745rwhp +R200 and out of gear. What now?

[SH4DY]

I currently have a 3.7 R200 with an MFactory LSD, WHP 300M stub and CV axles. On motor, the car made 465rwhp and trapped 128mph in the 1/4 which was about 6k rpms in 4th and was pretty much ideal. Well, that was almost 300hp ago. I twin turbo'ed it and now it makes 745rwhp (at only 7psi - plenty of room to grow) which should get it to trap in the mid 140's. With the current gearing, that would require a shift to 5th since I don't wind to wind this motor out more than 6,500.

So here are my dilemmas:

The 3.36 Ring and pinion for the long lose R200 seems to be unobtainium at this point and the 3.54 isn't enough to get the mph I need in 4th.

WHP has closed up shop so even though these axles are rated for 800hp, if I break them, I have no recourse. 

The R200 pinion flange only has M8 bolts (this is a T56 car so there is a lot of driveline shock). 

 

So what do I do now? There's 3 options as I see it:

Leave everything as-is and just lift before the end of the 1/4, and hope the axles and diff stay together.

Buy a sequential shifter and shift to 5th, and hope the axles and diff stay together.

Sell all of the IRS stuff and go with a proper SLA (4 link, Ford 9").

 

 

 

[rturbo 930]

Why not just move to the increasingly popular Ford 8.8 set up? Seems like that'd be the easiest and most appropriate solution for you. 

[JMortensen]

Agree. 8.8 IRS is easier than stick axle swap.

FWIW, 9" isn't that great as they came on production cars and if you went that route you'd need all custom stuff. You'd have to replace the housing to take that much power and housing will be too wide, etc. Can buy the whole thing upgraded and built to fit, but the pinion is really low, which is another issue. I'd rather go custom 8.8 solid axle if you're going to a solid axle. Almost as strong, cheaper, just as many gear options, better pinion angle, etc. If you want REALLY strong, Dana 60. 

[SH4DY]

The 8.8 IRS may not be cost prohibitive if I fabbed everything up on my own, but I'd still be limited by the IRS suspension geometry and wheel/ tire size. Also, it's not the strength of the R200 that I'm concerned about. There are cars using them going way faster than I am. 

If I went with an SLA I could easily fit the 275/60r15 drag radial I want to run in the stock wheel wells. Right now I'm limited to a 245 (currently running a 245/45r17 Hoosier DR2). I'm also not talking about a production 9" - I'd be looking at a Currie/ Moser 3rd member and possibly a Tin Soldier or Moser housing. After axles, that's close to the TechnoToys 8.8 swap cost (~$6k) but can handle 2,500+hp. 

 

Another alternative is finding someone to make a custom ring and pinion? I'm sure that won't be cheap though. Or find an old Kameari gear set?

 

I'll look into the 8.8 IRS some more. Maybe if I can find someone to buy my current setup I could offset the cost.

 

[Ironhead]

I don't have any input beyond what the others said...

 

I just wanted to say that picture you posted is pretty badass.

[Invincibleextremes]

On 9/27/2022 at 11:22 AM, SH4DY said:

The 8.8 IRS may not be cost prohibitive if I fabbed everything up on my own, but I'd still be limited by the IRS suspension geometry and wheel/ tire size. Also, it's not the strength of the R200 that I'm concerned about. There are cars using them going way faster than I am. 

If I went with an SLA I could easily fit the 275/60r15 drag radial I want to run in the stock wheel wells. Right now I'm limited to a 245 (currently running a 245/45r17 Hoosier DR2). I'm also not talking about a production 9" - I'd be looking at a Currie/ Moser 3rd member and possibly a Tin Soldier or Moser housing. After axles, that's close to the TechnoToys 8.8 swap cost (~$6k) but can handle 2,500+hp. 

 

Another alternative is finding someone to make a custom ring and pinion? I'm sure that won't be cheap though. Or find an old Kameari gear set?

 

I'll look into the 8.8 IRS some more. Maybe if I can find someone to buy my current setup I could offset the cost.

 

A $200 3.31 lsd mustang diff would easily hold your hp and then some.

 

The kicker would be the kit itself, which is substantially cheaper than the t3 setup but definitely not free. 

 

265mm tire on stock fenderwells won't be an issue.

[SH4DY]

Funny, I actually just got an '08 Explorer diff heading my way courtesy of ebay. I need to reach out to DSS about a custom set of axles and see what that damage is compared to the Apex kit. 

 

Does your car not squat? I'm stock fenders and with 245 dr2 Hoosiers you can see where they touch, presumably on the launch. That was with the stock cxracing springs though (240lb). I've got 500lb springs in there now but never got back to the track to try them.

Edited November 21, 2022 by SH4DY
Typo

[Invincibleextremes]

On 11/20/2022 at 7:02 PM, SH4DY said:

Funny, I actually just got an '08 Explorer diff heading my way courtesy of ebay. I need to reach out to DSS about a custom set of axles and see what that damage is compared to the Apex kit. 

 

Does your car not squat? I'm stock fenders and with 245 dr2 Hoosiers you can see where they touch, presumably on the launch. That was with the stock cxracing springs though (240lb). I've got 500lb springs in there now but never got back to the track to try them.

Explorer 8.8 and apex aren't going to hold your hp.  Guys with far less hp have issues with both the diff and the flex in the apex parts.

 

I was referring to the super 8.8, which is a 34 spline monster that costs peanuts and comes out of the 2015 mustang.

 

That gold car is andrews, and is a 6 speed car that puts down procharged 6.0 ls power effortlessly with the super 8.8 and mustang hubs.

 

Also, the 8 ball cv axles with 300m shafts cost HALF of what dss would charge you, and that's not even talking about the cost savings involved in not having to upgrade the 280z outer stubs etc.

 

Gold car is andrew waldony, not hard to find on Instagram, or just look me up, same name on Instagram as on here, i tag all my high hp customers in pictures of their cars.

 

You can waste your money, or you can get what actually works.