What's too heavy for a Powerglide?

After reading the Powerglide converter thread, I figured I would throw this out there since a lot of you are running Glides. Anyone running a Powerglide in a car that's around 3500lbs on small tires? If so, what's the combination? Mine is a 528ci on nitrous. I'm concerned it will fall on it's face in high gear being so heavy. My thought is to go with around a 1.68 low gear and 4.30 out back. I know converter is going to be a big factor in getting the car to work, especially on the surfaces I run on.

We have a Mopar guy I race with, in a heavy B-body with a 400 stroker. His exact words to me were, the glide will be slow at the hit, but faster to the 330ft mark....He highly recommends them.

are you looking for speed or consistence
if you want to go fast keep your 727
if you want to win races go glide

3500 lbs. is a little heavy....Used to be a 3000 lb rule with a glide weather you would pick up or not. I have run glides in several cars 3000 lbs and they wewre not slower with a glide. You have to gear and converter them right.

I figure it'll be softer at the hit than what I have now. I do mostly no prep and airport stuff, so the early rounds can be virgin asphalt. My SLR is around 8.5 now and I'm thinking if I can get it in the 7-7.5 range, it'll make power management a little easier as long as I don't get too much wheel speed early.

I need to be consistently fast.
This is not a bracket car, so I need to get A to B before the guy in the other lane.

3000lbs was always the cutoff that I always heard too, but I know converters have come a long way. I also think I'll be able to add power if need be to keep this land barge moving, just not sure how happy it'll be on the shift recovery. Ideally, I'd like to do a 3 speed TH400 with a 1.8 low gear set, but that gets a little pricey!

You're not too heavy for a nitrous car making the kind of power you are. For a slower N/A car, yeah it'll be a turd out the gate.

I suspect you're in the same boat (pun intended) I am. My car is a sled (nearly 3900 lbs w/ driver), but makes good power...and w/ a 727 on small tires (radials) it can be a challenge getting it to 60'.
I have friends w/ 3400+ lb nitrous cars w/ glides and they run REALLY good. EVERY one of them has been on me for years to put a glide in mine, but only the $$$$ keeps me from doing it.

3 speed no need for a glide

I have been 1.16 , leaving in 2nd 1.48 with 4.10 rear. BUT thats on a prepped track and at 3030lbs

Brad Watt has been leaving in 2nd with a 727 and it has been working well. Again this is on a prepped track,

you have a 727 now? Im pretty sure Cope makes the vavle body that you can leave in 2nd. Just remember that leaving in 2nd will require a different converter/ stator, but you dealing with Ultimate now so they should be able to set you up.

If your concerned about the RPM drop into high, consider a dump valve.

You could make a 3 speed work, but i think your better off with a 2 speed. Glide will be the lightest option, T400 the strongest. Honestly if it were me, i would try leaving in 2nd with the 727 first since you already have it. Dont be afraid to knock down the SLR. I know i might get flamed for this, but there are not a lot of guys on here that have experience with what your doing.

A 3 speed with a 1.8 will have the same SLR as a 2 speed with a 1.8. A 2 speed with a 1.5 or 1.6 will be even softer at the hit, and be lighter and use much less power to run, regardless the gear ratio.

Unless you need the 2.50 low gear, or the thing is so peaky it needs to keep the RPMs up, Glide.

Time for a bigger kit.....or a 2nd one !!!

Just speculating hear. With optional 1st and second straightcut gears available for the TF, could it be made to do the job and be as efficient and cheaper than converting to a glide?

I don't think there is a low enough (numerically) 1st gear available for a 727 to work very well in an application like this.

I'll try the 2nd gear leave VB from Cope in my 727 before I switch transmissions, but I'm leary of it b/c of my car's weight. I think I'd have to put a lot more rear gear in it to keep it from being such a dud and lugging the motor down bad.

i think the best way to approach this is , determine a target SLR. Then do whatever combination of 1st or 2nd gear to get that with a 4.10,430 or 4.56 gear. The converter guys like 4.56 or higher (numerically) because it puts less slip in the converter from a leverage standpoint. This is a nitrous car so usually its all in by 1.0. Also this car runs on the worst surfaces so it needs or will only tolerate 6 or less on the SLR ??

Usually it comes down to a lot of trial and error, pretty hard for the little budget guys to change trans ratios. Usually depending on power level (stroke) the SLR falls between 7 to 5

Need some more details (unless you're a grudge runner)

Is this a brand new build/setup? If not new, what has been its best perf on a motor pass, and on a nitrous pass?

Do you know exactly how much HP & TQ your 528 is making on motor alone?

Is the 528 specifically built for nitrous, or mainly N/A with some nitrous setup and just tickling it with a "middle of the road" nitrous hit?

Plate or Fogger, and how much you smashing it with?

Progressive controller?

Which small tire (slick or drag radial specifics) and suspension/shocks setup?

Are you talking 3500 in the seat at the tree/hand-drop, or 3500+whatever your driver weight is at the tree/hand-drop?

Let us know.......

However, with just ball-parking it I'd go with Tony's above advice.

Thanks for all the replies! I have a second gear leave CRT valve body that I had some issues with the 2-3 shift. It would drive right through the converter on the sauce on the shift(dropped ~500-600rpm). I put an A&A in and the shift drop is now ~800-900rpm on the sauce. Its been back to CRT for a change, but I haven't put it back in. Maybe I'll try leaving in 2nd and see if it likes it before going through the work of changing to a glide or TH400. I think the car needs about a 4.30 to make the 1/8th depending on converter slip. If Brad Watt can leave on a prepped track and not kill the 727, I think I'll be OK! I know that car makes a ton more power than my hoagie. Part of the reason for making the change is for durability.

I know when I made the change to the taller 2.28 low gear and 3.73's(8.5SLR), it made things much easier for power management. I need to be able to leave on a dirt road and generally can now, but I have to take a TON of power out to get it to leave.

You are right, Tony....I need a bigger jet! It has a 0.030n jet in it now, and I should be able to step it up a bit more to make it pull out the back half.

There are 100's of 3,500 lb cars running Powerglides. Everything will be fine. My car is 512ci with Powerglide. 3,200 lbs plus me and with a 9" tire it pulled the front wheels on it's first night out. I was impressed for a car straight off the showroom floor. Everyone ran 1.80 low for decades, I think that was because it was the strongest back then, but now they make strong gearsets with different ratios. (That doesn't mean I would want one.) I'm a Mopar guy. I prefer a 727. But because of the many reasons that you have already heard about, the Powerglide is much easier.

Just a .030??? OMG step it up to like a .052, then we are talking !!!

I figure it might make 700hp NA?? It's been 9.92 at 136 on the motor with 3.73, 29" tire and about as tight of a 9in converter as Lenny could make. It waddles like a duck on the motor. It's pretty much a nitrous build. Most events we do, it's an honest 3550 with my fat *ss in the seat ready to roll. I know it needs more gear, especially only running 1/8mi now, but I don't want to add rear gear without doing something for low gear to get the SLR down.
I run either a 28 x 10.5 or 29 x 10.0 slick. Cal-tracs with Viking DA shocks. Nothing exotic.

Hey NOW! That would wake it up....did I mention I need to be able to get down a dirt road? That might get interesting.
I think we'd do pretty well if we could get it to work on a 0.034 or 0.036 jet depending on the surface. Many times, my ramp is over 2sec just to keep the car north-south. On a "good" surface, we can shorten the ramp to 1-1.3sec.

Okay, Go back and try the trans since John rectified the issue, and leave in 2nd on your current 30 jet. If it seems to be seamless, then do the typical necessary changes to accommodate MORE jet/gear changes. FROM THE GO, AND THENNNNNNN ONNNNN OUT!

What controller do you use ? Dual ramp it !

I think that's the way to go. It'll only be a set of gears, which I know I need anyway and I can see how happy it is with a lot less SLR. Wallace Calcs puts me at about 950hp on a 0.030 jet. I'd like to be able to throw another 100hp at it without making a mess of the 727. You guys think that's doable?

Thanks again for the help!

There are higher second gear ratios. Somewhere around 1.7 to 1.8? Lofgren Auto had some on the shelf when i was there a week ago.

Edelbrock. We do run a dual ramp which has been a big help. Depending on the surface, we leave on anywhere from 25-30% and hold the initial ramp pretty flat(35-45%) at 0.7-1.2. 2nd ramp might have to stretch out 1sec or more too. Some of the airports are literally pebbles mid track so no sudden moves or you're sawing at the wheel...

When I had 440-1 heads , and 528 (4.15 x 4.5) I used to leave on a plate with a .070 jet and progressed a fogger ( .036n .026f) at 3300lbs it would run 5.30’s at 130- 133 . That’s was 3.70 rear and 3 speed t400 stock ratios .
If I was you I’d be looking at a plate or ? Something for a second stage or a better controller and more jet in the kit you have .
Fastest I went with a 727 was 8.38 @ 160 . That was at 3550 lbs , sorry but I don’t remember the 1/8 numbers . I’m sure a 727 can handle more than 950 . Only weak part of the 727 is the sprag , and that’s more about breaking it on the starting line than downtrack
It’s really do you want to invest in a 727 ? Eventually you will outgrow it . Best for you might be a glide with a 1.82 or 1.78 first and a dump valve to help with the 1-2 rpm drop
I have a OEM case t400 from rossler , I called him to just get a 2nd gear leave valve body , and I ended up with a Reid case 2 speed $$$$$ 1.49 first with his dump valve set up

I like the dump valve idea. That seems like it would give me some options on the shift to keep the motor happy and down low if we need to adjust a bit. Based on how the car works now at 8.5 SLR, my gut tells me 7-7.5 SLR would be about right. That would be 1.68-1.8 ish low gear that you guys are recommending with a 4.30 out back. I know I can throw a lot more at it down low with a much lower SLR, but I worry it's going to be a fine line between getting it rolling and too much wheel speed too soon. The easiest way to prove or disprove that is to try the 2nd gear leave I already have and see how it reacts then I can choose the right path.
I've been kicking all this around in my head for the last few weeks and I really appreciate you guys steering me.

And yes, a second kit would also get me the few mph I need to stay out on the much lighter turbo cars!