Recommend some tuning tips for this stock 86 GN

[TurboBuickSix]

I just got this 86 GN and need to know what to put my fuel pressure at.It is all stock with stock exhaust and catalytic conv still intact with stock downpipe also.It was at 50 psi with line off but that is high compared to the non IC car I had.The boost is spiking to 15 then drops down to 12,it pulls good but falls off on the top end like the timing is being pulled out.The motor has only 33k original miles.I have a adj wastegate,K&N,and adj fuel pressure regulator.Everything else including chip is stock and untouched.

I am going to mod it with the usual stuff over the winter but need someone to recommend what fuel pressure and boost level I should run for now or anything else I should know.The primary fuel is Sunoco 94.TIA

 

[Dan Thompson]

the first thing is to do the 'Spring Cleaning" this will get things ready for tuning and also get you familar with the car.

Check out this website

http://www.gnttype.org/maint/basics.html

Do you have a scan tool?

Fuel pressure is usually around 42 to 43 with the vaccum line off in idle.

It is not unusual for the stock orginal cars to fall off at top end because of the fuel pump.

Need hotwired fuel pump, I use a Quad Air XP+, and a new fuel filter.

Here is a good build up recipe

http://www.gnttype.org/techarea/recipes/recipe.html

 

[blackbuick87]

You are probably WAY rich. The stock chip only needs 38psi line off. The stock boost was only set for 13psi in that chip, so 12 is not far off.
You need to crank down the FP, throw in a 160 t-stat, and order a Thrasher 92. Also I would replace the fuel pump. These simple mods will give you about 50hp and 1 sec off your 1/4 mile. Your car will run much better also

 

[TurboBuickSix]

I lowered the pressure to 40 psi w/line off and it ran better when it warmed up.It ran horrible cold though,it is 50 degrees here tonight.I just remembered the previous owner told me there were splitfire plugs in the motor right now,If memory serves me right I thought that I heard that they are bad for our motors? I am going to pep boys tomorrow to get some cr43ts'.Thanks for the help.

 

[eiuskoalman]

you're on the right track by swapping the splitfires out for the cr43's. if you're gonna drive it like you stole it than dont wait for 2 things, a scanmaster and a fuel pump with a hotwire kit. the last thing you want to do is to break your new toy before you get to enjoy it in the nice cool fall turbo weather. good luck, aaron

 

[UNGN]

I have personally witnessed the trauma splitfires can do to a buick turbo engine. Remove them as soon as possible.

 

[84tt]

Just thought I would drop a line from Hawaii...
My friend has a stock 87 t as well that runs 12.90's all night on slicks in roughly 80 degree weather.....
He did some minor upgrades to get it into the 12's
Walbro 340
Hotwire kit
Autolite 24's
Fuel pressure 42.5 psi
8 position chip
Running only the downpipe, not through the exhaust
15-20 psi boost?? No boost guage or scanmaster
Cold air intake

Realitively cheap upgrades to do 12's
Aloha