Max Boost????

[Daniel Jost]

I have a 85 GN that has a few mods; like complete stainless exhaust headers back 3in down pipe,cold air intake and aluminum intake pipe, and so on. i was wondering what the max boost is that i can run safely with 110 race gas on a stock turbo?

 

[85 TR]

i beleive that the stock turbo is done around 17psi , i recently ported my heads and intake and it feels like my stocker is done at 15 psi i dont beleive there is any reason to run 110 with the stock turbo cuase you should be able to tune on pump gas well unuff to max out that turbo.

 

[racemybuick]

I believe with a stock turbocharger, and the 110 fuel, You can get away with 18 lbs of boost buuut... That is with very, very good tuning, a chip for the right combo, enough fuel pump for higher Pressure, an adj FPR...assuming that you have most of the basic mods, like the Adj FPR, the walbro pump (340), the right prom chip, and some fine tuning, the higher boost will cause too much knock over 18#'s. I think the sweet spot is right around there, no higher. If you want high boost, alcohol and a bigger turbo are the way to go! I am planning on having a custom turbo mounted (TA54 or TA60), 65 lb injectors, alcohol injection, and fully ported heads and intake. With that combo, boost can go upwards of 22#'s. If you want the best bang for the buck, save some $$, and buy one of John Craig's TA33c turbo's. They are the stock outside, performance inside turbocharger. I think he wanted $800 or around there. The turbo, along with alcohol injection, got my motor to a 12.8 in the 1/4, just before I bought it from Herb Fishman.

Anything over 18 lbs is asking for big knock problems, along with a mess of other problems. I think by keeping it moderate for a while, getting it tuned in at around 16 lbs and making everything run optimum should be the best start, then bump it up a pound and see how it reacts. Dont push it too far, and if you dont have the right guages, do not try pushing it at all unless you can see what is going on inside. Good luck!

John

 

[turbojitsu85]

I pushed 21psi with the stock turbo and 100 octane but when I pulled the car in the garage I could smell burning oil. So now I keep it at 18psi.

 

[GNBeswick]

I had heard that the stock turbo is useless after 20 psi not 17? I just installed Razor's Alky Kit on my car, so I figured Id try running 20 psi.

 

[Daniel Jost]

right now im porting my heads and i am looking at puting alky on my car soon before it comes out of the garage next summer, i am also looking at the 87 ecm,MAF, and ECM upgrade. i have a computer scanner right now for knock i also have a boost guage. i cant tell anything with this computer so with the 87 ECM i will probably be getting a turbo link.

 

[BuickTV6]

I was able to run 19 psi on the stock turbo with my current setup. and about 100 octane fuel. I was curious to see how the stocker held up with the intercooler kit. I was impressed. Ran outta steam at about 4500 rpm's and higher, but from light to light it pulled as good as my Ta33 I got now. I would say with good tuning, no more than 19-20. anything after that is just hotair and effeciency of the turbo lost. just my 2 cents

 

[Turbo Riviera]

I run 21 psi at 4400 ft. elevation in my 84 Riviera t-type. Same as turbo regal motor.

Stock heads, intake and turbo. I run VP C16 to get it to that level.

At sea level the car sits at about 27 psi WOT. It doesn't even start making HP until 17 psi. Between 17 and 21 it really starts to come alive.

I have had the same turbo on since '99 and the car has made over 500 1/4 mile runs on the stock long block. 75,000 miles.

 

[Daniel Jost]

Thanks for all the help if snyone has any other advice keep it coming