ZO6 LS7 does not run like I think it should.
11-20-2014, 10:57 PM
#21
Super Vic Setup
You could run a super or Junior Vic w/ a FAST 4150/4500 TB. Might help your air flow. You would have to run a speed density instead of the MAF sensor, but that is not a big deal w/ the right tuner.
11-22-2014, 08:06 AM
#23
have a 2008 ZO6 LS7. In my 32ford pro street truck. I do not think it has ever run, as fast as it should. HELP what is wrong. It has 1-7/8s stainless headers. Plus two different cams. It runs 6.40s in the 1/8 @ 105mph. And it runs 10.00s @ 127 in the 1/4. I have a turbo 400, trans. It has had two different gears & stalls. The 1st combo was 4800 stall & 4.30 gears. Second combo 2800 to 3000 stall & 3.50 gears. The truck is 2660 with me in it. I have had two different cams also. Both were custom grinds for the truck. Could it be the stock intake, air intake system, with just a high flow filter. Or is it in the drive by wire stock set up. It has been tuned twice. One time for each cam, and gear, stall combo. It is like anything we do to it. Makes no difference. Do I need to change the stock air box, and stock sensor? HELP!!!!!!!!!!!!!!!!
Both converters were.PTC 10" stalls. foot brake at 1700 rpm. No cats, 2 chamber flowmasters with turn downs just in front of rear end. I just run one set of O2s. Total exhaust length 2-1/2 feet.. Had one chambers on it. No difference. We checked compression & leak down. Everything OK there. Check my OP and you will see. I have had two different stalls & gear combos.
1st cam 2nd cam
intake & exh lobe sep- 114.2 112
intake center line 111.2 108
intake duration 242.6 234.4
intake valve lift 648 648
intake lobe lift 360 360
exh centerline 117.2 116
exh duration 248.6 242
exh valve lift 649 630
exh lobe lift 360 350
Both converters were.PTC 10" stalls. foot brake at 1700 rpm. No cats, 2 chamber flowmasters with turn downs just in front of rear end. I just run one set of O2s. Total exhaust length 2-1/2 feet.. Had one chambers on it. No difference. We checked compression & leak down. Everything OK there. Check my OP and you will see. I have had two different stalls & gear combos.
1st cam 2nd cam
intake & exh lobe sep- 114.2 112
intake center line 111.2 108
intake duration 242.6 234.4
intake valve lift 648 648
intake lobe lift 360 360
exh centerline 117.2 116
exh duration 248.6 242
exh valve lift 649 630
exh lobe lift 360 350
I've been researching cams for my LS7 swap 69 Camaro. Seems like the ones that work have much more duration split in favor of the exhaust. The Katech torquer, which I settled on, is 220/244 , 110 LSA. IMO your cam is not optimized for the LS7.
11-22-2014, 06:43 PM
#25
Launching!
Thread Starter
which cam do you like better? The 1st one or the 2nd one? I know with the specs side by side, it maybe a little hard to brake the two down. I will try and separate the two. The 2nd one is in the truck now. And as soon as I get the trans back in. We are going to test it. Keep in mind I race the truck at nostalgia events. But I also drive it on 100 miles trips as well now. cam #1 had been in the truck for about two years. Just installed the 2nd one, and right after that the tranny started slipping.
1st cam-------------------------------------------------------------2nd cam
intake & exh lobe sep- 114.2----------------------------------------112
intake center line 111.2 ---------------------------------------------108
intake duration 242.6 -----------------------------------------------234.4
intake valve lift 648 -------------------------------------------------648
intake lobe lift 360 ---------------------------------------------------360
exh centerline 117.2 -------------------------------------------------116
exh duration 248.6 ---------------------------------------------------242
exh valve lift 649 -----------------------------------------------------630
exh lobe lift 360 ------------------------------------------------------350
Last edited by bada; 11-22-2014 at 07:09 PM. Reason: ..
11-22-2014, 11:37 PM
#26
I'm hardly a cam expert, or experienced with a LS7, but the overlap of the first cam is about 17, and the overlap of the second cam is about 14. You dropped a good bit of duration and tightened the LSA just a bit and didn't change the amount of overlap much. Doesn't seem worth it. I'd say the first cam doesn't have enough overlap, and the second cam doesn't have enough duration. You're ending up with some really lazy valve events for the amount of air being pumped. You might want something over 240 intake and a +10 or so on the exhaust. And an LSA somewhere around 110-112 giving you an overlap near 30. A quick search turns up this from Martin at Tick...https://ls1tech.com/forums/dynamomet...k-exhaust.html
But, all that said, I'm still convinced you need to verify everything is working as it should and experiment with that intake first. Especially if you don't have good data with the new cam yet.
But, all that said, I'm still convinced you need to verify everything is working as it should and experiment with that intake first. Especially if you don't have good data with the new cam yet.
11-23-2014, 10:01 AM
#28
TECH Apprentice
iTrader: (21)
Join Date: Nov 2007
Location: Albuquerque, New Mexico
Posts: 398
Likes: 0
Received 0 Likes
on
0 Posts
Back to an intake solution. It would be rather inexpensive to switch to a much slimmer SPAL electric fan. Since SPAL fans are reversible, maybe even running it as a pusher for the strip-use could be a consideration. That would allow a much more gentle transition to the cold air system. Maybe with a 135 degree silicone tube.
11-23-2014, 02:52 PM
#29
Launching!
Thread Starter
Back to an intake solution. It would be rather inexpensive to switch to a much slimmer SPAL electric fan. Since SPAL fans are reversible, maybe even running it as a pusher for the strip-use could be a consideration. That would allow a much more gentle transition to the cold air system. Maybe with a 135 degree silicone tube.
11-23-2014, 03:04 PM
#30
Launching!
Thread Starter
Thanks for all the input guys. Hope to take the truck out, in a couple of weeks. May have a buddy of mine drive it. I just had knee surgery. And I can not get behind the wheel. But my buddy, is my size an weight. Plus he has an old race truck also. So with him driving. The results should be the same, as if I was behind the wheel. Since the truck is foot braked, at around 1700rpm & the shift light is set. All he has to do is, hit the shift points.
11-23-2014, 03:05 PM
#31
Launching!
Thread Starter
11-23-2014, 10:24 PM
#32
A trans needs to be tuned just like the engine does.
Has it only been tuned while on the chassis dyno? IMO a chassis dyno will get it close but there's nothing better than getting it out on the road or track to finalize the tune under real world circumstances.
Has it only been tuned while on the chassis dyno? IMO a chassis dyno will get it close but there's nothing better than getting it out on the road or track to finalize the tune under real world circumstances.
11-24-2014, 08:34 AM
#34
TECH Senior Member
iTrader: (7)
Have you considered running the stock cam, just so you can establish a baseline?
Hot Rod ran 10.78 @ 120 with a stock LS7 in a Chevelle.
http://www.hotrod.com/how-to/engine/...-engine-tests/
Andrew
Hot Rod ran 10.78 @ 120 with a stock LS7 in a Chevelle.
http://www.hotrod.com/how-to/engine/...-engine-tests/
Andrew
11-24-2014, 12:51 PM
#35
11-25-2014, 03:54 PM
#36
Launching!
Thread Starter
It has been street tuned and track tuned. But the turbo 400, has no way to tune it???
11-25-2014, 03:57 PM
#37
Launching!
Thread Starter
Have you considered running the stock cam, just so you can establish a baseline?
Hot Rod ran 10.78 @ 120 with a stock LS7 in a Chevelle.
http://www.hotrod.com/how-to/engine/...-engine-tests/
Andrew
Hot Rod ran 10.78 @ 120 with a stock LS7 in a Chevelle.
http://www.hotrod.com/how-to/engine/...-engine-tests/
Andrew
11-25-2014, 07:28 PM
#38
Yes had the stock cam in it, before either one of the 2 aftermarket cams. Same 1/8 mile times. But the 1st after market was 2 tens faster in the 1/4, and a couple of mph. But this thing should fly, at only 2660 LBs with me in it. I am just not pleasewith the ETs . With the light weight.
11-26-2014, 12:19 PM
#39
Launching!
Thread Starter
You might just be sweating it too much. Stock C6 Zo6 Corvettes run, on average, about 11.5 @125mph...give or take. You're 1.5 seconds quicker and 2 mph faster. You're weight difference is worth probably 1 second over the Corvette. You're essentially a cammed Z06 with headers on a lightweight chassis with bad aero. Your 10.0 ET is about right, and your MPH might be right considering it's an automatic and your brick-like aero.
11-27-2014, 01:34 PM
#40
You might just be sweating it too much. Stock C6 Zo6 Corvettes run, on average, about 11.5 @125mph...give or take. You're 1.5 seconds quicker and 2 mph faster. You're weight difference is worth probably 1 second over the Corvette. You're essentially a cammed Z06 with headers on a lightweight chassis with bad aero. Your 10.0 ET is about right, and your MPH might be right considering it's an automatic and your brick-like aero.