I recently drove a friends 01 FMII car. While driving the car I noticed that the off throttle transision is very VIOLENT . The whole car jerks ALOT when you let off from boost. Now the car does have a ACT stage one clutch so I know that starting was a biotch since I'm not used the that aggressive of a clutch yet. He also has a lightened flywheel and ONLY lowering springs (stock shocks). I have been in the hunt to do some FI on my Miata but this characteristic of his car scares me greatly. I track my car and that violent of a load shift at the wrong spot would put the car off at speed.

Is this normal for this car? My experience with Turbo cars has been all heavy Euro cars and I used to have a Turbo Integra (Upgraded clutch). None of these cars were not even remotely as bad as this. Is this something to do with the flywheel or is that just how Turbo Miata's are???????

 

What ECU is running the show? Sounds like a problem in the tune. BOV venting to atmo or recirc?

The injectors shut off when you come off throttle, so the car should roll smoothly and not jerk, kick, or stumble.

 

Hmm he has Link and BOV seems to be both. Its what ever came with the FMII Kit.

 

My clutch/flywheel would make the car act like that at times....since the rpms drop so suddenly with the flywheel being so light, if you dis-engaged the clutch while the rpms were on the rise, the car will jerk out of gear as the rpms plumpt rapidly. The tune on the Link could also be to blame. Otherwise, the thing should be smooth as silk.

 

id say either a bad tune or atmospheric BOV

 

ok so I have heard that cars with a MAF don't normally like Atmo BOV's. They normally run like poo with them (Atleast in euro land). Hmm I wonder if I can convince dude to slap a full recirc valve on his car to try it.....

Braineack-the condition would happen while in gear and just off throttle.

 

i dont buy that, since it's MAP based, not Air flow.

 

The NB Link may run off MAP, but when under vac the stock ECU runs the show. So dumping to atmo could cause problems, no?

Unfortunately the piggy link doesn't offer datalogging.

 

gotta point.

 

Ok well I shot the owner a PM on Miata.net to see if he would be willing to throw down a full recirc valve. I will let you know how it goes down

damn the emoticons own on this site!!!

 

I've had my '99 running with the voodoo box and stock MAF with my tial BOV. I had no stumble when i let off the throttle. The tial would open after reaching practically any level of boost so I say it was his tune.

 

You have a fantastic looking car if I say so myself. Much like how I hope mine ends up soon!!!

 

How's the idle with the tial BOV? What spring are you using?