ATi Lock up Trans/Converters

D

Diablo650Hemi

New member
Joined
Jan 4, 2012
Messages
62
So we all know you lose horsepower running through an automatic transmission compared to a Clutch. But with the newest ATI lock up style transmissions I am wondering how much power is lost through one of these? Is it more/less/ or about the same as a standard converter style transmission?

I am pretty close to giving up on the auto trans but still believe there is an advantage to them in the first 50-75 feet of a pull or on a "drivers" track. Where I seem to fall behind is on the power tracks. Our Data shows a huge amount of slippage for a sold .5-1.5 seconds of the run when the weight comes on. I've talked to Neal Chance/ATI/Coan and they all agree what i'm seeing can not be fixed due to how a pulling truck works with the load coming on all of a sudden.

So I am wanting to try ATI's new lock up style trans and converters. From what i'm told by ATI is becomes a clutch once it's engaged and should give me the best of both worlds.

No one to my knowledge has used one of this in N/A Mod pulling but maybe you diesel guys can give me your input.

Thanks
Diablo

sth13_019.jpg


[ame="http://www.youtube.com/watch?v=u4GwYlnBCQ8&list=UUjI6o33f3UOnXTG3EDhmZsg"]Diablo 4x4 Truck pulling 2013 Richmond fair. Full Pull - YouTube[/ame]
 
Should work like any of the lock up auto trannies we use with the diesels. I also feel autos have an advantage in certain conditions.
 
At what RPM do you let it lock up? How many RPM will it pull down an engine? Is there any chance the truck will start to bounce when it locks up?

Should I have it lock up early in the RPM range..... 5000-5500

Should I let it lock up before peak RPM? 8500?

I will be able to set the lock up to a RPM timer.

Anyone think of any problems i could fall into?
 
I think the lock up is something you will need to play with. My truck usually locks up around the 100' mark. I personally feel you should let the drive train catch up to the engine rpm before the converter locks. I usually lose 100ish rpm on lock up. I think with a little testing you could realy dial dial it in.
 
We went from a 48Re with an ATS 5 star converter to a reverser and Crower clutch this year. Were we noticed the biggest difference is in power to the rear tires. I would lock the converter at around 75 to 100 feet, we also started out in 3 gear with was 1 to 1. The transmission was hooked to a profab drop box. The auto worked great, But the control with the clutch is alot better in my opinion. The biggest down fall that I can see is it is a lot of work to run the clutch.(Adjust, Adjust and repeat) With the auto it was check fluid and go
 
You're talking about a lockup powerglide transmission/convertor?

As soon as the turbo is lit is when I believe most folks hit lockup. So within 50ft hopefully. :)

I have seen some people get some bounce with lockup. IMO there's multiple reasons why that could be - chassis setup not taking the load change of the lockup or the lockup is just too harsh causing too much of a load change which leads to the bouncing.


However, some say the DOT tires don't take the load changes as well (load and unload) and get into a bounce but you clearly run cut tires so that may not be an issue for you regardless?
 
Last edited:
largeride said:
We went from a 48Re with an ATS 5 star converter to a reverser and Crower clutch this year. Were we noticed the biggest difference is in power to the rear tires.
Click to expand...

Does this mean you don't think your lock up converter was actually locking up 100%?

With your crower clutch were you using a peddle or with no peddle?

And I am thinking of ATI's lock up powerglide/converter set up.

And just to remind readers is this is a NTPA N/A Mod truck. No Diesel/turbos. Its a 650ci 5inb Bore Space Hemi with 1500hp

si13_114.jpg
 
Last edited:
All the trucks around here setup like yours have went reverser and slipper clutch
 
I would say yes. Once the converter is locked it is doing the same thing as the crower. I still feel a torque converter can be an advantage when used properly. I also think locking up too early with a converter or clutch is not ideal....
 
One of these days people in the diesel pulling world will understand that when a good convertor is not one to one it’s not slip, but the convertor is multiplying torque. I have had many conversations with the best convertor designers on the planet. Jason Coan , Marty Chance and Marv Ripes .
All see this the same; the multi disc diesel convertors are very poorly sized and designed on the hydraulic side as fare as being efficient. The reason , is as you stack more and more clutches in the space available so that the end use can use it more like a clutch the less space available for a good true torque convertor. I would use a non-lock up THM 400, which is much stronger than the 47 or 48 R. Hang the motor on the convertor about 100 rpms below peak hp. At the end of the pull the motor will never drop below stall and stay in peak hp, and torque will be multiplied to the tires. Think of a good designed convertor as a variable gear ratio.
 
Diablo650Hemi said:
BUt the questions is why not a lock up converter? I now know why not a converter with slip but can a lock up converter keep up if not surpass?
Click to expand...

Not sure. Beside no torque multi the slipper clutch acts much the same. I am surprised the powerglide holds up. My buddy went reverser after his th400 exploded and come threw the floor board. Also this was before he had his mountain motor thats about your power range he was only 1000hp or so then.
 
I was curious so I looked at ati website, 5k for the lockup. Honestly if you have the money, I say try it out! May just be the next best thing!
 
pwrstrokenstang said:
Not sure. Beside no torque multi the slipper clutch acts much the same. I am surprised the powerglide holds up. My buddy went reverser after his th400 exploded and come threw the floor board. Also this was before he had his mountain motor thats about your power range he was only 1000hp or so then.
Click to expand...

The glide are holding up to 2000 to 2500 hp in Pro Mod without a problem . With 1.25 input , and 1.25 outputs The super Turbo 400 with billet cases are working with ever more . When you can stack ratios in a glide of 1.25 first and 1 to 1 this would make a good pair of gears
the Turbo 400 have hundreds of ratio's
most of this is not common knowledge
 
Diablo650Hemi said:
Our Data shows a huge amount of slippage for a sold .5-1.5 seconds of the run when the weight comes on. I've talked to Neal Chance/ATI/Coan and they all agree what i'm seeing can not be fixed due to how a pulling truck works with the load coming on all of a sudden.
Click to expand...

What's "a huge amount?"

I see no reason why lockup wouldn't work, it actually should be easier in your application because it spins so many rpm. Nice sounding truck by the way.
 
COMP461 said:
One of these days people in the diesel pulling world will understand that when a good convertor is not one to one it’s not slip, but the convertor is multiplying torque. I have had many conversations with the best convertor designers on the planet. Jason Coan , Marty Chance and Marv Ripes .
All see this the same; the multi disc diesel convertors are very poorly sized and designed on the hydraulic side as fare as being efficient. The reason , is as you stack more and more clutches in the space available so that the end use can use it more like a clutch the less space available for a good true torque convertor. I would use a non-lock up THM 400, which is much stronger than the 47 or 48 R. Hang the motor on the convertor about 100 rpms below peak hp. At the end of the pull the motor will never drop below stall and stay in peak hp, and torque will be multiplied to the tires. Think of a good designed convertor as a variable gear ratio.
Click to expand...


Marty Chance and I have been working on my set up for two years now and we have tried 5 different conventual converters (slip style) It has been the same problem each time. The efficiency is great and constant until the weight pulls the truck down and all of a sudden the slip goes crazy for a spilt second. The worse i've seen is a full second and a half. It is just how converters work and Marty and Coan says there are ways to fix this problem in drag racing with shifting gears and different rpms but in pulling we don't have that available to us. Also Marty says many dont notice this because its not really visible. But since I have a Dataquest brining in all sorts of data and I see whats happening. Our tire speed is dropping from 38mph down to 15-20 and then back up to 38.

This ATI lock up system is my last idea before having to move to the clutch. I'm sure (not 100% though) that the ATI converters must be made to allow for a proper converter and lock up side.

The reason i've been told i've never had any trans problems with my old 727's and now the powerglides is because there is no shifting or sudden rpm changes. Pulling puts a more general stress on the parts which makes everything live happily.

Comp461. Do you feel this may be a good direction to go? Can you see any problems trying it? I've said my problem i need to fix with the other converters. You think this will fix it and let me compete against the clutch trucks or will it bring on new problems?
 
Diablo650Hemi said:
Our tire speed is dropping from 38mph down to 15-20 and then back up to 38.

This ATI lock up system is my last idea before having to move to the clutch. I'm sure (not 100% though) that the ATI converters must be made to allow for a proper converter and lock up side.
Click to expand...

So it gets drug down to 15-20mph for almost a second or more? That sucks, lock-up should solve that, it'll just put the load on the engine instead. Most folks I've heard of run the Hughes lock-up glide, don't know about ATI. What diameter converter are you running?
 
I would look at an extreme close ratio 400 or glide. There are several gear sets out there. I have been talking to Jason about one like that. Are you allowed a Bruno style set up
With a 1.15 or 1.20 second and 1 to 1 high gear you could pull down a gear . I would forget lock up all together. Work on a convertor that is matched to the motor.
Talk to Jason directly, he is a comp racer and knows how to think outside the box. Most company’s don't want to even talk diesel . I have been working with Jason form many years on refining the open diesel convertor
 
COMP461 said:
I would look at an extreme close ratio 400 or glide. There are several gear sets out there. I have been talking to Jason about one like that. Are you allowed a Bruno style set up
With a 1.15 or 1.20 second and 1 to 1 high gear you could pull down a gear . I would forget lock up all together. Work on a convertor that is matched to the motor.
Talk to Jason directly, he is a comp racer and knows how to think outside the box. Most company’s don't want to even talk diesel . I have been working with Jason form many years on refining the open diesel convertor
Click to expand...


I'm not a diesel. And shifting is out of the question. We run in high 1 to 1 gear. Since we can't shift is the reason these converter can't seem to hold. We can run a Bruno but the same problem im having occurs with them
 
Tranny

Diablo I also think there is a advantage to running a auto pulling. Comp just can't seem to see past his own ego so good luck with him. If you want a lockup call Hughes they just come out with a 13" lockup deal for a powerglide. They have a bell that will fit a 13" and that was the holdup for many years with running a big convertor and a powerglide. I just got my bell and i'm waiting on the convertor. They run regular gm clutch packs in the converter so rebuilding is easy. Good luck and I like your thinking easy on parts.
 
You must log in or register to reply here.
Top