Surging z06
01-27-2019, 08:48 PM
#21
Former Vendor
Member Since: Aug 2011
Location: Tampa Fl
Posts: 1,307
Received 110 Likes
on
92 Posts
St. Jude Donor '12
Corvette tuner in Tampa
A large cam with a tight LSA is not going to act like stock, but a lot of the surging can be reduced. I look at timing and airflow in the problem range to reduce the issue of cam surge.
Its not the cam brand that's the problem.
Most tuners just focus on WOT, but the money is made under 3000 RPMs.
Its not the cam brand that's the problem.
Most tuners just focus on WOT, but the money is made under 3000 RPMs.
01-27-2019, 09:08 PM
#22
Advanced
Thread Starter
I just had a guy spend three days data logging it on the street trying to reduce the surging. I expect it to surge some but it’s jumping at 2500 rpms.
01-28-2019, 08:22 AM
#23
Former Vendor
Member Since: Aug 2011
Location: Tampa Fl
Posts: 1,307
Received 110 Likes
on
92 Posts
St. Jude Donor '12
Corvette Camaro tuner in Tampa E85
When someone tells me "I messed with the xxxx table" I ask them explain "mess with." Does "mess with" mean you added, subtracted, multiple or divided that table by something?
So when I ask you to find out specifically over three days of data logging, what did he change to reduce the surging.
01-28-2019, 10:19 AM
#25
Turn off your short term fuel correction and see if it fixes it. Typically intake surge is felt more at low rpm due to revision pulses from your intake manifold - 2500 isnt low.
01-28-2019, 10:50 AM
#26
Team Owner
Everyone has different tolerance. I had a customer with a baby little cam something like a 230/240 and he wanted to lug it around at 800-900rpm and didn't like that it wasn't exactly like stock. Plenty of people drive FREAKING huge cams and think they are fine on the street as they can drive around the trouble areas.
That being said, no reason that cam shouldn't drive "ok" at 2500.
That being said, no reason that cam shouldn't drive "ok" at 2500.
01-28-2019, 11:41 AM
#27
Former Vendor
Removing the filter may make matters worse.
BTW, do not get all caught up on many of these posted cam grinds, there is a lot more to it in terms of truly defining the nature of a particular cam than just comparing one grind to the next.
It appears to me that you need a good "street" tuning session, one that focuses on all aspects of street drivability...assuming you DO NOT have any mechanical issues. I've seen simple things such vacuum leaks (lines to TB, or Intake or brakes booster) cause drama. You can also run a leak-down test to determine if all is well inside valve covers...if all mechanical is well, then good tuning is your answer.
BTW, a cam switch will require tuning and if tuning is poor, the car will run like crap no matter the size of the cam.
Let me know if I can help.
Thanks,
Carlos
BTW, do not get all caught up on many of these posted cam grinds, there is a lot more to it in terms of truly defining the nature of a particular cam than just comparing one grind to the next.
It appears to me that you need a good "street" tuning session, one that focuses on all aspects of street drivability...assuming you DO NOT have any mechanical issues. I've seen simple things such vacuum leaks (lines to TB, or Intake or brakes booster) cause drama. You can also run a leak-down test to determine if all is well inside valve covers...if all mechanical is well, then good tuning is your answer.
BTW, a cam switch will require tuning and if tuning is poor, the car will run like crap no matter the size of the cam.
Let me know if I can help.
Thanks,
Carlos
01-28-2019, 12:51 PM
#28
Advanced
Thread Starter
Ask him specifically what he's doing/done to reduce the surging.
When someone tells me "I messed with the xxxx table" I ask them explain "mess with." Does "mess with" mean you added, subtracted, multiple or divided that table by something?
So when I ask you to find out specifically over three days of data logging, what did he change to reduce the surging.
When someone tells me "I messed with the xxxx table" I ask them explain "mess with." Does "mess with" mean you added, subtracted, multiple or divided that table by something?
So when I ask you to find out specifically over three days of data logging, what did he change to reduce the surging.
01-28-2019, 05:09 PM
#29
1/4 mile/AutoX
make sure all your vacuum hoses are hooked up ??? (especially the PCV) ours surged a lot and I found the guy who did the heads (wife's car before we met) left the PCV hose off behind the TB,was tucked under so it was hard to see !!! we have a Kohle 116 cam and runs very smooth !!!
01-29-2019, 06:34 AM
#30
Advanced
Thread Starter
I did notice the hose from the valley pan going to my catch can is loose. It’s hard to get to and I don’t know if crank case vacuum will have any effect on engine surge. That’s the only hose I can find loose.
02-02-2019, 04:17 PM
#33
Advanced
Thread Starter
02-02-2019, 06:00 PM
#34
Hmmmm - since you have no access to tune.. force open loop by unplugging the coolant temp sensor on driver side head. See if it goes away. If you had a GOOD tuner then this wont lean your engine out or go stupid rich...but it is rare to find good tuners now a day so only do it for a short drive around the block.
02-04-2019, 09:51 AM
#35
Hmmmm - since you have no access to tune.. force open loop by unplugging the coolant temp sensor on driver side head. See if it goes away. If you had a GOOD tuner then this wont lean your engine out or go stupid rich...but it is rare to find good tuners now a day so only do it for a short drive around the block.
This, most can do the talking part but not the tuning part and when it comes to the doing/tuning part, they talk again. I have a 250/258 that doesn't buck or surge and drives really good but it took a good tuner to finally get it right.
02-19-2019, 08:29 PM
#36
Advanced
Thread Starter
I have an appointment March 15 for Stephen at SSLSX to see if he can get the surge better. If a cam change is needed so be it. I noticed the cam spec are very close to BTR 4 and I have read that cam is tuff to get to drive smooth.
BTR 4. 247/258. 660/660 112
TSP 3. 242/250. 655/655 114
BTR 4. 247/258. 660/660 112
TSP 3. 242/250. 655/655 114