spinning that fast and boosting., that I have several supras to varify. just downshift and you'll be alrite.
I can testify as well that TTC is much easier on the turbos. It eliminates many potential shaft twist problems associated w/ kick starting #2 in sequential mode.
in fact, I just took out both butterfly that controls the AIC and EGC valves last weekend (got that idea from HKS Trac removal kit). no more leaky Toyota check valves, no more sequential operation.:D thats how much I love TTC mode after went back and fourth for 2 years.

Just drop a gear and thats it? LOL. Not starting a flame war here but didn't you get your ass handed to you by a Z06 b/c by time your turbo's kicked in it was to late? My car has only been BPU for @5-6 miles. Never ran above 1.4 bar (high boost) and 1.2 (low boost). Most be a freak reason why my second turbo died. I can personally say that I have never lost to C5 vette. I've run into two Z06 vettes that would not run my car. Driver ability is everything! Peace.
like you said, driver skill wins it all.
now what would be the difference if I slip/drop the clutch above 4000rpm between sequential/ttc mode? nothing.
no turbo lag above 4000rpm. C5 eat my shorts.

Zerosoul said:
in fact, I just took out both butterfly that controls the AIC and EGC valves last weekend (got that idea from HKS Trac removal kit).
How did you take out the AIC? I have the EGCV removed for better flow but still have the AIC. Since i can't go back anyways I would also like this to be removed.

1. disconnect vacuum hoses connected to the metal vacuum tubing. you wont be able to disconnect the vacuum hose at the back so just push the tubing aside so you have access.

2. losen the rubber connector that joints turbo manifold located right beside the engine....also losen 2 nut that holds manifold to top of #2 turbo. be'll come out.

3. once that manifold is out, you can see the butterfly inside holding by 2 small screw, take it out. as for that bar that holds the butterfly, I just left it cuz I dont have thing to fill the hole if its taken out. not much restriction anyway.

4. I also disconnected the VSV and actuator which is no longer needed, put a resistor to the VSV connector, and re-install manifold back.

now, its your term to explain to me how you take your EGC butterfly out. I havnt done that. I think the EGC valve part of exhaust manifold can be taken out? or did you pull the EGC butterfly out while leaving it attached to the turbo?

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