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Discussion Starter · #1 ·
I have been giving serious thoughts to going Glide in my car. It is a 4 door Fairmont with a turbo LS and a 3.55 rear. I currently have a 4L80E with a triple disc billet converter that was re-done by Lenny @ Ultimate Converter. The trans works great, but I feel like it: (1) has too much parasitic loss; (2) it is too heavy; and (3) it is giving me issues launching on the street.

I have recently completely re-done the suspension and it has been professionally set up, so the hooking issues may be remedied or partially remedied. However, I still think a Glide would serve me well. The car is currently 3450 with driver and I think with a tubular K-Member and A-Arms as well as a Glide, I could be able to get that weight down a couple hundred pounds. I also currently have 58% weight bias in the front, and a lighter trans would certainly assist with that.

To date, best 60 foot (with the old suspension), leaving off of the footbrake and anti-lag is a 1.36.

I have heard many opinions on this switch and I really only want to do it if there is going to be a significant improvement. I am willing to lose a little cruise ability for a reduction in ET and increase in MPH. I am running a 28 inch tire at this time.

Opinions?
 

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Just think about all your power going through (1) pump, (1) drum, (1 low gear).

Not only will it produce more rwhp with the right converter but it will give you the ability to turn existing power up to it's further potential if there's any restriction going on from your end now in the tune. You may also open up new converter core opportunities as well with a standard GM spline trans. Like ones that weigh 29lbs as opposed to 45 lbs.
 

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Discussion Starter · #7 · (Edited)
The car makes in excess of 1k at the crank. It has a cast 80mm on it, so it is probably limited to 950-1k at the wheels on kill. I don't want to disclose everything about the car, but the previous combo made an easy 852 RWHP @ 16 psi and 725 RWTQ with factory ported head castings...let's say I plan on making over 850 torque now with the current combo. It has a Circle D triple disc billet that I do not lock (except under cruise) as Lenny @ Ultimate did a great job for me on the converter.
 

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It could be made to work either way. The converter is the key to both combos. Obviously the glide is lighter but I like torque multiplication. I'd keep the combo and work on the suspension and torque management if it were mine.
 

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If you were over 1200 HP, the Glide would probably work good, but with 3.55 gears, the weight, and ~1000 ish, I agree with VENGNCE, keep the multiplication. It will likely slow down with a Glide, it would definitely be less streetable, and converter would be more critical. It sounds like you're in good hands with the converter and if it's setup good now, squeeze all the performance you can out of it.
 

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Discussion Starter · #10 ·
If you were over 1200 HP, the Glide would probably work good, but with 3.55 gears, the weight, and ~1000 ish, I agree with VENGNCE, keep the multiplication. It will likely slow down with a Glide, it would definitely be less streetable, and converter would be more critical. It sounds like you're in good hands with the converter and if it's setup good now, squeeze all the performance you can out of it.
Interesting. I have a friend with almost the exact same combo. He had a TH400. With no other change but a Glide he went 3 tenths faster. I would think a TH400 is similar to an 80 in terms of torque multiplication and parasitic loss.

I would go to Lenny again for a good converter.

I have been told everything from I would be 5 tenths quicker to I will be slower.

Tough call. I want to hear more.
 

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Interesting. I have a friend with almost the exact same combo. He had a TH400. With no other change but a Glide he went 3 tenths faster. I would think a TH400 is similar to an 80 in terms of torque multiplication and parasitic loss.

I would go to Lenny again for a good converter.

I have been told everything from I would be 5 tenths quicker to I will be slower.

Tough call. I want to hear more.
I bet the car will fly with the right converter and a glide. The 4L80E is heavy and is killing your combination at the track.
 

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If he went 3 tenths faster with a similar combo, he had a converter change that netted most of that.

Converter is obviously very important.

A Glide is a great piece but a properly setup TH400 (or 4L80E) simply works better in most normal weight cars that are making less than 1000 HP and have "streetable" gear ratios. 3.08-4.10 IMO.

We've done back to back with a TH400 and 4L80E using a converter that was spec'd the same from the same builder. Both converters flashed 4400 rpm, the combo was a 3600 lb car with 4.10 gears and a NA 496 BBC with AFR heads, solid roller, etc. It ran 104 mph in the 1/8th with a TH400, and 105 with the 4L80E, consistently. It was a few hundredths quicker with the 80E. That tells me the 4L80E wasn't eating much more HP than the TH400 and whatever it was was being compensated by a slightly better converter build or atmosphere.

A customer of mine who is a fairly well known tuner did back to back chassis dyno testing between a 4L60E and a 4L80E and there was only a very small difference measured.
Here's a link to a thread with that graph.
http://ls1tech.com/forums/automatic-transmission/1691174-60e-vs-80e-dyno-comparrison-questions.html

Faster cars benefit from more efficient transmission designs more so than a slower setup. My rule of thumb for this is that if you aren't running bottom 10 second quarter mile times or better, you're wasting your time worrying about lighter transmissions or parts. Once you get faster than this (and it sounds like you should be) it's something to take into consideration but it's NOT the primary consideration. Primary consideration is gear ratios and converter selection.
Some combos benefit from a 3 speed, some from a Glide, some from a 400 based 2 speed. I don't think you have enough rear ratio or power that a Glide will go faster. I think your combo would slow down very slightly with a Glide. My guess would be a tenth or so if all else is equal.
You MIGHT go faster but I think you would end up changing rear gear ratios and restalling the converter to make it equal or faster.

Launch the 4L80E in 2nd and see how the combo likes it.
 

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I currently am running 4l80 in my camaro and would only consider a powerglide if it was a track duty car only. I could see a three speed on the street but damn having that 4speed is nice.
 

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Discussion Starter · #14 ·
If he went 3 tenths faster with a similar combo, he had a converter change that netted most of that.

Converter is obviously very important.

A Glide is a great piece but a properly setup TH400 (or 4L80E) simply works better in most normal weight cars that are making less than 1000 HP and have "streetable" gear ratios. 3.08-4.10 IMO.

We've done back to back with a TH400 and 4L80E using a converter that was spec'd the same from the same builder. Both converters flashed 4400 rpm, the combo was a 3600 lb car with 4.10 gears and a NA 496 BBC with AFR heads, solid roller, etc. It ran 104 mph in the 1/8th with a TH400, and 105 with the 4L80E, consistently. It was a few hundredths quicker with the 80E. That tells me the 4L80E wasn't eating much more HP than the TH400 and whatever it was was being compensated by a slightly better converter build or atmosphere.

A customer of mine who is a fairly well known tuner did back to back chassis dyno testing between a 4L60E and a 4L80E and there was only a very small difference measured.
Here's a link to a thread with that graph.
http://ls1tech.com/forums/automatic-transmission/1691174-60e-vs-80e-dyno-comparrison-questions.html

Faster cars benefit from more efficient transmission designs more so than a slower setup. My rule of thumb for this is that if you aren't running bottom 10 second quarter mile times or better, you're wasting your time worrying about lighter transmissions or parts. Once you get faster than this (and it sounds like you should be) it's something to take into consideration but it's NOT the primary consideration. Primary consideration is gear ratios and converter selection.
Some combos benefit from a 3 speed, some from a Glide, some from a 400 based 2 speed. I don't think you have enough rear ratio or power that a Glide will go faster. I think your combo would slow down very slightly with a Glide. My guess would be a tenth or so if all else is equal.
You MIGHT go faster but I think you would end up changing rear gear ratios and restalling the converter to make it equal or faster.

Launch the 4L80E in 2nd and see how the combo likes it.
Interesting. I will check out the test between the 60 and 80. The car is a good bit faster than 10's. As a matter of fact, I was looking for the Glide to help it get well into the 8's.

Thanks for the info, much appreciated!

Mike
 

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If you were over 1200 HP, the Glide would probably work good, but with 3.55 gears, the weight, and ~1000 ish, I agree with VENGNCE, keep the multiplication. It will likely slow down with a Glide, it would definitely be less streetable, and converter would be more critical. It sounds like you're in good hands with the converter and if it's setup good now, squeeze all the performance you can out of it.
Wouldn't slow down a bit........since you would be able to leave on probably double the amount of boost with the improved SLR from a 1.80 glide, it would probably leave a lot harder. May need to step up the rear gear to like a 3.89. But, I'd bet the car would be substantially quicker with a glide and the ability to leave on a lot more power. Although the O/D is nice for street manners, for ultimate track performance I think you would be a quantum leap ahead with less SLR.
 

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Discussion Starter · #16 ·
Wouldn't slow down a bit........since you would be able to leave on probably double the amount of boost with the improved SLR from a 1.80 glide, it would probably leave a lot harder. May need to step up the rear gear to like a 3.89. But, I'd bet the car would be substantially quicker with a glide and the ability to leave on a lot more power. Although the O/D is nice for street manners, for ultimate track performance I think you would be a quantum leap ahead with less SLR.
It is an 8.8, so the next step up would be 3.73 and then 4.10. Someone may make a 3.90, not sure. Then it would be a dedicated trailered machine. I do drive this car everywhere. With a 3.55, I still could. 3.73 is iffy...3.90 or 4.10 is a no.
 

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I you must have the compromise, then stick with the O/D. But it would be much quicker with a glide......as far as e.t.'s go.
 

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I vote keep the 4L80E with the 3 gears and OD at least until you stop driving it on the street.

My car has a AODE with a 2.84 first gear, 3.25 rear ratio and 30" tall tires. Everyone swears that Turbo cars like a low gear ratio to run fast but I routinely run cars in TS that run faster MPH but slower ETs. What does that tell you?

My 3550lb car easily runs mid 1.2x short times, routinely runs mid-8s and has gone 8.35 and is very efficient using the existing power with a 3 speed transmission.

I would put my money/effort into making the car leave and hook.
 

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Discussion Starter · #19 ·
Took the car down the chassis shop today and I drove quite a bit in 3rd. I came to the conclusion that I don't like the way it cruises above 60 mph in 3rd and I will miss my O/D. I am going to focus on boost control and suspension tweaks. I may re-visit the Glide at a later date.
 

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I started with a TH400 and a 3.23 gear as I drive the car everywhere like you.

Swapped in the 4L80 and won't go back. OD is nice on the highway.
 
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