Well I've came into a bit of a predicament. I have 2010 hhr ss auto. Now i know the first thing is well sell it and buy a manual. Here's the thing I got one hell of a deal on it to the point to wear buying a manual I'd be loosing money, a lot of money. So my question is do I attempt to build the auto trans. Spend 3k on that or do I go the prove route and do a 6 speed swap roughly 5k. So I'd like to hear everyone's input on this subject. Both trans have there plus side I just can't decide on what in the end will be the best route. Thanks for your guys opinions.

 

a built 4t45e will hold ALOT more power then a 6 speed swap will.

 

That's what I was thinking to but I haven't found anyone who has a built one or knows where to get a built one. I love driving stick but the auto will be faster at the strip. And remote start is awesome lol. However I can't find a reliable 4t45 that can handle 450hp and 400wtq. That's why I'm considering the 6 speed.

 

There's a local place here in NJ called precision transmission in cinnaminson nj that can do a built 4t45e no problem, they did my buddys 4t65eHD and that trans was amazing when it was done. ZZP also sells a built 4t45e on their site but its very expensive, i think to the tune of just under 3 grand.

 

ZZP uses a 4t65e HD Ryan's cobalt, atleast in this video.

 

I used to work at zzp lol. While zzp makes great stuff and those guys do great work I feel that the 4t45e in my eyes is underdeveloped there they do have a better trans but for 3k it can only support 400whp. I need something that would be bulletproof. Swapping it to a 4t65e is out of the question cost on that would be ridiculous like 10k ridiculous. I would definitely like some info on that place in NJ if anyone has any more.

 

For your goals and if they're available, I think a Powell built 4.45 lsd would be your best bet for around 2k. I found one used for only $1550 and I'm going for 600+whp lol

 

This is something ive been curious about, is the 4t65e case the same dimensions as the 4t45e?

 

Where exactly did you get the 400whp rating? Automatic transmissions are rated in torque capacity not horsepower. lol and the 4t45e is rated at 325 ftlbs of gearbox torque from the factory, i dont see why it wouldnt support at least double that with all of the modifications readily available for the 4t45e.

Here is the info for precision trans.

Precision Transmission Of South Jersey

 

I understand transmissions are rated in tq the highest we had a trans go to when I worked at zzp was 400hp that's why I said 400hp I don't remember the tq. and I would do the Powell 4.45 but I still have to get a clutch pedal assembly, clutch and flywheel, master cylinder and lines, center counsel and shifter assembly. So that in theory makes it about 4k at least. I'm gonna call precision and see what they say. Like I said I'm not sure what upgrades there are for the 4t45 and haven't heard of anyone making over 400wtq reliably.

 

This is the route I am going but when will Powell have them ready?!?!

 

Need instal details.

 

The 4t65 is heavier. The input shaft on the 4t45e is a huge weak point, and it is actually cryo treated from factory from what I understand and one HHR owner has snaped one during a burn out. If they can't offer a better input shaft, then u are playing with fire for sure

 

I was never able to get ahold of them... but there are 2 guys ik of on the hhr forum who have 4t45s and they're holding up well. One is on e47 and an intake down pipe. He's been putting down 1.8 60fts on slicks and running low 12s for years. The other guy has just put a s256 kit and hasn't had any problems yet he should be around 380-400 whp.

 

Dave is the one with 12.3 1/4 mile and 1.8 60' on 15" M&h slicks. He dialed back the power now in fear of tranny failure. He said the only things you need are different fluid(can't remember which) and reduce shift times via HPT. That setup should be good for around 400ft lb for a while if not abused. I'm sure his car would dyno in the 400+ TQ range since he brings in the boost super quick in the K04.

George with the s256 is tuned by term2 and his setup is still relatively new. No track results yet. It's mostly a show car right now.

Edit...that moment you realize this thread is a year old

 

Lol yeah this thing is old. Dave said he runs valvoline full synthetic dexron.

my plan right now is to get to as high of hp as I can while keeping tq around 380ft lbs then trying to find a wrecked wagon to gut and do a manual swap.