Is my torque converter too tight?

[Waco84GN]

I have taken my car to a local track tonight and last friday and the car was very hesitant to build boost on the line.

The car would initially spool to around 5psi and around 1800rpm and then would hit a wall. The most I have been capable of is around 10psi, but that was sitting at the line from 4.5 to 6 seconds trying to build boost.

What effects building boost on the line?

Exhaust back pressure? Running an open dump

A rich condition? Took out 5% gas in first gear on the TT chip

Stall speed on converter? Around 1800 initial to around 2800 by sitting there for ever.

What else?


Thanks for your help guys,

Jerry Berger

 

[boostmaster]

Stall Speed

Sooooooo.......what did it run?

Anyway to answer your question a rich fuel mixture can very much affect spool. What stall should your converter be and what type of converter is it?

Brake stalling which is what you where doing is very bad for the converter you should not brake stall for more than a few seconds on a routine basis. also it it not the proper way to determine stall. Typically flash stall is more accurate and close to what your actual stall may be.

Flash stall is when you apply the accellerator the initial flash or jump to RPM before the car starts to move. There will be a quick ramp in RPM then movement and that is pretty close to your actual stall. But stall can be also be altered by H.P. which why if your tune is off or real fat your vehicle will typically stall lower. So before you go bying a converter make sure your tune is right. You can determine this very simple. If your 60ft is low and your e.t. is low but your trap mph is very good then you have a stall issue or traction issue. Because once you get moving stall has no effect on H.P.. But if your et is low and you're trapping low mph it may very well just be a tuning issue.

Hope this helps, Pete

 

[Waco84GN]

Time and et

The car ran 12.78 at 107. The 107 should be around a 12.50. It ran a 1.9 60ft and a 8.36 1/8 mile. I have some logs to post up.

These runs were with c16 and spraying alcohol starting at 12psi.
The converter is a converter I bought from full throttle. Supposedly a 2800 but it does not even get close to that.

I'll post logs later.

Jerry jr

 

[Waco84GN]

Logs

I know that the car was getting hot at the end of the run. But the coolant was fine the whole way home (thought it might have been thermostat sticking). Anyway the rpm looks like it flares too about 1700 or 1800?

On 3.19.10.2 the car died as soon as I tried to apply boost at the so that is why it looks weird.

Jerry jr.

 

[boostmaster]

Log Files

Sorry Jerry but I don't have the file extension to view the logs. But from your description it sounds like your converters too tight. Sometimes when converters are not built per spec sheet of the car it's going in the stall is off. I learned that years ago about buying a generic off the shelf stall converter because most times those converters are built to be accurately stalled within a specific horsepower range and when that range is off so is the stall. I would get a custom stalled 3000 rpm converter and never look back. 3000 would be accurate within + or - 200 rpm and perfect for the street or strip with a mild build. If you ask for 2800 it will be the same within 2600 to 3000.I know with my 3000 stall I get no lag and tires spinning with no brake stall or killer burn outs with minimal (1-2 seconds) brake stall.

Pete

 

[charlief1]

Jerry, how is the waste gate set up. Are you on a controller or running a stock system?

 

[Waco84GN]

Wastegate system

Controlled by a rjc style manual boost controller had always been rock solid at what ever level of boost I have set it at. I don't think this is the problem, but can check the valve with our compressor. The wastegate comes directly off the compressor scroll into the valve back to a stock style wastegate actuator. Has always regulated boost with no creep.

Jerry jr.

 

[Boost231]

converter seems alittle tight.

Whats with the KNOCK ????

 

[Waco84GN]

dunno really

I was running c16 and spraying denatured alcohol (old smc kit). I will back it off and see if it goes away. It was with a TT race chip (a lot of timing). As you can see the car was really hot for some reason, but I dont think I was leaning the motor out was I? What should I shoot for on EGT with race gas if anyone knows?

I think the motor heat may have contributed to some of the knock.

I wasnt hot lapping it and cut the motor off on the lanes. The temp was fine during the entire drive home, temp gauge didnt go above 180.

Boost231, if you dont mind me asking, what stall converter does your car have? I know it is basically combo specific, but I'm just curious?

Thanks for the input guys,

Jerry jr.

 

[charlief1]

Not gonna argue with the convertor being to tight Brent or Jerry, but it almost sounds like you're not getting a good seal on the puck Jerry. See how it's siting on the hole and check the waste gate to make sure there isn't a pin hole in it.

 

[Boost231]

Boost231, if you dont mind me asking, what stall converter does your car have? I know it is basically combo specific, but I'm just curious?

Thanks for the input guys,

Jerry jr.

ok, let me see here. I will give you my opinion for what its worth. this is just knowing alittle about your car and the setup it has. also this will be looking at your data log's and what i see. reminder its just my .02

Frist thing TPS. yours is reading .48 at idle, thats the max it should be i would bump it down. i like to set mine at .44 closed throttle. For WOT, your at 4.38, thats not bad but i would bump it up some. i like to see 4.50, this a good safe place for it to be.

IAT-- Where is the sensor at? filter from what i can see.

A/F ratio- you really need to get a WB sensor on there. Tuning with 02's and even egt's at 30psi is crazy IMOP

Shift's Points/Tranny- Your trans looks ok. the shifts are not super fast but they are good, no real slipping that i can see. also you are getting good RPM drop 600-800 is good. One thing i see however is why are you letting it shift into OD???? leave it in 3rd. Also IMOP with your 208/208 cam and ported heads you can rev that motor out more. there isnt really anything easy to make the shift points higher at this point in time but you can do it. i would probley shift your car around 5300-5500. so with that being said leave the car in D and let it rev out on the top end. im sure that car will pull good in the upper RPM's. your losing alot letting it shift into OD and 87 MPH @ 4500 RPM's.

MAF- looks good for the track but how is it on the street? it took to 23psi of boost before it would max at 255. IMOP it should be maxing out alot lower then that.

Coolant temp- just looked at more logs and more data. I hope you don't have a head gasket issue. I would really look into it 241 deg. WOW . i dont like what i see for knock and i do believe the knock is real. i also believe thats why your temps are hitting 241

Injector duty cycle- looks good. if you get up in the 90's just add more alky

Exhaust Gas Temp- your is at 1450. thats safe. when we use to tune for Exhaust temp we would shoot for 1600's. now things might have change. But like i said i hate tuning with just EGT's becuase its effected in alot of different ways.

Boost Pressure- IMOP your Boost is way to high as of right now. you need to IMOP slowly bring the boost up more and more. start at 18 or so and slowly work your way up. it has taken me several track visits to get mine to 25. i bring mine up in slow increase to make sure everything is good. last thing i want to do is hurt my new motor by rushing things. so IMOP TURN THE BOOST DOWN :biggrin:

Knock-- even though you have c16 that doesnt mean its going to stop knock or allow you to run 30 psi. your knock doesn't start till around 27psi of boost. now from what i looks like its real. how can we tell. turn the boost down to 22and run it or hell even 20. also with the way the timing is set in this chip i wouldn't be running no 30 psi at 25-26deg of advance. you need to start lower on the boost and timing and work your way up. find out if this is false or true knock. IMOP i believe its true and hopefully you havent hurt the motor.

Bat- battery looks good.


02's- they look good but we will never know the true a/f without a WB sensor. your o2's are around 770 and from some of the data i have goten on my car thats around 10.00-10.30's but its hard to say as i have got 815 on other passes where the true a/f is 10.00-10.20's. so you can see how 02's suck.


ok with all that being said this is what i would do, you need to check to see if the motor is hurt, headgasket?

i would also lower the boost and next time out lower the 3rd gear timing to around 21 or so max. i would maybe bump the 1st gear timing down to around 24 from 26.

your spool up issue. are you sure you dont have any exhaust leaks. just want to make sure no cracks in headers or anything. there is no reason that converter shouldn't spool the turbo you have.

humm, not sure what else to put. lets go from there and see what others have to say. im not happy with what i see

O and for your question about my car and converter. well the converter i have is a PTS billet 9x11 2800-3000 flash lockup unit. now this converter has been great for me from 13's to high 11's. spool my 54 super fast and locks hard. now that i have changed a few things with my setup :wink: im changing it out.

o and about timing. i know you have an intercooler and all and the intercooled cars can get away with more timing i wouldn't push your setup to hard with timing. slowly work your way up and see what your car likes. i was running 19deg in 3rd for a long time since my IAT in the intake are 200+ deg. i just bumped it up to 21deg and the car reacted well. this is with the boost at 23 or 24 psi (cant remember). i will now keep adding more boost till i get to my target of 30 or so . once i do this i will probley play with the timing more. this is just to give you an idea on how low my timing is. my low gear timing is at 21.5 deg. so you can see im running low timing in low gears as well. basicly 21 to 21.5 deg the whole way down. now with that being said and how fast my car is running now just think once i go all out and bump the timing and boost up, what she will run

hope this helps some

Brent

 

[Boost231]

damn, thats a long post. hell thats not like me.

 

[Jerryl]

damn, thats a long post. hell thats not like me.

No it is not, but it is very well written and solid advice (!!) on the spool KR, tuning etc.

 

[Waco84GN]

Wow that is a long post

Ok I will check this stuff and report back. My iat is located just before the tv in the black snorkel. I found it fits pretty good in the hole where the valve cover breather was attached.

I'll check for HG damage and adjust the timing on that chip. That was only the second time I had ran the car with the TT race chip.

There are no audible exhaust leaks and I had the headers off and blasted them and didn't see any cracks.

Thanks for your input,

Jerry jr.

 

[cwmccray]

Jerry
Your convertor is a tight for your combo. Pull the convertor and have it re stall (3200-3500) should turn it into a real ANIMAL.

 

[boostmaster]

Too Much!!!!

Jerry
Your convertor is a tight for your combo. Pull the convertor and have it re stall (3200-3500) should turn it into a real ANIMAL.

C'mon dude that's wayyyy too much for a daily driven street car!!! 3500 Chuck be for real dude. Too much slippage on the street plus without the necessary upgrades to move his powerband up he'll be leaving a lot of H.P. down low. This aint a BB Chevy with nitrous so stop Chevyizing everything.

 

[Dusty Bradford]

Jerry
Your convertor is a tight for your combo. Pull the convertor and have it re stall (3200-3500) should turn it into a real ANIMAL.

Bad idea. His rpm drop is 500-600 rpm so that tells you the converter is not too tight. He has some sort of issue with the car not making torque at low rpm. He said he was seeing 5psi at 1800rpm. That can seem like a bad converter but when you take into account the rpm drop, it rules the converter out. Loosen it from 1800 to 2800 which is 1000rpm and it will never couple.

I'd be looking at the tune. Even if it's very rich it won't loose that much power, but if it's rich enough to cause a miss, the loss of a cylinder will make it loose torque.

He also needs to verify the timing. Something could be causing the timing to be very low. If you know the car should have 30 degrees of timing, it needs to be verified on the balancer with a timing light.

 

[Jerryl]

........ His rpm drop is 500-600 rpm so that tells you the converter is not too tight. He has some sort of issue with the car not making torque at low rpm. He said he was seeing 5psi at 1800rpm. That can seem like a bad converter but when you take into account the rpm drop, it rules the converter out. Loosen it from 1800 to 2800 which is 1000rpm and it will never couple.

I'd be looking at the tune. Even if it's very rich it won't loose that much power, but if it's rich enough to cause a miss, the loss of a cylinder will make it loose torque. .

You know what Dusty, you are exactly right.
I remember having a 1500 rpm drop with a non-PTC converter . . . It was than that I learned more about converters from the experts like yourself.

In this case, if there is in fact a tuning or other mechanical issue, and the OP is only seeing a 500 rpm drop, it will be real loose once the bugs are figured out.

It will be interesting to see what it is.

 

[Dusty Bradford]

To build 5psi by 1800rpm sounds like it could be a severe retarded timing issue. Possibly ecm issues, cam has jumped some teeth.

I'd be getting a timing light on it to verify the timing is where it should be and going from there.

 

[Waco84GN]

Got some questions...

First of all, I don't think I hurt the motor. I wanted to check for blown HG so I looked in the radiator for bubbles. With the car dead cold there was water flowing and foaming in the radiator like crazy (2 week old Failsafe thermostat failsafed at the track). Kinda scary when your checking for foam and you open the cap and that is all you can see.

I took the water pump belt off and the bubbles and foaming quit totally and the car is not missing at all. Oil also looks good and clean.

So that seems good

Okay now questions...

During what condition should I check timing? At idle?

Then check timing via timing light versus what the powerlogger is showing the car to have?

Just put a new cam and heads on the car prior to these runs, and installed the cam (208 / 208) per the spec card.

I believe everything mechanical is in proper order so if the timing light time is far off from the measured ecm timing what would the suspect part be? ESC module?

Thanks for input,

Jerry jr