max boost

[oldschool226]

hey guys does anyone no how much boost you can get out of an stock turbo from an 85 gn? the factory gauge said about 11 lb when the motor was pulled.

[Keller]

The maximum boost from the factory for all 84-87 TRs was set to be 1 Bar, or 14.7 PSI. If the car wasn't making that much boost, it could have been caused by a clogged catalytic converter, an issue with the wastegate or its hose routing, or another issue.

Yes, you can increase the boost. Stock turbos are limited to about 20-21 PSI before it becomes counterproductive. Larger turbos can handle more. Note that with more boost you have to use race fuel or alcohol injection and adjust timing in order to not have detonation.

[oldschool226]

Thanks for the info sounds like turbo needs help. What replacement turbo would you recommend. I've got a stock block and heads, 86 intake, 86 1 1/2 headers, 3 in exhaust intercooler, accel dfi, and 40lb injectors.

[charlief1]

The fact that it looks like you're switching over to an IC set up then you can pretty much put what you want on it for a turbo, providing you have the supporting upgrades to go with it. The best thing you can do is set a goal on how fast you want to go before you decide anything else.

One thing I can tell you is a very good piece of advice. Build it for the 10's and run it at 11's without breaking anything.

[Keller]

First, if those are the Accel 40# injectors, I say use something else. Even the Accel trainer saw a GN at the dyno shop were at with these, and told the owner, "Why do you are you using those? We don't even make them anymore. They are JUNK!" The comment was totally unprovoked.

"What turbo?" and any other questions are based primarily on ET and HP/torque targets. Decide what you want to do, and then plan from there. The "Performance Recipes" section of the site has some help in this regard.

As far as PSI, every turbo has a limit where going to a higher boost simply generates heat, and does not make more power.

First, pick a target and then fill in the 'wants' with the correct products. We can point you in the direction once there is a target.

[oldschool226]

Thanks guys i'll get it in and running then see where i want to go with it. low 11's and streetable sound real good!!