Going to go auto for my Backhalved 3000 lb. street / strip Vette. Talked to Mikes transmissions and they reccomended a Powerglide over a turbo 400. I was a little suprised since the Vette will weigh over 3000 lbs with me in it. I am familiar with the 2800# rule. Mike told me with the power the car will make, 572 on nitrous (1200-1400 hp), it will be quicker with the glide.

Any opinions ?

If Mike says a glide will work .. it'll work.
I know of a few cars 3200 lbs + that bracket race stock case glides.

with that much motor i'd go glide too. the weight deal isn't that big of an issue when you have 572 cubes. i know dozens of cars that weigh 3400lbs + and are running faster with powerglides. all those cars are big inch nitrous or supercharged engines.

Sorry about jumping in here, but I have a question.

This may be a stupid question, but why when you start making really serious power do the experts recommend powerglides? I would think the more gears the better. I know 'glides have less HP loss through them when compared to Turbo 400's, but I would think with the kind of power we are talking about it would be negligible.

Poweglides help with "traction control". Even with a Hot little 307 in my friend's 70 'bu we noticed how much easier it was to break the tires loose with a TH350 than his old PG. Add 1000+ horses and i bet the torque on those monsters just loves frying tires up.

PG's are also more consistent since there is only one shift so there's only one time that the transmission "interrupts" the engine. Powerglides also have less internal parts to break, which should be a nice problem at 1000HP levels.

Lighter cars don't need as much gearing since they dont need as much torque multiplication to get to the ground to get them moving, and once they're moving the RPMs can make them fly, the longer 1st gear lets the engine do it's thing longer.

Least this is what some old hot rodders have told me.

i don't know about bracketracing, but the reason most guys i know that run them are doing so for traction purposes off the line. they do take a slightly less amount of power to turn, but if you could hook the th350/th400 the gear ratios would more than make up the difference in power lost turning the tranny, IMO. i don't know about the consistancy part of it, but it makes sense that the less you have to shift the more consistant it would be. but again, the only cars i see that benefit from the glide are really light drag cars, or power adder cars, usually on small tires where traction is a big concern.

You simply are waisting time using a 3spd auto in a car with that big a motor and a 3000# weight. The extra gear isn't needed if you use the correct convertor. I have not seen much starting line traction difference between a glide and a 400 (Glides with a brake hit real hard) but you can have some real issues with second gear wheel spin on a track that is not the best in the world.

I too have seen cars in the low 3,000 lb range go faster with a 'glide at that power level.

A glide, along with a 7531 box should allow you to get the most out of the car. Mike's is a quality shop where lots of high hp cars have gotten reliable transmissions. I've always thought that race TH400's are reliable to ~ 1,200 hp, and 'glides are reliable to ~ 1,600 hp. At your power level I too would want a 'glide, even with a middleweight car.

Thomas

I am surprised how evenly split the opinions are on this, even from very knowledgable racers. It is pretty much split 50 /50. To be honest I am leaning towrds the 400. I think it will be beter on the street and the really fast guys (7's) I have asked for an opinion all say go with the 400.

I appreciate all the input

If you are on the fence, the 400 is about a quarter of the price if you are going to make much more than 1200hp.

I don't have any exotic parts in my 400 - just your typical sprague, machined the piston for more clutches etc. I have never hurt a hard part, only clutches and I am absolutely brutal on trannys on and off the throttle (and fogger) several times a pass.

If you are inclined to spend money (and you would be if you bought a monster glide!) you might as well buy a real racing transmission like a lenco. I wouldn't spend the money on a $4000-5000 glide if a few more grand would get you a lenco!

I'm going to stick with my TH400's because they are cheap and bulletproof. We keep a spare and can freshen mine for a few hundred bucks within a timeframe of 6 beers. (3 each). I know my car would go faster with a glide, but they are just SO expensive it's hard to justify.

The way I understand a P/G, it is like a four speed auto with respect to the rearend trying to catch the front b/c the converter is slipping.

You launch, spin the converter, (AND tires), hook the converter, shift and repeat this sequence of events until it hooks up in high gear..

I.e., launch with low gear spinning for less gear, then locking to correct gear and repeat through the same after shifting into high...

And since you only have two gears, it's more constant or dependable to do it the same every time!!

pdq67

Ryan, don't get me started on the Lenco!!!! I REALLY want to run this thing as a clutch car. I have (after several months of fighting it) excepted the fact a 1200-1400 hp clutch car is out of my leauge (in terms of tuning and upkeep). I would like to run one of the Lenco or Bruno drives, but 10,000.00 for a tranny set up is too much money for me.

Well until my homebuilt TH400's start breaking hard parts, I'm too cheap to run anything else. I will cripple the car with a low numerical rear gear or even change the first gear ratio to 2.10:1 before I spend the money for a monster glide. $5K US! Damn!

I have been into quite a few of Mike's trannies, and IMO they are a bit pricey for what you really get. Look at what his Glides go for! I am able to do a Dedenbear or JW Bell/Case Glide with rear roller bearing, ringless Vasco input, 1.80 straight-cut gearset, roller tailhousing and governor support, dual ring low servo, 8-clutch high with Torrington thrust bearing, Kevlar band, good brake, good pump, yada, yada, for $3500. Upgrades include a TH-400 sized output shaft, 10-clutch high gear, etc. Hate to say it, but it seems that if you price stuff high then people perceive it must really be worth it, lol. I have had Glides live very well behind nearly 2K hp.

I gotta, I just gotta!!

OK, Steve, I want a built, old style, B&M - Olds four speed, Clutch-Hydro for my big motor!!

I think I even have the old '55 block P/G half of the bellhousing to mate it up to my motor somewhere in my old junk??? I think it's buried under a fallen down barn out where my Buddy used to live????

Can you fix me up??

pdq67

Back again, don't pay me no mind b/c I'm just being a smart a--!! He, He!!

Please carry on..

pdq67

I gotta, I just gotta!!
OK, Steve, I want a built, old style, B&M - Olds four speed, Clutch-Hydro for my big motor!!
I think I even have the old '55 block P/G half of the bellhousing to mate it up to my motor somewhere in my old junk??? I think it's buried under a fallen down barn out where my Buddy used to live????
Can you fix me up??
pdq67 Yes I can! Just grab your phonebook, and thumb to the "rentals" section. Call around and get the best deal you can on an endloader, and get after that barn mess... graemlins/thumbsup.gif

He, He!!

What's left of my junk 301 is under that mess of fallen down barn as is a bunch of other parts I had collected when I worked at the metal salvage yard in the summer while going back to school back in the late '60's early '70's..

Thanks Steve, I'm just joking but I am really glad you know what I mean..

AND I do have that P/G hoghead front half b/c I wanted to put a Hydro out of a '55 Pontiac in my car at one time so I grabbed hold of it..

It's probably nothing but rust by now though??

pdq67