Help please with SR20DET

[Lewis Maudlin]

My car was running great as a T25 mildly modified SR20DET. Maybe I should have stayed in the low 200'srwhp. Anyway, here is my problem.

 

 

I sent these questions to Scott at Enthalpy. Does anyone else have any suggestions?

 

My car is SR20DET, 740's, GT2871R, Z32, usual mods.

 

 

 

1. At vaccuum, cruising down highway at 60 mph in 5th gear it runs for 15 minutes then stalls. I can smell gas and the car seems to be flooded out. I suspect a lack of fuel pressure regulator. Could this be the problem? If so, do I need a retune if I add one?

 

 

 

2. Before the car warms up, it runs like crap breaking up and stuttering.

 

 

 

3. My car spools to 5-10 psi, pauses, then spools the rest of the way as a function of boost. It does not max out boost at normal rpms. It only maxes boost out when it maxes out rpms.

[Lewis Maudlin]

Please ignore issues 1 and 2. I fixed them. Really, I caused them. It was an electrical issue caused by installation of a kill switch which I was forgetting to turn on. For some reason, the car was running even with the switch off, just poorly.

 

I will take the bonehead prize for the day.

[Hugh]

THis spooling issue is killing me...

 

Have you tried running with the vacuum line off the wastegate, so it stays shut?

 

What does it do then? Does it just rocket right up to insane boost levels? Or does it still pause?

 

Please try this and let me know what happens.

 

Just remember to let off the gas when the boost hits crazy levels. (it will happen very quickly)

[cheftrd]

It almost sounds like the timing retards heavily under boost. If the WG is not open at 5-10psi it's an engine management problem.

[oinojo]

THis spooling issue is killing me...

 

Have you tried running with the vacuum line off the wastegate' date=' so it stays shut?

 

What does it do then? Does it just rocket right up to insane boost levels? Or does it still pause?

 

Please try this and let me know what happens.

 

Just remember to let off the gas when the boost hits crazy levels. (it will happen very quickly)[/quote']

 

with no vacumm line on the wastegate you would be running unlimited boost. Thats why people post threads like "blew my motor" on other forums that i am on because either their vacumm line melted or their manual boost controller failed.

[Lewis Maudlin]

I will try this tomorrow. That would explain a lot. If it still pauses, then it is a wastegate or actuator issue, right? Or would it be an engine management issue?

[Lewis Maudlin]

I just kept thinking it is a boost leak issue. Just a small leak like through a BOV. Like something is opening a little at 7-10 psi, then it is only increasing when the GT2871R puts out large amounts of air.

[Lewis Maudlin]

OK, here is the update. My car has run fine for the past two days with that spooling issue.

 

Remember, it pauses at 5 psi then spools slowly.

 

Today, it ran like crap for 10 minutes then when it started running correctly, the spooling issue was corrected.

 

It now spools past 14 psi to at least 20 psi which is where I let off the gas.

 

I suppose I now have the opposite problem. Any suggestions?

 

My mbc is disconnected. My wastegate is routed back to a T to my HKS SSQV and intake manifold. The turbo is a GT2871R which is supposed to be internally wategated at 14 psi.