Well....I finally got the new powerglide in the car... It feels and runs GREAT.

So I head out to Island today.... and BAM!!!... the confusion sets in.... I think I have some Ideas whats goin' on...but I would like some educated guesses. So, heres the time slip..

60':1.36
330':4.27
1/8 :6.70
1/8 mph: 102.47
1000':8.84
1/4: 10.73
1/4 mph: 112.07

It should be pretty obvious whats goin on....unless I'm missing something...

BTW ....see if you can tell when I started bouncing off the rev limiter....

Other car particulars....
Weight:@3100#
gears: 4.11's
28" e/t drags
last readable HP 565/649 torq...Damn glides don't like to give good hp numbers

 

Your 1/8 mile and 1000 foot both say you should be around 10.5. Sounds like you need a taller tire or a higher shift point. Exactly what size are those 28" ET drags? I know the 28x9"s are only 27.3" tall.

 

Maybe I'm the one missing something.

Yes obviously you ran out of gear, but what are you confused about? Did this setup run before with another tranny and the gearing was OK or?????

From here, looking at only one pass and nothing previously (to base what it *should* do) the Incorrect gearing is the only things that jumps out......

Just curious as to what the car weighs, a Glide seems like a rare choice in these cars, especially considering the weight required to run a Glide effectively....

Congrats nonetheless(I think?)

 

I am with KT here

 

The MPH is way to low for a 10 second car. Even with normal converter slip that should be at least 121-125 mph so something is wrong with the setup. As I mentioned above, both the 1/8 mile and 1000 foot both say you should have crossed the finish line quicker. If I had to take a guess, you hit the rev limiter just as you hit the 1000 foot mark.

I did that earlier this year when I went to a lower elevation track, Yakima Div 6 bracket finals. My setup with 4.56 gears is perfect for the local track. My shift light comes on just as I cross the finish line. At the lower elevation track the shift light came on at the 1000 foot mark and I bounced off the limiter to the 1/4 mile and floated a couple of valves doing it. I need another 9" center section with 4.3x gears for lower elevation tracks.

High HP heavy cars can handle a glide better than low HP heavy cars. There are many cars in the 8-10 second range that will use a glide. Since they have so much HP and torque they don't need the torque multiplication of lower gears. They'll use first gear to get out of the hole then quickly shift to high gear and do a brute HP pull all the way to the finish line.

 

your car is a little too heavy for a glide. other than that, it will be hard for anybody to figure anything out unless you provide more background information. what is the exact tire size? what tranny were you running before? what ET/MPH were you running before? were you running different gearing with the old tranny?

 

Stephen...I'm runnin' the 28x10.5Wx15 e/t drags on drag lites

KT... I had the race weight listed at 3100# (I know it's kinda on the edge as far as weight for a glide ( I should be under 3000 by spring) ...but it had no problems outta the hole or down to the 1000' mark... but then it just fell on it's face

The part that really seemed strange to me was... I thought we'd have to go with at least a 4.56 gear out back... but now it looks like we may have to drop it down...

I had a t56 in there before (same gearing), with traps @ 126 (127 best) running almost identical 60' and a little slower in the 1/8 (@99mph). I expected to lose some MPH.... But 15 seemed a little excessive.

My main confussion ( I guess I should have stated this earlier)...not previously having experience with glides (or any automatics before) is..... could there possibly be any other issues aside from gearing that could be affecting the results. Kinda tryin' to get some Ideas before I go swappin' in new gears (4.11s only have 7 passes on em' and the glide is brand new)....

Any assistance here would be greatly appreciated...

other car particulars..
4800-5200 stall (8")
left on the trans brake at @4000rpm

 

What are you shifting at? Even with converter slippage, the 28" tall tires and 4.11 gears should be good for ~132+mph @7000rpm in the quarter. Maybe the converter is slipping too much??
Matt

 

I have my limiter set at 6400... I only make good hp till about 5900.. after that it falls off substantially.

I shift at @6000 on the 1 to 2

But I'm bangin' the limiter before the 1000' mark

 

"last readable HP 565/649 torq" and only shifting at 6000 rpm? What are you running, a 540? Why are you shifting so low? It sounds like your valve springs may be shot and you're getting valve float. Most engines producing that much power should be red lining around 7000 rpm and shifting between 6500 and 6800. My shift point was 6700 rpm. At 6800 I could feel the car nosing over.

The 28 x 10.5 x 15W is 28.1" tall so the tire isn't smaller than the number listed.

Bringing your shift point up will be the same as going to a taller tire or using less gear.

 

I'm still runnin' a stock bottom end..... and hydraulic lifters... While I have SUBSTANTIAL work done to the heads... I won't be goin to a solid roller/ stroker motor till this winter.

With the very limited knowledge of engines I have..... I am under the understanding that the lt1's can't (or don't) like to rev that high without workin the bottom.

 

Something just doesn't add up to me. You should be turning it at least 67-6800 rpms. I turn my Hotcam 6500. You probably need a hydra rev kit and definately need to shift higher than 6500 with the kind of cam you must have to make that kind of power. If the car falls off at 5900 then you are supposed to shift 500rpms higher at least. A stock lt1 shifts at 5900. Is this a N/a or with n20 that would make more sense. Still you should shift 1-2 at 6500 and raise the limiter to 6800 and just let it cross. You should have no probs crossing with a 4.10 gear. My dad's car that I drive crosses at 7200 with a 4.10 @140mph. It has a 30 inch tire but you should still be able to go over 120mph before hitting the limiter. Later

 

This is an N2O car... We have pulled this car on the dyno at least 30 times... and every time; the car maxed at 5900 on the power.(torque maxed and flat lined at @ 2100) (keep in mind I'm using a pretty large shot (@175-200)) and it is a nitrous cam.

Just got off the phone with Strange engineering.... He said pretty much the same thing my mechanic said. Go with a 3.73. I make enough power to pull through the gear, and they all agreed that if I'm making peak hp at 5900 I should be shifting it about 6100-6200 ( exact words were "why spin the engine if your not making any hp that high). I'll do the gear swap on friday and run it saturday at e-town and see what happens.

The only thing I'm REALLY concerned with is the car falling on it's face outta the hole. That would spell BIG trouble on the happy gas.

 

You should have told everybody it was a N2o car to start, that makes all the difference in the world. You don't need turn a n20 motor that high and it won't fall on it's face either. Nobody could understand how a N/A motor could make that kind of power that low in the rpm range b/c it can't at 350 cubic inches unless it has n2o or a blower. When asking questions you need to give all info it will get you better answers. Later

 

I'm worried about the same thing. My current combination has me shifting at 6700 with 4.56 gears. Next year on alcohol I'll be making a lot more bottom end power. So far it looks like my best combination is to install 3.73 gears and shift at 6000 rpm. I don't know if the alcohol will let me build power to 6700. My cam is good to 7200 and my converter stalls at 5000.

I'm expecting to pull off a mid 10 second pass (at altitude) if I can get the 9" slicks to hook up.

If I keep the current combination it should at least pull good wheelies