Which servo?
Which servo? So i'm trying to figure out which servo to go with while doing my 4l60e build. I know sonnax makes good stuff but how is the PATC servos? They claim like 35% more holding power over corvette servos. Anyone have any experience with them?
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PATC doesn't make anything and IMHO over-promise and under-deliver.
If they aren't saying its a Sonnax, then it might be a cheap Chinese clone of the Sonnax.
The pro builders can confirm or correct me, but the Corvette servo with a good wide carbon band is all you need up to about 550HP. Above that get at least the Sonnax 2nd gear servo; add the 4th gear servo if the budge allows.
If they aren't saying its a Sonnax, then it might be a cheap Chinese clone of the Sonnax.
The pro builders can confirm or correct me, but the Corvette servo with a good wide carbon band is all you need up to about 550HP. Above that get at least the Sonnax 2nd gear servo; add the 4th gear servo if the budge allows.
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http://www.sonnax.com/parts/2473-4th...dual-servo-kit
Unless you a towing a trailer with a truck or track racing above 120 MPH, I would install the billet 2nd gear servo before the 4th gear servo because you will rarely be even close to WOT in 4th gear.
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Yeah see i dont want it to be too harsh under part throttle just a nice firm bump, i think i'm gonna see how the stock reacts after all the tranny upgrades and hd2 shift kit then make a decision, thanks for the input anyway
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As pro builder GMCSIERRA suggests, use at most one washer.
PBA (Dana) suggests using zero. Drilling the feed hole bigger will firm up the shift without the "slam" that can break parts.
Now that I am running correct fluid levels mine shifts nice and firm with the Corvette servo. I could actually hear the tires getting a scratch on the 1-2 and 2-3 at the track last Friday and that's on a Hoosier DOT radial.
Alto Red low clutches
Borg Warner 3/4 clutches shimmed on the tight side
wide carbon band
Trans Go HD2 kit (admittedly drilled on the large side as I didn't realize I had a fluid level issue starving the trans, not a feed issue)
Sonnax HD 2-3 shift valve
Trans Go high RPM pump kit
PCM is tuned to max line pressure at calculated torque of 300ft/lbs and higher
The car is making 438rwhp with the converter unlocked and a bit lean. I think now that its tuned it would make 445rwhp or so.
Does the billet servo serve any other purpose if the GM servo is not showing signs of weakness?
Alto Red low clutches
Borg Warner 3/4 clutches shimmed on the tight side
wide carbon band
Trans Go HD2 kit (admittedly drilled on the large side as I didn't realize I had a fluid level issue starving the trans, not a feed issue)
Sonnax HD 2-3 shift valve
Trans Go high RPM pump kit
PCM is tuned to max line pressure at calculated torque of 300ft/lbs and higher
The car is making 438rwhp with the converter unlocked and a bit lean. I think now that its tuned it would make 445rwhp or so.
Does the billet servo serve any other purpose if the GM servo is not showing signs of weakness?
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Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
