There seems to be some confusion out there on what a safe max level of boost to run on a stock motor is. Some people say you will experience head lifting at 18-20psi so ARP bolts maybe necessary. Exhaust valves and other valvetrain maybe at risk etc. We all know E85 can take a stock motor up to some serious boost levels depending on the turbo. Spoolin runs very high boost levels but only puts 1500 miles a year on the car, so that may not be relevant for people who put 5-6,000 miles or more on the car.

So what are some real world experiences out there for people running stock motors. What boost levels do you run, fuel type, how many miles on that boost level etc. Any problems at 20-22psi level?

What is the consensus for what is a safe level to run for a daily? I am currently running 18psi on E85 with a stock motor wih no issues so far. I do not drive like I stole the car however. Mainly just some 3-4 gear pulls.

Any input would be appreciated.

 

I respect the car but still have fun with it.. 22 psi 2000 miles so far in 2 months

 

You need to understand there is a lot of misinformation on the forums. The majority of people saying not to run a certain boost level have no real world experience. That goes for any engine. There are a lot of variables involved in "not running more than xxlbs" on an engine. Backpressure, quality of petrol, intake air temperatures, maintainence, etc. As long as you have a good tune, good setup and keep up with oil, fuel filter, etc. You will be fine at 22lbs.

 

Good to know! Thanks

 

And here i was, about to start this same topic...


Im currently running 19psi on e85 only because 3 respected tuners I know on seperate occasions
(without suggestibility influences from each other) all agreed for me to not go past 19psi with my setup.
Seems like consistant advice to me.

But like i was telling Corey, I would be happy to know I can safely turn it up to 22psi (or w/e),
but considering all the variables such as what induction performance mentioned, is it really worth the risk?

Thats what I'm contemplating. Theres a lot to monitor to decide...

 

Does cylinder pressure matter? Also, wouldn't there be any concerns with the stock piston rings?

 

My opinion; using "boost level/PSI" as a guage to determine what is safe for a stock motor is not the best way guaging what a motor will hold. There are a lot of varibles involved in determining when a motor will pop.

I always thought the Horsepower level, efficiency of the set-up and the type of fuel will determine what is "safe" for a motor whether it's stock or not.


For example:
19psi with a ball bearing Precision 62/62 and Sidewinder manifold is not the same as 19psi on a (log manifold) Greddy kit.


93octane or E85 will with any of the two set-ups I listed above will determine whether the set-up is "safe" or not. I wouldn't feel comfortable running 93octane on 19psi with a ball bearing Precision 62/62 and Sidewinder manifold.


My last B-series (Acura GSR) motor made 630hp on stock sleeves and took about 20-25 passes at the track. Most people say that 500-550hp is the most those stock sleeves can handle. I beg to differ.

 

100% stock AP2 motor now with about 60,000 miles on it.

580whp/470wtq
Ptuning GTX30R @ 22psi
Jeff Evans Tuned
93oct with 100% meth @ 700cc/m

just about to hit the 10,000 mile mark with this kit.
I DD the car spirited driving style...and I've gone though about 6 Gallons of Meth so far, I think thats a fair amount of WOT pulls

 

I'm glad this thread came out. I plan to run 17 psi on m y setup with e85 and hopefully hit 500whp. This will max out my injectors and pump.

If I had 2000cc injectors and a single 340 pump I'd shoot for 19-20 psi and near 575whp.

It's not psi that u need to shoot for. It's is your emap Climbing? Is your setup efficient? Do u have enough fuel.

I think full-blown hit 750whp on e85. Spoolin has like 740.

U will exceed your trans and diff far before u exced your motor.

If anything. People should say if stock trans and diff don't go above 550whp. Seems most break shit in gear above this.

 

20lbs on a GT40r and i beat the LIVING PISS outta the car, lol stock motor besides headgasket and arp headstuds...