Cam'd LS3 help
Cam'd LS3 help I bought a 2008 C6 with a mild cam (228/232/598/600/113), CAI, LT's and tune.
I have had a really bad surging problem since I have had the car, really bad. Bucking and surging under light load. I replaced the original Callaway Honker (known to cause some LS3 maf turbulence) and replaced it with an LS3 C6 Airaid. That took care of about 85% of the surging.
I installed a set of TSP 1 7/8 LT's w/o cats and I ported the intake knowing I was going to get a retune.
Yesterday at Diablosport, Johan retuned the car and it made 475rwhp (untouched as I got there) and the fuel was way off everywhere. After adjustments it ended up @ 485rwhp on a stingy load bearing dyno, on a Dynojet it would have been even better. Seeing the fuel off so much we didn't bother "street" tuning the surging out since a small test drive in 1st and 2nd it seemed to resolve it.
After jumping on the interstate on the way home I noticed the surging is still there and it is mainly noticable in 3rd and really noticeable in 4th @ 2K. It almost feels like a plug missing though that's not the case. Plugs are new and gapped @ .40 (FYI).
I am (not so) sure it's MAF related since just changing the CAI made such a huge difference.
Can anyone offer advice for us to try on the next tune? Any help would be appreciated. Any adjustments to the maf table or something? I am trying to do some homework so we don't waste too much time.
Complete mod list
2008 M6 1LT
TSP Off road 1 7/8's 3x3
228/232/598/600/113 cam
Dual Valve springs
Airaid CAI
Ported TB
Ported LS3 intake
UD pulley
New GM LS3 maf (installed it before the dyno, same exact symtoms)
Thanks,
Jason
I have had a really bad surging problem since I have had the car, really bad. Bucking and surging under light load. I replaced the original Callaway Honker (known to cause some LS3 maf turbulence) and replaced it with an LS3 C6 Airaid. That took care of about 85% of the surging.
I installed a set of TSP 1 7/8 LT's w/o cats and I ported the intake knowing I was going to get a retune.
Yesterday at Diablosport, Johan retuned the car and it made 475rwhp (untouched as I got there) and the fuel was way off everywhere. After adjustments it ended up @ 485rwhp on a stingy load bearing dyno, on a Dynojet it would have been even better. Seeing the fuel off so much we didn't bother "street" tuning the surging out since a small test drive in 1st and 2nd it seemed to resolve it.
After jumping on the interstate on the way home I noticed the surging is still there and it is mainly noticable in 3rd and really noticeable in 4th @ 2K. It almost feels like a plug missing though that's not the case. Plugs are new and gapped @ .40 (FYI).
I am (not so) sure it's MAF related since just changing the CAI made such a huge difference.
Can anyone offer advice for us to try on the next tune? Any help would be appreciated. Any adjustments to the maf table or something? I am trying to do some homework so we don't waste too much time.
Complete mod list
2008 M6 1LT
TSP Off road 1 7/8's 3x3
228/232/598/600/113 cam
Dual Valve springs
Airaid CAI
Ported TB
Ported LS3 intake
UD pulley
New GM LS3 maf (installed it before the dyno, same exact symtoms)
Thanks,
Jason
Last edited by JayplaySS; Dec 26, 2009 at 01:02 AM.
Seeing the fuel off so much we didn't bother "street" tuning the surging out since a small test drive in 1st and 2nd it seemed to resolve it.
PM sent.
A 228/232 cam should be fine. A common cause of bucking and surging is too much timing. Data log while the car is in the "bucking surging zone". Via the data logs determine at what RPM and at what cylinder airmass (g/sec) cylinder the bucking/surging occurs. Then find the corresponding area in your Main Spark / High Octane table and try lowering the timing. As a test try lowering it by 5-10 degrees to see if it makes a difference.
A 228/232 cam should be fine. A common cause of bucking and surging is too much timing. Data log while the car is in the "bucking surging zone". Via the data logs determine at what RPM and at what cylinder airmass (g/sec) cylinder the bucking/surging occurs. Then find the corresponding area in your Main Spark / High Octane table and try lowering the timing. As a test try lowering it by 5-10 degrees to see if it makes a difference.
PM sent.
A 228/232 cam should be fine. A common cause of bucking and surging is too much timing. Data log while the car is in the "bucking surging zone". Via the data logs determine at what RPM and at what cylinder airmass (g/sec) cylinder the bucking/surging occurs. Then find the corresponding area in your Main Spark / High Octane table and try lowering the timing. As a test try lowering it by 5-10 degrees to see if it makes a difference.
A 228/232 cam should be fine. A common cause of bucking and surging is too much timing. Data log while the car is in the "bucking surging zone". Via the data logs determine at what RPM and at what cylinder airmass (g/sec) cylinder the bucking/surging occurs. Then find the corresponding area in your Main Spark / High Octane table and try lowering the timing. As a test try lowering it by 5-10 degrees to see if it makes a difference.
PM sent.
A 228/232 cam should be fine. A common cause of bucking and surging is too much timing. Data log while the car is in the "bucking surging zone". Via the data logs determine at what RPM and at what cylinder airmass (g/sec) cylinder the bucking/surging occurs. Then find the corresponding area in your Main Spark / High Octane table and try lowering the timing. As a test try lowering it by 5-10 degrees to see if it makes a difference.
A 228/232 cam should be fine. A common cause of bucking and surging is too much timing. Data log while the car is in the "bucking surging zone". Via the data logs determine at what RPM and at what cylinder airmass (g/sec) cylinder the bucking/surging occurs. Then find the corresponding area in your Main Spark / High Octane table and try lowering the timing. As a test try lowering it by 5-10 degrees to see if it makes a difference.
Question-
If there was too much timing, would plug gap affect it at all? They are at .40 now so would opening them or closing them affect that? Just curious.
In other words, if I went out and gapped them at .50 today, would it affect it at all if it is timing? Tough call probably.?
Trending Topics
Which spark plug are you running?
For your setup I would recommend the TR5 gapped @ 0.040".
Regarding my earlier suggestion, it may be a good idea to switch the car to pure MAF mode. I realize this may seem a bit counter intuitive (because you are wondering if your MAF is possibly to blame) but if your car has been modded (which is has) your VE table will no longer be correct and will not be correct until the car is properly tuned. If you switch to pure MAF mode, (and assuming your MAF transfer function is correct) your fuel trims should then be pretty good, versus the VE fuel trims which (because of your mods) would be incorrect.
For your setup I would recommend the TR5 gapped @ 0.040".
Regarding my earlier suggestion, it may be a good idea to switch the car to pure MAF mode. I realize this may seem a bit counter intuitive (because you are wondering if your MAF is possibly to blame) but if your car has been modded (which is has) your VE table will no longer be correct and will not be correct until the car is properly tuned. If you switch to pure MAF mode, (and assuming your MAF transfer function is correct) your fuel trims should then be pretty good, versus the VE fuel trims which (because of your mods) would be incorrect.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Which spark plug are you running?
For your setup I would recommend the TR5 gapped @ 0.040".
Regarding my earlier suggestion, it may be a good idea to switch the car to pure MAF mode. I realize this may seem a bit counter intuitive (because you are wondering if your MAF is possibly to blame) but if your car has been modded (which is has) your VE table will no longer be correct and will not be correct until the car is properly tuned. If you switch to pure MAF mode, (and assuming your MAF transfer function is correct) your fuel trims should then be pretty good, versus the VE fuel trims which (because of your mods) would be incorrect.
For your setup I would recommend the TR5 gapped @ 0.040".
Regarding my earlier suggestion, it may be a good idea to switch the car to pure MAF mode. I realize this may seem a bit counter intuitive (because you are wondering if your MAF is possibly to blame) but if your car has been modded (which is has) your VE table will no longer be correct and will not be correct until the car is properly tuned. If you switch to pure MAF mode, (and assuming your MAF transfer function is correct) your fuel trims should then be pretty good, versus the VE fuel trims which (because of your mods) would be incorrect.
I am going to forward all your advice, thank you.
11 Second Club
Joined: May 2007
Posts: 226
Likes: 1
From: Sydney
cheers
The 08s are not like the 411 box cars, they do not have a VE.... They have coefficients. Coefficients are tough to grasp, but the PCMs are VERY fast.
SD is not needed with this setup.
I can get that cam to run well to 12-1300 with no issues. You can call me if you would like to discuss it over the phone.
SD is not needed with this setup.
I can get that cam to run well to 12-1300 with no issues. You can call me if you would like to discuss it over the phone.
^^^Yeah, but with the E38s, even if the base airflow is dialed in, there's aggressive interaction between the timing tables that causes harsh bucking. It's evidenced by a saw tooth pattern in the timing in the data logs. There's some "trickery" to getting this out.
There's some other tricks to making the E38s drive smooth, but that's all the secrets I'm willing to share today. Check with me tomorrow LOL.
There's some other tricks to making the E38s drive smooth, but that's all the secrets I'm willing to share today. Check with me tomorrow LOL.
Also, as I stated before, make sure there's no harsh timing adjustments being made by the PCM. Make sure your timing line in your scanner looks steady.
The 08s are not like the 411 box cars, they do not have a VE.... They have coefficients. Coefficients are tough to grasp, but the PCMs are VERY fast.
SD is not needed with this setup.
I can get that cam to run well to 12-1300 with no issues. You can call me if you would like to discuss it over the phone.
SD is not needed with this setup.
I can get that cam to run well to 12-1300 with no issues. You can call me if you would like to discuss it over the phone.
^^^Yeah, but with the E38s, even if the base airflow is dialed in, there's aggressive interaction between the timing tables that causes harsh bucking. It's evidenced by a saw tooth pattern in the timing in the data logs. There's some "trickery" to getting this out.
There's some other tricks to making the E38s drive smooth, but that's all the secrets I'm willing to share today. Check with me tomorrow LOL.
There's some other tricks to making the E38s drive smooth, but that's all the secrets I'm willing to share today. Check with me tomorrow LOL.
How do you normally get it to iron out? Fuel. How do you add more fuel with out the trims taking it back away? Thats the question of the day
Stop by Richmond on the way to TX and have a beer or so 
If the items mentioned in the thread are logged and the event time is noted, you should be able to see where to attribute it in the log.
If the items mentioned in the thread are logged and the event time is noted, you should be able to see where to attribute it in the log.
As mentioned by the masters above, timing is really a small part of the problem. The bigger problem is getting your running airflow correct (it never is right after a cam swap) and get the fueling right (this requires revising the VE coefficients and rescaling the MAF tables). First, you must get the airflow tables right because if you don't address these, you'll be chasing your tail with the fueling and timing tables. The ported TB is not doing you any favors here by the way. When in doubt, err on the side of being a little rich in your transitional fueling. This takes a lot of the stumble out of the system as you go from light to heavier load.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.