3100 small port.

[Oedwards]

I have a 94 3100 swapped in my 95 cavalier. It pulls nice up to 85 mph, but from there it feels like it's dead. It's completely stock, so I know that has a big part to do with it but 85 just seems like a pretty low drop off point..

4t60e trans btw.

What benefits these 3100's the best? what would make it pull harder, and higher?

[Nick-G]

3400 top swap.

[98goldZ]

3400 top swap.

i have most of that if interested....

[1988GTU]

I have big ports lower intake. 20.00 for local pick up. Will ship for extra charges.

[IsaacHayes]

Keep in mind if you only do the LIM on up, you will need to grind the LIM to clear the rockers. 94 did not get roller rockers and will hit the LIM. I had to grind mine. And 94 do not have notches in the head to swap to the roller fulcrum rockers.

[Superdave]

judging your top end flow by a "felt" dropoff at 85 MPH (which is 10 above the highest limit in the US) is pretty in-accurate.

My old 2.8/TH125 cavalier would do 120 easy and those heads flow much worse than yours.. lol


What RPM is the car at when you feel the loss of power?

[IsaacHayes]

Dave, the 4T60-E is geared horrible. At 85mph he is shifting into 3rd gear at 3450 RPM or already there. (trans shifts 2-3 at 5400 stock. 1-2 is higher though) Going to a big-port intakes/good exhaust and it will help, even at that "low" RPM and high load.

I know mine gets there faster than stock and the momentum by accelerating faster seems to help when it does upshift and "bog" down.

[robertisaar]

aren't the 125 and the 4t60e geared the same?

just that the shift points suck?

[IsaacHayes]

Nope.

4T60-E
FDR - L body 2.94, W body etc 3.29-3.33. N body quad4 3.73? N body 3100 2.94
Gears:
1 2.92:1
2 1.57:1
3 1.00:1
4 0.71:1

TH125C 3T40
FDR (L body) 3.18 don't know other apps.
Gears:
1 2.84:1
2 1.60:1
3 1.00:1

top of 2nd, 85mph vs 78mph for L/N body FDR.

Similar. I thought the 2nd gear was far different, but from this info I found looks like mainly the FDR was better.

[robertisaar]

so the gearing is certainly close, but the FDR ciuld be WAY different...