How much boost can a 2G Stock Head & Bottom End hold up to?

[irn__man]

Just curious I am running about 22psi right now on my green. And I am just curious about how much psi I can push on stock head, and stock bottom end? 24psi is the number that is staying in my head, but I have seen some guys pushing 28psi on race gas with stock, head and bottom.

iron

 

[Mike 99GSX]

I've been running 24 at the track with a 50 trim and havent seen any problems sooooo far

 

[Kingdom]

the 7-bolt is really unpredictable. Some have lasted a long time and some havent.

Mine lasted about 1.5 years on a 60trim running 18psi daily, but I only put around 8k miles in that time and it spun a rod bearing really bad, I mean really bad.

I ran 24psi a couple of times but thats it.

Play it safe, and start saving for a 6-bolt. better yet buy one know and build it and once this one quites do the swap. I wish I had done this when I had crankwalk instead of getting a new 7-bolt from the dealer, could have had a built 6-bolt

 

[Mike 99GSX]

Like he said. I would run it and not worry about it. Just have it in your head now that its going to eventually crankwalk and at least you'll be prepared mentally. I'm looking for a 6 bolt right now as a winter project.

 

[theTuner]

im pushing 60k miles on my 7bolt, i have almost no thrust bearing movement... but i bet soon i will throw a rod, or blow my headgasket because im pushing 20 psi daily... and No stock motor can handle that for too long, maybe a t25 @ 12 psi for 150k miles, but aths about it

i wouldnt build your 7 bolt , just get a 6 bolt once something happens to ur 7 bolt

 

[HyperGSX]

Damn you guys are maniacs---daily driving with 18-22psi

 

[born4music04]

I would keep it nice and low around 16 on the road and then bump it up to 22 on the track. The reason I say this is beacuse your engine will take a lot of boost but it's how long it can take it. Don't expect your DSM with stock internals to last forever at 24 psi.

 

[igs]

I'm running 25 psi on stock engine and stock fuel system. It's not the psi that matters, but HP.

 

[Mike 99GSX]

Originally posted by igs
I'm running 25 psi on stock engine and stock fuel system. It's not the psi that matters, but HP.

Ka-Boom!!!

 

[Mike 99GSX]

Originally posted by igs
I'm running 25 psi on stock engine and stock fuel system. It's not the psi that matters, but HP.

Ka-Boom!!!

 

[DSMSpyder99]

well i know that my friends 95 GST has 160K+ no signs of a weak engine. He has Full exhaust, intake, UICP, MBC, re-wire wire fuel pump, & a Small 16G @ 14PSI. I agree with Kingdom 7-bolts are tricky

 

[BOMEX DSM]

I heard that the most u can run is 24 because after that the head will lift(stock head studs) if you get ARP ones u should be able to push as much as your engine can handle. My opinion is just save for a 1G head and then do the studs. I got this info from RRE so im sure they are right oh and im running 20Psi on pump(yes on the green).

 

[brads]

20-22 PSI daily driven on a 50 trim. stock block, stock head, web cams. After running at 24 PSI for a while, I started noticing a little coolant leaking from what appeared to be my head lifting. I put in ARP head studs, and that was that. Been running close to a year with the ARPs at the 20-22 PSI boost level, no problems, I think I have 15K on the car since the turbo swap?

The boost pressure isnt the issue, its the cylinder pressure you have to worry about. If you have it well tuned, with little knock(which is a huge cylinder pressure spike), you can get away with more boost. Lots of knock and excessive cylinder pressure, and things break quick.

Brad

Almost forgot to mention, I didnt even pull the head when I did the studs, just swapped them out one at a time, leaving the stock head gasket in. So the car still has the stock head gasket, and it seems fine so far, no leaks now.

 

[race my talon]

i have been running 21 psi on pump gas for over a year now and 25 psi at the track on race gas...no problems so far..not saying problems wont arise but none have surfaced as of yet

 

[slowAWDTSi]

Lets put a whole new idea into the mess...Timing! Intead of trying to get massive boost into the motor lets try and get the most we can with the boost we have. If you have a stand-alone computer or somethign of that degree add abotu 15 degrees of timing in the upper end with about 15 psi but keep it a little rich and usually it will run like it has 18-20 psi
Just an idea.
Drew

 

[lowridin2g]

I'm running 25 psi on stock engine and stock fuel system. It's not the psi that matters, but HP.

25 psi on stock fuel system???????????? 25 psi on the t25???????????
dude u do realize your prob running lean as hell your engine is gonna blow up and so is the t25. 17psi on the t25 is significantly shortening the life of the lil guy. smarten up man unless u got a garage with lots of tools and lots of knowledge and another daily driver.

 

[Cirus_93TSI]

u shouldnt really be worried about how much boost ur stock bottom end can handle, what u should be worried about is how much a certain ammount of boost will increase ur risk of crankwalk
if u run 22 psi daily on a green ur head will probally be fine, and ur bottom end will most likely hold up fine, but when ur crank walks one day out of the blue u know what caused it, too much boost, i wouldnt push my luck with a 7 bolt 2g engine, unless u have plenty of time and money to fix it when it breaks, and another daily driver
and as for the guy running 25 psi on a stock t25, expect for ur turbo to blow one day in the near future, ur not supposed to run over 16 psi on a stock t-too small turbo, every time u put the gas down at 25 psi ur taking a month or 2 off the life of ur turbo, unless u have a new turbo waiting to go on i would turn ur boost down alot, cause when ur turbo goes bad and u cant run any boost ur not going to be happy

 

[igs]

Originally posted by Cirus_93TSI
ur not supposed to run over 16 psi on a stock t-too small turbo

myth

 

[igs]

Originally posted by lowridin2g

17psi on the t25 is significantly shortening the life of the lil guy.

old wives' tale

 

[Mike 99GSX]

Originally posted by igs


myth

You can run more boost than this if you want but you're just going to go slower. Anything beyond this and you're way out of its effeciency range. You're just ramming a bunch of hot air in your manifold and your ECU is going to pull timing because the intake temps will be so high. More boost doesn't always=more power.

 

[lowridin2g]

igs u need to smarten up man. your engine and turbo is gonna burst

 

[igs]

Originally posted by Mike 99GSX

You can run more boost than this if you want but you're just going to go slower. Anything beyond this and you're way out of its effeciency range. You're just ramming a bunch of hot air in your manifold and your ECU is going to pull timing because the intake temps will be so high. More boost doesn't always=more power.

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http://www.dsmtuners.com/forums/showthread.php?postid=97337#post97337

 

[Mike 99GSX]

It also says later in that thread that he ran 14.3 with it at 18 PSI. I'm not claiming to be an expert on the T25 because I removed it about a week after I got my car and but don't just spit out recycled info that isn't correct. There are a few people on this board have run some mid 13's with a t25 which is amazing to me. Maybe one of them will chime in on their setups and what kind of boost they were running to get those times.

 

[igs]

Originally posted by Mike 99GSX
It also says later in that thread that he ran 14.3 with it at 18 PSI. I'm not claiming to be an expert on the T25 because I removed it about a week after I got my car and but don't just spit out recycled info that isn't correct. There are a few people on this board have run some mid 13's with a t25 which is amazing to me. Maybe one of them will chime in on their setups and what kind of boost they were running to get those times.

What are you talking about? Stock quarter mile time on the T25 is over 15 seconds.

 

[ddimestalon]

Originally posted by igs


What are you talking about? Stock quarter mile time on the T25 is over 15 seconds.

its about 15.1 to 15 flat