Originally posted by Mike Rietow: [QUOTE]Originally posted by ts393c: Only reason for asking is. I never felt the car ran as good as it should. 6.40 3500# car. It works good and deadly consistent.
That's not bad for what you have. It's really a max effort in between nitrous / N/A.
I've built a few like this, one a 427 went 5 teens 1/8 with 400 on a plate system.
A little more compression and a more max effort N/A cam and it would make 50 more hp for you. This is a in between nitrous cam you have.
We're working on a pump gas in between now similar idea on the cam to run fairly well N/A and exceptionally nitrous.
Kirk at Bullet Cams.
Honestly I have always felt the car should run in the 30 to high 20 range. I do run radials. They are a little faster but not much.
The amount of deformation in a bias tire is the variable in regards to how much faster a radial will be. So if your suspension works with 20 psi with a bias tire, you may not see a tenth. It's the deformation which causes the energy loss with a bias tire - higher rolling resistance.
I suggested a radial to DLR for the reason, there's a car local similar sbc/weight car that picked up a tenth.
September 18, 2020, 09:26 AM
Mike Rietow
http://classracer.com/classfor...d.php?t=74517&page=2 I've never run radials on my Nova BUT I've seen several reports of picking up a tenth and seen it first hand. It's the difference in deformation depending on how much air you run in your bias tire which determines how much you pick up with a radial. Typically big bias slicks like DLR run, don't have much air in order to make em work, which leads to high energy losses - higher rolling resistance. .
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September 18, 2020, 09:42 AM
NC3x58
quote:
Originally posted by TOP38: When using the right cam the only reason to install it a few degrees advanced is to account for timing belt or chain stretch which retards the cam timing.
With your CID, RPM and compression and especially for that weight, you have too much duration. Without knowing the exhaust to intake flow ratio I can't comment on the 14 degree split on duration but I would say it's too much also. Both of these adjustments would close the lobe separation.
If your happy with the current performance then just keep racing, if not them there is room to improve. BTW there is nothing wrong with Comp Cams.
Is the usual number around 2* advanced from what the cam card says to account for the belt stretch?
Nick Craig
1971 Camaro Split Bumper 376ci LS3
September 18, 2020, 09:57 AM
Mike Rietow
Max effort N/A would be around
730 670
270 280
106 installed on a 102 3500 lbs
With a dominator
14.5:1 compression
750hp
September 18, 2020, 10:09 AM
1320racer
desk top dyno shyt right rhere.
September 18, 2020, 10:21 AM
Mike Rietow
Home brew Engine and Transmission
September 18, 2020, 10:39 AM
TOP38
quote:
Originally posted by NC3x58:
quote:
Originally posted by TOP38: When using the right cam the only reason to install it a few degrees advanced is to account for timing belt or chain stretch which retards the cam timing.
With your CID, RPM and compression and especially for that weight, you have too much duration. Without knowing the exhaust to intake flow ratio I can't comment on the 14 degree split on duration but I would say it's too much also. Both of these adjustments would close the lobe separation.
If your happy with the current performance then just keep racing, if not them there is room to improve. BTW there is nothing wrong with Comp Cams.
Is the usual number around 2* advanced from what the cam card says to account for the belt stretch?
1 to 2 degrees so ya
September 18, 2020, 10:41 AM
TOP38
quote:
Originally posted by Mike Rietow: Max effort N/A would be around
730 670
270 280
106 installed on a 102 3500 lbs
With a dominator
14.5:1 compression
750hp
14.5 to 1 is a max effort!
September 18, 2020, 11:10 AM
1320racer
exactly!
September 18, 2020, 01:42 PM
Bucky
I see trying different cam timing and doing lash loops as just part of the tuning process. If you don't check, you don't know what you have missed. Sometimes also, when you discover that a cam runs better advanced or retarded, or likes more or less lash than the card calls for, it gives you clues about where the cam is weak for your application. And also where improvements can be made. If you like to get every bit of performance out of what you have, trying different setups with your cam is no different than putting different jets in the brand new carb you are trying to dial in.
Foxtrot Juliet Bravo
September 18, 2020, 02:26 PM
Triple Nickel
Absolutely picked up 0.15 going from a bias ply to a drag radial right here.
3200 lbs, 049 oval ports, 598, injected on methanol, 1.80 PG, 4.30 gear, cal tracs and split mono's.
14x31x15 goodyear vs. 29.5x10.5x15 Mickey PBR. 6.05 vs. 5.90 back to back passes. Swapped tires and rims after the first shot on bias plys MPH was the same. That car hit the tire pretty hard tho, was awesome on all sorts of tracks until we stepped up the power level to the 1000 hp range. Then it started trying to ride the bumper most days and was a little harder to manage and bracket race.
September 18, 2020, 03:16 PM
Mike Rietow
quote:
Originally posted by Triple Nickel: Absolutely picked up 0.15 going from a bias ply to a drag radial right here.
3200 lbs, 049 oval ports, 598, injected on methanol, 1.80 PG, 4.30 gear, cal tracs and split mono's.
14x31x15 goodyear vs. 29.5x10.5x15 Mickey PBR. 6.05 vs. 5.90 back to back passes. Swapped tires and rims after the first shot on bias plys MPH was the same. That car hit the tire pretty hard tho, was awesome on all sorts of tracks until we stepped up the power level to the 1000 hp range. Then it started trying to ride the bumper most days and was a little harder to manage and bracket race.
That's running good. We've seen .15 down in Florida as well, bigger radial tire sizes especially. Nice pickup in et.
September 19, 2020, 06:39 AM
ts393c
So it sounds like I need less LSA and less duration. So this would make it more aggressive on the bottom end? Another question I would have is. Would doing the raise trap rpm? It don't pull the big end maybe 6700 range.
September 19, 2020, 07:50 AM
1320racer
All your ET n/a is by the 330’ cone and it starts with how quickly you 60 foot.
All your ET n/a is by the 330’ cone and it starts with how you 60 foot.
I'm starting to see the light. I'm just trying to learn a few things here. I will admit I never knew much about camshafts but I'm always willing to learn.
September 19, 2020, 08:36 AM
A39Coronet
quote:
Originally posted by Mike Rietow: https://youtu.be/5Fdhx6u-d5o If I put radials on the Ripper it would go sub 1.20 60 ft.n/a home brew sbc
If your 1.27 now, I can't see you dropping that much just with a tire change. I've seen cars drop a tenth going to radials, but they were 11 second cars that were running tubed bias plys, and it was a tenth over 1/4 mile.
September 19, 2020, 08:42 AM
Mike Rietow
quote:
Originally posted by ts393c: All your ET n/a is by the 330’ cone and it starts with how you 60 foot.
I'm starting to see the light. I'm just trying to learn a few things here. I will admit I never knew much about camshafts but I'm always willing to learn.
I had one guy I talked camshafts 25-30 years from when he was at Comp Cams to Lunati to Bullet Cams named Richard Woods, he's putting out fires for an automotive parts manufacture no longer in the high performance industry, however he has turned us on to a new contact at Bullet Cams named Kirk, super nice guy. Talk with Kirk.
September 19, 2020, 08:42 AM
ts393c
quote:
Originally posted by TOP38: When using the right cam the only reason to install it a few degrees advanced is to account for timing belt or chain stretch which retards the cam timing.
With your CID, RPM and compression and especially for that weight, you have too much duration. Without knowing the exhaust to intake flow ratio I can't comment on the 14 degree split on duration but I would say it's too much also. Both of these adjustments would close the lobe separation.
If your happy with the current performance then just keep racing, if not them there is room to improve. BTW there is nothing wrong with Comp Cams.
Top I wouldn't say I'm un happy. It is a very consistent set up. But if I could get some more et and not sacrifice consistency I would love to do that. I have always felt there is some left in this combination.
September 19, 2020, 08:47 AM
ts393c
quote:
Originally posted by Mike Rietow:
quote:
Originally posted by ts393c: All your ET n/a is by the 330’ cone and it starts with how you 60 foot.
I'm starting to see the light. I'm just trying to learn a few things here. I will admit I never knew much about camshafts but I'm always willing to learn.
I had one guy I talked camshafts 25 years from when he was at Comp Cams to Lunati to Bullet Cams named Richard Woods, he's putting out fires for an automotive parts manufacture no longer in the high performance industry, however he has turned us on to a new contact at Bullet Cams named Kirk, super nice guy. Talk with Kirk.
Mike I believe I have dealt with Kirk before. When I had my 582 and my dragster. They was good to deal with. Never understood why they always wanted to run a lot of lift. The lift was way higher than any other places that recommended a cam for it. But like I said I don't know a lot about cams.
This message has been edited. Last edited by: Mike Rietow, 
