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S197 3V A horse with no name, a build with no name Build Thread

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Well, to say that progress has slowed would be right up there with the understatements of the year(s).

I did get the fire extinguisher bracket more properly put together . . . I don't think I posted this picture before.Revised fire extinguisher mount.JPG

And I did get the rear ride height raised up.


Norm
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Between life and a couple of health issues, the Torsen/3.73 modification is still incomplete. I got distracted by re-emergence of the S197 water leak issue. Still not sure I've fully solved it.

But I have at least come to the firm decision to not swap the TR3650 out, at least not at this time. Near as I can tell, I wouldn't be dropping lap times by nearly enough to justify installing a Magnum XL at $4000+, or even a TKX at somewhat lower cost. Whether I even get back out on the track has something to do with this, too.

This decision came out of running quite a number of comparative simulations using a spreadsheet approach that I've been tinkering with since before there was such a thing as PC spreadsheet software.

Here's a basic acceleration comparison. 3rd and 4th gears cover nearly all of the situations on track, absent traffic, so there just doesn't look like there's much to be gained from either 2nd or 5th in the Magnum.
Acceleration comparison.jpg

I've got some more detailed plots that aren't quite ready for prime time just yet.

Norm
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Exiting a corner in 3rd (5900 rpm shift point with my 4.6), the plots practically fall on top of each other - no surprise there, really.
Speed and Distance comparisons 2, Magnum XL vs TR3650.jpg


But even using 2nd with the Magnum doesn't help - you gain a little for the few mph that you're using 2nd, but you give it back with the extra shift and the slightly taller 3rd gear. Way out past 2000 feet, having an 0.80 5th in the Magnum vs 0.68 in the 3650 begins to catch up.Speed and Distance comparisons 3, Magnum XL vs TR3650.jpg


Norm
 

Boone

Professional Thread Killer
Exiting a corner in 3rd (5900 rpm shift point with my 4.6), the plots practically fall on top of each other - no surprise there, really.
View attachment 67742


But even using 2nd with the Magnum doesn't help - you gain a little for the few mph that you're using 2nd, but you give it back with the extra shift and the slightly taller 3rd gear. Way out past 2000 feet, having an 0.80 5th in the Magnum vs 0.68 in the 3650 begins to catch up.View attachment 67743


Norm
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
I've run these 3650 vs T56 several times, and I'm with you. The only reason a T56 is in my future is the torque rating. If I do toast the 3650, I have to go back better, stronger, faster (or whatever the quote from Six MM $ Man was).
A big thank-you for the real-world feedback. It means a lot.


Norm
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Well, I'm slowly getting back into this project. I'd gotten only partway through the Torsen/3.73 swap before having to button everything up for a while.

Anyhoo . . . I'm starting to make a little progress. I never was entirely sure the pinion depth was going to be where it's supposed to be but based on notes I'd taken before I think it's going to be close enough. Naturally after measuring pinion head and shimming so I could run the numbers based on the replacement Ratech tool, I stumbled across the one I'd bought before. Grrrr.

The good news is that if my notes were any good, I may be a few thousandths closer with the 3.73 pinion as shimmed to essentially the same thickness as the 3.55 was originally than the 355 was. We'll see . . .

Here's what I put together today for taking the play out of the pinion bearings while doing the Ratech measuring thing. I'd hoped to find a short length of tube, but that didn't happen.

Pinion depth checking setup using and sometimes repurposing available pieces.jpg

A couple of people are aware of why my current progress is slow, but the short story is I'm dealing with a medical issue that from time to time limits what I can - or should - do. Never mind that if I went at it anyway it would make my wife kind of nervous. Maybe I'll have some pinion depth measurements made (and double checked with the tool I thought I'd lost).


Norm
 
Last edited:

carver

breaker of wrenches
340
438
ontario
Well, I'm slowly getting back into this project. I'd gotten only partway through the Torsen/3.73 swap before having to button everything up for a while.

Anyhoo . . . I'm starting to make a little progress. I never was entirely sure the pinion depth was going to be where it's supposed to be but based on notes I'd taken before I think it's going to be close enough. Naturally after measuring pinion head and shimming so I could run the numbers based on the replacement Ratech tool, I stumbled across the one I'd bought before. Grrrr.

The good news is that if my notes were any good, I may be a few thousandths closer with the 3.73 pinion as shimmed to essentially the same thickness as the 3.55 was originally than the 355 was. We'll see . . .

Here's what I put together today for taking the play out of the pinion bearings while doing the Ratech measuring thing. I'd hoped to find a short length of tube, but that didn't happen.

View attachment 68691

A couple of people are aware of why my current progress is slow, but the short story is I'm dealing with a medical issue that from time to time limits what I can - or should - do. Never mind that if I went at it anyway it would make my wife kind of nervous. Maybe I'll have some pinion depth measurements made (and double checked with the tool I thought I'd lost).


Norm
"Keep on trucking" Norm! It's good to stay focused on a project or two. I just had my knee replacement surgery Fri. so I'm out of the driver seat for 4-6 weeks !!! I'm already getting impatient ! Lots of work to finish on my Boss. :hellyeah:
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Looks like I'm in for an offset PHB due to my choice of one of the finned aluminum diff covers that are plumbed for cooling. I'm probably only going to use it for any increase in fluid capacity, the ability to drain without having to pull the cover off, and what should turn out to be easier refilling. And for giving the axle vent a better place to live than on an axle tube. Might as well order a spare set of bushings for it while I'm at it.


Norm
 

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