Too much boost, too small of injectors?

[LaserRSTAWD]

Ive had a couple 1st gens and a 2nd gen over the years, and now My buddy just bought a 2nd gen GST, and it came with a cluster f___ of stuff that looks like a duct tape mechanic put together. It came with a FMIC, with 2.5 inch piping, BOV, crappy battery in trunk job, leaking cam cover, ebay intake CAI system, stock TD05 off a 1st gen (well it came with one but i put mine on it bc the other was smoking), braided stainless fuel return line and regulator, and 3 inch cat-less exhaust (it looks too big and hangs down low), to which i added my pacesetter header and i cleaned/polished the 02 sensor housing.

We hooked the wastegate up straight to the outlet of the turbo, so i could see how much boost it added withough a MBC. Well I didnt know till later but he wasnt pulling the 15 that i thought, no, it was like 18 psi a lot of times.

Welp an exhaust hanger broke under the driver seat area, and since the only other hanger was in the back, it put a HUGE load on the header with its much thiner walls. And also in this time frame: the header developed a crack, he maxed it out bc his gf was dirty W__re and he was pissed, and he was PULLING 25 PSI (stock injectors btw), and this cracked the header hardcore, and now NO PSI.

Im trying to tell him that he might have caused serious damage to his engine, and he probably needs a compression test. He has a crappy AFR gauge that only shows rich, and just lights, no numbers (which i contantly get on him for), also if the lack of pressure was only due to the header (which is being fixed) he is VERY lucky (just read that the turbos dont like 17 psi all that much), I beleive the wastegate is fine and if it is, Im trying to explain that his exhaust is way to unrestricted and he should not get more that like maybe 12-13, maybe like 15 psi at the most without a MBC? Dont know who true this is, but he should not be getting 18psi, let alone more (other than boost creap, yuk). It just doesnt seem that his car will last long and he is used to chevy crapp so its all new to him, plus he is 19 and I remember the grand illusion of that age.

Basically I know i rambled on way too much but i guess it boils down to this:

1)Whats the chance he fried the motor/rings, it still runs tho, but no boost?

2)I take it the reason that he cant control his boost is most likely the fact that he has no back pressure.

3) Please god someone else say how important number 2 is

4) Please god someone else say how important an AFR gauge is

5) He wants to trade parts for a 16g, however he wants to fix all this at once, i told him NOT till he gets the boost controlling aspect fixed and gets an AFR gauge, please somone back me up on this, I just keep :deadhorse: thanks

 

[crash89]

1) A pre turbine exhaust leak will cause little to no boost.. Which you said he has since his "header" cracked due to the entire exhaust hanging on it.. 2) a stock 14b SHOULD boost ~7-10 psi. The 3" exhaust doesnt really have an effect on boost at this point. Sounds like the wastegate might be junk. 3) 25 psi without getting some kind of fuel cut? hmmm?? 4) with a stock fuel system he should run 15 psi MAX. Even with a MBC.

Sounds like your friend is an idiot, buy the car from him and give him an integra.

 

[XiKeiyaZI]

Do a little reading on the exhaust system also. From your post it seems like you lack a little understanding in what backpressure is, does, etc.

http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/168578-exhaust-straight-scoop-backpressure.html

 

[LaserRSTAWD]

1) A pre turbine exhaust leak will cause little to no boost.. Which you said he has since his "header" cracked due to the entire exhaust hanging on it.. 2) a stock 14b SHOULD boost ~7-10 psi. The 3" exhaust doesnt really have an effect on boost at this point. Sounds like the wastegate might be junk. 3) 25 psi without getting some kind of fuel cut? hmmm?? 4) with a stock fuel system he should run 15 psi MAX. Even with a MBC.

Sounds like your friend is an idiot, buy the car from him and give him an integra.

Ya and I THINK, not sure, but I think the crack got much worse after the
25 psi incident, but I know that now it wont build any and I know thats at least 1 issue, if not another possible issue.

As far as fuel is concidered, its got braided stainless return line, and an aftermarket (forget which brand) fuel pressue regulator. The fuel pump has been rewired, but unsure if it has been upgraded or not, its not my car so I havent had the chance (or time) to find out, but its deffinitly not entirely a stock fuel system.

As far as him building the extreme boost, I know that from my experience, when I have had any type of open exhaust, my boost went crazy high. Like here on both of these instances:

1) On my 95 GST, with that same header and same turbo as he now has, it had the 3inch down pipe, however it was not connected to the rest of my exhaust. When i ran it like this (even with the boost controller turned ALL the way down), it would boost like crazy (forget the psi bc this was 4 years ago and i had a BAR pressure gauge), but it would boost so much i would get fuel cut. Once I connected the rest of exhaust, 2.5 inch i do believe (no cat tho), it would actually regulate the boost, and all was well.

2) Skip to this year, and Ive since bought an SRT4 with a bunch of goodies, including a huge turbo. Well I wasnt building ANY boost (actually i could never get it above 12 psi before this), and found it to be my cat had gotten completely plugged, so i cut it off and ran it like that on a test drive, and HOLY CRAP, my boost gauge only goes to 20 right now but it maxed that out instantly so i pulled my led foot quick, and this was with the boost turned all the way down. Put the test pipe in, and wahla, i could control my boost.

Basically his exhaust (that it came with), is at least 3 inch, could be bigger, not sure, its pretty much straight back, little to no bends (hangs down really low, and bangs the ground sometimes), and a coffee can muffler that you could see through if it was off. And there is no cat, so to me, it seems very little to no back pressure, and simply putting a Cat on would help with this (and get rid of that damn engine light). I understand and beleive that the wastgate could be the issue as well, but I know that it was working when I took it off my 95.

Also when he bought the car, it also had a TD05 on it already, same exhaust (minus the header), and no boost controller, just straight vacuum hose from the turbo to the WGA, and it was getting like 15 psi or more, so either both WGA actuators are bad or something else is up

 

[WES_393]

We hooked the wastegate up straight to the outlet of the turbo, so i could see how much boost it added withough a MBC. Well I didnt know till later but he wasnt pulling the 15 that i thought, no, it was like 18 psi a lot of times.

Running a line straight to the wastegate should result in the lowest possible boost pressure. And a boost controller can't adjust boost lower than wastegate spring pressure (8-10psi stock). Sounds like a wastegate issue to me.

Any possibility this "TD05" turbo is a genuine Chinese knockoff? They like to use 1-BAR actuators, which means 15psi minimum boost can be expected.

2)I take it the reason that he cant control his boost is most likely the fact that he has no back pressure.

No, the reason he can't build boost now is lack of exhaust pressure. The manifold is leaking the pressure needed to spool the turbo.

You want the lowest possible pressure after the turbo. A free flowing exhaust can promote boost creep, but the root cause is still an inadequate wastegate. Back pressure is not an issue here.

 

[rydereclipse]

Ive had a couple 1st gens and a 2nd gen over the years, and now My buddy just bought a 2nd gen GST, and it came with a cluster f___ of stuff that looks like a duct tape mechanic put together. It came with a FMIC, with 2.5 inch piping, BOV, crappy battery in trunk job, leaking cam cover, ebay intake CAI system, stock TD05 off a 1st gen (well it came with one but i put mine on it bc the other was smoking), braided stainless fuel return line and regulator, and 3 inch cat-less exhaust (it looks too big and hangs down low), to which i added my pacesetter header and i cleaned/polished the 02 sensor housing.

We hooked the wastegate up straight to the outlet of the turbo, so i could see how much boost it added withough a MBC. Well I didnt know till later but he wasnt pulling the 15 that i thought, no, it was like 18 psi a lot of times.

Welp an exhaust hanger broke under the driver seat area, and since the only other hanger was in the back, it put a HUGE load on the header with its much thiner walls. And also in this time frame: the header developed a crack, he maxed it out bc his gf was dirty W__re and he was pissed, and he was PULLING 25 PSI (stock injectors btw), and this cracked the header hardcore, and now NO PSI.

Im trying to tell him that he might have caused serious damage to his engine, and he probably needs a compression test. He has a crappy AFR gauge that only shows rich, and just lights, no numbers (which i contantly get on him for), also if the lack of pressure was only due to the header (which is being fixed) he is VERY lucky (just read that the turbos dont like 17 psi all that much), I beleive the wastegate is fine and if it is, Im trying to explain that his exhaust is way to unrestricted and he should not get more that like maybe 12-13, maybe like 15 psi at the most without a MBC? Dont know who true this is, but he should not be getting 18psi, let alone more (other than boost creap, yuk). It just doesnt seem that his car will last long and he is used to chevy crapp so its all new to him, plus he is 19 and I remember the grand illusion of that age.

Basically I know i rambled on way too much but i guess it boils down to this:

1)Whats the chance he fried the motor/rings, it still runs tho, but no boost?

2)I take it the reason that he cant control his boost is most likely the fact that he has no back pressure.

3) Please god someone else say how important number 2 is

4) Please god someone else say how important an AFR gauge is

5) He wants to trade parts for a 16g, however he wants to fix all this at once, i told him NOT till he gets the boost controlling aspect fixed and gets an AFR gauge, please somone back me up on this, I just keep :deadhorse: thanks

1. Do a compression test.

2. No control is a wastegate issue. He would be unable to build boost due to the aforementioned problems pre-turbine.

3. number 2 is important, is that what you really wanted reinterated

4.The "blinky light " AFR gauge needs to go. Get another that shows true values. Just my opinion, but you really shouldnt be messing with any kind of MBC, or fuel components, until you can properly monitor your air/fuel ratios.

5. This seems like solid advice....but if he stays with what he has..well..you can't polish a turd.

Re-reading some of what you mentioned...

You state he has an AFPR, rewired fuel pump and stainless steel braided line..does he have bigger injectors as well? All the supporting fuel items are good to be sure..but if he is just feeding stock injectors ...

If he does get bigger injectors, he will still need a way to tune for them...and if he has them, how are they being tuned..SAFC, EcuFlash, chip burned....???

 

[LaserRSTAWD]

Running a line straight to the wastegate should result in the lowest possible boost pressure. And a boost controller can't adjust boost lower than wastegate spring pressure (8-10psi stock). Sounds like a wastegate issue to me.

Any possibility this "TD05" turbo is a genuine Chinese knockoff? They like to use 1-BAR actuators, which means 15psi minimum boost can be expected.



No, the reason he can't build boost now is lack of exhaust pressure. The manifold is leaking the pressure needed to spool the turbo.

You want the lowest possible pressure after the turbo. A free flowing exhaust can promote boost creep, but the root cause is still an inadequate wastegate. Back pressure is not an issue here.

I know its not a chinese POS, i personally removed it from a bone stock 1g.....thats what i was fearing, i hope the other stock WGA is good. This kid really needs to do research, nothing worse than a broke teenager wanting more power, they carelessly build power without the thought of being safe, i really dont think he understands what i tell him about NEEDING an AFR gauge, i know bc i was there, now i have that and a programmer and SOOOOOO GLAD!

1. Do a compression test.

2. No control is a wastegate issue. He would be unable to build boost due to the aforementioned problems pre-turbine.

3. number 2 is important, is that what you really wanted reinterated

4.The "blinky light " AFR gauge needs to go. Get another that shows true values. Just my opinion, but you really shouldnt be messing wit, h any kind of MBC, or fuel components, until you can properly monitor your air/fuel ratios.

5. This seems like solid advice....but if he stays with what he has..well..you can't polish a turd.

Re-reading some of what you mentioned...

You state he has an AFPR, rewired fuel pump and stainless steel braided line..does he have bigger injectors as well? All the supporting fuel items are good to be sure..but if he is just feeding stock injectors ...

If he does get bigger injectors, he will still need a way to tune for them...and if he has them, how are they being tuned..SAFC, EcuFlash, chip burned....???

Thank you jesus,i thought i was taking crazy pillsbut ya this is PRECISELY what ive told him, but instead he spends money on lame sause Fast and Furious stuff, ie z3 fenders and ### wing.....the only thing that he has bought that makes a LICK of sense is a gm MAF and translator, but not installed......as far as num 5, no ya cant but u can spray it with fabreeze, least for 7 months till he done with school and has a real job,..........as far as the fuel, all that i know is there is an aftermarket FPR,and braided stainless fuel line......the Pump is ?????? and they are Stock Injectors