when doing any transmission work, GTM is not the only way to go, in fact I recommend against ever using GTM. Not only have there been nothing but problems from everyone I know who uses them, but they have a huge wait time for anything done.

I would recommend find a good transmission shop that is comfortable doing performance mods. There are plenty out there. Avoid the valvebody as they have many issues when modding and they don't really do much. Work on other areas such as the clutch pads and gaskets. Ask the tranny shop what they recommend to do as well. That is the smartest idea. Unless you live next to GMT they are a terrible idea as you will be going back to them for repairs all the time, and they steal your parts! I know from personal experience!

 

I hear you. I'm almost certain GTM is the only company that can build the 7AT at this point in time. That is why I would recommend for the OP to buy a manual or go with an 08/09 G with the 5at to build. I bought upgraded clutches and had my 5at built locally. I hope you were able to get most of your parts back from GTM.

 

^^^ Lots of good information in this thread.

My experience: The 5at is stronger. The record book shows this, too. I don't know of ANY 7AT which comes close to strip times. I know the OP isn't specifically asking for this, but it sure is a parameter of strength and speed.

BTW: The 5AT has 3.69 gears and the 7AT has 3.35 gears, although people claim it's geared shorter? (I've never ridden or driven one to know.) I did not go faster with the 4.08 conversion on the track, but I loved it on the street.

The clutch pack rebuild AND a torque converter upgrade make all the difference. Highly recommended. Yes, running an auto is costly, but it will stomp away from a 6MT all day long. However, the 6MT (any manual) is simply fun to drive.

Coop

 

Coop is the man^^. He's one of the few that has pushed an auto to its limits on this particular platform.

 

Thanks MKai0.

Truth is, I stumbled into this knowledge by buying the ONLY VQ37VHR platform with the 5AT (2008), and we all learned. The TT loved those long legs in first and second at the strip.

My most gratifying conversion, bar none, was the higher stall speed torque converter. it came alive.

I'm reminded as I drive my 'peppy' Mini Cooper S with a manual trans how much fun shifting is. However, some AMG auto just WALKED away from me today while he was chatting with his GF. Autos are so deceptively fast....

Coop

 

In the end, it all comes down to how hard you beat on the transmission.

From personal experience with the 5AT, I'd still recommend the Trans-Go shift kit. I drove without one for a little while and can say that when the boost comes on, the transmission takes noticeably longer to make the shift. That leads to higher AT fluid temperatures which is not a good thing.

When using a shift kit, the time it takes to shift goes down as the line pressure goes up. And when not driving aggressively, the transmission shifts normally.

 

My 7AT is built by GTM.
Although it was a significant wait (as was previously mentioned - and I agree) my car makes just shy of 600whp and 500trq.
The tranny takes the beating like a champ from launches to hard WOT at 60mph or faster.

Previously I had the valve body upgrade only and I could see a good improvement over stock shifts, but on hard acceleration under boost I could notice slippage especially in 3rd and above.

Hope that helps

 

I have an 09 xs sedan. I'm waiting for my 7AT trans upgrade from GTM. It's supposed to ship out today. hopefully there is a tracking # tomorrow to verify this. also, still waiting on a twin supercharger kit.
How long have u been running the car with the trans upgrade? approx. miles? Meth kit? My goal is 600-700WHP

 

My car has had the built trans for 7,500 miles. I ran the valve body kit for 3,000.

 

Lots of good points, but just to clarify gtm is NOT the only company that builds 7AT at this point. As long as you go to any well known transmission shop they will do it for you. gtm is just the only one that puts on the website they specialize in it. BUT just because you specialize in something, doesn't make you good at it! lol. But again this is just IMO and from my past experiences with them. I wouldn't trust them with a 10 foot pole!

 

Please do share with everyone who else builds "stronger" 7AT's. Also, which companies sell stronger 7AT clutch packs, valve bodies, and such?

 

The internals of most transmissions (at least main parts) are for the most part universal for most parts as all these transmissions are made from the same people. For example the same people that make our transmissions make honda transmissions. Any shop that is trustworthy will install the upgraded parts which you can find from most parts dealers, or have them source out for you. I have used places in the past that give guarantees with their work (which gtm wont). For example I am up in Canada and there are places like aalltech who will do this work. They are not a specialized high performance shop, but they know what they are doing with transmissions and will install any performance mods you ask for.

All you need to do is call a transmission shop and ask if they will do installs of certain parts. Easy as that!

 

From all the info I collected when researching this topic I found that the 5AT is better for FI applications than the 7AT. There is a plethora of issues I've read people put about FI 7AT. You should get the trans rebuild regardless for longevity! GL with your choice and project!

 

Just go to Level Ten and have them upgrade your transmission. Their very knowledgeable and professional ask Coop. I will be going to them in the near future. I am equipped with the GTM Twin SC and GTM VB upgrade. By the way I've a 7AT.

 

Level Ten FTW, great customer service and they will keep their word, unlike other shops...