first race for my new mr2

[nepopolus]

ok my first real drag is coming up with a little rich boy who thinks his car is invinsible(05 gt auto with air intake and exhaust) now i have a jdm swap 2nd gen,intake,custom 3"downpipe and exhaust,ecu chips,and a 50 trim ct-26 and of corse manuel, i would think i already have him beat BUT just incase i am going to get a boost controller to go from 7 psi to 14 with these stats is there a dought i can loose?

o btw will my stock engine be fine on 14psi? the jdm motor had 40k on it

[clem]

if i was you i would turn up the boost to 16psi with race fuel,the car will be fine.Jeff was well over 400hp on a stock motor with over 100,000 miles on it! The only thing u should need to work on is your reaction time and u will be fine!

[MR2Jedi]

I don't know about the race fuel, but I would try to keep it around 15psi. anything above that would be safer to run a bigger IC. other than that your stock motor is fine.
are you talkin' 05 Mitsubishi GT?
anyway, don't over rev the engine. hit your optimum shift points. wind that 3rd and 4th gear.
let us know how this turns out--and be safe.

[JekylandHyde]

Stock boost pressure is 11.8, if you are only getting 7 psi there is something wrong.
For some reason you are stuck in "safe boost."

I would not run over 15 psi with the stock turbo even with race gas and/or a better intercooler.
Nothing you do like that will change the inefficiency of the stock turbo over 15 psi.

[nepopolus]

k tnx and the car is a mustang gt

[toyotaspeed90]

there is always doubt..... you could have engine/car problems or he could actually be a better driver than you.....

and in a 1/4 mile race, he has an advantage over you... since you have the possibility of mis-shifting

[numbone]

If You have a jdm 2nd gen swap i assume u also have the jdm ecu. this would explain your 7 pounds of boost due to standard low octane fuel. running 104 octane will allow the ecu to run 10 - 11 psi. 16psi with 104 octane would close the deal clem and i both use 104 with the JDM MR's when we know theres some guage pegging to be done.

[mr2_dori]

well i have a question then. i have a 3rd gen swap and my stock boost is like 8psi. if your saying that 2nd gens are stock 11.8 then whats is mine. is my stock boost that low because of the fuel i use too. and whats safe boost?

[JekylandHyde]

Originally Posted by numbone

If You have a jdm 2nd gen swap i assume u also have the jdm ecu. this would explain your 7 pounds of boost due to standard low octane fuel. running 104 octane will allow the ecu to run 10 - 11 psi. 16psi with 104 octane would close the deal clem and i both use 104 with the JDM MR's when we know theres some guage pegging to be done.

You are a bit backwards on that.

The JDM cars have HIGHER octane fuel available which is why they put out MORE power and boost.

You should see at least 11.8 psi in any stock turbo MR2.

[mr2_dori]

so why is my 3rd gen at 8psi. if you are saying that its 11.8 on any mr2 turbo.

[JekylandHyde]

Stock boost on a Gen3 is 13 psi and fuel cut was raised to 18 psi.

Why is your stock Gen3 running 8 psi?
Obviously because something is wrong.

My guess is that either the T-VSV is keeping you in low boost for some reason or your boost gauge is wrong.

[mr2_dori]

what is t-vsv? and how can i fix the problem?

[JekylandHyde]

I'm not as famialir with the GenIIIs as I am the Gen 2s, but on the Gen 2s there is a T-VSV. That is a turbo vacuum switching valve.

Basically the wastegate is set up to open at 7 psi. As long as conditions are normal and healthy, the ECU opens the T-VSV to vent off some pressure so that you actually run 11.8 psi of boost. If the ECU senses things that it does't like, it limits boost to 7 psi by closing the T-VSV.

It will limit boost if ambient temps are too low, if coolant temps are too low and a few other situations. I'm not familiar with all of them. If you are not making full boost on a Gen3, I would talk to someone who is knowledgable about that specific engine.

[mr2_dori]

ok thank you. you have been helpful.

[numbone]

if its japanese ecu then you'll only see full stock boost pressure on high octane given that u havent upped the boost manually. if that fuel doesnt help jeff's point on the VSV is very probable. had the same problem with my car when first getting it.