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4R70W vs 3650

  • Thread starter Thread starter Stumbaugh
  • Start date Start date Dec 12, 2010

Stumbaugh

Member
May 13, 2010
903
13
19
Russellville, Ar
Dec 12, 2010
#1
  • Dec 12, 2010
  • #1
Alright, here's the deal. The 3650 in my car is going to need to be rebuilt more sooner than later. It's also in dier need of a new clutch and pressure plate. When I do the rebuild, I am going to switch to a 26 spline input shaft, all new syncro's, new clutch, pressure plate, and flywheel. So here's about the cost I am looking at;

26 spline input shaft - $375
Carbon syncro kit - $500
Clutch kit - $450
Flywheel - $350

So that's a grand total of $1,675. I can install the input shaft and syncro kit myself, so I will save money there for sure. With doing that, the transmission would be good to over 700rwhp.

I can get a complete auto swap w/ the transmission for $200. The transmission needs to be rebuilt also. If I do this, I will go with a manual/auto valve body w/ transbrake, and a 3500 nitrous converter. So here's about the cost I am looking at;

Rebuild kit - $400
Valve body - $800
Stall Conveter - $550 (got the hook up from TCI)
Shifter - $150
flexplate - $200

So that's a grand total of $2,100. That transmission also would be good to well over 700rwhp.

Now when I looked at the prices at first, I said "For that price difference, I will just stay manual. BUT, I can sell all my manual stuff and make up the difference. Now I am looking at this from a performance stand point. The car is NOT a daily driver anymore. It's a pure street/strip car.

I am not trying to toot my own horn, or brag or anything like that, but I definitely have the driver mod when it comes to driving a standard. That's the other thing that's stopping me jumping all over the 4r70w.

So what do you think? Under those circumstances, which would you do?
 
I

ItsStock02

Member
Aug 18, 2008
492
4
19
Westland, MI
Dec 12, 2010
#2
  • Dec 12, 2010
  • #2
Stay manual. A stalled auto would be sweet and all, but the only time id go auto would be if I was making some crazy amount of power.
 

sneaky98gt

10 Year Member
Apr 23, 2008
2,387
144
114
NC State University
Dec 13, 2010
#3
  • Dec 13, 2010
  • #3
I have a buddy that used to have a nitrous Mach 1 (he's working on a turbo build right now). All the bolt ons, gears, a little suspension work, 150 wet shot, and a built Lentech 4R70W with a 3800 stall. That car was freaking NASTY. He might have been in the 10s with it, I can't remember for sure. Very consistent as well, within a few hundredths every time.

I've seen your videos; you definitely have the driver mod. However, I don't care if you are John Force, you can't shift a manual as fast as that auto is going to shift. You'll knock time off right there, probably more than you realize. Going from a lazy shifting auto to a hard shifting auto (via the J-mod), I dropped a couple tenths. I suspect you'd see similar, if not better, results.

While a manual car is a lot of fun to drive, and as a daily driver, I really wish mine was a manual, for street-strip purposes the auto is a better choice. Most people don't really realize how fun a stalled, geared, J-modded (or something similar) car is. Launching at 3500+ on the street on an auto........

So if you don't mind the lack of a third pedal in the floor, and it is not a daily driver, and is mainly a track car, and you are going to be replacing the transmission anyway, I vote 4R70W.
 
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