Interesting cam question
05-20-2020, 09:19 AM
#2
100% Redneck
I'd think the dynamic compression would be to high closing the intake to soon with your high static 12.5 CR. In a lower compression build it helps with bottom end torque. My "little chopper" has a intake closing 36* ATDC and the cams recommended static compression is 10.5 and lower.
The following 2 users liked this post by RedXray:
00pooterSS (05-20-2020),
swathdiver (05-20-2020)
05-20-2020, 02:12 PM
#3
Should be a pretty big difference, yes.
If you look at cams for trucks, and cams for cars. You'll usually see truck cams have around 33-35 IVC and cars around 40-42.
And if you've ever talked to someone that put a LS6 cam in a truck they say they can't stand it and it's slower than the truck cam because it lost so much low end.
HOWEVER redxray made a really good point, you'd REALLY need to check up on your DCR to make sure it'll fly. And you'd absolutely need to run 93 IF that is even enough.
AND with your stall converter I don't think it would really be worth it. You'd be shifting torque down lower to pick up in the 2k ish to 3k range vs peak being closer to 4k. I'm no cam guru, this is my best estimation from doing lots of reading things people much more experienced with this than I am.
I'd put a call in to cam motion and discuss with them and see what they think. Your 41 with 12.5:1 may be about as low as you can go..
If you look at cams for trucks, and cams for cars. You'll usually see truck cams have around 33-35 IVC and cars around 40-42.
And if you've ever talked to someone that put a LS6 cam in a truck they say they can't stand it and it's slower than the truck cam because it lost so much low end.
HOWEVER redxray made a really good point, you'd REALLY need to check up on your DCR to make sure it'll fly. And you'd absolutely need to run 93 IF that is even enough.
AND with your stall converter I don't think it would really be worth it. You'd be shifting torque down lower to pick up in the 2k ish to 3k range vs peak being closer to 4k. I'm no cam guru, this is my best estimation from doing lots of reading things people much more experienced with this than I am.
I'd put a call in to cam motion and discuss with them and see what they think. Your 41 with 12.5:1 may be about as low as you can go..
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swathdiver (05-20-2020)
05-21-2020, 11:15 AM
#5
I hear ya. I think you have enough motor, compression, and cam to have good low end already. If I remember right you have a 370? If so you should have fairly high DCR with that 222/224 cam and 12.5 SCR. That's just a guess though.
I may be wrong, but I'm having a feeling you're wanting a little more low rpm grunt, if so, the converter may be really what you need to change, due to it being a bit sloppy in low rpm's causing it to feel weak in that area.
I may be wrong, but I'm having a feeling you're wanting a little more low rpm grunt, if so, the converter may be really what you need to change, due to it being a bit sloppy in low rpm's causing it to feel weak in that area.
05-21-2020, 11:34 AM
#6
I hear ya. I think you have enough motor, compression, and cam to have good low end already. If I remember right you have a 370? If so you should have fairly high DCR with that 222/224 cam and 12.5 SCR. That's just a guess though.
I may be wrong, but I'm having a feeling you're wanting a little more low rpm grunt, if so, the converter may be really what you need to change, due to it being a bit sloppy in low rpm's causing it to feel weak in that area.
I may be wrong, but I'm having a feeling you're wanting a little more low rpm grunt, if so, the converter may be really what you need to change, due to it being a bit sloppy in low rpm's causing it to feel weak in that area.
I can't decide how low of a converter to go. CircleD's 265mm triple disc can go as low as 2500 I think but I'm wondering if I should go lower? The only way to go lower is their 310mm converter but they don't offer a triple disc.
05-21-2020, 03:18 PM
#7
I once bought a converter used for my SS because I thought it was a bad *** yank with low miles for cheap..ish. It was a PYE 3400, what I didn't know is it was spec'd for a 800+ hp blower car. So it would only stall to a max of 2500. It felt really close to stock. And I hated it. It was a hair better than stock though.
In my current truck, the stock converter will actually stall as high as 2400 or so before breaking the tires loose. So I imagine it will flash higher than that, and it feels stock, because it is lol, and I could bear a little bit more converter.. however that being said, I can tell a major difference in this trucks low end and jump off the line that my 04 with it's stock converter that stalled at 1200. So 2500 would probably be decent, but I'd probably lean toward a tight 2800-3000. Or loose ish 2500. If you smell what i'm cooking.
Before you do that though, have you considered bringing the lock up speed down lower and changing the throttle percentage to a lower percent so it locks up at lower rpm and speed? I did that with my camaro and it helped out quite a bit. But a loose stall will always be a loose stall and the above is really just a bandaid.
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05-21-2020, 04:23 PM
#8
I don't know for sure what you should pick but here's a couple of things I can tell you.
I once bought a converter used for my SS because I thought it was a bad *** yank with low miles for cheap..ish. It was a PYE 3400, what I didn't know is it was spec'd for a 800+ hp blower car. So it would only stall to a max of 2500. It felt really close to stock. And I hated it. It was a hair better than stock though.
In my current truck, the stock converter will actually stall as high as 2400 or so before breaking the tires loose. So I imagine it will flash higher than that, and it feels stock, because it is lol, and I could bear a little bit more converter.. however that being said, I can tell a major difference in this trucks low end and jump off the line that my 04 with it's stock converter that stalled at 1200. So 2500 would probably be decent, but I'd probably lean toward a tight 2800-3000. Or loose ish 2500. If you smell what i'm cooking.
Before you do that though, have you considered bringing the lock up speed down lower and changing the throttle percentage to a lower percent so it locks up at lower rpm and speed? I did that with my camaro and it helped out quite a bit. But a loose stall will always be a loose stall and the above is really just a bandaid.
I once bought a converter used for my SS because I thought it was a bad *** yank with low miles for cheap..ish. It was a PYE 3400, what I didn't know is it was spec'd for a 800+ hp blower car. So it would only stall to a max of 2500. It felt really close to stock. And I hated it. It was a hair better than stock though.
In my current truck, the stock converter will actually stall as high as 2400 or so before breaking the tires loose. So I imagine it will flash higher than that, and it feels stock, because it is lol, and I could bear a little bit more converter.. however that being said, I can tell a major difference in this trucks low end and jump off the line that my 04 with it's stock converter that stalled at 1200. So 2500 would probably be decent, but I'd probably lean toward a tight 2800-3000. Or loose ish 2500. If you smell what i'm cooking.
Before you do that though, have you considered bringing the lock up speed down lower and changing the throttle percentage to a lower percent so it locks up at lower rpm and speed? I did that with my camaro and it helped out quite a bit. But a loose stall will always be a loose stall and the above is really just a bandaid.
Now once I’m up to speed, which really doesn’t take long, I lock 4th up at 50.
If I need, I pull down to 3rd and it locks and I can pull a decent grade and 60-65.
05-22-2020, 10:43 AM
#9
Hey @00pooterSS -
What if I swap the rear gear from 3.90 to a 4.56 with 34in tires?
I have the 80e and final drive ratio of .75.
At 75mph I come up with around 2600 RPM.
What if I swap the rear gear from 3.90 to a 4.56 with 34in tires?
I have the 80e and final drive ratio of .75.
At 75mph I come up with around 2600 RPM.
05-22-2020, 11:53 AM
#10
TECH Junkie
When I had my turbo truck and 4l60 I had a loose 3k that I could get 4400 out of in boost. I hated it because it was lazy as hell unless you nailed it. Had it tightened to about 2500 and it became very responsive then with light throttle. Obvious I know but I liked it a lot better. I could still push through it when I wanted to. I hate a loose one for a Daily.
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00pooterSS (05-22-2020)