Big turbo and cams on an automatic
Thread Starter
Senior Member
Joined: 05-02-2014
Posts: 227
From: Oshawa, Ontario
Big turbo and cams on an automatic
I have an '09 automatic and I plan on installing a .63a/r gt2871r and cams in my hhr. The cams are machined Equinox cams with a larger fuel lobe. First question, since it's an automatic and holds boost during shifts, a VTA blowoff valve wouldn't hurt performance, would it? Second question, the cams are equivalent to ZZP stage 2 cams with the bigger lobe, I need valve springs, right? Third question, I figure I'll be close to 400whp and I have no idea what the torque will be like, will the transmission hold up? I have the TTR motor mount, would a decent trans mount help protect my trans from breaking?
Thanks
Thanks
Deceased
Joined: 06-30-2010
Posts: 25,739
From: Kannapolis NC
Per GM....
2009 Hydra-Matic 4T45 Transaxle ( MN5 ) Prduced from 3/18/2008 onward.
Type: four speed front-wheel-drive, electronically controlled, automatic overdrive transaxle with electronically controlled torque converter clutch.
Engine range: 2.2L - 3.5L
Maximum engine torque: 221 lb-ft (300 Nm)
Maximum gearbox torque: 325 lb-ft (440 Nm)
Gear ratios:
First: 2.95
Second: 1.62
Third: 1.00
Fourth: 0.68
Reverse: 2.14
They'll take 300+ hp reliably, 400 hp and above may require some beefing up of internal components.
Try a Google search on Performance Hydra-Matic transmission builders.
2009 Hydra-Matic 4T45 Transaxle ( MN5 ) Prduced from 3/18/2008 onward.
Type: four speed front-wheel-drive, electronically controlled, automatic overdrive transaxle with electronically controlled torque converter clutch.
Engine range: 2.2L - 3.5L
Maximum engine torque: 221 lb-ft (300 Nm)
Maximum gearbox torque: 325 lb-ft (440 Nm)
Gear ratios:
First: 2.95
Second: 1.62
Third: 1.00
Fourth: 0.68
Reverse: 2.14
They'll take 300+ hp reliably, 400 hp and above may require some beefing up of internal components.
Try a Google search on Performance Hydra-Matic transmission builders.
Senior Member
Joined: 11-05-2011
Posts: 417
From: simi valley CA.
if you email zzp they may give some advise. I know there's company right now that will go through the trans and gears put a bigger torque converter and make it a 3 speed. I read the article and was empressed, it can handle a lot more HP. I would definitely get a good trans cooler, like this one,
Transmission Rebuild Components & Cooling - MAPerformance
Tim
Transmission Rebuild Components & Cooling - MAPerformance
Tim
Senior Member
Joined: 04-26-2009
Posts: 669
From: City of Champions
Walking the fine-line, between massive torque / massive destruction...
Not for the faint of heart...
But the 4t45e, handles it well, just as strong today, as it was 5 years ago...
Senior Member
Joined: 02-19-2010
Posts: 1,529
From: Buffalo ny
The guy that rebuilt my auto trans (planetary gear blew up) at 66,000 didn't seem to think it was built to handle the tune....When I told him it was tuned and probably close to 300 lbs/ft of tq he was sure that was the cause...I also have no changes to the transmission with my tune....so that could have been my problem?
Thread Starter
Senior Member
Joined: 05-02-2014
Posts: 227
From: Oshawa, Ontario
You have the automatic? What turbo are you running? I know a small T3 isn't very easy on the transmission because it's so snappy.
Thread Starter
Senior Member
Joined: 05-02-2014
Posts: 227
From: Oshawa, Ontario
The guy that rebuilt my auto trans (planetary gear blew up) at 66,000 didn't seem to think it was built to handle the tune....When I told him it was tuned and probably close to 300 lbs/ft of tq he was sure that was the cause...I also have no changes to the transmission with my tune....so that could have been my problem?