Torque converters and rpm

[Quickstop [UK]]

Re: Torque converters and rpm

But if I can get it restalled, how much will that be and who will do it? Shipping is going to be about £250 each way probably, then the potential headache of someone opening it up and saying "we can't do anything for you"...

Any idea how much a restall is?

I am in the wrong part of the world for this passtime...

Got to remain positive right?

 

[dgoodhue]

Re: Torque converters and rpm

I don't think that is a billet 9/11. My cover doesn't look like that.

 

[Quickstop [UK]]

Re: Torque converters and rpm

So much for doing the truck once and leaving it!!!

Do my graphs tie in with my explanations? Do you agree? It's all wack?

 

[e95 Ty]

Re: Torque converters and rpm

I told you already what to try.....That looks like a real nice billet tc. Lock it as soon as it shifts into 2nd gear, then the slippage won't matter except for the launch, and I told you how to help tighten that up. Try it before pulling that tc out.

 

[0966Sy]

Have you confirmed the stall speed on the brake and flash? Before going further I would confirm these too. Otherwise moving forward to another TC would leave you guessing what you "don't" want again.

Normally hold the brake pedal and ease into the throttle while watching your RPM. When you feel the truck start to want to move forward that is your stall speed.

Flash stall is typically 300-500rpm more than your brake stall speed. You should cruise in third and punch it to the floor. While watching your rpm's shoot up fast before it starts to pull forward is your flash stall. The loose converters I have felt flash much higher than 500rpm more than brake stall.

It has to do with the design of the stator and how the fluids creates a centrifugal force to get it moving. Top rated TC builders have some pretty wicked custom built TC's that will cruise at low rpm and flash tight with a higher brake stall. Your build will effect the outcome of a custom TC.

What cam are you running?

The electronic trans stuff is new to me, I'm sure you have capabilities tuning shift points and slippage in the lock-up. I'd look deeper into your software for the 80e

It doesn't surprise me the lack of performance from Waller. I've seen and heard of a lot of problems with not only quality of his work but quality of parts he had sold his customers.

 

[Quickstop [UK]]

Re: Torque converters and rpm

I told you already what to try.....That looks like a real nice billet tc. Lock it as soon as it shifts into 2nd gear, then the slippage won't matter except for the launch, and I told you how to help tighten that up. Try it before pulling that tc out.

Hey Matt,

Yeah, thanks - I am going to try the HyGard first. I found it here - 10qts for $40 isn't too bad so I'll go that route before trying anything else.

Have you confirmed the stall speed on the brake and flash?

Hi 0966Sy

If I apply throttle with no brakes, I can reach 2400 rpm before the truck starts to move. This is the flash stall I believe.

If I apply brakes, I have seen up to 3700 rpm and 13psi (on DM) but I have also had the truck brake boosted up to 25 psi (the wastegate needs dialling in - above 15 psi the turbo spools incredibly fast). I'm guessing that's around 4200rpm. I would have thought that I would reach the brake stall before then or the wheels would turn and beat the brakes.

If I can spin that high with that much slip, a lot of power is going to heat and noise rather than acceleration.

I'm going to dyno it with 2nd locked up so that should allow me to tune it but the application of that power looks to be a headache.

I appreciate all the comments and suggestions. Now I need to get the HyGard into the trans.

:tup:

 

[Quickstop [UK]]

Re: Torque converters and rpm

Did a bit of research into this Matt. Just for the benefit of others/future reference, TY6354 is J20C equivalent fluid which is the normal viscosity fluid for HY GARD. (Much thicker than stock trans fluid)

The other P/N is TY22000 which is J20D and that is the low viscosity stuff, basically the same as regular trans fluid in terms of how thick it is. (Units are Cst. at 40C and 100C)

Mercron III:
40°C: 34.35
100°C: 7.23

JD Hy-gard regular:
40°C: 59
100°C: 9.4

JD Hy-gard low viscosity:
40°C: 33
100°C: 7.1

The UK equivalent for TY6354 is VC-81824.

It cost me £25 for 4.8kg = 5l. So just over 1.3 US gallons. What do you guys pay there?EDIT : $52 fr 5 gallons. Damn UK socialist taxes! :rant:

Now to get it into the house and in the truck!

 

[0966Sy]

Sounds like the TC is not bad at all at 2400. But you need to lightly hold the brake to load up the engine a little more. The truck should move as soon as you give it gas not being on the brake. I think you have a problem with the TC if its not even moving in 1st when you let off the brake. I would go over your tune for the trans to make sure everything is where it should be.

We have the hyguard here but have replaced it with a super s tractor fluid that has the same fluid properties that doesn't require going to Deere for buckets. I've heard of using it in automotive racing applications but haven't seen it first hand yet.

 

[Quickstop [UK]]

Re: Torque converters and rpm

Well, I did some datalogging this morning just before breakfast with relatively empty roads. I had to collect my new Black Air DVD from the post office! (Thanks Paul!!)

At the suggestion of one of our Dutch members, I reprogrammed the TCC on the Ty to lockup at about 8mph. The engine bogs quite a bit when downshifting but that's by the by...

The result?

Holy crap the truck is fast now! None of that rubbish high rpm/sluggish pulling away from the line. This test now rules out the trans slipping and confirms the TC is rubbish.

I have received the Hygard fluid but at this point wonder if it's going to be enough. I want a stall speed of 2400-2800 at about 10psi. I was getting 2800rpm at 4psi and 50% slip. The TC just isn't putting the torque through the wheels. What I read was that the Hygard will make the rpms will come down by maybe 1000? I suppose I am guessing until I try. I'll have to think about it.

I'll post up some datalogs later. Hope someone finds this useful.

 

[Quickstop [UK]]

Re: Torque converters and rpm

Here it is.

You can see the green line climbs steadily after a small gap. TCC lockup was set for about 6kph.

The purple line is the Turbine speed and that matches the vehicle speed exactly, the whole way up. If there was any transmission slip, these two lines would separate.

The truck felt completely different. I will set the TCC a bit higher as it bogged when I came to a stop but it was so much more fun to drive. There was no turbo lag either.

I need a really tight stall for this truck. Boost appears at 2400 rpm again. I don't want a converter any looser than that really.

 

[IGottaSy]

Re: Torque converters and rpm

Thanks