Is my cam too small? Expert and personal advice welcome
#1
Is my cam too small? Expert and personal advice welcome
Hi guys I'm looking for opinions and experience on my combo and if I would benefit from a bigger cam. My power train setup when I ran 11.92@113 w/ 1.69 60ft was:
- SBE LS1
- PRC 243's which are CNC ported with stock valves and milled .030", measured ~60.5 cc combustion chambers
~300cfm @ .600" lift.
- Stock head gasket so compression should be about 11.1:1
- 228/230 .629"/.604" 112+2 cam
- PAC 1519 beehive springs
- LS6 intake/ ported stock throttle body/ 85mm maf/ 98mm lid/ gutted air box with K&N
- 1 3/4" long tubes with 4" cutout under the passenger rear seat
- MAF tuned to lambda .85/.88 (or 12.5/13.0 in gas terms) and 29-30 degrees
- E85
- 39 lbs injectors
- under drive pulley
- Built 4L80e with 245mm triple disk ~4500 stall. I foot brake to 3300 rpm then when I floor it rpms immediately shoot up to 4000 before the car starts to move and within 4 tenths 4500rpm before the curve slope decreases according to my hpt scans. I attached a pick to show what I mean.
- Stock rear end with 3.73 gear.
- 28" mickey thompsons
- race weight was approximately 3710 lbs with me in it.
- shifts were 6600-6800 rpm
11.92@113 w/ 1.69 60ft was with the converter unlocked and from what I can tell from my scans it would run about 11.8@115 with the converter locked in 3rd. Seems a little soft especially in the MPH considering weather was really good in MI October air. The car pulls pretty good especially out of the hole but feels like it pulls pretty linear with topend that is nothing to **** your pants about.
Over the winter, so far, I've added:
- Vengence ported fast 102, NW 102, 102 lid
- 60 lbs injectors
- SD tuned
- 26X11.5" mickey thompsons on 16" rims.
I'm expecting about 11.7@117 with the new setup and I plan on adding a 9" with 4.10's which should put me at 6600rpm@118 mph and should help get my 60 ft down a little. I still feel like 11.5's are still too slow for my mods. I was thinking something more aggressive like around 236/246 .650"/.650" might be a better idea since I'm at 4500rpm right off the line and never below 5500rpm after each shift. Plus, any low end I lose should be below 4500rpm not to mention a 4.10 should make up for that anyway. What do you guys think? Thanks for the read.
Oh don't mind the a/f ratio on the scan the wideband wasn't hooked up for this run.
- SBE LS1
- PRC 243's which are CNC ported with stock valves and milled .030", measured ~60.5 cc combustion chambers
~300cfm @ .600" lift.
- Stock head gasket so compression should be about 11.1:1
- 228/230 .629"/.604" 112+2 cam
- PAC 1519 beehive springs
- LS6 intake/ ported stock throttle body/ 85mm maf/ 98mm lid/ gutted air box with K&N
- 1 3/4" long tubes with 4" cutout under the passenger rear seat
- MAF tuned to lambda .85/.88 (or 12.5/13.0 in gas terms) and 29-30 degrees
- E85
- 39 lbs injectors
- under drive pulley
- Built 4L80e with 245mm triple disk ~4500 stall. I foot brake to 3300 rpm then when I floor it rpms immediately shoot up to 4000 before the car starts to move and within 4 tenths 4500rpm before the curve slope decreases according to my hpt scans. I attached a pick to show what I mean.
- Stock rear end with 3.73 gear.
- 28" mickey thompsons
- race weight was approximately 3710 lbs with me in it.
- shifts were 6600-6800 rpm
11.92@113 w/ 1.69 60ft was with the converter unlocked and from what I can tell from my scans it would run about 11.8@115 with the converter locked in 3rd. Seems a little soft especially in the MPH considering weather was really good in MI October air. The car pulls pretty good especially out of the hole but feels like it pulls pretty linear with topend that is nothing to **** your pants about.
Over the winter, so far, I've added:
- Vengence ported fast 102, NW 102, 102 lid
- 60 lbs injectors
- SD tuned
- 26X11.5" mickey thompsons on 16" rims.
I'm expecting about 11.7@117 with the new setup and I plan on adding a 9" with 4.10's which should put me at 6600rpm@118 mph and should help get my 60 ft down a little. I still feel like 11.5's are still too slow for my mods. I was thinking something more aggressive like around 236/246 .650"/.650" might be a better idea since I'm at 4500rpm right off the line and never below 5500rpm after each shift. Plus, any low end I lose should be below 4500rpm not to mention a 4.10 should make up for that anyway. What do you guys think? Thanks for the read.
Oh don't mind the a/f ratio on the scan the wideband wasn't hooked up for this run.
Last edited by JDMC5; 02-04-2016 at 08:11 PM.
#6
I thought 1.69 was pretty decent considering it does 55 in 1st gear with the 4L80e, 3.73 and 28" tire. No?
Gotta remember my 3.73 acts like a 3.02 compared to a 4L60e in 1st gear.
I also feel like it will get low 1.6's with the 26" and 4.10's.
Gotta remember my 3.73 acts like a 3.02 compared to a 4L60e in 1st gear.
I also feel like it will get low 1.6's with the 26" and 4.10's.
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#8
I wasn't aware that the gearing was that much different.
I bet with the intake upgrade 4.10s and a 26" tire it will run lower 11s. I bet it will go 1.5x 60 as well
What kind of power do you make ?
#9
I would need like 4.56's to leave like a 4L60e with 3.73's lol.
I have no idea what kind of power it makes, but I will know soon. I know it does 0-60 in 3.5 though, well it did at least, probably a tenth or two faster now.
#11
I know it will gain a decent amount from the 4.10's since it will leave harder and go through the traps at 6600 instead of 6000. Just not sure how much the weight and power los of it will offset the gains ya know?
#16
The gears are not hurting much with that 4500 stall. The gears are just going to make the converter feel tighter. The stall will still flash the same rpm and net the same shift extension regardless of gear. The 26" tire will help due to less weight and rotating mass.
Imo you have added weight to the car which counter acts making more power going to a 4L80. I could see warranting such a trans upgrade in a 700whp+ car...not a H/C 346. I would look into valvetrain stability issues. What cam lobes, lifters, push rods, and valves? The Fast would definitely help. The cam looks fine but you could go bigger with that big stall.
Imo you have added weight to the car which counter acts making more power going to a 4L80. I could see warranting such a trans upgrade in a 700whp+ car...not a H/C 346. I would look into valvetrain stability issues. What cam lobes, lifters, push rods, and valves? The Fast would definitely help. The cam looks fine but you could go bigger with that big stall.
Last edited by kinglt-1; 02-05-2016 at 08:27 AM.
#17
Seems your car runs really close to mine did with similar mods. Which is highly abnormal...usually a f body is a couple tenths and MPH quicker in the 1/4 with equal mods.
Do you have a dyno graph or have you tried other shift points? You could be overrevving it?
If not you might weigh it, could be heavier than you think.
The intake could help you a bit. I doubt a gear or bigger headers would net much gain. I would definitely agree the car is under performing a little.
Do you have a dyno graph or have you tried other shift points? You could be overrevving it?
If not you might weigh it, could be heavier than you think.
The intake could help you a bit. I doubt a gear or bigger headers would net much gain. I would definitely agree the car is under performing a little.
#19
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