Do I need to upgrade to a 6 speed transmission if only aiming for 200 RWHP?
 

Caveat: I did a search on this but didn't see any real answers


Due to unforseen financial issues, I'm down grading my 300hp "do everything properly" build to a 200hp "mostly stock" build ... so my question is:

do I still need to upgrade to a 6 speed?
for 300hp, yessiree ...... but what about 200hp??


All advice welcome :hustler:

If you are planning on tracking the car often I would recommend picking up a spare 5 speed, or go to a 6 speed now. On the track the 5 speed will be on borrowed time.

No, not at 200 whp.

+1 If you drive it to and from the track, consider it a minimum of $500 in your pocket...$200 for the tow truck and $300 for the entry fee.

FWIW I blew mine at 215 rwhp and about 130k miles on it.

I sheared a tooth off of a gear when shifting at redline from 1st to 2nd at autox. The car was boosted for about 2 yrs and autoxed quite a bit.

Save up... get a 6 speed when you can.

The car is a dedicated Spec Miata (non-road legal) race car with full cage ...... so will be only tracked

Then you would be stupid to not install a 6 speed now. I would not trust a 5 speed at 200hp on the track to do any w2w racing.

I didn't think the scca liked turbo cars... Esp. In spec miata.

I popped my 5 at 200whp. Stripped 3rd after a fast 2-3 shift.

You can run the 5-speed, shift it slowly, always worry about it, and it will probably last a season. Or, you can do the 6-speed, shift it as fast as you can, and sleep soundly at night. We suggest a 6-speed in every forced-induction build.

What rear gear is everyone running with the 6 speed? I've go 4.10s and pretty sure I would loose my mind on the highway with a 6 speed.

I'm new to the miata world and am so suprised there isn't a better option out there for < $2,000.

I have a 3.9 with my 6sp and even at just 10 psi of boost 1st gear is uselessly short.

I have a 6sp with 4.10, sometimes I start in second gear at traffic lights. 1st is too short, and 2nd is too tall. I cant wait for my 3.636

I would use the five spd. If just doing de events for fun. Just dont beat the shit out of it. I still dont drag launch my 6 spd or bang thru the gears

I have the 6speed and 4.10 in my car, I think I can count the number of times I have used 1rst gear on 1 hand. I simply just always start in 2nd and then pretend I am using a 5 speed.

which sucks, I was reading about the 6-speed and how it was used in other cars, have any people consider using a 6-speed from another car? from skimming the thread on grassroot, a bell housing swap was all thats needed?

http://grassrootsmotorsports.com/for...g/18158/page1/

Yes, but half way down is the problem. Cost. Someone posted a link to a lakewood adapter. The problem is that the 600 adaptet mates a 2000 trans. I think most on here are looking for a sub 1k solution. We need a popular (ie mass produced and cheap from junkyard) strong transmission that puts the shifter in the right location, and a way to produca an adapter plate on the cheap. Driveshsfts can be alteted fairly cheaply if tailhouding is too long. Then we need all the high hp race guys to endorce said swap so adapter plates become the norm and "everyone" does this swap for reliability.

Sorry about spelling, on phone

So use 2nd. Making 1st gear usable in a 250+whp Miata is an exercise in futility unless you are going to run drag radials/slicks.

I heard the naturally aspirated guys don't have a problem with an uselessly short 1st gear - maybe that's what we should all do :giggle:

FYI - the black car will light up 3rd from a 40mph roll. And when I say "light up" I mean "hangs on the rev limiter until the car gets to 80mph". I'll trade 300wtq for a usable 1st gear any day.

Spoolin2bars has like 50 track days with his 240whp miata and is only on his second trans which has been in the car for for about 25 of those days. Unlike most of the Cali guys I prefer the wider spread of the gates of the 5spd. I think shock loading is the killer of the 5spd.

I agree completely. Just set your boost target at the track to hit more gradual. This is probably a good idea for anyone actually.

Damn you MS people.

Any adapter plates out there for a T56?

There is a secret conspiracy to make a T5 bellhousing to the BP. I shall not speak of it, but he can.

I heard that *he* ended up getting a 6spd b/c for the same reasons there isn't an adaptable bellhousing yet - $$

;), one day the dream may come true then.:bowrofl:

I do too, but to match what I used to have with the 3.9 and 5 speed, I need a 3.3 to go with my 6 speed. That would give me the same 1-5, and an overdrive 6th.

A 3.6 would make the 6 speed's 1-5 similar to a 5 speed with a 4.3, which isn't too horrible. Still a bit too short IMO.

T56 carries a 50-60lb weight penalty. Too much IMO.

This is how you should look at it. Figure your cost if you miss track time, and or missed track time plus the replacement 5spd. I would see where you end up before you decide.

yeah, drag racing and auto-x is alot harder on the trans. than a road course. my 180,000mi. original tranny broke at an auto-x due to my old welded diff. "unwelding" and locking the tires while drifting a sweeper. my car was a street/drag racer in it's past life, so i think it did pretty good. just don't crash the gates and it should be fine.

This is the same way I describe it and I love it. I'd prefer a 3.90 if I could get a lower-ratio 6th since I floss on the highway. I pretty much cruise in 5th from 30-70mph, then use 6th. On the track 1st is for the trailer, 2nd is for cruising the pits to holler at bitches, 3-6 is for the track so it's effectively a 4-speed.

A guy at NASATX-Hallett this year who I have more than one story about drove 5-hours to blow-up the trans in his ultra-modded GT2 in the 2nd session of the weekend. I've been fortunate with my 6-speed. Don't waste the weekend becuase you thought you could make it on the 5 speed, get the 6 and spend the cash on the ring and pinion. People make this out to be a chore or a compromise, I believe it makes the car better in every way. The car will be significantly faster with the more favorable gearing and it will be more reliable. If you think the gears are too close, then skip one on the next upshift.

Listened to all the good advice ..... and just secured a 6 speed

Thanks all!

Good boy! Now here's a bone...

https://www.miataturbo.net/attachmen...ine=1323915833

hey Steve, this is Felipe. Zach's friend with the white miata. i also secured one of the 6 speeds ;)

well damn, I guess all the cool kids are doin it guess I'll have to be next. I'll trailer to track events but not to an autox and knowing that where I'll blow the thing up.

After reading this thread it would seem that the 6 speed is the way to go, but what if you are not going to track events or autox? But you have just about 250rwhp? Would anyone recommend the 5 speed, or is the 6 speed the way to go in any situation?

I think it depends on your driving habits, if you are pretty easy on the suspension then i think the 5 speed would probably last long enough to be of value.

I am not turbo charged btw. Just speaking from reading about this topic.

I will recommend a 6 speed in any miata that is above 200hp. I think I got about 2 years out of my 5speed at 200hp hp before my 3rd and 5th synchros started to go.

Ok thanks, does the 6 speed bolt right up to the NA driveshaft?

Yes. It is a direct swap, no other parts are required.

I actually like the 6sp/4.10 in my currently NA car... with my light flywheel the 5sp first would bog a little, now it doesn't. The 6sp also has a better gear spread IMO.

Why are we talking about HP in this thread? It's wtq that's the problem.

" My 5spd only lasted 5k with 250whp the trans had 100k on it, my new 6spd with 45k has 20k miles at 250whp and is great."

:)