b4c01

Hey guys, Im trying to help out my best friend that has no internet, computer, smartphone etc...

He drives a 2001 Camaro (z28?) B4c, Ls1 (ls6 intake mani?) With just an Slp cold air duct/lid with K&n filter and Slp loudmouth exhaust, and rebuilt 4l60e automatic transmission. Ran a 13.2 at the track last weekend.

Anyways, almost 2 years ago his stock 150k mile 4l60e died after tons of abuse and had a local "auto trans specialist" rebuild a lower mileage used 4l60e for him.
During the rebuild he installed a Transgo shift kit and upgraded clutch packs and bands.

We recently went to the local dragstrip and he ran a 13.2, at I believe 106 mph and a 1.9x 60ft. His only complaint is the 1-2 shift and kind of the 2-3 shift from time to time. it doesnt seem to shift as quick or firm as it should and kind of bounces off the limiter for a second before shifting. So he is looking into other mods for his 4l60e to help with his 1/4 mile times (short of a high stall converter for now, one day though)

He asked me about the Corvette servo, which I remember reading helps make the shifts quicker and firmer while helping the transmission "hold" more power or torque. But I also kind of remember hearing that all v8 Camaros with the 4l60e came with the "Corvette" servo, and that the Vette servo is only really an upgrade for v6 camaros, trucks etc.

Is that true? Or is the "Vette" servo still an upgrade for him?
How else can we help make the shifts quicker and firmer so it doesnt "bounce" off the limiter between 1st and 2nd?

We are going to change his atf again and install a B&m atf cooler sometime soon and were looking to do the servo at the same time, if it is actually an upgrade for his Camaros 4l60e.

What does everybody think of the Jet Power Shift? http://www.summitracing.com/parts/je...FSRo7Aod6BYA_g

His 4l60e was just rebuilt with a "performance rebuilt kit" with upgraded clutch packs/steels and bands, and a Transgo shift kit. We just want the 1-2 and maybe 2-3 shifts firmer, quicker and more positive so it doesnt bounce between shifts.

Thanks Guys!

01ssreda4

iTrader: (96)

Yes, all fbody v8s got the vette part numbered servo. If his trans is still in good working order it sounds like he may need a good tune with hptuners. Getting the auto trans tuned properly can make a world of difference.

mrvedit

While all factory F-body 4L60E include the "Vette" servo, it is possible that the rebuilt unit does not.
I would try things in this order:
1. Overfill the trans by 1/2 quart. This often helps a lot with the stock shallow pan.
2. Confirm that the trans has the .500 boost valve; the Transgo HD2 kit includes this, but maybe something else was installed. This is easy - search this forum for "boost valve" and "mrvedit". (Sorry no time now to give details.)
3. While the pan is off, remove the 1-2 accumulator to check it - post a picture of what you find. This will tell us what shift kit is installed. The HD2 kit has optional washers, but even one washer gives you an extremely firm shift, especially with a stock converter.
3. Consider having a tuner decrease the "WOT Shift MPH". This needs to be done for any higher-stall converter. Decrease it by 5-10%; the stock tune makes it much more "precise" than it needs to be. The tuner can also increase the shift pressure to firm up shifts.
4. You could check for the Vette servo, but it is hard to get the servo out of most cars due to clearance - you have to significantly lower the trans to get it out.

If it still hits the rev limiter after that, the trans is likely worn out.
(This is just a quick summary - gotta go.)

mrvedit

Yeah, as 01ssreda4 says, getting a tune is the best first step, assuming you have access to a tuner. However, since a lot of people don't know where to find a tuner and/or pay for one, I made it a later step. There are excellent mail-order tuners (check this forum - tuning section). Or tell us where you are located; maybe someone will volunteer to help.

b4c01

We are both fairly sure his 4l60e is not worn out, as it was just rebuilt not even 15k miles ago a reputable auto trans guy, and the trans works perfectly fine - we would just like the 1-2 shift to be a little better.

My friend, the owner of this car, somehow knows the builder. He owns his own auto trans shop, and owns a few built Gm's. He seemed very knowledgeable and knew what he was doing. He was the one that suggested doing the Transgo shiftkit while he was rebuilding it, and mentioned using some alto uprated clutchpacks,steels and bands while doing it. There was no mention of any servos, of if the new 4l60e that was about to be rebuilt was from a Camaro/trans am or truck or not, so Im not sure about the servo.

Are there any good servo's that would be good use in this trans to replace the stock vette servo?

Would the Jet power shift be of use? http://www.summitracing.com/parts/je...FSRo7Aod6BYA_g

What ways can we tune his engine and transmission short of taking it to a pro tuner?

01ssreda4

iTrader: (96)

The handhelds can alter some trans stuff, but im not sure what exactly as Ive never fooled with them. HPTuners or EFILive is your best bet, to keep cost down you could get a mail order tune.

b4c01

Yeah I have seen a few handheld devices for his car to "tune" the engine, and most seem to say they can alter the auto trans as well, Kinda curious about that Jet piece that only controls the trans instead of both engine and trans.

Also, I know I should ask which handheld "tuner" is the best, but, which is the best for an automatic 4l60e 2001 Ls1 Camaro that can "tune" both the engine and auto trans?

I know a REAL tune is always better than any off the shelf, out of the box generic "tune", but my buddy said he doesnt want to pro tune his car until he gets a cam, but, he IS interested in a handheld device that comes with "performance tunes" on them, can adjust some engine parameters and can adjust the auto trans shift points and firmness and line pressure.

01ssreda4

iTrader: (96)

Diablosport I think is the best handheld last time I did any checking.

mrvedit

That Jet Powershift looks like a $150 bandaid. Save your money for a real solution.
Isn't a Diablosport like $450? Expensive for its limited capability.
For $650 you can get HP Tuners or EFI Live and can then install any existing tune from their libraries, or of course learn to tune it yourself. Not just the trans, but later the engine.

I would suggest hooking up a pressure gauge to your trans and taking it for a drive to see what the pressure is when it shifts. Anything else and you (and any experts) are just guessing. You can buy one on Amazon for $32 - search "ATD 5550".

murphinator

iTrader: (2)

it sounds like the low fluid issue and/or combined with the tripping the limiter due to manually shifting instead of leaving it in O.D. (mrvedit could explain it better but out of od shift position utilizes more fluid capacity. If it doesn't do this on the street but only at the track where your likely hooking up better and "stacking" the fluid at the back of the trans then adding more atf will likely cure your issue.

you should be able to find someone in your area with hp tuners even if they aren't f body guys ...when I was into modding supercharged w bodies I did some tuning on friends ls1 Camaros before I owned one myself.

You can also pick up used hp tuners on w body boards for $400 or less but realize a new standard hp tuners is only $500 its the pro that is $650 and the new units come loaded with 8 credits worth $50 each so if theres none or only 2 credits left on a used unit vs a new one with 8 credits for $500 the new is the better deal .

NEVER pay anywhere near $400 for any handheld!!!!

Having a tuner also opens up the door to a type of enhanced mail order tune where you can send an hp tuners scan file along with a tune file and the remote tuner can review the scan data and make changes to the tune file based on the scan vs an educated guess then send another scan to see if it needs to be touched up or any time you mod further.

Dropping the wot mph threshold so it only needs to meet the desired rpm is also a great idea (mrvedit again lol) then if you have your own tuner you can tweak it from there.

01ssreda4

iTrader: (96)

^^All good info.

b4c01

I know a pro tune be it on a dyno or a street tune by a legit tuner using a real deal tuning software would be ideal, but we are not looking to pro tune just yet with just bolt ons, but absolutely when a new cam and stuff goes in.

Right now the car only has Slp lid/cold air duct and Slp loudmouth exhaust, and a rebuilt 4l60e with Transo shift kit.

All we are looking to do right now is make the 1-2 shift quicker and firmer without bouncing a few times before shifting. It shifts much better after the rebuild/shift kit, but there could still be an improvement in the 1-2 shift.

If there is a good transmission "tuner" (Jet power shift, B&M shift plus etc...) that is probably exactly what we need to hold us over until cam/protune later down the road. If all of these transmission "tuners" are junk, and the more expensive handheld engine/trans tuners (HP, Diablo etc...) are better in regards of adjusting the transmission with the added benefit of slightly tuning the engine ecu, that would be good too.

Just really need suggestions, as I really know nothing about these transmission tuners and handheld tuners, other than the Cobb Accessport (for my Wrx) and the Shark Injector (my old bmw e36) and having my old honda pro tuned with Hondata.

What is the "best" transmission tuner/ shift improver?
If they all are junk, whats the best handheld tuner for this car in regards to the auto trans?

And is there a servo that is an "upgrade" for vette servo equipped a/t's that would help the 1-2? and possibly other shifts?

mrvedit

There are upgraded servos available - the Sonnax 2nd gear servo #77911-03K is probably the best: http://www.sonnax.com/parts/2486

However, I know that I can make the Transgo HD2 shift kit with the Vette servo perform a 1-2 shift extremely hard. Way to hard for my liking that breaks the tires loose each time.
One question you have to ask yourself is, would you purposely hit your transmission gears, u-joints, driveshaft and other parts with a sledge hammer? No? Then don't aim for harsh shifts either because that is exactly what harsh shifts are doing to your drivetrain. Obviously I would need to "feel" if your shifts are too-soft, properly firm or parts-breaking harsh.

It could be that your band is worn or bad. Start by measuring the servo end play: while holding a small ruler near the servo, use a crow bar to press in on the cover. Estimate how much it moves. Much over 3/16" indicates the band is worn and that will slow down your 1-2 shift and soon cause it to slip.

You are getting good advice here on tuning and tuners. Consider that 01ssreda4 has over 19,000 posts. We have seen too many people here try to save money with inferior products and in the end having to throw all that away and buy what she should have, and which we suggested, in the first place. And that is the best scenario, the worst is that the inferior products cause thousands in damage and take months to repair.

So either, get a mail order tune now, or safe up for HP Tuners or EFI Live.
I do highly suggest you to determine the servo end play and let us know.

bbond105

Has it been determent for sure if it has the Vette 2nd gear servo? It not the only way to know for sure is to ask the builder or remove and verify. I agree with the Transgo HD2 the trans should be shifting pretty good even without the Vette servo.

I don’t think a servo change will make it shift faster, just harder. As Mrvedit says the band could be worn and that needs to be checked and if within specs your problem is most likely with your tune. Most mail order tunes are around $150 which is way cheaper than a hand held. If you go the mail order route call the tuner and tell them what is going on with your shifts. They can increase the line pressure which will firm up the shifts and adjust your shift RPM and MPH.

jrzdude

iTrader: (4)

I'm having a similar issue. Takes forever to shift. I'm spraying a 125 shot though and it only happens if I'm spraying (not spraying through the gears, shuts off 200 rpm before shift) Tuner says my line pressure is maxed, but he kept 50% torque management. Could it be the Torque Management or would I benefit from installing a billet 2-4 servo? Any help is greatly appreciated. I've been dealing with this for a while now

sorry for the jack

01ssreda4

iTrader: (96)

IMO, the torque management needs to be deleted. If it hits the limiter on spray but not on motor, then the tune likely needs to be tweaked.

kinglt-1

iTrader: (26)

You might need to lower your commanded shift mph for the power increase because the motor is revving faster. Proper trans tuning is very critical for keeping the 4l60 alive. Get rid of the Torque management, get a shift kit, and a cooler.