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Auto to Manual Conversion Idea...

18K views 49 replies 23 participants last post by  mi04se1 
#1 ·
I've been checking into this forum for a while in the hopes that someone would have some good info regarding swapping a manual trans into one of these cars... but so far the only thing I've seen is an overwhelming response that says "sell the car and buy a GXP w/ a manual" People have gotten quotes of up to $7000 for the job, but that seemed a little high to me, so I did my own checking and have come up with what I think is the most reasonable (and least expensive way) to convert a G8 to a manual.

First up, my idea only applies to those willing to do the work themselves. If you are going to have somebody else do it, then this may not work for you (it could, but I don't know how much labor it would take so I can't guess the cost for that alone).

My first step was to actually determine what the cost of just selling my GT and buying a GXP would be like most people suggest... Well according to Kelly Blue Book, the difference in price between the two vehicles is currently around $7500. This is assuming I sell my vehicle outright (not trade it in), and then buy the GXP from a private owner. If I traded my car (and got trade in), then paid retail for the GXP, that "cost" to upgrade would nearly double. Where I live I'd also have to pay sales tax on the vehicle. That would be roughly $2300 at my local tax rate. Then I have to consider the cost of financing the GXP. Given that I got my G8 when GM was doing 0% financing, ANY interest rate for any amount financed would add right on top of the "cost" of upgrading to a GXP. This finance cost could easily be another $3000 - $4000 depending on the loan terms. I won't even get into being "upside down" on the loan on my current '09 GT, nor will I consider the money I've already lost in depreciation, or the higher insurance cost over time of the GXP.

Needless to say, the actual cost of selling my GT and buying a GXP would easily exceed $10k (in my personal case it would be over $15k if I did it at current market values and interest rates). Suddenly spending even the $7000 I've seen quoted on this site to convert to a manual seems like a pretty good deal! But I think you can get it done cheaper.

Rather than just try to swap in a manual and deal with all the wiring headaches, programming, etc... why not just swap in an entire LS3/manual take out from a new SS Camaro? The Camaro and the G8 drivetrains should interchange effortlessly. I have talked to a couple of different salvage yards, and the going rate for an extremely low mileage (less than 5000 miles) LS3/manual take out is about $11k shipped to your door. This always includes all the wiring, accessories, hydraulics, pedals, etc. I'm guessing as these cars get extra mileage, the cost will slip to well under $10k shipped. If you look at the price for a L76/A6 combo out of a G8 GT, it’s currently around $6k. So even if you could only get 1/2 of what you paid for the Camaro powertrain for your take out, you are at a cost closer to $5k to install the manual WITH a more powerful engine.

$5000 is still a lot of money of course, and you'd still have to likely get a diff. with a 3.45:1 ratio (though you could once again sell you're to offset some of the costs), and likely a few other little things like a driveshaft and a shifter plate for the interior, but with the LS3 you would be adding 65 hp (that is still factory smooth) and additional torque. So in a way you are adding hp mods at the same time as the manual swap. I don't know if I consider this a freebie since you are paying for it... but its more power AND a manual for less than people are getting quoted for the manual alone. That has to count as some type of value to the swap.

If the power increase is not desired, then you could also source a salvage drivetrain from a Commodore from Australia (can be found on ebay). These drivetrains are less expensive than the LS3/manual combo, but would have higher shipping costs. I'm positive it would still be less expensive than the LS3 sources locally by a couple thousand bucks.

In all cases, buying a complete take out w/ engine solves all the headaches with wiring and programming. It would work like a factory engineered package because it is one. Plus I think that the drivetrain out of the G8 would be easier to sell to someone looking to retro-fit it to an older car than just trying to sell the old A6 by itself. Of course it’s a lot more work to remove an entire drivetrain from a labor standpoint, but the problems encountered should be manageable.

For those considering "upgrading" to a GXP as the only option because they can't stand the automatic any longer... I suggest they consider the entire cost of the moving to the GXP verse the cost of the swap. I know in my case the costs aren't even comparable to make it worth buying the GXP. Sure there are other upgrades to the GXP, but are they worth the extra costs. This is not an insult on the GXP, as I wish I’d done one from the beginning too… but if you already have the car with an auto, I think this is a better option.

I'm not in the position to be the first to try it (unless there is someone generous to donate the money to me for "research and development" of the concept), but I will at some point. I’d be happy to help somebody locally do it sooner.

What do you think? (sorry for what is a really long first post).
 
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#3 ·
That depends on how much you like to shift... personally, I can't stand the lack of control with the auto. Its enough that I don't think I'll ever own another car with an automatic. But for now I'm stuck with it.

Plus some people actually enjoy working on their cars. More work = more fun.
 
#4 ·
Oh I agree that shifting gears IS more fun and I've been building cars as my hobby for 25 years now so your preaching to the choir on that one. LOL! But I have to ask have you ever done an auto to manual swap before? They always seem not that hard till you get into it and something ALWAYS pops up that you didn't expect and your left searching everyjunk yard from here to BFE for the little thingamajig your missing and suddenly your for fun swap turns into a nightmare with someones car stuck in your driveway for weeks if not months before its finialy done in glorious half-a$$ backyard hacking up of crap to get said thingamajig to work. Same thing with swaping a V8 for a V6, something allways pops up that turns it into a nightmare.

I'm in no way knocking you or your idea which is just like every other auto for manual swap I've done, better sounding on paper then in your driveway. ;)
 
#5 ·
I've done 2 auto to manual swaps before. One was actually pretty easy the other was a nightmare I learned from.

The easy one was me getting ahold of everything from a donor car and basically only having to drill some holds for the hydralics and cut a hold in the tunnel for stick to come through. I will admit that when it was done I had to pull the trans again because it needed synchros and that I never got the speedo to work accurately (old mechanical speedo gears are a pain for a ratio combo that never existed from the factory... could have swapped the rear gears but never did). But in one weekend I got it done and drove it to work on Monday. It was like factory and got tons of complements.

The other was too much custom stuff to ever be easy. Custom trans crossmember, "clearancing" the tunnel with a hammer, a clutch that wouldn't disengage, etc. But that was trying to put together a combo that never existed from the factory.

I guess I feel like a total pull out from a car of the same platform should be as easy as this type of stuff could ever be... But I'm sure there is something I'd be missing... like the gauges wouldn't work right without some custom stuff. I imagine you'd still end up needing a custom tune before it would work right. To me it would be worth it. The auto in my car drives me more nuts than any auto I've ever owned before. Not enough to cut up the car while its under warranty, but enough to do it some day :)
 
#6 ·
I’m pretty sure that the Tremec TR-6060 that comes in the Camaro SS and the G8 GXP are 100% identical. Can anyone confirm if this is true? If they are the same, then all you would need is to get the transmission and differential out of a junkyard Camaro and have a custom driveshaft made. Seeing as how that exact transmission was an option in the GXP, one would think that installing it would be a pretty simple bolt on job.

What wiring and programming would need to be done? I didn’t think that would be necessary because the A6 has its own computer that runs separate from the engines computer. Variations of this car is available with a manual transmission in basically every other country that it is sold other than the USA, so it’s not like putting a manual in this car is some super crazy custom thing. I may want to do this some day so I would really like to hear more discussions about this.
 
#7 ·
I have no problem controlling my GT in full manual mode. With a trans tune my car bangs gears like it has a manual trans, and I don't have to use a clutch pedal.
 
#8 ·
something about that clutch pedal though and running through the gears that puts our sport shift to shame. Though it is nice to be able to have some more control with it vs strictly auto. I remember owning my manual Hyundai accent for a brief period of time, and if I can have fun with that lawn mower, I'd be in heaven if my GT had a stick. Wish it was an option since I was convinced my next car would be manual, but I didn't want to wait for the GXP.
 
#9 ·
For me, I just couldn't afford a GXP...but I'd MUCH MUCH MUCH prefer a stick over our auto. The auto is good, but I miss my stickshift.
 
#10 ·
The manual is much harder to launch consistently and it seems to be the cause of excessive wheel hop with the G8. Also the automatic is faster in the quarter mile, so I see no reason to want a manual. I had manual shift cars before and I wouldn't own one ever again.
 
#12 ·
Very true.

I still love the feeling of driving a manual though. It's so visceral and just gives you a level of control an auto can't ascertain from your brain, but the Sport shift does help considerably. I would agree though that you can get better and more consistent results at the track with an auto. The manual can also be a pain in the ass in traffic, but with these cars you could keep it in 3rd and still get going which is nice. No way my Hyundai could do that haha.

I think if you could have an auto DD and a manual toy car gives you the best of both worlds. I just wish sport mode was reversed in our car. I hate pushing the paddle forward to upshift. Can't tell you how many times I hit the rev limited in 1st when I first owned the car trying to shift into 2nd. My instinct kept wanting me to throw that baby back!
 
#11 ·
I've done one auto to manual conversion, on a 1989 Mustang 5.0 GT.

It went smoothly because both the auto and manual versions were production models, and I had a pony car specialty salvage yard pull all the necessary pieces, and all I had to do was figure out how to assemble the puzzle. Oh, it was pretty dang cheap, too.

It was a good weekend's work.

I would not consider it on a G8 unless I could get every GM bit and piece needed from a manual G8 that used the same engine, to assure 100% compatibility.

I'd bet that trying to fit a Camaro drivetrain would not be the simple solution offered by the OP.

Much as I love manual transmissions, I don't think my G8 has one in its future.
 
#13 ·
The bottom line is that a lot of people just find a manual much more fun to drive. For some, it is a much more rewarding experience that an auto will never come close to matching. I personally do think that there are a few solid advantages to a manual but I will not go into it because I don’t want to derail the thread into an auto vs manual debate.

Zaphod B said that he did a conversion on a Mustang and that the project was simple and inexpensive due to the fact that he was installing a part that could originally come on the production car. The project was basically bolting on the pieces in the places that they were supposed to go.

What I’m saying is that the G8 GT with a manual transmission is a normal production, just not in the USA. This exact same car is sold with a manual in Australia as a Holden, throughout Europe as a Vauxhall, ect. So if one were so inclined, they should be able to import all of the parts from one of those cars and can reasonably expect to be able to just bolt them into their G8, correct?

Because the costs may be high to import those parts, another option may be to just use a Camaro SS transmission. That transmission is the same that comes in the GXP, so one should be able to expect to be able to bolt it up in a G8. All one would need is the transmission, the rear end for gearing reasons, and a custom drive shaft. If the only thing you may need is the transmission, clutch pedal/lines, and differential from a wrecked Camaro SS M6, the interior trim for a M6 G8, and a custom length driveshaft. Thanks to the Camaro eliminating the need to import transmission and parts, a manual conversion may actually be really cheap and easy to do on this car. I would love to hear some more knowledgeable people weigh in on this…
 
#16 ·
Dont forget you will also need the ECM, TCM, and BCM reprogrammed with the manual transmission parameters as well.

The ECM and TCM will be easy, but unless you are Chris White or have connections at the dealer you will not be able to get the BCM reprogrammed if it needs any done. You will also need the gears from at least a A6 GXP or the 3.70 that come in the M6 GXP in order to not lose any performance.

I did a write up on the gearing ratios for the GT and the GXP and you are going to lose alot of performance with a M6 in a GT equiped rear end. It would be a great highway car though.
 
#17 ·
The reason I suggested that a total engine/trans/computer swap would be easier is due to the fact that I don't really know just how the engine is communicating to the transmission. I realized that the auto trans has a stand alone computer, BUT I can't believe the engine's computer is not still fully aware of what the trans is doing on a car this new (OBD II controls). On older pre- OBD II cars, the computer was NOT receiving ANY signals from the auto trans. You could swap to the manual and leave the harness that plugged into the auto unplugged and the car did not know the difference. I don't think that's the case with our cars (but don't know that as a fact). Unless the signals that the engine ECM receives from the manual trans are the same as with the auto (and any electical connections), I honestly just see it as easier (and long term probably cheaper) to stick with a complete manual engine/trans package that is programed to work together. By the time I modify the wiring harness, and get the custom programming it just seems like a lot more work. If you've ever looked under the hood of a new Camaro SS, then you know its exactly the same car under the skin as our G8's. I personally don't think unbolting an engine and trans and pulling it from a car (late model or not), is really that difficult. Especially if the cars are structurally identical.

If somebody showed me that the ECM and wiring harnesses are the same between a manual and an auto, then I'd say it was no longer an obsticle.

I do still believe that it would be easier to sell the used A6 out of the car if there was an engine bolted to it (I don't see a huge demand for used A6's vs. the retrofit crowd), but that is just an opinion.

Finally, who wouldn't want more hp and torque that are factory engineered?

And if your not into the manual, then your obviously not going to think its worth it. If all you care about is drag racing, then you are probably going to want to keep an auto. But if you are into really driving your car and controling as much of the experience as possible, there will NEVER be a replacement for a proper manual transmission. Once again an opinion, but one I feel I am not alone on.
 
#18 ·
Agreed on the desires of the manual! Taking my G8 to Germany this summer for 3 years and fully intend on getting a Vauxhall M6 installed one way or another while their! With a few connections I should be able to keep the project under $2500 with me doing the labor which like others have said is not cumbersome but enjoyable. As for the ECM, TCM and BCM issue...I'd be hard pressed to believe that if I took all 3 managers from a car that had the full 6.0L M6 in it like a Vauxhall from a salvage yard that it would not work. Several salvage yards in the states will offer you the cars computers for free if you purchase a complete package such as this.
 
#19 ·
I don't care about launching or drag racing. I love the ability to manually select gears when I choose. For me, having the manual is part the driving experience that I think adds to the fun factor.

Also, if we were to do a track day, at lets say, Watkins Glen, I'm almost certain you'd burn (fade) your brakes and overheat your transmission fluid before the second or third lap. Another problem with the auto on a track like this is its inability to perform manual gear selections and short shifts with quick yet finesse precision. Autos programmed to perform hard snappy shifts can get you into trouble really fast once the suspension takes a set in a turn at the limit. Perhaps if the G8 came equipped with BMW SMG transmissions and brake ducts.....

If you have the money, time, and patience to perform the swap, go for it! I've always felt they should have offered the GT in an auto anyway, gas mileage be damned.
 
#20 ·
They both have their advantages and disadvantages, and for everyday driving in stop & go traffic, the automatic is clearly the winner. I have owned quite a few manual shift cars, and after a while shifting gears constantly gets old. Plus I have no desire to run my car on a road course and I'm sure many other G8 owners feel the same way. But many of them do drag race their car, as you can see from all the talk that goes on here.
 
#26 ·
Tfor everyday driving in stop & go traffic, the automatic is clearly the winner.
Speak for yourself. Automatic gear hunting drives me crazy, and it's worse with the new breed of 6- to 8-speed autos. Manual modes are programmed so conservatively they won't prevent hunting in normal traffic. Automatic transmissions insist on kicking down every single time you want to accelerate, hurting both smoothness and fuel economy. In rush-hour traffic, my blood pressure is way lower with a manual. This is a matter of taste, not "clear" at all.
 
#21 ·
I agree that auto's and manuals both have their merits. BUT, I've never owned a performance oriented car and thought it was better off as an automatic. Now if I'm driving a "regular" car, the there really isn't a point in the manual. It takes all the joy out of rowing through the gears if the thing is struggling just to get up to the speed limit.

As for drag racing, while I agree that an auto is generally more consistent, easier on parts, and potentially quicker as a result, I don't think its worth it until the car gets really quick. On a typical street car like probably 95% of the people on here who modify there G8's AND drag race, I'd still take the challenge of nailing the launch just right with the manual and then actually having to do something besides sit there behind the wheel and wait for the next 12 to 13 seconds to go by. Every time you pull up to the line with a manual trans car on a drag strip, its a challenge to see if you can make a perfect pass. With the auto, all you are really worried about is cutting a good light and not blowing off the tires. With the manual you have to nail your reaction time, let the clutch out just right, feather in the throttle perfect, THEN after you are moving hit at least 3 gear changes perfectly at the right rpm. That's a little more involved and in my opinion more fun too. IF you are any good with a manual at all, you can be very consistent on a drag strip.

As has been said, its all about driver involvement AND personal taste. I know that I like my G8, but I would love it if it was a manual.
 
#22 ·
Agreed.
 
#23 ·
As has been said, its all about driver involvement AND personal taste.
If you want to shift put it in manual mode and you'll be involved. Evidently those that wanted a manual shift and got a GT bought the wrong car. If I prefered a manual I would have bought a GXP or a GTO and got what I wanted, not wish my car had that type of trans.
 
#24 ·
You would be correct if you said I likely bought the wrong car. However, its not as easy as just getting a GXP or a GTO. In my case there was not a "right" car that met all of my needs.

Not everyone would think it was worth it to spend $8500 extra for no other reason than to get the manual. That's before you even consider finding one (at the point I bought mine, production of G8's had already stopped... you got what you could find).

And if I needed a coupe, then I could have gotten a GTO. I sold a coupe to get this car because it was no longer big enough. Some of us need the massive back seat in the G8. I'm in that camp. This is a family car (a fun family car, but a family car none the less). I need it to fit 3 kids across the back (you can't just shove them in the back of a GTO that only has 2 seats).

When most people buy any car, it is a compromise. The G8 GT was my compromise. Hence, given the price range I had to shop in, the space that I needed, and the fun factor I desired, the G8 GT was the only logical choice. Just because it was the "best" choice for my particular circumstances does not mean that it was the "perfect" choice. Add the manual to the GT... now that might have been the "perfect" choice.

That doesn't mean I can't think of ways to make the car better to me. I'm not sure why it bothers people to change some parts of a car, but not others. Its OK for somebody to add a supercharger (a part that is available on a number of production cars), but not change the transmission?

I started the thread to give those of us interested in creating a manual shifted G8 GT another approach to accomplishing that goal. I really didn't think it would turn into a manual vs. auto trans. discussion.

As long as somebody likes what they have, great. If you don't, then change it.
 
#25 ·
I'm not sure why it bothers people to change some parts of a car, but not others. Its OK for somebody to add a supercharger (a part that is available on a number of production cars), but not change the transmission
Swapping a manual trans into a car with an automatic is a lot more difficult than installing a blower. Cost is also a huge factor, for what you get by swapping the trans compared to installing a blower, it's hard for most people to justify the expense. And evidently that's true, since quite a few people have a blower on their G8 and nobody has installed a manual trans in a GT.
 
#27 ·
Your missing the point. The reference to a blower was simply to point to the fact that just because a car doesn't come from the factory the way you want it, doesn't make modifying it to be that way wrong or not worth the effort. Maybe I should have used a paint color instead. If I wanted a yellow G8 (like the factory offered yellow on the new camaro), then I'd have no choice but to get the car painted myself. It would cost a lot, and most people would argue that it wasn't worth it. But the arguement, that if you want a yellow car you should just buy one that comes in yellow is not a great arguement.

If somebody wants a car different than what is available, they will just make it themselves. The value of that modification will be based on the person making the modifications budget and tastes. I'm not following why this is so hard.

I'd agree the the job is more labor intensive, but I'm not sure I'd agree with the cost being radically different. I doubt the difference in price is all that great. Have you priced the blower? I'd be shocked if you could do it for significantly less than the tranny swap.

As far as why more people have done the blower, that's easy. Its available as an easy bolt-on that anyone with basic mechanical skills can do AND some blowers even cover the warranty on your car if you do it. I'm not sure many people are ready to do a basically irreversable modification to cars that are still dealer fresh. Once the warranties start to expire AND the parts availability for the swap become more common, I expect you will see auto to manual conversions start to happen.

Will they ever be common? I doubt it. Once again, I'd consider this a mod that is reserved for a select group in which there is no replacement for a manual (no matter how good the "manual" shift is programmed).

The entire post is just a brainstorm on a way to get it done. When I asked for opinions, it was more about the logic of the approach, not whether it should or should not be done. I kind of assumed anyone interested enough to read the post was interested in having a manual. If not, I'm not sure why they would read it.
 
#28 ·
If somebody has the budget AND the desire, I'd be happy to donate my time for free to make this happen and end the debate of "worth".

I happen to have 3 kids with one on the way. ANY modifications to a daily driven car at this point in my life are on hold... otherwise, I'd already have the car appart in my garage to change a host of things I would like to change. But I could say this regardless of what car I bought. There is ALWAYS room for improvement over the factory.
 
#30 ·
If I had my druthers, as they say in these parts, I'd druther be driving a manual.

But (1) the G8 GT wasn't offered with one, (2) I didn't want to wait for a GXP, and (3) my wife can't drive a stick anyway, so it would have been useless as a shared family car.

So no stick for me. Who knows, if I hang on to the car long enough, and used conversion parts become available (likely as a snowstorm in hell considering that it's an orphan car), I might consider it.

The auto transmission does a fine job of auto-sticking so it's not a completely bad situation. I can live with it. :)
 
#31 ·
I'm in the minority here when I say the way a car handles is more important to me than hole shots or drag racing. This also includes a manual transmission as part of the package. While an auto might be great (and faster) in a straight line, it will be plagued by issues on a road course and slower. I'm sorry, but you cannot compare the manual shifting of an american slushbox to an auto sequential gearbox or manual with a competent driver on a road course.

While this entire auto vs. manual debate is entirely subjective, each has its merits and drawbacks. It's really just an issue of personal taste and ultimately choice in what you desire. I've seen guys do track days with their autos and they still have a great time, issues aside. For me, no manual would have been a deal breaker.

If I were looking to do a manual swap, I'd consider locating the entire GXP drivetrain which should include ECU, driveshaft, and other components. It would probably be cheaper than attempting to source all of the extra parts.
 
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