yenkomike

iTrader: (2)

I will try it but the initial throttle movment seems to be fine but if I hold it at that rpm in high gear I can make it flutter for a good 7 or 8 seconds even with the ve table set 3 x higher than all the cells around it.i can make flutter when going 10.0 rich in that area

my ve in that area is 40 to 50s and I have went as high as 130 in that are to calm it down.

dburt86

iTrader: (2)

id be looking at the injector data and ignition timing.

if you want, send me the tune and log dburt86 @ gmail.com

pdxmotorhead

Another thought,,, I'm on a roll this morning.. Have you watched your alternator/battery voltage during the flutter? I had a alt with bad brushes once that would freak out half the car electrical at mid range rpm...

stevieturbo

His throttle is not moving quickly, it would not make any sense for it to be a throttle enrichment issue.

yenkomike

iTrader: (2)

changed alternators as well steady 14.2. volts. old one was 13.7 ish so I swapped it .

I have unhooked or replaced everything except the intake ,throtlebody and tps with no change. even unhooked the tach and wired ecu directly to the battery.

imma_stocker

iTrader: (19)

Had a similar issue with fuel damper.... ditched it and no more surge. It was a mechanical "over-engineered" problem cured by KISS.

Could also be mismatched cam to intake causing a bad spot of pressure waves colliding.

Ben.

How much timing have you got in it? I couldn't see it clearly in the pic above.

Making the timing flat is a good idea, maybe try reducing it to see if that helps.

yenkomike

iTrader: (2)

timing is about 28-30 *

brandon6.0

iTrader: (32)

when u step up to a larger tb u need to change the effective area in the tune. I also wanna say there is another table that deals with intake volume. your using megasquirt tho correct?

yenkomike

iTrader: (2)

yes micro or ms2 im going to check on that

yenkomike

iTrader: (2)

I messed with the fuel long enuff . so I swapped back to a stock truck intake and it runs better everywhere with no surge. better idle ,cruise, wot. the car is just a better car with a stock intake. spools faster as well. another 1/2 hour drive tuning and it is ready for some track tuning.

jasonsnova

I wonder if I'm having a simular issue....mine is fine From a roll /part throttle but From a dead stop it's a pig till boost kicks in .....falls o face , spits sputters...etc.

yenkomike

iTrader: (2)

I had this one running good in all but a 200 rpm area. and could not stop the surge. but after swapping intakes it is a different engine idle and cruise are much smoother with better throttle response.and the tune is still a little ruff for this intake.

jasonsnova

my engine builder seems to thi k he can get mine straightened out....if not I may try a stock ls3 intake

Nitroused383

iTrader: (10)

Possibly too much airflow from IAC because of the big throttle body. If it surges bad in an area and reducing running airflow doesn't help try knocking the timing down around 13-18 degree range with a slight rich condition (13.5-14.0 afr).

yenkomike

iTrader: (2)

I thought about that . at one time I was running the iac closed and 20* timing but it changed very little. even at 11.0 afr .

I'm sure it was some kind of intake ,cam harmonics causing the air to flutter. in real time you could see the map dot shake when it did it.

what really surprises me is how much better the car runs ,drives and gets in to boost with the truck intake over the holley. it is quite a bit faster at 12# boost with the truck intake than the holley. at the same timing and afr.

jasonsnova

Mike do you feel it was the intake or large TB?
My sniper style intake /102 tb is giving me tuning fits. Im gonna bring it to someone who is a tad better at tuning before i condem it tho....

topbrent

iTrader: (1)

What's the rest of the combo? Trans/Rear, ect? Is this in your Nova?

yenkomike

iTrader: (2)

I never tried a smaller t.b. but I think it was a mismatch of cam reversion and plenum size. I had it running and driving good thru the rest of the rpm/boost map pretty good. but from 2000to 2300 rpm no way. it sounded like a slow 2 step and the real time display whould shake like the pressure was bouncing. it is running damn good now with the stock stuff.

forcd ind

iTrader: (7)

While prob not the problem, the surge valve can cause a problem if it is opening and closing in a certain area due to vacuum hi/low. Never messed with MS so I don't know anything about their controls. A lot to be said about stock intakes/TB's, great drivability, lol