Question for all the turboed N/Ts

[nates6969]

Hey guys, I just did a turbo install on my 91 talon and so far its running awesome!! I started with 8psi then bumped it up to 10psi. Im logging and not really pulling any knock. My question is how much pressure have you guys been able to boost on stock n/t internals? And what supporting mods have you had to make a long the way?

[david-b]

It's recomended on the 420a motor not to run over about 7 psi. I know you got a 4g63 though. If I'm right, you got the exact same setup as the turbo guys. 4g63 and 4g63t are the same, just one's turboed. I would imagine you'd be fine up to about 15-18psi before you start playing with fire. I may be wrong though. Maybe the internals are different.

[nates6969]

ya the internals run a 9:1 compression in the n/ts compared to 7.8:1 on the turboed cars so its hard to run that much boost safely because 10 psi on a 9:1 is like 14 psi on a turbo motor roughly. Just a comment about the 420a, I've heard of guys going to 12psi safely but you need a strong fuel system. Anybody else with a 4g63n/t t?

Hey also I see your pic says your aiming for 210 whp out of your 420a N/T? How close are you to achieving that?

[Killa]

I will just run 8 psi, just to be safe.

[l_eclipse_l]

Originally Posted by david-b

It's recomended on the 420a motor not to run over about 7 psi. I know you got a 4g63 though. If I'm right, you got the exact same setup as the turbo guys. 4g63 and 4g63t are the same, just one's turboed. I would imagine you'd be fine up to about 15-18psi before you start playing with fire. I may be wrong though. Maybe the internals are different.

Man if that were true then the guys with the 4g63 NA would be ungodly slow. Good thing it's not.

[nates6969]

Hey what compression ratio are you 420a guys running stock?

[SilvrEclipse]

I dont know to much about turboing a 4g63 motor, I dont think to many people here have done that so you might have to search another forum to find your answer. People have ran as much as 15psi on a stock 420a motor. Now thats getting very risky and if your tune isin't damn near perfect its going to blow that motor up.

[nates6969]

huh thats crazy, 15psi on a 420a! I've seen one guy with a 1st gen 4g63 n/t running 19 psi on stock nt internals but had a full front mount, 16g, and full fuel system. I never talked to the guy so I just wanted to see what other guys are running safely

[l_eclipse_l]

Originally Posted by SilvrEclipse

People have ran as much as 15psi on a stock 420a motor. Now thats getting very risky and if your tune isin't damn near perfect its going to blow that motor up.

I would say that's more than risky, that's a death wish for your car. Run a stock 420A above 10-12 psi and it's only a matter of time, no matter how good you have the car tuned.

To answer the question about the compression ratio on a stock 420A IIRC it's around 9.6:1

[vanilla gorilla]

I would recommend 7-8psi daily. No more than 12psi IMO just to be safe. I'm not sure if the trannies are the same between non turbo and turbo 63's. If not the transmission could be a limiting factor, especially if you have an automatic. The internals of the N/T tansmission could be weaker, but not sure.