Got it. Agreed. Start stocking them for $3K

On a serious note, would specifying one with dogs that give a "wide window of oportunity" for streetability make them suck for flatout application?

 

Pretty much decided i am having a custom box made. next question is 5 or 6 speed case and 5 or 6 speed box.

what are considered 'ideal' ratios for a 400-450whp race car?

 

1.55
1.25
1.0
0.85

Doesn't matter whether they're in the 3-4-5-6 position or the 2-3-4-5 position.

 

what about a gear for getting off the line? ~2.5?

i'm thinking 5 speed at the moment as is the builder to give more room for bigger/stronger gears.

What about a 5 speed box in a 6 speed housing? you think the stronger case would be worth it? the 5 speed has a better shift.

 

i dont understand why you would bother with custom gears in a stock case at this level. buy a racing tranny and adapt it, Quick time has all the info they need as the already offer a bell housing for a 4bolt muncie,t10 pattern to a BP. They should be able to make you a housing to fitt and gearbox pattern you want.

Gforce allows you to specify ratios and output shafts, why not go with a dog box thats been engineered as a unit and not some gears in a old case. The cost should be about the same.

 

Do a little research Hank, geez. Dog boxes are flatout.


My worksheet so far
4500-9000rpm
4.3 diff

2.8
2
1.52
1.22
1
.87

 

Awful close to a Nismo AZ6

2.987
1.989
1.537
1.218
1
.862

HPI 6-Speed Cross Transmission S13 S14 S15 Silvia 180SX - RHDJapan

lists confirmed torque compatability 362 ft-lbs
confirmed power compatability 424 Hp

Wish they made that in a direct miata fit.

 

I shot them an email. For $4000 though, I'd spend the extra $2.5k and get a dog conversion from PAR

 

No, more specifically if we're talking about total custom... I am talking about this:



I would guess that noise and abruptness of shift matter little to none - just curious if there was any other insight on this part.

 

I want a quick shifter. I'm sure that'll be fun.
I like my clutch though.

 

You still have a clutch with a dog box, you just don't use it once you're moving, unless you have to shift slowly.

 

True, personally I find no down side to dogbox gears. I'd love to have them.
The sound too...mmm mmm mmm.

Actually isn't the 6speed equipped with a straight cut reverse? I buddy with the S2K says his is.
He's putting 400hp/290ft/lbs down. He's been told not to do long pulls in 5/6th as it'll put to much load.
Seemed correct when I think about it.

 

Whats the issue with 5th? Isnt that the direct drive gear? Well besides the s2k having a set of drop gears. Sounds more like, "you boost control setup cant control your boost in 5th and 6th at WOT."

 

4th is the weakest link in the Miata 6speed. 5th doesn't use any gears. its just the input shaft locked to the output shaft via the slip ring cant loose 5th unless you brake a shift fork.

 

I believe this.

 

Ron was talking 250 torque limit on the sequential in the 6 speed case. I hope to squeez under the limit with my low torque Rotrex power plant.

 

after further talks with my box builder these are the ratios he recommends.

2.214
1.625
1.276
1.050
0.900

thoughts? i have all graphs etc if there is a way to attach an excel document.

 

4. 1 rear end? Sub 140mph top end, no?

 

no its a 3.636 rear end. 150mph @ 7250rpm

 

Won't the gears and guts out of one AZ6 fit into another case?