Lowest AFR target for low boost track car - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Supercharger Discussion For all you misguided souls.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 04-03-2016, 10:26 AM   #1
Junior Member
Thread Starter
 
Join Date: Dec 2010
Posts: 403
Total Cats: 3
Default Lowest AFR target for low boost track car

Folks,

I'm running the 90mm pulley on my Kraftwerks Rotrex-equipped '99 HPDE car. She's hitting just shy of 7 pounds boost at WOT and about 6800 rpm, and I'm seeing around 10.8 AFR. I'm making some changes that require a re-tune--removing the gutted MAF and adding a sealed cold air duct. Should/could I have it leaned out just a bit at WOT?

Thanks,

poormxdad
poormxdad is offline   Reply With Quote
Old 04-03-2016, 12:15 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,867
Total Cats: 1,790
Default

there's no reason to run that rich. Us turbo folks like to target 11.8:1. S/C setups can get away with slightly leaner. I'd be targeting ~12:1; no leaner.
Braineack is offline   Reply With Quote
Old 05-20-2016, 06:06 PM   #3
Newb
 
Join Date: Mar 2016
Location: Bay Area
Posts: 30
Total Cats: 5
Default

I'm at a solid 11.5 AFR from 4k-7k. My car has seen over 20 track days at 8-12 lbs boost pressure(Rotrex c30-74 with 80mm pulley). I'd be more concerned with your timing map honestly..
HomebrewYata is offline   Reply With Quote
Old 05-22-2016, 03:00 PM   #4
Junior Member
Thread Starter
 
Join Date: Dec 2010
Posts: 403
Total Cats: 3
Default

Quote:
Originally Posted by HomebrewYata View Post
I'm at a solid 11.5 AFR from 4k-7k. My car has seen over 20 track days at 8-12 lbs boost pressure(Rotrex c30-74 with 80mm pulley). I'd be more concerned with your timing map honestly..
Your post reads like you're talking about my particular timing map?
poormxdad is offline   Reply With Quote
Old 05-22-2016, 03:05 PM   #5
Newb
 
Join Date: Mar 2016
Location: Bay Area
Posts: 30
Total Cats: 5
Default

Quote:
Originally Posted by poormxdad View Post
Your post reads like you're talking about my particular timing map?
Sorry for the confusion. I was only trying to stress the relative importance of a solid ignition map. There's no magic AFR target to follow, I run something that makes good power but below 12:1
HomebrewYata is offline   Reply With Quote
Old 05-22-2016, 08:43 PM   #6
Junior Member
Thread Starter
 
Join Date: Dec 2010
Posts: 403
Total Cats: 3
Default

No worries. I asked the question because there has to be a compromise between using richness to help cool the motor, and having too much fuel contaminating the oil.
poormxdad is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Closed loop boost control starting numbers HeresJohnny MEGAsquirt 14 09-26-2017 09:53 AM
Mobile ads are bullshit aidandj Front Desk 16 05-18-2016 03:18 PM
Uber Ghetto Tupperware Airbox / Cold Air Intake zossy1 Engine Performance 24 04-10-2016 09:33 AM
Link Map sensor and air temp sensor kww502 Miata parts for sale/trade 4 04-05-2016 08:40 PM
Is this stupid idea even worth pursuing: Flipping an air cooled 911 skidude Insert BS here 9 04-01-2016 10:13 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 01:24 PM.