Some years back I did a cam swap on my 98 TA. I went with an MS4, LS6 intake, LT’s, true duals, Yank SS3800 in my stock 4l60e, and 3.73s. I always felt like that cam never ran like it should (now swapped to 228/233 112.5+4). I know it probably needed to breathe better but it still seems like the car doesn’t drive or pull like it should even with the new cam. I started a thread a long time ago about the MS4 making low power numbers on the dyno and it seemed like maybe the stall was the problem. So I just want to try and narrow it down one last time before I tear the thing apart again to see if it’s a stall problem, tranny problem, or that stall speed is just a little too loose for my taste. I made a few videos of “normal” city acceleration and WOT. I appreciate your thoughts.

Normal Acceleration





WOT

 

I did not watch the videos...

but...

Have you ever inspected what the cranking compression/ pressures are... performed a leak-down test???

You could put a camshaft into an engine that should make massive power...
But if the engine is not healthy... Ain't no power gonna be made.

Ever see a 10,000 HP engine make 2,000 HP because the valves/ springs can't keep the air/ compression in the chamber???

 

Your shift points are WAY too low !
You need to spin both those cams a whole hell of a lot higher than 6100 rpms.

Were you shifting the ms4 around 6100?

Here is my 239/244 112 lsa
4400 stall

 

OP I don't like that oil pressure gauge. Is that a stock oil pump and have you put a mechanical on it to see what you have for pressure?

 

It’s never been to the track. And it’ll probably never end up there. Just a street care at this point.

 

When the first cam went in, it went in a stock 2000 vette motor with 60k miles on it. It has maybe 61k on it now. The power problem I think was a different story....dyno’d with unlocked converter, maybe bad tune?, needed more mods, etc. New cam feels MUCH more powerful but the car doesn’t feel “daily driveable” like a lot of people with bigger stalls say are “daily driveable” or “streetable”. That’s what I’m trying to decide.

 

As far as I know shift points haven’t changed. Those pulls are with the tranny in D. The new cam is based off the cam motion titan 4. Just adjusted slightly to give a couple degrees more overlap. But my tuner acts like the RPM should drop more during shifts at WOT.

 

The oil pump was changed during the original cam swap but I don’t remember what was put in. To be honest the oil pressure was a little higher with the MS4. On the highway it reads between 30-40 psi.

 

There is a lot of slip in your converter. A LOT. You’re only dropping like 500 rpm between shifts and it’s taking a lot of throttle just to get the car rolling under normal driving. I had this happen with my chevelle and it was a bad converter.

Can your tuner look at how much converter slip you have? Because that’s just way too much imo. It’s slipping under normal driving conditions like it’s a 5000 stall lol.
I’ve got a FTI hard 4000 in mine and it drives way better than that, so I’d say you’re right on the converter.

 

This is actually the first stall I’ve ever had in any car I’ve ever owned. So I’ve never had anything to compare it to. But I’ve read about people daily driving 4k stalls and I’m like “if a 3800 is like this then I don’t see how people with 4k stalls are doing this all the time.” So I keep asking myself if I just have old man taste and don’t like a lot of slip 😀 or if I have a stall issue.

If the collective consensus ends up being that I have a bad stall then the next question is what speed to go with to match this new cam. It seems like 3600 is the magic number for most setups (including 228/232-ish cams).

 

I think something is wrong with the stall. My 4000 doesn’t slip like that at all. It does have slip but yours acts like it’s a 5000 stall vs a 3800. You should have some slip but no where near what you’re seeing. Plus the 500 rpm drop at wot is another dead give away you have an issue.

I think if you pull the stall out I’d call and see if Yank will rebuild it vs buying new. Those are nice converters so I’d fix the issue and it will have less slip plus it’s cheaper than buying another.

 

I just re-read your first post and it says you have a stock 4l60e. Is there a cooler on this thing? Not the factory one on the radiator but an external cooler?

You may be cooking that stall with high temps. A stock 4l60 also isn’t going to last forever with a stall converter either.

 

Yeah it put a tranny cooler on it when the stall went in. I bought the stall used here on the forum and it has always acted this way. The transmission isn’t exactly perfect anymore. Sometimes on the 2-3 shift you can feel a little thump. It was also doing that before I put the stall in.

My tuner mentioned the 500 rpm drop also. He said it should drop more like 1000 rpm. Does that sound right?

 

Yes, those shift extensions should be more around 900-1100 rpm drop.

 

At WOT are you shifting out of 2nd at 55 mph at wot ?
That's what I think im seeing in the video, just wanna make sure im right.

That's about 30% converter slip which is awful and means the converter is toast.
That converter should see around 8%

 

Yeah I'm not sure. That first drop in rpm is me letting off the gas because it's spinning so I'm not sure if it shifted from 1-2 during that but I would assume that first gear wouldn't pull to 55 right?

 

No, 1st gear would not come close to 55 mph

 

That's what I figured. So accelerating through 2nd gear feels to me like the car is spinning but it's really not, which I would think helps support your excessive slip theory. So since I'm looking at a restall does anybody have a recommendation for stall speed? It's a weekend car....won't be going to the track. 3200? 3400? 3600?

 

I would do the 3800. That converter when right combined with 3.73's will drive very nice.

You also need to look at spinning that motor higher, probably somewhere around 6700 rpms.

 

There's a dyno graph in this link (post #6). I'm assuming this was with an M6 but cam specs are nearly identical to mine. 3600 seems to be really popular but how much difference are we talking between 3600 and 3800...street or WOT?

https://ls1tech.com/forums/generatio...o-finally.html