what damage does running over factory psi do?
would adding more fuel up the limit?
marcus
does blowning up your motor sound fun, get the chip helps alot ... :lol:
I was just thinking if it starts running leen from too much boost I could mount two fuel injectors before the turbo. the fuel would hit the turbo and get shot everywhere. there would be alot of fumes. more fuel would ever it out. if thats what the chip does (up the fuel when boost goes up)then ok.
but that might be a way of doing it without upgrading the chip.or going past the chips limit.
marcus
(the crazy scientist who WILL one try something and blow his motor out the hood) :twisted:
Only problem is that you will need to modify your MAP sensor or build a chip to bypass the factory boost limit of 9.5LBS. Once you hit that without one of the two things it will shut the fuel off to your car... 8)
Does Jeff M.'s chip actually increase boost?
if you remove your bcs vacume hose you bypass the stock 9.5 setting. you will boost to the stratosphere but like what was just said you WILL blow your motor. its chip or nothing and i believe the chip is set at a max 12psi for safety.
Yeah...His is set to 11.66LBS of boost on the chip...more importantly is that Jeff increases the amount of fuel supplied to compensate for the boost increase... 8)
I've noticed that chip values seem to never be round numbers. Is there a reason for this? IE 11.66, or 8.47 boost limit etc.
Chris
the factory manual is very specific, 9.5lbs i think, but the MAP sensor will have accuracy issues with age and such, I think people are just saying what they read on their boost guage when cut out occured. boost reading can vary with where you tap it in.
Chris
The values are set in the code by way of Hexidecimal numbers. I think it is the direct translation of the Hex number to decimal numbers. Just a hunch though... 8)
Boost with Jeff's chip is 9.5- 12 PSI DEPENDING on the car... without jeff's chip you will hit fuel cut at 8.5 PSI and any attempt at bybassing it will cost you a motor... :oops:
Then again its not a tgp, but close. I have gone 15psi(Sunpro vac/boost gage) without fuel cut off(installed LED on the pump positive and neg. to see when the pump was on(dash mounted small led). Man i thoght I was going to walk home several times(wastegate hose poped out..solved). It launched like a ZR1 VETTE at 3k when it overboosted, then after that, it felt like shit. I heard low booming comming from the engine(prob detonation). I have everything from the TGP turbo sys minus the computer its self and wires. I do have the oem TGP chip in the Beretta ecm.
It is strange you all have this problem of fuel cut off. Do the TGP have electric fuel sensors for pressure. THen thats what it is.
Those 2.8 pistons are sturdy suckers.
IMO leave the 3.4 alone! Try to cram in a 3800 which is more torquey and more reliable and more aftermarket parts. you got pics of your GTU turbo?
3800? I don't know. I want to use the 60degree v6 cuz I don't want to spend more money on getting one to fit, not to mention changing to a compleately new turbo, exhaust manafolds,wires, hoses, alternator, steering pump, clarance issues on the rac-n-pinion, you get the idea. I don't think I'll go full blown aftermarket, or all out race only.
I'll use the 3.4 or 3400 cuz I could adapt everything I already have intoit, including the turbo(maybe just a compresor and turbine upgrade), and reprogram the computer myself(yea, I'll try) or get a Haltec or simmilar programable unit.
Pics? well theres no extention to dowload from my computer. I'll post them on village photos or something so you could check them out on my next post.
3800 is a bolt-in no cutting or welding! check out this site. http://luminasupercharged.com/ If my TGP motor goes then I am definitely going 3800 n/a or sc. It will also mate to a 282 :twisted:
Or if all else fails,, then a SBC kit from the fiero guys. Uses the G-282 5spd.--B&M blower anyone? LS1 anyone? Dammit, I want to snap my axles too like Curtis!
Jeffs chip also has much less aggressive timing above the stock 9 psi limit. For example, the stock chips timing curve flattens out after like 9 psi or something. So at 9psi you have lets say 10 degrees of timing, and at 10psi you have 10 deg, at 11psi you have 10 deg, and so on. They basically stopped tuning the timing after 9 psi because no one would ever go past that (yeah, right).
Forced induction engines need to have the timing retarded as boost increases, or you will have knock, ping, etc. Jeffs chip has all the timing above 9 psi you need. His chip continues the timing retard past 9 psi, so at 10 psi you have 8 deg, 11 psi you have 6 deg, etc. The numbers aren't accurate, they are just an example. This is why Jeffs chip is a great chip. Even if you happen to go past the 11-12 psi, the timing there will at least somewhat protect the engine. With the stock chip, going past 9 psi is bad (if you can disable boost cutoff)...I'd be scared to go any higher than 12 psi with the stock chip at all.
And the boost cutoff I think is actually a spark cut. The pump is not going to turn off (bad idea in any case). If you remove fuel in a high boost situation, you could go lean long enough to damage something. But if you remove spark, there is no combustion. No chance to go lean. Just my observation...
So get Jeffs chip, you will be much happier and safer than any other way. And there is no point to running past 12 psi with the stock turbo. There is no power increase because the turbo is working way too hard at that point to feed a fairly large engine. For example, most ricers will use a T3 to feed a 4 cylinder engine (a T3 is way bigger than our T25). But, our T25 is feeding a 6 cylinder engine. You get almost no turbo lag, but you do have a ceiling of boost. If you really want to go faster, get a T3 or something bigger, get your heads ported, larger injectors, chip....you'll be going plenty fast then.
Jason