Trans or Converter issue....power logger files inside....

[streetknight]

Ok everyone, I've been fighting an issue for quite some time. Not sure where I should be looking.

The car is the one in my sig, it has a PTC 2800 NL converter. I'm wondering if it could be too tight or if I have a trans or other issue. The car drops about 1000-1200 RPM's on the 1-2 shift but about 1500 on the 2-3 shift.

The car seems to pull fine up until the 2-3 shift. The car noses over and the boost drops off about 8 psi then picks back up. It looks like it could have a flare on the 2-3 shift to me from the logs, but I'm not sure. My other car definitely had a flare on the 2-3 shift, but the boost would spike up, so this has me confused.

You can also see I get a good KR spike on the 2-3 shift I assume is from the motor being drug down by the converter.

Any ideas?

 

[wmerrell]

did you ever get a reply? i am having a similar problem. the car noses over and then picks up. fuel pressure is good. i was told i might need a better torque converter.

 

[bison]

Ok everyone, I've been fighting an issue for quite some time. Not sure where I should be looking.

The car is the one in my sig, it has a PTC 2800 NL converter. I'm wondering if it could be too tight or if I have a trans or other issue. The car drops about 1000-1200 RPM's on the 1-2 shift but about 1500 on the 2-3 shift.

The car seems to pull fine up until the 2-3 shift. The car noses over and the boost drops off about 8 psi then picks back up. It looks like it could have a flare on the 2-3 shift to me from the logs, but I'm not sure. My other car definitely had a flare on the 2-3 shift, but the boost would spike up, so this has me confused.

You can also see I get a good KR spike on the 2-3 shift I assume is from the motor being drug down by the converter.

Any ideas?

What cam, turbo, boost, and converter design. Is it a 9.5"?

 

[Boost231]

Idle TPS is a hair high. lower it to .44

Trans needs a rebuild, Flaring at the 2/3 for sure

inlet temps where high, must have been hot out.

Looks like its time to upgrade your injectors. you have some room left but not much

Also boost creep/drop is weird, you port the hole on the turbo? what kind of wastegate? thats what i see.

Trans being the main issue IMOP from the data

 

[streetknight]

Bison,

The car has a flat tappet 200/200 cam, OLD school Ruggles ported irons from the 90's. TA60 turbo Boost was around 19 psi IIRC and it's a PTC 9.5" NL converter 2800

Boost231,

The could be an issue, but was not having any problems with the boost dropping off until I put the PTC in. I was thinking it may be coupling so tight on the 2/3 shift it's dragging it down, like the converter is too tight.

As far as injectors it has 009's but the TT chip that's in the car was in my car that had a stock engine with the TA60. I hurt my car so we put the turbo, injectors, chip, etc on the GN (which is the car in ? here) so I think the chip needs more fuel since this motor has cam and heads.

Thanks guys

 

[bison]

I can't see the logs on my phone but the converter is probably coupling too hard for the engines power level. I still find it odd that its dropping boost with that small turbo and heavy load on shifts. Is there a possible Wastegate leak? Without knowing the air fuel ratio you will be running in circles if it has a chip for stock heads and you have ported heads it will need a lot of fuel everywhere

 

[streetknight]

Bison, the AFR is around 10.8 to 1 on the PL. Car is on 93 and Razor's Alky kit.

I got the converter for another car and never used it, so I put it in this car. The trans has good parts in it, but it was built years ago, The car has about 100 passes on the trans and 700 street miles in the last 10 years. It was done by Mike Kurtz in TX years ago. I'm on the fence on which way to go. I hate to spend the $'s to have the tranny gone thru if it's the converter coupling too hard. I also hate to pay to have it loosened up if that's not the problem.

Only other converter I have on the shelf is a stock D5. I guess I could stick it back in and the lock up stuff back in the trans and try it. If it's still nosing over and boost dropping then I guess that would take the converter out of the equation.

 

[Dusty Bradford]

The 1-2 drop is not too high which suggests the converter is close unless the 1-2 swap is at a lower than optimal rpm. Converter may be a tad tight but nothing out of the ordinary. I can't see the files from my phone but the excessive drop on the 2-3 is either rpm flare or the knock retard is pulling enough timing out to loose enough HP that the flash stall of the converter drops with the reduction of HP. Usually boost will go up in a higher load situation though. So looking at all possibilities if boost drops at the same time rpm drops it can be tune related. Too much fuel can cause knock as well and that rich condition can bog the motor making the boost drop from the change in exhaust gases. What rpm does the 1-2 and 2-3 gear change take place?

 

[TurboBob]

the 2-3 is hitting at about 4800 RPM, which is probably a bit lower than your old converter. The trans flares pretty badly, and the shift does not complete well. But it looks like your turbo has RPM related boost creep, so at the lower RPMs it doesn't make the boost.

Aside from fixing the trans (perhaps overfill it some in case its starving for fluid), holding the shifter in "2" until a higher RPM will help the boost drop off.

The tune is probably involved in the issue, but delaying the shift will probably fix it.

Bob

 

[tonka]

Idle TPS is a hair high. lower it to .44

Trans needs a rebuild, Flaring at the 2/3 for sure

inlet temps where high, must have been hot out.

Looks like its time to upgrade your injectors. you have some room left but not much

Also boost creep/drop is weird, you port the hole on the turbo? what kind of wastegate? thats what i see.

Trans being the main issue IMOP from the data

Looks to me like trans is sliding into 2nd also, instead of a crisp 1/2 shift.

Definitely needs bigger injectors, can see at the top of the rpms before the shift fuel is not keeping up.

4400 rpm after a shift should be enough to keep that turbo spooled, need to look for exhaust leaks, or wastegate control issues.