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Discussion Starter · #1 ·
So I am looking around to replace my old trusty Dodge colt93 with a Mini Cooper S. The reason I even dare to bring anouther car other than my GT into this forum is the 6 speed Tranny is a Getrag 6 am I dreaming would it be a possible for this, think of it a 6 speed GT :D Wow:

Come on tell me what you know or think of this idea. Still working on those CF panels.

:Razy opelerideas
 

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Well it sounds good but wouldn't that destroy a brand new mini cooper which is sort of pricey unless you go for a wrecked one but I don't think there's many of those yet. Can you order one in a crate?

Sounds fun but what do you need a 6speed for? Aren't 5 enough? Hey, I have 4.

Opeler Forever
Ben
 

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I found salvageable Mini That was being parted out. And may be buying a new Mini. As for why get a 6 speed, the way I see it is I wanted to replace my 4 with a 5 anyway but if its possible to go with a 6 why not.
 

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Besides if 5 gears are better than four , then Six is certainly great ... also the lower gear will prolong clutch life and certainly launch quicker. Me myself I am waiting for the 8speed to make it over:D :D
 

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get over? already here!

You could always get one of Mantapart's old t-10 adapters and use it to hook-up a 'vette 4+2 transmission. Never mind the dents in the floor, "these are not the dents you are looking for..."
 

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OK lets pretend I found the Dent's in my head ... tell me more about the 'vette tranny . would it be too much to hope that it would be an actual manual transmission or is it auto? The 8 speed i was referring to was the Opel/Vauxhaul 8 speed that is scheduled to go into either BMW, MERC. or Audi I am drawing a blank right now I just got in from work and i don't even remember which way is up!Having a bellhousing made would be no prob. if it is a manual , woo wee wouldn't that be fun a 200 HP 2.4 with a 8 speed transmission uhhh!
oh I finally got it dent's in the wallet (sorry told ya i just got in, no brain tissue left had to throw it out to keep ballast ...)


RITTER
 

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all manual

the 'vette 4+2 was a 4 speed manual transmission (richmond, I believe) coupled to an overdrive box that was independantly shiftable. That means each of the 4 forward gears (and I suppose the single reverse gear) could be coupled to the axle in either straight through or overdrive, for a total of 8 forward speeds. Unfortunatly, the 'vette crowd stlll keeps the transmissions in the $1500 range, but you never know who'll get lucky at the junk-yard. The Mantapart adapter was to bolt-up a t-5 to the Opel bell-housing, and as far as I know all chevy manual transmissions share a common bolt pattern.....

MG's used a similar set-up, as did Volvo through the mid 80's. Volvo had an electronic overdrive box that only allowed the overdrive shift in 4th. There is supposedly an adapter to replace the tail housing on the Opel with and adapt the Volvo overdrive to the Opel transmission. I have been looking for one for 13 years with no luck, but again, who knows? I may just buy that lathe and make my own. If I do, I'll let everyone here know first.
 

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oh yeah

You could also get the same effect with either a Nash or a Plymouth overdrive from the 50's. Both were cable operated overdrives that mounted between the transmission and the axle, and connected to both with very short driveshafts.

The one I have will fit into a GT with only minor masaging of the floor, but even with the front u-joint going directly from the trans to the gear box the resulting rear driveshaft is only 3" from cap to cap, and needs a slip joint. If only there were a way to use a different axle that would allow for a longer rear driveshaft.....

These Overdrives can be had for anywhere from free to $200. If anyone finds one in their local junk yard, get it, if not for yourself then for me please, I have LOTS of projects they will work on.
 

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More like 80-85 hp in reality.....

But regardless, you are correct. Most of the modern 5 and 6 speed trannys are designed with fuel economy in mind. So we're talking about double and triple overdrives, which an Opel with a 3.44 final drive CAN'T pull. And I'm curious, how was the transverse Mini cooper tranny (front drive) going to be installed in a rear-drive car? Anyway, the only logical application for a 6-speed in an Opel is either:

A. Accompanying an engine swap, or

B. Using a true close-ratio racing 6-speed. In this case, the 6th gear ratio is usually 1:1, and all the prior gears are merely closer together for better acceleration. Top speed would be a matter of HP, final drive gear, and aerodynamics. Fuel economy would be no better than a 4-speed's.

Imagine fitting a ZF tranny from a 'Vette? With a .50 overdrive in 6th gear, you'd get a 1.72 final drive in your Opel! The only Opel I know of that can pull this is a Lotus Opel Omega...with a 360 hp twin-turbo straight six.

Bob
 

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A proper close ratio 6speed would be great in a GT.
As a long time autocrosser and lapping event driver I know that having the proper gearing when coming out of a corner =speed !
Gearing CAN make up for not having power if it keeps the engine in the power band. Every course/corner is different so having a close ratio gear box is an advantage. In autocrossing an OPEL is at a disavantage to a VW that has a close ratio box as we have to shift alot more due to the wide ratios in our boxes. So I totally disagree with the last poster why do you think all the high end performance cars are starting to come out with 6spd trans, it's not just economy look at the overall gearing.



Lee Frisvold
73GT 2.4 long time autocrosser
 

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I have to agree with Lee , Keeping any car at their respective powerband is the way to go as far as racing.This is only accomplished by working all components together. Firstly any good engine builder knows where he wants his peak torque and horsepower coming in at. Secondly is to provide yourself with a means to keep the engine in the respective RPM range of those peaks.Easily the best way to do this is multiple gears, and with the CR Transmissions you can pretty much set it up any way you want (also depends on rearend gears), but this is where track knowledge and driver abilities comes into play. I wouldn't recommend the high purchase of such a tranny to the regular driver this kind of tranny is really only needed by racers , but it would be awesome to have. Besides a properly configured gear setup will outperform cars with more torque and horsepower that aren't configured correctly, and better economy to boot!

RITTER
 

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actually, many European and Japanese cars with 6-speeds still have only one overdrive gear. The rest are all closer together, which would be an added benefit for the low power the GT puts out.

The only cars I know of which have more than one OverDrive gear today are the Corvette (Mustang, and F-bodies, too) and Viper.
 

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Nissan Sentra SE-R Spec V is at least 2 OD's, maybe 3 and has a 6-speed tranny. Even my plain-jane 5-speed 1991 1.6 Sentra has a .91 4th gear and a .73 5th gear!
 

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But Bob what is the final drive thats what dictates what the over drives do. VW's have 5spds with an overdrive but at 60mph the engine is spinning at 3800rpm. Overall gearing including the final.



Lee Frisvold
73 GT 2.4 long time autocrosser
 

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My Sentra has a 3.89 final drive and I think the Spec V has a 4.17, but I'm definitely not positive. Of course, that car also has 215/40ZR17 tires and mine came with 175/70R13's stock. My WRX has nearly the same tranny ratios as my Sentra ironically
(two overdrives) and the same final drive of 3.89, but it also has much taller 205/55VR16 tires. The difference is, the WRX has torque and can pull those gears, it feels fine. The Sentra feels Opel-like, it seems to either be revving too high in a lower gear, or bogging in an upper gear. Not enough torque.
 

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Bob your Sentra must be a 1.6 se model and I know what you mean about the gearing I've work on and driven a few of them.
I've also autocrossed a WRX and a Sentra Spec V, both were fast but only as long as the boost was up on the WRX and the revs were high on the Sentra. I felt the Spec V was faster on the courses that I drove due to it was easier to keep the revs up than the boost on the WRX. It's very interesting the WRX has the same ratios as a the base Sentra. Yes I agree that the wider the spacing between the gears the more torque you need to compensate. But then I've never driven a 4 cylinder that didn't need to drop a gear to properly pass on the street from high gear unless you were on positive boost or in the rev range sweet spot of the cam. Maybe the Sentra Spec V felt faster due to the shorter 215x40x17 tires. But I still stand on my original statement about close ratio gear boxes with the correct spacing between gears to keep the engines revs or boost in the correct spot for the turn.

Lee Frisvold
73 GT 2.4 longtime autocrosser
 

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Your Celica GT-S weighs a lot more than a stock GT! A GT only weighs about 2100 lbs.
The WRX's redline is 7000, and fuel shutoff is 7200.
The Opel has a redline of 6200-6300. All done making power by 5500 though.
But a close ratio tranny is critical just the same. In fact I feel it's one of the most critical things you can do for a high-po Opel engine. Everyone wants Getrags, but personally I feel they're crap. I mean, they're great for mileage, but the gearing spread is worse than a stock Opel's 4-speed. A close ratio tranny knocked 4 seconds off my 0-100 times off one Opel I owned.
 

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Bob

I'm a Toyota Master Tech now turned Instructor and the Celica w/6speed needs the close ratio box it has due to it's narrow power band anything below 6k and it's a slug but above that wow just like a V-Tec or a motorcycle or a turbo car. I've felt the same way about the OPEL gear box for years for it's being the weakest link for performance. Driving a Opel on an autocross is harder than say a VW as you can leave it in second where as a Opel you need to shift at most corners. It takes a few runs to get the shift points correct. Now I have a Getrag and it's alittle better due to the 2.4's torque but I'm still shifting but not as much now it's more like throttle over steer. The getrag also doesn't shift as nice as the Opel box after a few sessions.



Lee Frisvold
learning to treat the throttle as if it were egg shells but it's fun
 

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I was just wondering in fact how many owners haven't made some modification to their "stock" GT in order to get more torque and HP out of it. I know the only one I have that is Factory is my '72 and it's a pig, you almost have to push it to get it going in first ( too tall of a first gear ) , My '70, albeit it does have 422's but I have added a few extra's but I wish I could find out what Flat tappet cam is in it the motor it's powerband seems to run from 2800 RPM's to 6000 RPM's this is very wide from the '72 . Needless to say the'70 runs like a dog with alchohol on his ass ( don't ask how I know) .It's one helluva fun car but runs out of gears at 90 mph by that time your twisting 6300 Rpm's (ok , yes i get scared ) I mean who would want to hurt such a little engine for a prolonged period of time like that, for god's sake it is 33 years old... Basically what i am getting at i guess is any one that can afford a CR sixspeed should not be worrying about the engine having enough torque and horsepower anyway , because usually the first mods made are to the engine. And yes the 1.9 maybe somewhat limited but there are certainly other 4 cyl. Opel motors out there that are not. RallyBob and others have proven it. I like Opels , partial to Toyota for dependability , would love to drive a Porsche 911 turbo, but all these people and most of us know in Racing you do what ever you have to to keep the engine in the powerband or you lose the Race period. Whether that be adding horse power / torque or gears you just do whatever keeps your engine in the "sweetspot".

RITTER
 

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Amen

Who hasn't reached for the transmission to try and grab the 5th gear that isn't there while driving down the highway?
 
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