Stall/ Spool-up help from Expert please

[GTEATER]

Just put a set of HGs on the car and new 9" converter.

Rolling along around 2500rpms (in any gear), kick it and the following happens.

Boost/ vac equalizes, then slowly builds to 5# around 3000rpms, continues to build to 10# at 33-3400, then laziley goes to 15# about 3800, then shoots to 20# @4000 rpms then pulls like mad to 23# throughout the rest of the power band.

Same problem out of the hole...car will only foot stall 2200 rpms at launch, then slowly goes through the condition above.

Car feels great above 4000, but is a complete pig below that level. Thought it was a rich lowend condition, but FAST shows good AF. Same program as before converter and HG.

My guess is convertes is too tight, looking for second opinion.

Thanks

Bart Patrello

 

[azgn]

what stall is the converter supposed to be? It certainly sounds like it is way tight.....

 

[Steve Wood]

and what turbo?

 

[GTEATER]

it supposed to be a 3300 stall....pt 68 qtrim turbo

 

[azgn]

hmmm, sounds like you need a "bit" more stall and some fuel work on the spoolup....you may well have a 3300 stall converter...prolly need like 4000

 

[Quick6'n'-K.C.]

Same problem out of the hole...car will only foot stall 2200 rpms at launch, then slowly goes through the condition above.

*********

loosen the convertor

 

[UNGN]

This is pretty common on art carr 9" converters in the past (not the real art carr, I guess, I personally seen this happen to 3)

One guy couldn't break the tires loose at the slipperyest track in Texas - Yellowbelly. It would only brake stall to 2100 rpm. he sent it back, got it fixed and became a happy camper.

 

[Steve Wood]

The converter is way tight...someone screwed it up or gave you the wrong one...I would think you would want to be able to foot stall it to 3800-4000 rpm with around 10# of boost.

Call up whomever you bought it from and tell them what is going on.

 

[robh]

Sorry to hear that. I had the same problem. Supposed to be 3000 and was actually a 2100 stall. I asked numerous questions and took forever to troubleshoot and ended up paying another $150 to get it restalled. If you have a problem take care of it soon so you won't have to pay any more for the converter you orignally ordered.
good luck.

 

[RealFastV6]

What converter is it exactly?
(19930 or 16930?)

 

[GTEATER]

The converter was originally a 16930 from Reno AC. After several tries to get it from blowing through the converter on the top end...I sent it to YANK. The converter is great above 4000 and seems to be very efficient now, but have the first stated problem.

I spoke with Mike @ YANK today he felt the engine was not making enough power to stall the converter, suggested timing/ fuel probs.

Local respected turbo mech said he felt the cam/ turbo combo was too big and/or not timed correctly. Said the old converter would perform well on bottom because it was so loose and ineffient? He suggested advancing the cam until cyl pressure stopped increasing.

My concern is that the old combo was great except the rpms would stoot up and stay up( not droping between shift). Only replaced HG and converter...why would this "tighter" converter not like the engine topend combo, which is as follows:

TTA Champion heads, 218/212 Comp roller, pt 68 qtrim, CAS FM, 83#inj, w/ Speedpro/FAST system?

 

[TurboJim]

Stall is low, but I wonder if your crossover is leaking. Or wastegate flapper is too loose. Stall being low will casue slow spool, but exhaust leaks/wastegate leaks will cause it to act like that (slow to a point, then whips up)

 

[Steve Wood]

As it runs well once it is in the power band of the turbo, I still think the converter is too tight. It's really difficult when you have different people telling you different things...

It sure sounds like that everything runs well once you get to the point where that turbo can spool.

 

[UNGN]

A normally aspirated, 8:1 compression 231 hp v6 will run a 100% stock D5 to 2200 RPM (how much HP/Torque is that? 175 peak @ 4100 RPM/220 lbft max?).

Your 9" AC only goes to 2100. What does that tell you?

Man that has to be frustrating.

 

[TurboJim]

Originally posted by UNGN
A normally aspirated, 8:1 compression 231 hp v6 will run a 100% stock D5 to 2200 RPM (how much HP/Torque is that? 175 peak @ 4100 RPM/220 lbft max?).

Your 9" AC only goes to 2100. What does that tell you?

Man that has to be frustrating.

Assuming the motor isnt falling off and making its 160 or so NON turbocharged HP.

I dont mean to discount the stall is low. I agreed it was low, but my car acted this way when my gate was sticking. Once fixed, spool was kinda slow but slow all the way yp to 20. When the gate was stuck it would spool extra slow to 10 or so, then come up ok.

 

[GTEATER]

not sure what the stock hp comp tells me?. The car dynoed 486 rwhp with the slipping old converter.

 

[UNGN]

Originally posted by GTEATER
not sure what the stock hp comp tells me?. The car dynoed 486 rwhp with the slipping old converter.

A converter that stalls at 2100 isn't a 3300 stall converter.

 

[GTEATER]

OK, I agree the converter is tight, that is my hope anyway...not a bad engine combo.

As to exhaust leak, I have noticed a blowning or rushing air sound other than turbo whine when the car is trying to spool. It does sound like a leak...can't hear it under idle when I was listening for leaks after I put the engine back in, but I can definantly hear it when accelerating.

Hope it is the crossover....I was hoping for some lag to control wheel spin, but this is way too much.

thanks for all the comments, they are very informative and helpfull.

 

[Steve Wood]

check the turbo hoses.

 

[Quick6'n'-K.C.]

i dont think that a leaky header is going to keep the stall only to 2100-
my t-type has a HUGE leak, everyone can see it, and i point it out to everyone just to prove that leaky headers is not always the culprit in slow spool up-- my car spools awesome, and it has the largest leaky header one would ever want on their car

i wonder if you could advance or retard the cam sensor to help compensate the timing issue-

oh-- two weeks ago my buddy joe and i were talking about this wump wump noise he was hearing at low idle, he wasnt sure what the noise was, but thought it was coming from the back of the motor---
4 passes later the headgasket finally pushed out into the intake tract, and he is in the process of putting it back together-
im wondering if you have a headgasket on the virge of pushing out, and leaking some under the intake-- this would cause slow spoolup too- just shooting in the dark there-

wonder if the backing plate oring on the turbo has a leak?

sorry for the rambling, but it still sounds like convertor is too tight
how much larger is the pt 68 qtrim over the te45a??