Don't take your foot off the gas.

 

This happens to me on occasion. If I'm in boost and quickly feather off the throttle it'll jerk a bit. No idea what causes it. I just try to avoid it.

 

well im not on boost...

im talking crusing @ 60kp/h in 4th and then taking the foot off the accelerator..

same thing with 2nd @ 25km/h

 

It's called coasting fuel cut by DSMlinkers. DSMlink gives you the ability to push the RPM up as high as you want, or effectively disable it. IIRC, AEM calls it DFCO (Decel Fuel Cut On) and you can set it up however you want. It's strictly an emissions thing, no need to be burning fuel when you're coasting. The ECU looks for RPM over the set value, plus idle switch or throttle closed switch made, and it cuts fuel.

 

Good lord we have some smart people on this forum (no sarcasm).

 

................

 

I've had this every since I switched to the Exedy Twin w/ lightweight flywheel. I've just gotten used to taking my car out of gear everytime I decelerate heavily. Then blipping the throttle and rev-matching every time I get back on it.

It does get kind of embarrassing, jerking around.

 

Emabarrassing huh, embarrassing is setting your IC deenergize knock point to 2 counts then getting 2 counts of knock in the process of dropping a mustang. 18 psi is embarrassing when tuned for 30.

Shortly after I set the knock point to 3 counts. Too much protection can be very embarrassing

 

get a forge front motor mount...
...jerking is a thing of the past. Night and day difference

 

See I would have set the cell light to come on at 3 counts and have it pull boost at 5 counts.

Sometimes I think people go a little ape**** with the protection.

 

That would be embarrassing.

I got walked by a WRX w/ STi powertrain when I was limping around at 10psi.

 

I've had the Forge motor mount for a year and a half.

 

I have an Exedy Twin also...

Also depends on the DV/Bov you have...and what setting it's on also...too stiff / too soft...etc

 

+1 on the front motor mount. Either get a front motor mount or an ingalls stiffy and set it high. That will stop the jerking motion. All this talk about BOVs and timing and such is stuff to try if the mount/damper doesn't work. Also remember, its a transverse mounted engine; theres gonna be some rocking at low RPMs.

(I KNOW you like that proper use of the semicolon )

 

I've got the HKS SSQV. And I know exactly what you're talking about there. That's when boosting and trying to modulate throttle at higher rpms, though. This happens to me when just cruising, and releasing the gas at a fairly slow speed. I hope it's not the clutch, because I'm already on my 2nd twin disc with one rebuild in there since the February prior to last. (Long and painful story.) And I only have about 2k miles on this clutch, with extremely proper break in.

I've been told that it's just the nature of the lightweight flywheel, which I tend to believe. It's something I can live with. I just hope all the clutching I do doesn't wear out my TOB too quickly. Well, you gotta pay to play.