What transmission would you reccomend for 2.4 six conversion. What would be realistic price for the transmission you reccomend.

The same one that's already in your car

Its FREE!

QUOTE (Dominic @ Jan 28 2006, 09:33 AM)

The same one that's already in your car Its FREE!

Someone mentioned that it might not be up to the extra power and be geared wrong.

I've been running a 901 behind my 2.7 for 4-5 years.
It was a fresh rebuild from a local guru and gone thru end to end.....this guy has his shit together(which is bout the finest compliment I can give anybody ). Cost me 1k + my old tranny that was real good also. It shifts as well as when it was new....including down into 1st at any speed I have the guts to do. I'm gonna have him swap some gears out & look it over again this winter....if I ever get my shit together.

Treated with respect (which I don't always do) the 901 will hold up fine behind a 2.4L. Be gentle when it's cold. Bent shift forks are a common problem...according to guru.

Someone is wrong and/or just trying to sell ya something......bet it was someasshole at PMS...

I abused....I mean thrashed a 901 with a warmed over 3.0 for years.....had an LSD and it was a used tranny when I put the LSD in....lasted...until 1st and reverse let go....pulled the LSD and slammed it into another used box....still running last I heard.

IMO, 1st & 2nd are a bit short for a 6.

Some say 5th is too high...from an engine cooling aspect, but that can be cured with an aux cooler should it be an issue....which I never had. There are some other cooling "tricks" which can help a lot and are almost free.

Grant, I know you are excited, and rightly so

The powerband of your conversion motor is very important if you are searching for gear sets.

Mine runs best from 5-7k rpm's.

I like the M-S-X 3rd, 4th, 5th.

For a/x I believe you will want a lower 3rd geared box so you will be on power immediately out of the 2-3 upshift.

For example: let's say you have a 6500rpm redline and you "tach out" 2nd gear as you make the shift to 3rd.

This would mean you would be at 52 mph in 2nd at 6500.
You shift to 3rd and now the engine is "bogging" at 4000 rpm's costing you time while the motor rev's back into the strong part of the powerband.

The stock 3rd gear is a "N".

By using the "M" you would have upshifted into 3rd at 4500 rpms, instead.

If you rev to 7k, like me, you enter 3rd at 5k rpm's. Yay!
Entering 4th I'm at 5200 and into 5th 5500. Screamin'

Hope this helps.

You *may* need a ride


KT

I think the answer to your question lies in the cars intended use.
There is factory advice that the 4cylinder 5th gear was a tad high for a car designed to be primarily a highway car with stock motor hp/torque curves....

however your motor is not a stock one.
to really really get the gearing right, you would need a dyno print out of your powerbands and also experience of tracks that you intend to use it on.

however......
for a street car I would think this was ABSOLUTELY unnecessary.

if you do much track driving then lower the gearing somewhat.

if its street only, then don't worry about the gearing.
perhaps add a head temp guage and see if your 5th gear cruising is failing to cool the motor if you intend to do LOTS of free way driving.

brant

If you plan on pushing any kind of dramatic HP, then don't plan on using first gear on the track. It's not supported on both sides, so for starting only and then stay 2-5.

QUOTE (grantsfo @ Jan 28 2006, 09:29 AM)

What transmission would you reccomend for 2.4 six conversion. What would be realistic price for the transmission you reccomend.

Transmission: 901
Price: $0

Hewland=$7,500
New gears for above=$2,000
The look on your face when a $0 901 beats you=Priceless.

btw. i'm going to run my 901 behind the 3.6L ...

:fingerscrossed: Andy

Alright!!! A squirrel with some nuts! And If he blows his 901, then a 915 would handle it easy. Right? Or he could go all out and get something with paddleshifters.

QUOTE (alpha434 @ Jan 28 2006, 11:15 PM)

Alright!!! A squirrel with some nuts! And If he blows his 901, then a 915 would handle it easy. Right? Or he could go all out and get something with paddleshifters.

problem with any used 915, by now, they're just as old and worn out as any 901. by the time you "rebuild" that 915 you got that great "deal" on, you'll be out a couple of $1000 bucks as well.

getting something that is "fool-proof" out of the box will cost you $$$. always.

that's why i'm going to run my 901 just the way it is. got a spare one too, just in case.

by the time i'm done with both, i hopefully have the spare $15k for a WEVO 915 with LSD ...
Andy

Yeah yeah. Just don't use first. Thats the one that'll make it schplode.

Get the paddleshifters. I think I know a good company that makes them with our bolt-hole pattern. Kinda pricey, but not insane.

Chris,

the 1st gear in a 901 will decent power if your not dumping the clutch and abusing it.

In fact I'm regearing my 1st position into an "F" (normal 2nd gear) so that I can use 1st gear extensively on the track.

The guru that developed this little trick, runs 901's this way up to 200hp

brant

Yeah. But how many HP is the 3.6 putting out. And I would like Sir Andy's car to be a designated Viper-Killer.

And it's not really the HP that does it. It's the torque. Same goes for Viper-Killing.

And the 2nd gear might work well in first position. Thats what we do to 356s. But remember that 1st isn't supported on both sides. So your trying to put more force through the same spot. The spot where it breaks. Except I know for a fact that a 2nd gear in first strategy would be good to 150hp . Just check your gearbox for failure twice a season. We take ours apart after every race.

Hi Grant,

My opinion is that the 901 will live fine behind a 2.4 given it starts out in good shape.

I don't know if you were around in 2003 and 2004 when Doris and I were last running our 914-6 hot rod, but I'm sure people would tell you we didn't baby it. Our motor was putting out ~230HP at the flywheel (2.7L, 10.5:1 JE's, etc) the 901 seemed to be doing fine. It had 2 seasons on it with the hi-po motor and slicks.

Our 901 was the "Q" box variety and had an 80% LSD in it along with the intermediate plate. The plate may have helped in stay together, I don't know.

As far as regearing, I really enjoyed the shortened gears of the "Q" box. It is slightly shorter in 3-4-5, so it makes for a great AX box, probably better than an M-S-X. However, I did find 3rd to be slightly short at a few tracks, namely Laguna and Sears. At Thunderhill I could get it into 5th.

PM off line if you want the gear calculation spreadsheets I have for both the "Q" and "MSX" boxes. I also have a 915 calc as well.

Bill P.

901 all the way.....

what size tires are you running? it makes a BIG difference on gear choices.

I have a frankentransmission made from a 911 and 901 side shifter. Basically it's a 911 (aka 901 with a pull clutch) with the side shift tail housing and shift rods installed. It's hooked to my 2.4 L MFI motor, and it works fine. It was built with the best of the parts from 3 transmissions, I only bought the gasket set for it. It shifts great!!!


If I were going to do it again, I would use the standard 914 clutch setup. The later 911 pull clutch is very heavy without the helper spring the 915 has.

I used this gearing.

1st. A (The standard first gear from a 914/4)
2nd. F ( The standard second gear from a 914/4)
3rd ZD Flipped (This is the fifth gear from a 914 /4 transmission)
4th S (This was the fourth gear from the 911 transmission)
5th HB Flipped (This was third gear from the 911 transmission)

This gives me a close ratio 4 speed with a really tall freeway gear. Sometimes I think its a bit too tall, the engine runs about 2200 rpm at 80 MPH.

If you are running 15 inch 50 series tires, the fifth I have would be great. I have 16 inch tires, and the rolling diameter is the same as the 165SR15 that came stock on a 914. So the gearing is just a bit too tall. I am thinking of pulling it and changing it to a ZD fifth (same as a 4 cylinder 914).

I hope that info helps.

clay and i have the same box (cept 5th) ROFL...

QUOTE (ClayPerrine @ Jan 29 2006, 05:12 PM)

If I were going to do it again, I would use the standard 914 clutch setup. The later 911 pull clutch is very heavy without the helper spring the 915 has.

Clay, did you think about using the pedal assembly from a '74 or later (but pre-power brake) 911 that has the helper spring on the clutch pedal?

QUOTE (alpha434 @ Jan 29 2006, 12:38 AM)

Except I know for a fact that a 2nd gear in first strategy would be good to 150hp . Just check your gearbox for failure twice a season. We take ours apart after every race.

the 2nd gear strategy is good for more than 150hp.
I base this on Allen Johnsen's personal car that he drives in around 8 races a year. I believe that he dyno'd his 2.2/4 at 205hp. And thats a 4cylinder so its a lot more torque than a /6

He told me that he has 3 years on his tranny without having ever opened it.

He told me that he won't build a 2nd gear into 1st postition over 200hp.
and on a normal 901 with a normal unuseable 1st gear, he won't install the tranny into a race car with over 250hp.... puts 915's into everything over 250hp because its more cost effective over the course of 1 or 2 seasons combined.

heck I used to run 150hp through my 901 with the 4 cylinder (somewhere close to it anyways) and only rebuilt the tranny twice in about 12 years.

I agree that the 901 has its limits, its just not so fragile that it is impossible to use it if treated right.

brant

QUOTE (James Adams @ Jan 29 2006, 07:08 PM)

QUOTE (ClayPerrine @ Jan 29 2006, 05:12 PM) If I were going to do it again, I would use the standard 914 clutch setup. The later 911 pull clutch is very heavy without the helper spring the 915 has. Clay, did you think about using the pedal assembly from a '74 or later (but pre-power brake) 911 that has the helper spring on the clutch pedal?

It could make a difference. I may give it a try before I go to the hydraulic clutch setup like Rich Johnson has on his tranny.

Very informative thread guys.. thanks for the hard numbers.