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-   -   4 speed vs. 5 speed for stocker (https://classracer.com/classforum/showthread.php?t=25870)

EdgarTurbo 05-20-2010 03:16 PM

Re: 4 speed vs. 5 speed for stocker
 
Quote:

Originally Posted by Jeff Lee (Post 188437)
All I know is the late Bob Pott (K/S & L/S 5.0 Mustang); now driven by his daughter Kelly Pott-Hall) switched from a 4-speed Jerico to a 5-Speed. He was told by "all the experts" the cost difference of a 5-speed wouldn't make any noticeable difference, so that's what he ran for all those years.
Then he made the switch. With no other changes he picked up two tenths.
I'm under the impression the less the torque and the less the RPM capability of the engine, the more of an advantage a 5-speed has over a 4-speed.
And if there was a difference of $5K between the two offerings and I thought I could get two tenths without any other changes, I think it is money well spent.

I'd also highly recommend the Sportsman dual 7" clutch assembly. The idea here is to keep the weight as central to the crank centerline as possible. Again, I think small engines really need this. PM me if you need more info.

By the way, I think an '03 MACH 1 would be a really fun stocker! What class does it fit?


Thanks Jeff for your words, I think the 03 mach-1 would be fun, I did the calculation and as far as I know will fit on E/S.

Edgar

Mike Keener 05-20-2010 04:23 PM

Re: 4 speed vs. 5 speed for stocker
 
I agree with Dave Casey's findings and I will be the first to admit I know nothing about the Ford engines power band, or how it effects performance when switching from the 4 speed to the 5 speed, but I do know about the LT1 Chevrolets' abilities in these very same areas.

Probably few remember but Merc and I ran a 94 Camaro LT1 powered car in 1999 and 2000 which Woodro did the engines for and was the D/S NHRA National Record Holder @ 10.52 which was pretty quick in it's day. For what it is worth this car never ran as quick with the 5 speed as it did the 4 speed. On the best days it was a wash and most of the time the 4 speed was a couple hundreths quicker, so unless there has been some startling new developments in this area lately (like a higher/wider rpm power band) I think the data we achieved in this application is fairly factual.

In fact I still have a like new G Force 5 speed available with a 3:16 low and a 3:25 low gear set complete with a Long Shifter and the correct driveshaft for a late model Camaro if anyone out there is interested.

MK

EdgarTurbo 05-20-2010 06:25 PM

Re: 4 speed vs. 5 speed for stocker
 
Quote:

Originally Posted by Mike Keener (Post 188486)
I agree with Dave Casey's findings and I will be the first to admit I know nothing about the Ford engines power band, or how it effects performance when switching from the 4 speed to the 5 speed, but I do know about the LT1 Chevrolets' abilities in these very same areas.

Probably few remember but Merc and I ran a 94 Camaro LT1 powered car in 1999 and 2000 which Woodro did the engines for and was the D/S NHRA National Record Holder @ 10.52 which was pretty quick in it's day. For what it is worth this car never ran as quick with the 5 speed as it did the 4 speed. On the best days it was a wash and most of the time the 4 speed was a couple hundreths quicker, so unless there has been some startling new developments in this area lately (like a higher/wider rpm power band) I think the data we achieved in this application is fairly factual.

In fact I still have a like new G Force 5 speed available with a 3:16 low and a 3:25 low gear set complete with a Long Shifter and the correct driveshaft for a late model Camaro if anyone out there is interested.

MK

Great point Mike, the fact is that comparing with the LT1 engine CI the ford 4.6 is 69 CI less than the LT1, fact is that this engines can rev way up to 9500 rpm with the proper parts. But that is a good point, thanks

Edgar

Jeff Lee 05-20-2010 11:48 PM

Re: 4 speed vs. 5 speed for stocker
 
The bottom line on most of this stuff is you never really know! So if you want to go fast, you have to try, try, and try again! And yup, that sure can get expensive!
And since you are looking at racing a basically unchartered path with this combo, you will have considerable time and effort involved into making this a successful venture. That unfortunately sometimes, takes a fat wallet!
Look at Mike Keener here, two transmissions taking up space.
I think I'll PM Mike and see if I can steal one from him...:D

Mike Taylor 3601 05-21-2010 06:42 AM

Re: 4 speed vs. 5 speed for stocker
 
I was wondering on these 4 -5 speed comparisions about first gear ratios could ones that ran better w 4 speed had lower first in the 5 speed and not enough rpm to get enough wheel speed with lower first gear and that hurt there performance?
Mike Taylor 3601

randy wilson 05-21-2010 11:00 AM

Re: 4 speed vs. 5 speed for stocker
 
I am just now getting ready to use 5 gears for the first time. will let everyone no. but if 4 gears were faster, prostock would be using them. Just my 2 cents.

Chris1529 05-21-2010 11:15 AM

Re: 4 speed vs. 5 speed for stocker
 
I think your advantage would come from having less drop between the gears.

First may not be all that much lower in a 5 speed, but the drop isn't as great to the next gear. I'll bet that most people's fifth gear is still 1:1.

randy wilson 05-21-2010 11:43 AM

Re: 4 speed vs. 5 speed for stocker
 
All high gear drag cars in class are 1 to 1.

Mike Dahl 05-21-2010 11:54 AM

Re: 4 speed vs. 5 speed for stocker
 
I think it is true that the engine's specific power band plays a part in the question of what improvement is seen with a 5 speed. However, I am pretty sure a 5 speed will need to be shifted differently than a 4 speed.

Here's what I'm thinking...

We grossly over rev our Super Stock engines on the gear change. 4 speed guys are revving them about 700-1000 over peak HP, maybe more. My limited understanding is comp guys with 5 gears are running about 300 over peak HP before shifting. Please chime in if you disagree with my #'s. I am not an expert with comp engines.

My belief is the more gears you have, the less you will need to run past peak horsepower to recover on the subsequent gear.

Also, I wonder if the finish line over rev could/should be reduced with a 5 speed. Again, my limited understanding is that comp guys are running about 400-500 over peak HP instead of us Super Stock guys running 1300-2000 over.

Just some thoughts...

SSDiv6 05-21-2010 01:28 PM

Re: 4 speed vs. 5 speed for stocker
 
Any manual transmission, either 4-speed or 5-speed, needs proper gear ratio selection for optimum performance based on the power band of the engine. Engines with narrow power bands, benefit with 5-speeds.

The gear ratio selection needs to be optimized to allow the engine to recover and stay in its power band through all gears.

In order to keep their engines in the power band, I have known of SS racers with small CID engines, that must run a 4-speed, put a 1.1 or 1.2 high gear on their 4-speeds.


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