Will this kill my 904 ?

-
Retroboy

Retroboy

Well-Known Member
Joined
Jul 1, 2014
Messages
215
Reaction score
102
Location
South Australia
Hey there knowledgeable folk.
Unlike most here I don't have aan A body rather I drive a slingshot (with a 360). I run a 904 TF with a 2.45 st gear 1.45nd gear. I have a 4.3 rear and run 1/8 mile. No I don't want to go to a Power Glide (from here in know as a taxi cab transmission lol). Bloody thing is violent off the line and at times hits the wheelie bars and unloads the tyres throwing me off the gas. Thinking if I leave off the brake in second gear I can get rid of my wheelie bars and 45 lbs of lead off the nose and the weight of the battery if I go to a remote battery again. I know it will be now lazy off the line but should mile an hour higher than it ET's (if that makes sense?) and as I run dial in type racing the slower ET compared to MPH might even help?

Will I kill my Torque-flight leaving in second gear?
Cheers and Happy Christmas
 
We are gonna have to demand photos of this here slingshot!!! What does it run? Sounds like fun
 
67Dart273 said:
We are gonna have to demand photos of this here slingshot!!! What does it run? Sounds like fun
Click to expand...
FB_IMG_1545615933463.jpg
 
You are correct ,as far as I know it will only launch in first , try launching at a lower rpm ? Two stage ignition box?
 
Retroboy said:
Hey there knowledgeable folk.
Unlike most here I don't have aan A body rather I drive a slingshot (with a 360). I run a 904 TF with a 2.45 st gear 1.45nd gear. I have a 4.3 rear and run 1/8 mile. No I don't want to go to a Power Glide (from here in know as a taxi cab transmission lol). Bloody thing is violent off the line and at times hits the wheelie bars and unloads the tyres throwing me off the gas. Thinking if I leave off the brake in second gear I can get rid of my wheelie bars and 45 lbs of lead off the nose and the weight of the battery if I go to a remote battery again. I know it will be now lazy off the line but should mile an hour higher than it ET's (if that makes sense?) and as I run dial in type racing the slower ET compared to MPH might even help?

Will I kill my Torque-flight leaving in second gear?
Cheers and Happy Christmas
Click to expand...
I like your thinking.
I'm not a racer so can't offer a solution.
But it seems to me there's gotta be a better way than throwing away first gear. What you seem to be saying is that you have too much torque on the startline and are willing to give up TM(Torque Multiplication) to take off slower/easier; the exact opposite of most streeters!
You are talking about a 40% reduction in TM. That is an awful lot of TM to completely give up at a time that really really counts; when it seems just a few milliseconds of power-delay, might accomplish a similar result. But what do I know, I ain't no racer, and I'm sure you already thought of that ....... lol.

Decisions, decisions so many decisions. I'd hate to be in your shoes,lol.
 
Last edited:
Not sure if this helps or not, but I raced my Barracuda for a year launching it in second gear along with a myriad of other tweaks to slow my 10.5 car down to 12.0 to compete in Sportsman. It worked REALLY well all year until the last regular season race. 2 weeks before the division finals it started slipping really bad (burned up the clutches, stunk to high heaven)...had to have a friend rebuild it for me quickly before the big race.

This was on a 727 trans...and it had probably 8-9 years of racing on it, so it may have just been time for it to go...but I thought I'd throw that out there for food for thought. I really don't know if I was hurting it doing a second gear launch or not.
 
What is the stall on the converter? What about going to a 3.5 gear.
 
AJ/FormS said:
I like your thinking.
I'm not a racer so can't offer a solution.
But it seems to me there's gotta be a better way than throwing away first gear. What you seem to be saying is that you have too much torque on the startline and are willing to give up TM(Torque Multiplication) to take off slower/easier; the exact opposite of most streeters!
You are talking about a 40% reduction in TM. That is an awful lot of TM to completely give up at a time that really really counts; when it seems just a few milliseconds of power-delay, might accomplish a similar result. But what do I know, I ain't no racer, and I'm sure you already thought of that ....... lol.

Decisions, decisions so many decisions. I'd hate to be in your shoes,lol.
Click to expand...
Then again, your not a drag race
:lol:
 
Gee a fair bit of love for my old bus !! Nar mo Taxi cab power glidel trans for this car. The 904 as fitted has no extension housing rather we chopped the output shaft off at the governor and use the govenor splines to hook into a home made coupler. There is no MSD 2 step to soften the launch. Just a traditional internal coil Vertex mag. Excluding the starter there is about 3' of wire in the car. I had thought about going to a 3.89 rear but I'm going through the engine at the minute (see my post in small block engines about MP forged pistons) so don't have anything resembling spare cash for gears. An other idea could be some type of damper on.the throttle to just ease the hit - I'm old but don't understand the easing into the throttle thing -my eyes just sort of roll back in my head when the engines running and the helmets on second last amber and smack the throttle. By the time I've let go of the brake lever and reached down to the shifter 1st gear is all used up. 38 years since my first pass in a slingshot or 39 years since my last pass in a tin top. Leaving in 2nd washes .4 off my et.
 
Retroboy said:
An other idea could be some type of damper on.the throttle to just ease the hit
Click to expand...
That's kindof what I was thinking.
I've rigged up a few things for my junk; a two-stage throttle was one such. Nothing complicated. Just a light return spring on the first part of travel, then a heavier one on the latter part, with an adjustable sliding stop to change the cut-in point.The springs were chosen to make the cut-in point obvious.
I used coat-hanger wire bent into an elongated S shape with one long leg, and a wire clamp from the lawnmower dealer;real simple. Drilled a hole in the throttle return-spring anchor for the long-leg.Took about 10 minutes to build and set. Don't know if it would work on my high-rise AirGap as originally built, but it worked on other intakes. Pretty sure I could make it work on the AG if I wanted to.
I used it for a couple of purposes on different cars. On my DD the early part was set to stop the throttle opening to just achieve 62 mph as a poorman's cruise control. I just laid my foot on the pedal and eventually it got there, great for fuel mileage. A little heavier foot got into the second spring for passing and such. I think on the DD it has over 400,000 kilometers on it and still works.
I'm still not a racer tho.
 
AJ/FormS said:
That's kindof what I was thinking.

a two-stage throttle was one such. Nothing complicated. Just a light return spring on the first part of travel, then a heavier one on the latter part, with an adjustable sliding stop to change the cut-in point.The springs were chosen to make the cut-in point obvious.
I used coat-hanger wire bent into an elongated S shape with one long leg, and a wire clamp from the lawnmower dealer;real simple. Drilled a hole in the throttle return-spring anchor for the long-leg.Took about 10 minutes to build and set.
I'm still not a racer tho.
Click to expand...
But your crafty and came up with a simple solution for your needs.
 
Retroboy said:
Hey there knowledgeable folk.
Unlike most here I don't have aan A body rather I drive a slingshot (with a 360). I run a 904 TF with a 2.45 st gear 1.45nd gear. I have a 4.3 rear and run 1/8 mile. No I don't want to go to a Power Glide (from here in know as a taxi cab transmission lol). Bloody thing is violent off the line and at times hits the wheelie bars and unloads the tyres throwing me off the gas. Thinking if I leave off the brake in second gear I can get rid of my wheelie bars and 45 lbs of lead off the nose and the weight of the battery if I go to a remote battery again. I know it will be now lazy off the line but should mile an hour higher than it ET's (if that makes sense?) and as I run dial in type racing the slower ET compared to MPH might even help?

Will I kill my Torque-flight leaving in second gear?
Cheers and Happy Christmas
Click to expand...

Joe at Tranzact says he has had transbrakes that work in second gear for awhile now....your might not...but might be able to be updated.
 
No offense but your problems are exactly why one switches to a glide. Let the convertor soften the launch and if needed tune it with convertor pressure if needed. The low gear first is too much for no rear suspension. I've also got a buddy with a slingshot running a blown Buick of all things. He uses the pulley size to adjust the hit. That's after bending the chassis on a really tall wheel stand. He's got a BOP TH350 in it. Weight wise, cost wise, a PG is what you need.
 
You must log in or register to reply here.
-

Back
Top