95 Chevy 355 TBI Build

[Roadknee]

Last night when I was driving around (highway cruise) it kept locking on me at low rpms 1000 to 2000 whenever I would roll into throttle. I would have to let completely off throttle, then roll in too throttle fast to get it to tach up and not lock. The scenario you just explained sounds like what was happening to me? Correct me if Im wrong.

The stock trans tune locks the converter at light throttle above 40.5 mph in third and OD, releases at 39 mph light throttle, and unlocks at no throttle. I bumped those up quite a bit in my tune with a stock LO5, and you'll probably need to do the same. You might consider acquiring an Autoprom so you can do some of the trial and error fine tuning yourself after Dave gets you a drivable tune. It's pretty sweet to be able to make a small change, and change it back if you don't like with a few keystrokes and without burning/changing chips.

[Roadknee]

This is rebuild kit I used:

http://www.oregonperformancetransmission.com/mm5/merchant.mvc?Store_Code=OPTI&Screen=PROD&Category_ Code=4L60E&Product_Code=ORE-4L60E-RBHP

I did use Sonnax Performance Pack:

http://www.oregonperformancetransmis...NX-HP-4L60E-01

Sonnax Servo's I used:
http://www.oregonperformancetransmis...ode=SNX-77767K

http://www.oregonperformancetransmis...=SNX-77911-03K

The converter is fairly loose, but is still good for DD, does get cam in power band just fine, so far no failures, and was not by any means being easy on it, good converter for the money.
Link:
http://www.revmaxconverters.com/index.php/4l60e.html

I used a 1995 TransGo separator plate, I called dealership and asked about a factor one, they said it was discontinued. I did eliminate PWM.I plugged the PWM hole with the little plug that was in Sonnax kit. In the Sonnax Performance Pack you can choose how big you drill the holes in the separator plate for different levels of shifts, of course being a young dumb kid I drilled them to maximum performance which was .094. The shifts are tolerable for me, they are solid/harsher under throttle/load. I wouldn't recommend drilling that big if you like shifts that are soft. The parts in Sonnax kit and Servos are very high quality trick looking pieces. Very well laid out to in bags labeled for trans. I would recommend reading directions twice over they are confusing in some parts (unless you are a trans guru). IMO to get full potential of the aftermarket parts you need to tune the transmission. Dave changed parameters and it is getting way better.

Thanks a lot for that info. My stock 1995 4l60E has nearly 160k. We're going to rebuild it as a matter of preventative maintenance. I probably won't install as many high end parts as you did since my power levels are lower and I don't care for harsh shifts.

[dave w]

Re-did Logs after I installed new TPS. I think those are the correct xdf. and adx. files to few logs on TunerPro RT. Let me know if they are not. There are daily driving, starting, idle, highway cruise, and WOT data logs, all on 87 octane (if that matters). Opinions or advice is welcomed.

Also, I'am a rookie at this. Dave from Old School EFI has helped me tremendously with this. Thanks again Dave!

Max

Attached is the "Sorted" Excel spreadsheet that combines all the data logs from the previous post. I sorted out AE, PE, and Open Loop. Near Idle is 3 MPH or less / 2.7% TPS or less. Some areas in the "Sorted" Excel spreadsheet are rich / lean, which indicates the injector flow parameter in the chip is accurate.

dave w

[dave w]

The stock trans tune locks the converter at light throttle above 40.5 mph in third and OD, releases at 39 mph light throttle, and unlocks at no throttle. I bumped those up quite a bit in my tune with a stock LO5, and you'll probably need to do the same. You might consider acquiring an Autoprom so you can do some of the trial and error fine tuning yourself after Dave gets you a drivable tune. It's pretty sweet to be able to make a small change, and change it back if you don't like with a few keystrokes and without burning/changing chips.

355chev has an Ostrich 2.

dave w

[Roadknee]

I looked through your 80 mph datalog a few times and compared it to a WOT log from my stock 160k mile 1995 K1500.

My engine rpm went from 4,600 rpm to 2,800 rpm on the 1-2 shift. In comparison, yours went from 4,425 rpm to 3,200 rpm on the 1-2 shift. Given our 4L60E gear ratios are the same, you have a lot more slippage going on. I'd guess it's your higher stall converter, but you may want to sniff the trans fluid just in case.

My truck pulled from 2,800 rpm in second gear to 4,500 rpm in about 7 seconds. Yours pulled from 3,200 to 4,350 in about 6.5 seconds. It would have been more accurate to look at mph, but in general performance between out trucks is about the same right now.

Your o2 voltage is around 800 mv which I think is too lean for WOT. You're also only running about 18 degrees total timing (assuming you've set base timing to 0 degrees at the crank with your timing light). It may not tolerate much more with 87 octane fuel and your compression ratio. I'd run 92 octane to get the most out of that engine. You should be able to run 25 degrees WOT ignition lead. More ignition and more fuel should make it come alive.

[dave w]

Your o2 voltage is around 800 mv which I think is too lean for WOT. You're also only running about 18 degrees total timing (assuming you've set base timing to 0 degrees at the crank with your timing light). It may not tolerate much more with 87 octane fuel and your compression ratio. I'd run 92 octane to get the most out of that engine. You should be able to run 25 degrees WOT ignition lead. More ignition and more fuel should make it come alive.

See attached Excel Spreadsheet for (combined all data logs posted) Knock Retard Analysis greater than 2 degrees.

dave w

[355chev]

355chev has an Ostrich 2.

dave w

This product is an excellent investment. Im glad Dave recommended it, works great with the long distance, instead of waiting for chip in mail!

[355chev]

I looked through your 80 mph datalog a few times and compared it to a WOT log from my stock 160k mile 1995 K1500.

My engine rpm went from 4,600 rpm to 2,800 rpm on the 1-2 shift. In comparison, yours went from 4,425 rpm to 3,200 rpm on the 1-2 shift. Given our 4L60E gear ratios are the same, you have a lot more slippage going on. I'd guess it's your higher stall converter, but you may want to sniff the trans fluid just in case.

My truck pulled from 2,800 rpm in second gear to 4,500 rpm in about 7 seconds. Yours pulled from 3,200 to 4,350 in about 6.5 seconds. It would have been more accurate to look at mph, but in general performance between out trucks is about the same right now.

Your o2 voltage is around 800 mv which I think is too lean for WOT. You're also only running about 18 degrees total timing (assuming you've set base timing to 0 degrees at the crank with your timing light). It may not tolerate much more with 87 octane fuel and your compression ratio. I'd run 92 octane to get the most out of that engine. You should be able to run 25 degrees WOT ignition lead. More ignition and more fuel should make it come alive.

My initial base timing is give or take alittle 8.1 degrees advanced with ESC unplugged. Trans fluid smells good, not burnt, I dont know why that would be, I assume converter slips maybe at that point in time because its not a high end one? Not sure.

[355chev]

Thanks a lot for that info. My stock 1995 4l60E has nearly 160k. We're going to rebuild it as a matter of preventative maintenance. I probably won't install as many high end parts as you did since my power levels are lower and I don't care for harsh shifts.

I would recommend the Sonnax Performance Pack, you still can get smooth shifts. IMO