Stock PSI on GST?

[feardafish]

hey guys,
a friend of mine is buying a 98 eclipse GS-T and the dude who is selling him the car claims that its running 21 psi on the stock turbo...is this possible? could he have somehow tweaked the stock psi with like a boost controller (assuming it does wut the name presumes, im kinda a noob so forgive me )? and even if it was running that much psi...wouldnt that be damaging to the engine? the other mods it has is a short ram intake and a custom duel exhast with headers. i thought i'd throw that out there just in case it mattered . Thx

but there was no boost controller...the only thing in it was a turbo timer. Could he have tweaked the boost and got rid of the controller? or is his guage messed up...someone told me earlier that its been a problem with 2g DSMs boost guages to read more boost than its putting out. also the engine was rebuilt 5k miles ago with paper work to prove it...so even if it was running that much boost, would it be too late to tune it down and make the engine last? when we went to check it out (i went with him) it looked like it was running real good, started up nice and quick, idled smoothly, and when he test drove it he said it drove very nice. Better than his current car (91 3000gt vr4 119k miles). so im wondering (hoping) that this guy is lying or his guage is messed..but the car was a pretty good deal, i mean it was a 98 eclipse gst with a few mods (listed above) full body kit, tinting, and some nice leather interior and sound system for like $6500 with 79k miles on the body, 5k miles on the engine with reciept from dealership (it was warrenty work so they kept in on file). im assuming its not knocking ### from another forum it said knocking would only last for a few seconds before it melted a hole in the middle of a piston and cause engine failure.

and if for some reason he did tweak the boost, and it was that high, is there anything you can do to find out if its knocking or causing engine dmg... ### im thinking if he catches it early that hopefully he can prevent alittle of the damage if its only been 5k miles.

i asked the guy selling it if at any point did he have a manual boost controller, and he said no. the car came stock reading 18 psi, and when he adjusted a screw on his blitz BOV it started to read 21...but at no point did he manually adjust the boost...so im thinkin its a glitch in the guage which i believe is aftermarket guage becuase he claims he never had a boost controller, becuase i never saw one in the car. could it also be the BOV thats throwin off the reading? and since he never manually adjusted it, wouldnt that mean its just running stock psi whatever that may be (8-9?)? My brother is also thinking that he possibly hooked up his boost guage to some other vacuum line and its reading the pressure from that. my brother and i are going to look at it this weekend (he didnt come with the first time and he knows his shit pretty well). if you guys could help me out that'd be great...thx

 

[MCDGexx]

I dont think anything over 16 is possible on the T25 Turbo...

or maybe thats just w/ completly stock car, I dunno. i'm a newb

 

[eclipsegsx1736]

First of all, yes you can adjust the boost of the stock turbo, but anything over 15-16 psi is just useless on it. 21 psi on the stock turbo is impossible, and it either can't hold that boost or the turbo won't last too long. I hope he was kidding or mistaken. Turbo cars don't have headers, we have exhaust manifolds, o2 housings, and downpipes. Stock boost is usually around 10-11 psi. Are you readign from the stock gauge or an aftermarket? The stock gauge is useless. Maybe he disconnected the wastegate, so it never opens and the boost goes thru the roof, but for your sake I hope not

 

[m1nd64m3]

I would run far away from that car. If he already destroyed one motor he is probably trying to unload the car cause the current motor is about to go to. 21 psi is not even possible with the t-25. It will just spike up to 21 for a second and drop down to 16 or so psi. Sounds like the owner knows nothing about the car.

 

[RotaryRyan]

It isn't impossible to reach 21 psi on the stock turbo. But it will most likely be a spike. I have seen 22 psi on the T-25 myself ( by mistake ofcourse). I wouldn't do it on purpose. It held a little longer than your typical spike, but not much. Stupid

But it is possible. It won't really hold it though.

 

[feardafish]

well i believe hes reading it off the stock boost guage...as for the motor rebuild i believe it was only the head that was rebuilt...he had the reciept for the machining and rebuilding of the head and thats it, but he claims they also put in new pistons and rings...but no proof of that. But the head rebuild was off of warrenty work, meaning that (correct me if im wrong) it must have been a fault of the dealership that caused the dmg...or else why would warrenty cover it?. and as for the PSI that should be run on the car with stock injectors and turbo, wuts safe? 15-16? or should it go lower. what does it come with straight from the factory?

 

[eclipsegsx1736]

As posted before, it has around 10-12 psi stock, depends on the car. I don't understand how he can read that off the stock gauge, as the stock 2g gauge only has blank marks, but the 1g gauge has actual numbers. Either way it's useless. I would run no more than 14 psi without some way to log the car to make sure it is staying in tune, but that's me. You never want to go over 16 psi on the stock turbo, and the stock intercooler.

 

[EclipseGST95]

that guy is lying theres no way a t-25 makes 21psi

 

[Iceman90]

A T-25 can spike to 21+ PSI. I've seen it personally. However, it is incapable of holding that PSI all the way to redline.

 

[CanadianTSi]

A T-25 can spike to 21+ PSI. I've seen it personally. However, it is incapable of holding that PSI all the way to redline.

This is Correct.

 

[Silverstrocker]

Stay away far far away, i ran 16psi for about a year and more is nearly impossible and useless, even with 16 it only lasted a year

 

[machv83]

Man i would stay away from that car that stock boost guage will tell u nothing the stock boost is 10 to 12 psi depends if u have a manual or a auto ...

 

[EclipseGST95]

if he doenst have any fuel mods then its running way to lean cause running 21psi on stock fuel is not good and your are going to get massive fuel cut and if its run like that long enough it will burn up a piston

 

[feardafish]

sorry, but wuts fuel cut? is it a visable sign of it running lean? if not, then is there any way of telling if the engines running lean or not, becuase that would be a perfect way to tell if this dude is telling the truth with 21 psi or if hes just milking it to make it seem "faster" or more powerful to sell it quicker or something.

 

[eclipsegsx1736]

Youll hit fuel cut if youre flowing too much air. You'll step on it, and somewhere in the gear, usually higher RPM, the car will suddenly stop accelerating, and usually backfire, then start accelerating again. It jerks pretty hard. A lot of people say it's like hitting a brick wall, but if they were to really hit a brick wall during a 3rd gear pull I think they would say differently

 

[feardafish]

ahh ok thanks. we test drove the car and my friend stepped the gas to WOT to see how much pep it had...seemed to run perfectly fine, nothing like a fuel cut. So might that be a sign that this guy is just lying? and he has a stock guage, with no numbers so not like he'd know how much PSI it had anyways.

 

[luvmygst]

Does the car have a aftermarket boost gauge? What is the guy reading to tell you 21psi? The factory gauge has no numbers. I would check and make sure the wastegate is hooked up correctly. IF the car is still running factory boost, and the guy is just asaying stuff to impress you, then the car is probably worth it. I dont see anyone actually running 21psi on a t-25 its not possable. Good luck

 

[itola]

Sounds to me like the guy is jerking your chain. If he is telling you its running 21 psi and he dosent have an aftermarket boost gauge he is pulling numbers out of the sky. He seems like he is trying to impress your friend into buying the car.

 

[the_red_pooch]

Personally, I would walk away from the deal right now. I don't believe in giving some honduh idiot my hard earned cash if he can't even be up front with me about the car. He seems to be feeding constant lies and misinformation to you... Specially since this guy seems to have absolutely 0 knowledge of anything to do with a DSM. I'll bet almost anything that nothing but the head was reworked, because of his ill-witted ability to maintain a vehicle. He probley had no idea as to when he was supposed to replace his timing belt(60k at most) and he just drove it till the belt broke and ruined the head completely. Why would they have proof of only HALF of a motor rebuild, what dealership would say "OK here's a reciept for half of your motor build, we didn't feel like writing down the rest of the parts we replaced, but they're in there!" The guy claims 21 psi on a T-25, which in itself is outragous, but he also seems to be pulling this number straight from his behind... Where would he get this number with only a stock boost gauge? Is it spinning circles or what? Not only is the stock boost gauge %110 worthless, but it uses dash marks along the gauge, no numbers. Thats like looking at your gas gauge and saying "hmmm, just over 1/2 tank, I bet I got 7.9328758 gallons left to go!" I guess the decision to buy the car or not is not up to us, but I hope we're atleast pointing you in the direction of the correct decision... Best of luck to you and your friend.

 

[v01dy]

talk him down to 3k then swap in a new engine

 

[FORMONTOYA]

A stock 98 GS-T T25 will spike to 14psi then "leak" past the BOV to 11psi. Boost will start to fall off around 5k. As stated anything more is just a spike or someone just tearing up a turbo. You could run up to about 16, maybe 17psi with a different BOV and boost controller.

I would stay away from it also.

Jim

 

[yekrahs]

Is your "friend" buying the car? or are you? you seem pretty interested for someone who's not buying the car....

 

[coving21]

A stock 98 GS-T T25 will spike to 14psi then "leak" past the BOV to 11psi. Boost will start to fall off around 5k. As stated anything more is just a spike or someone just tearing up a turbo. You could run up to about 16, maybe 17psi with a different BOV and boost controller.

I would stay away from it also.

Jim

I have a pretty much stock 95 tsi with autometer boost guage no MBC and I am hitting 14 almost 15 psi and drops to 13.5 or so near redline and I have stock BOV so I'm not sure if it's different from car to car or what. I know you guys are probably going to say your car can't hit 14 to 15 stock but the guage is not leaking the line into the engine bay in new so no leaks there either but the car with no boost control on its own will hit almost 15psi, is this normal?

 

[FORMONTOYA]

The 14-15psi is normal during a pull, then it should "bleed" down to around 11ish psi. Maybe your BOV is sealing better than most 2G BOV because they will 'usually' leak at around 11-12psi. Maybe the restrictor was removed in the BCS.

Although that has to be one stout T25 to hold 13.5psi at redline. I can honestly say my old one never did it.

Jim

 

[FORMONTOYA]

I quess the real question to ask...

Is it stock exhaust? Cat-back, turbo-back, what size?


Jim