How to plan for an efficient driveline.
 

I plan on putting a Shafiroff 598 BBC that will be pushing 875 at the crank in a '69 Camaro. I want to be able to put as much of that to the rear wheels as possible. I am doing my research on driveline components that will yield the most efficient driveline.

What suggestions do you have? Transmission? Driveshaft? Other Components etc. Thanks

Robert

That's a lot of beans. :hail: Manual or Auto? What will you use for rear tires? Will you also run slicks in addition to street tires? What is target vehicle weight? What are your intended uses for the car? Assign percentages for the car's life at the track vs street? What are cam specs? Carb or EFI? What is the altitude where you live (very important on carbureted monster big blocks.)

This is a tough topic. Monster big blocks are in a class by themselves. They make crazy torque just off idle and then hold that number thru redline until they run out of air. This subject always generates a lot of differing opinions. But very few people have any actual experience with motors bigger than about 509-540. Even fewer have experience with big inch motors built for the street. During your research, be sure to weigh all thread responses against actual personal experience--not: "I saw a guy on some message board who made a pass in the 8's with a junkyard TH350 transmission that was accidentally filled with sand. It was a blown V6, not a 598, but his cousin's sister SWEARS it makes 900HP. Here's a link to the video of that one pass...." :rofl:

My personal project experience includes the following:
Blown and NA carbed 632
NA carbed 638
NA EFI 705

Here we go.

This is intresting.. 8s with trans full of sand:lol:

Okay but seriously,is there really difference between 9" or 12bolt rears?

I have heard at 9" takes more power to run?

Be careful with a hot big inch big block.

As Steve said, They make Crazy Torque!

Heed his words, you might be getting into Too Much of a Good Thing. No Kidding!

Save your money (And your life) and start with something a bit more reserved. (454 HO or something like that) Learn to drive it, enjoy it, then sell it and buy the Engine you mentioned. If you still want it.

I had a BBC that made 650 hp. I thought biggest is best. It wasn't worth a crap on the street, because unless you did nothing more than concentrate on what you were doing, it was way too easy for things to get way out of control. Forget altogether Driving in the rain.

Maybe Shafiroff could build you something about half that power to start with, then upgrade it as you get comfortable with it.

Good Luck!

Ty

You know, that's a good point. My last motor was a 412" small block with all the goodies..ran mid 11's with a crappy 60-ft (high 1.8's). Now I have a bone-stock LS1 motor...and I like the drivability much better. The 412" motor was fun in some ways, but it was WAY to easy to lose control of the car. Now, I can put my foot in it pretty hard, still go fast, and maintain some control. Less tire smoke, more foward motion.

I'll admit it's not as fun for car shows when people ask "What'll do in the 1/4?", but who cares...it's all about driving the thing.

If you're not going to put sticky tires on it, a 8.5" 10 bolt, TH350 and steel driveshaft will be fine... Spend all the money on the rebuilds though, you'll need it.

If you're going to drag it, I'd probably only change the trans to a TH400.

Good artice for determining wheel torque. Put yer thinkin cap on before reading.

http://www.mustangsandmore.com/ubb/D...orqueVsHP.html

Steve can u translate that page for us :D

The bottom line is that your complete engine/drivetrain combination boils down to "Wheel Torque" And wheel torque can be determined mathematically thru the following:
-Engine Power Band
-Coupling Device (converter or clutch) Multiplication Factor where applicable.
-Transmission Gear Ratios
-Rear End Gear Ratio
-and Tire Diameter.

For example, double overdrive is of little use if it takes your engine out of its power band. Gearing your engine to take advantage of double overdrive might render 1st gear useless. A drag car is usually more concerned with taking advantage of 1st gear, while a touring car is more concerned with making the most of overdrive.

We cannot and should not take this conversation further without first getting answers to the basic questions:

Thanks for the replies. Steve you are going to make sure I get an answer! Thanks :thumbsup:

Proposed specs:

Transmission: Auto
Target Vehicle Weight: 3400# max
Vehicle Usage: 90% Street 10% Track - Both drag and road.
Induction: Carb
Altitude: Sea Level
Rear End Gears: 3.72
Tires: Rear 345/30R18 Michelin Pilot Sports PS2 Street, Comparable size slick for track.
Engine Power Band: 4000 -5500 Max TQ at 4800

Probably TH400 trans, but don't know what gearing would be right now. That's what I am trying to decide. Which transmission, what gearing options I would have for it.

Thanks again.:bow:

Robert

You mean 345 30's, right. 345/70's are 37" tall. :rofl: That's donk territory. I'm guessing you have a Dominator. 3 circuit probably. Any idea on cam specs? I'm sure the specs look crazy (min 740 lift and 270 deg duration). But on a 598, the numbers are actually nominal. Does the dyno sheet show power levels below 4000 rpm?

Options are TH400 and 4L80E. By the way, I think Shafiroff had DSE build him a 69 Camaro. So I highly recommend that you pick his brain on the subject. If you get that chance, ask about available torque between 2500 and 4000 rpm. I think you will be spending a lot of time in that rpm range, so finding out power levels between 2500 and 4000 (even if they are guesstimates) is key.

On the street, won't tire friction be weak link in 1, 2, and maybe 3rd gear. The torque of a big block can only be used at the strip, or on the street over 100mph.

hmmm
 

with all that tourque id build a driveline that gave me no headaches instead of worrying about the last 2%... my best bet would be a 4l80e with shrifter.. and a 9 inch (possibly with 12 bolt ring and pinion if you are really anal about efficiency)

also id get the regulkar 745 hp or 705 hp EC (extended cruicing) option from shafiroff instead of the SS that you are talking about... i mean fi you intend to run it 90% on the street then why get a Saturday-night Special motor.. besides you can always add a shot of nitrous in second and two in third if you feel things are a bit slow with a 750 Hp big block...

oh yeah, and you are NEVER going to get a decent launch on 30 profile tires... so be sure to get brakes that accomodate a 15 inch rim in the back...

and 3.73 might not be the best choice with an OD tranny..

At that power level... you better believe there is.