I was wondering which tranny would be best for my 400whp plus d16z6 build because my old tranny is starting to go out and I was seeing which one is betterr or should i just do a rebuild on my ex/si tranny.

 

Neither.

D16Y8 with MFactory LSD and FD, or D16Y7 with the same depending on how much power, RPM, and tire size.


Or you will likely get one of these.

Stock FD, sub 250whp, street tires.


Stock diff, 450whp


Broken 88-95 shifter fork

 

when you're making 400whp gearing doesn't matter as much. Some people like the DX better because the longer final drive makes the first gear longer which helps 60ft times.

I would guess that if you're making 400whp on a D-series that your power is mostly in the higher RPM's, so the closer ratios of the z6 trans would keep you in boost a little better.

Another consideration is that some of the DX trannies have weak differential pins, which break under higher horsepower.

No matter what trans you choose please install an LSD.

 

Longer FD is going to kill your times, especially on slicks.

All open diffs are weak, cable trannys have the weaker diff pins.

 

So what kind of lsd kit should I get and how much will it cost and is the obx lsd kit or the the phantom grip which one would be better

 

MFactory LSD. Don't bother with OBX or PG. If you need a trans built I can take of everything for you (see first pic in my first reply, WDR built trans).

 

how much does it cost to do lsd build on a s20 booo tranny because I just got one today I hope everything is ok with it

 

Stock OEM FD has held 400 whp..........and then some.

Lets look at the clutch and driver......

 

Can't do anything about the clutch, it takes a heavy pressure plate to hold the power. Driver, well not everyone gets it or cares to.

I'm doing a Y8 trans for a member on here as he was tired of breaking the 3/4 shift fork in his Z6 trannys. According to him he broke a few FD's before he figured out the driving part. His last Z6 trans shredded the teeth off of 3rd. 300whp D on street tires. He was having a local rebuild them, which I think is the cause of the 3rd gear shredding, likely a mismatched gear set.

 

A longer first gear helps 60ft times, this is basically the only advantage of a longer final drive gear. With the gearing options (1-5) available for D-series I don't see point in an aftermarket FD.

Lot's of proven setups with OBX LSD and stock EVERYTHING else. Not sure what the Mfactory LSD's cost, but they are a good company. I've driven several d-series trannies with M-factory 3/5 set, they're great. No experience with the FD, but I really don't think you need anything other than stock gearing + LSD for a turbo car

 

Even when going with a 3" taller slick?

 

Gearing with slicks and strength. You'll also put down a little more power with the MFactory FD's, especially the 4.5. Stock FD is one of the weak links in the trans. I have a pile here of broken stock FD's. I've even broke one myself during an HPDE on street tires, sub 100whp at the time.

 

That's easy for you to say, you sell them.

 

And I've had tons of problems with OBX's, which is why I had the MFactory LSD made.

If someone wants to spend more on a Quaife then more power to them. They get slightly worse runout than MFactory and a nice written warranty. (Which Quaife upholds, but it took 6 weeks for them to replace the housing on a D LSD I sent them for a customer).