PT

Since I started this original thread, here's my update
I have decided to change individual gears as opposed to R&P for 2 reasons - I drive the car to/from track and its easier to do.
I ended up shortening only 3rd & 4th based upon the tracks that I go to. At the Glen, I hit 6500rpm in 4th before the bus stop, so for me, the gears are good. If I had changed the R&P, every gear would have been shortened. That would make 1st quite useless for street driving, and I also enjoy the long 2nd I have for track (in fact, maybe I should have lengthened 2nd by a tiny bit).
YMMV...

Sameer

Guys,
Can anyone tell me whats the difference between the Andial R&P and the one from Guards?

SGOGT4

Can anyone provide the part numbers for those two units?

Tom F

I am puzzled by what you say about 1st gear. I feel that ALL of the stock gears are too tall for street driving - 1st gear because it's hard to get off the line and 4th gear because the engine is turning over too slowly at any reasonable cruising speed on US highways. In other words, I feel that 1st gear is useless for street driving because it's too tall, not because it's too short. My car is a '77, which has the aluminum flywheel, so that is also a factor in getting underway from a stop.

I have an Andial 8:39 sitting on my bench, waiting to go into my transmission, but your comment makes me hesitate. Am I making a mistake putting the 8:39 in my car?

Sameer

Tom,

A 8:39 R&P with a rear tire/wheel of 265/40/17 will give you the following;

1st 47mph
2nd 81mph
3rd 118mph
4th 168mph

You will cruise at 3030 rpm's at 75mph in 4th gear. Now is'nt 47mph enough for 1st gear? I think it's perfect.

PT

Tom, I dont race on the street and with a shorter 1st, as soon as I step on it, I'll hit red line making it a rush to shift all the time. At the end of the day, its a personal choice, given we only have 4 speed
I know many who loves and swears by 8:30 R&P. For me, I care more about how it is at high RPM.
Factory did gear the car as a GT a.k.a. a fast Sunday cruiser but also be able to hit top speed on the good old Autobahn (when there's not this many cars) IMHO.

PT

Forgot one small but important point... when I drive the car on the street, I'm actually towing a small tire trailer 95% of the time, so yeah, I dont even try to race with a Hyundai

Tom F

I certainly don't street race. And, it's not the Hyundais that I'm worried about - it's hard to drive this car in traffic. It's hard to find the middle between starting out like a snail, and laying two fat, black rubber strips!

Anyway, I appreciated you input. Having bought the Andial R&P, it's pretty much a given that I'll put it in. I'm surprised that more people on this board haven't tried it.

Sameer, I came up with the same numbers, and I like the looks of the R&P change based on what I see.

nathanUK '81 930 G50

Even with my 5speed specially shortened G50/52 box in my 930 it's hard to get away without either not getting any boost and too little power, or lots of power and lots of screeching. I think the ratio's are stock G50/52. 5th is not much higher than 4th, they are rather close to each other. I found 1st gear to be perfect at the dragstrip last year with the stock engine. Hope to have near 400FWHP when I go back to Santapod next year.

As for my '83 3.2 carrera with a 915 I find it easy to stall when pulling away. I find the ratio's spot on but maybe a lower 1st would be nice for traffic. Engine is stock with K&N air filter.

Rob S

I'd agree that the suitablity of a lowered first gear, such as from the 8:39 R&P is a matter of personal preference. On car with a heaviliy modified engine, you might find that the lowered first is hard to take advantage of, in that it will be an exercise in self restraint to avoid wheelspin. When the engine is closer to stock, it might be just fine. The real problem, in my mind, is the spacing between the gears, especially first and second, and the overly-wide ratio range. Changing the R&P doesn't address that. But having only four gears really limits your ability to dial it in for all circumstances.

Tom, as I've detailed in other posts, I went the other way and raised first gear considerably (revs out at 72 mph now), left second alone, and I lowered third and fourth (revs out at 161). For my interests, this will be perfect for the tracks around here (first is now a usable racing gear), but of course, it will be very doggy from a standstill. I know of a couple of folks around here to track their 930s with stock gears and the 8:39 R&P with very good success (both from the standpoint of performance and longevity). Another thing to consider is the strength. If you're building a very high horsepower engine, you'd be better off with the original 9:38 R&P or with a G50/50 gearbox.

PT

I agree with RobS comments totally about spacing of the gears. Dropping ~2200 rpm from 3rd to 4th is A LOT.

schnele

I have the 8.39:1 ring and pinion and my car blows through the 168mph pulling like a freight train around 6250 RPM in 4th my car has 3.4 P&C, modded fuel head, andial I/C hybrid K27/29 B&B headers etc.

Fast82930

Rob S. and I have had a few discussion about these two options.

I've been running the Andial 8:39 R&P since 2001 and love it compared to the stock gearing. It fixed all the corners where 2nd was too low and 3rd was too high. But it's a compromise.. that works on the street, track and A/X course.

I'm still CIS and for what I do, it has been a huge improvement over stock.

My gear chart for a 25.8" dia. 315/35/17 rear tire shows the following MPH's at 7K RPM.

Stock 9:38 vs. 8:39

1st 50 43
2nd 92 79
3rd 148 128
4th 204 176

When I am "forced" to go EFI, things might have to be changed......... But only when something breaks...

Just make your decision and go out and have some fun.

Sameer

schnele,
Where did you get your R&P from? I think it's time for me to start saving for it as I hardly autocross and mainly do street racing or once in a while a blast down the highway. Plus the roads here in Singapore are short.

SGOGT4

Tom -

Would you mind providing some pics and part numbers for your Andial 8.39? I have a unit sitting on my bench for which I am trying to verify its origin and application.

Thanks!