bucking - Page 3

Wall96cobra · 09-28-2005, 03:26 PM

Quote:

Originally Posted by Italian LX

Jonathan and I had both mentioned that maybe the BOV may be not opening properly and is causing some surging across the MAF that starts the cycle.

As far as the rest of the tune goes, the car feels really good under acceleration and we now have the KAMRFâ€™s staying relatively close to 1.000. There seems to be no bucking as long as the vacuum is below 14 in-hgâ€¦ but anything above that and youâ€™re very prone to a bumpy ride.

Yeah I'm still leaning towards the blowoff valve, that mondo vlave was set very loose and I believe the pre-load spring was even cut. The min race BOV is smaller plus probably set tighter so he may need to adjust it and add my old bosch bypass valve to it. It really sounds like a BOV problem to me, my car used to buck and surge before I added a second BOV although in the end I was able to run just one but I had to cut the pre-load spring in the BOV and set it very loose...and even then there was a slight buck but nothing too noticable.

86GT · 09-28-2005, 03:48 PM

Try two things:

1) Try unpluging the spout to remove EEC spark control.
2) The BOV is what I was going to suggest too. Disconnect and plug the vacuum to the BOV and see what happens. Is this an adjusable BOV? Draw Thru? If it is one of the typical Bosch Bypass valves then make sure it is installed in the right direction. I had Powerdyne tell me that it did not matter which direction it was installed. That is not the case. If you have positive pressure fighting the return spring on the Bypass valve then it will take a lot more vacuum to open it.

Wall96cobra · 09-28-2005, 04:03 PM

It's a blowthru setup and the BOV is a vortech mini-race which is adjustable. I was gonna let him try my bosch bypass valve in there with the mini-race, it doesn't take much vacuum at all to open the bosch and with the intercooler that is a large volume of air to try to bypass with just one BOV

86GT · 09-28-2005, 04:16 PM

If adjustable, then it should be set to 2-5 psi above the idle vacuum. If the BOV is prior to the MAF then just vent it. If it is after then it must be re-routed to the intake.

Pictures???????

Italian LX · 09-28-2005, 04:19 PM

Quote:

Originally Posted by 86GT

If the BOV is prior to the MAF then just vent it.

It is vebt to atmosphere.

Italian LX · 09-28-2005, 04:19 PM

Quote:

Originally Posted by 86GT

Pictures???????

QWKSNKE · 09-28-2005, 06:46 PM

QWKSNKE · 09-28-2005, 06:48 PM

Quote:

Originally Posted by 86GT

If adjustable, then it should be set to 2-5 psi above the idle vacuum. If the BOV is prior to the MAF then just vent it. If it is after then it must be re-routed to the intake.

Pictures???????

what do you want pics of?

86GT · 09-28-2005, 10:02 PM

I was refering to the MAF and BOV setup.

86GT · 09-28-2005, 10:06 PM

Quote:

Originally Posted by Italian LX

09-28-2005, 03:48 PM	#22
86GT Member Join Date: Mar 2005 Location: Sacramento California Posts: 449	Re: bucking Try two things: 1) Try unpluging the spout to remove EEC spark control. 2) The BOV is what I was going to suggest too. Disconnect and plug the vacuum to the BOV and see what happens. Is this an adjusable BOV? Draw Thru? If it is one of the typical Bosch Bypass valves then make sure it is installed in the right direction. I had Powerdyne tell me that it did not matter which direction it was installed. That is not the case. If you have positive pressure fighting the return spring on the Bypass valve then it will take a lot more vacuum to open it. __________________ EEC Analyzer A9M, TwEECer, 306ci, 73mm C&L w Tuner Tube, Cobra Intake, 42# inj, Edelbrock 6037, E303 cam, 155 fuel pump, FPR, 70mm TB, E-Fan, 3.55 gears, Powerdyne 9psi actual 5psi...way more.

09-28-2005, 04:03 PM	#23
Wall96cobra ooooo cake!!! Join Date: Dec 2004 Location: Saks, AL Posts: 1,630	Re: bucking It's a blowthru setup and the BOV is a vortech mini-race which is adjustable. I was gonna let him try my bosch bypass valve in there with the mini-race, it doesn't take much vacuum at all to open the bosch and with the intercooler that is a large volume of air to try to bypass with just one BOV

09-28-2005, 04:16 PM	#24
86GT Member Join Date: Mar 2005 Location: Sacramento California Posts: 449	Re: bucking If adjustable, then it should be set to 2-5 psi above the idle vacuum. If the BOV is prior to the MAF then just vent it. If it is after then it must be re-routed to the intake. Pictures??????? __________________ EEC Analyzer A9M, TwEECer, 306ci, 73mm C&L w Tuner Tube, Cobra Intake, 42# inj, Edelbrock 6037, E303 cam, 155 fuel pump, FPR, 70mm TB, E-Fan, 3.55 gears, Powerdyne 9psi actual 5psi...way more.

09-28-2005, 06:46 PM	#27
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Re: bucking __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

09-28-2005, 10:02 PM	#29
86GT Member Join Date: Mar 2005 Location: Sacramento California Posts: 449	Re: bucking I was refering to the MAF and BOV setup. __________________ EEC Analyzer A9M, TwEECer, 306ci, 73mm C&L w Tuner Tube, Cobra Intake, 42# inj, Edelbrock 6037, E303 cam, 155 fuel pump, FPR, 70mm TB, E-Fan, 3.55 gears, Powerdyne 9psi actual 5psi...way more.