Car exhaust burbles at cruse ROE 710 cam

[pokeyl]

I this a normal function caused by the waisted spark and/or the valve timing overlap. It is only at light throttle cruse configuration. I have no decel popping and the plugs look perfect. short and long term fuel trims are within the 10% window.

Under any acceleration it clears up. most of the time it is at 1500-2500 RPM when you here it.

Parts in the motor
710 cam
Slow bleed lifters
Beehive springs
HD pushrods
Gen 4 head gasket
Stock valve size but bowl ported (.013 off the heads to make then flat and remove imperfection)CR should be 9.8-9.9
ROE throttle body
K&N intake with Unifilters
Mopar racing 3 inch exhaust (no cats)
170 Deg T-sat
93 Roe tune for the above items

I have not been to the dyno yet, and I can't locate my wideband O2. I may just pick up a new one.

Thanks for any input!

[Whiskey]

...as in a miss-fire? Have a video?

[pokeyl]

It's not a misfire, My ZX-10r has the same thing. It is only under light load, cruse. I just have never felt it in a car. If you start to accelerate any, it clears up.

[plumcrazy]

It's all in the tune

[Hrysler]

It's all in the tune

I would call Roe. I know A+C performance does remote tunes. If they can't figure it out. Hopefully Roe can help you.

[plumcrazy]

A&C > roe at tuning

[Dan Cragin]

That's a fairly big cam that does not work too well at low rpm. Because of the overlap, you will get some surging/burbling at low rpm.

Maybe you could give some more information about exactly what its doing.

Good luck.

[pokeyl]

That's a fairly big cam that does not work too well at low rpm. Because of the overlap, you will get some surging/burbling at low rpm.

Maybe you could give some more information about exactly what its doing.

Good luck.

The car runs perfect as long as you accelerate (even under the lightest throttle) MAP shows less that 2, never any surge or burbling. As soon MAP is over 5-6 Hg (60-65 MPH at 1700-1900 RPM) you get the burb! No surging ever! I have seen the same in my ZX-10 motorcycle after a free flow cat-less exhaust and a preformance tune.

I figured it was just the high Hg along with the valve overlap pulling hot gas back inside the intake. All the fuel trim data looks good I do not have a WB connected up yet.

[Dan Cragin]

If your fuel trims are good then burble is most likely not tune related. I think that cam runs around 240 degree's of exhaust duration, so most likely its just a combination of the cam and catless exhaust.

[Hrysler]

Did you get everything figured out on your car? Did you end up go to a Dyno?

[pokeyl]

Did you get everything figured out on your car? Did you end up go to a Dyno?

Car is all good, very powerful, dyno next month. I had 504 RWHP before the cam/heads work.

[99RT10]

Car is all good, very powerful, dyno next month. I had 504 RWHP before the cam/heads work.

Who is doing your tuning? Torrie?

[pokeyl]

Who is doing your tuning? Torrie?

Canned tune from Roe, custom to my part. Feels very good, If I could find my wide-band O2...
I have a data logger for all the ODBII, that data is all spot on.

Adam from Innovative Street Technologies will do any final tune. Dyno at Emerald Coast Motorsports, they did the head work.

[Hrysler]

Dyno numbers yet??

[pokeyl]

Dyno numbers yet??

Friday 0900 CST

[pokeyl]

First pull 592.6 RWHP 662.9 torque
Second Pull 621.1 RWHP 679.8 torque

Will post PDF when I get home

PS... car is very rich 9 to 1 so when we get it leaned out I should be around 650ish

[J TNT]

Nice numbers , congrats !

[Hrysler]

First pull 592.6 RWHP 662.9 torque
Second Pull 621.1 RWHP 679.8 torque

Will post PDF when I get home

PS... car is very rich 9 to 1 so when we get it leaned out I should be around 650ish

Wow! Awesome! Mustang dyno?

[99RT10]

First pull 592.6 RWHP 662.9 torque
Second Pull 621.1 RWHP 679.8 torque

Will post PDF when I get home

PS... car is very rich 9 to 1 so when we get it leaned out I should be around 650ish

That is pretty damn god. That is Greg Good power. Kudos!!!!

[pokeyl]

04 Viper.pdf

viper.jpg

[pokeyl]

https://www.youtube.com/watch?v=UkvQJghxWcohttp://

[pokeyl]

New tune is here, will load tonight.

[Hrysler]

New tune is here, will load tonight.

Cool. Let us know how it goes.. would you do cam and heads again? Or Paxton? I'm trying to decide what I will do...

[pokeyl]

Cool. Let us know how it goes.. would you do cam and heads again? Or Paxton? I'm trying to decide what I will do...

I have a 2010 SC 370Z, pain to set up but I have been running 10 PSI boost for 7 years now without problems. I did not want the problems with clutch/half shaft/trans... that com with SC vipers. So, Heads/Cam for me.

[Hrysler]

I have a 2010 SC 370Z, pain to set up but I have been running 10 PSI boost for 7 years now without problems. I did not want the problems with clutch/half shaft/trans... that com with SC vipers. So, Heads/Cam for me.

I hear you. Do you have a stock clutch? You might need to upgrade that eventually.. i did..I think the half shafts are good just don't like wheel hop. I