Kinda strange experince - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 04-17-2007, 09:25 PM   #1
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2007
Location: St Louis Park MN
Posts: 163
Total Cats: 0
Question Kinda strange experince

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???????

Last edited by Strider; 04-17-2007 at 09:55 PM.
Strider is offline   Reply With Quote
Old 04-17-2007, 09:39 PM   #2
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

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.
Ben is offline   Reply With Quote
Old 04-17-2007, 09:50 PM   #3
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2007
Location: St Louis Park MN
Posts: 163
Total Cats: 0
Default

Hmm he has Link and BOV seems to be both. Its what ever came with the FMII Kit.
Strider is offline   Reply With Quote
Old 04-17-2007, 09:53 PM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

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.
Braineack is offline   Reply With Quote
Old 04-17-2007, 09:55 PM   #5
I'm Miserable!
iTrader: (1)
 
Join Date: Oct 2005
Location: Columbia, SC
Posts: 858
Total Cats: 0
Default

id say either a bad tune or atmospheric BOV
SloS13 is offline   Reply With Quote
Old 04-17-2007, 10:00 PM   #6
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2007
Location: St Louis Park MN
Posts: 163
Total Cats: 0
Default

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.
Strider is offline   Reply With Quote
Old 04-17-2007, 10:04 PM   #7
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

i dont buy that, since it's MAP based, not Air flow.
Braineack is offline   Reply With Quote
Old 04-17-2007, 10:09 PM   #8
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

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.
Ben is offline   Reply With Quote
Old 04-17-2007, 11:21 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

gotta point.
Braineack is offline   Reply With Quote
Old 04-18-2007, 01:30 AM   #10
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2007
Location: St Louis Park MN
Posts: 163
Total Cats: 0
Default

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!!!
Strider is offline   Reply With Quote
Old 04-18-2007, 01:35 AM   #11
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

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.
cjernigan is offline   Reply With Quote
Old 04-18-2007, 07:05 PM   #12
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2007
Location: St Louis Park MN
Posts: 163
Total Cats: 0
Default

Quote:
Originally Posted by cjernigan View Post
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!!!
Strider is offline   Reply With Quote
Old 04-18-2007, 07:41 PM   #13
Senior Member
 
Join Date: Jun 2005
Location: WA
Posts: 500
Total Cats: 0
Default

Quote:
Originally Posted by cjernigan View Post
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.
How's the idle with the tial BOV? What spring are you using?
RusMan is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Need help - Stock Balancer and Fastforward overlay pulleys Frank_and_Beans Supercharger Discussion 13 09-12-2016 09:17 PM
Old guy buys old Miata b&t Meet and Greet 3 09-22-2015 10:32 AM
1997 Miata Misty_Miata pineda92 Meet and Greet 4 09-20-2015 10:22 PM
Noobie first post p51ofaces Meet and Greet 6 09-17-2015 10:08 AM
VE values too low? compuw22c MEGAsquirt 4 09-12-2015 08:42 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:37 AM.