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

Here's a thought...

Old 05-04-2008, 11:36 AM
Thread Starter
Join Date: Apr 2008
Posts: 1
Total Cats: 0
Default Here's a thought...

Ok, I'm pretty sure I'm running a bit rich. No, I don't yet have a wideband sensor, but based on the gas mileage I'm getting and some things I've read about the JR M45 being a little rich, I think I'm close to right. SO. I'm sitting right at 5psi right now. I have the JR BTC, so I can adjust ignition timing to some extent. I also have their RRFPR (which apparently is blamed for richness). Would it make sense to get a slightly smaller nose pulley? It would up the boost a little more. Which could even out the AFR, and take care of the richness. And then retard spark a bit.


Would that setup just make more boost with the same richness problem?

I want megasquirt and an intercooler, basically.
Eryan36 is offline  
Old 05-04-2008, 01:47 PM
Elite Member
iTrader: (5)
akaryrye's Avatar
Join Date: Jul 2006
Location: Central California
Posts: 2,510
Total Cats: 0

There may be a reason that JR designed the setup to run rich. I think those blowers can heat up the air a good bit (more than a turbo) and without an intercooler, I bet intake temps get pretty high ... especially on a hot day. That extra fuel might be what keeps you from detonating. However, if you do go with the other pulley and you dont have to pull more than a few degrees of timing without detonation then go for it.

Also, you do realize that the RRFPR does nothing until you tip into boost right? This means that you should get normal gas mileage if you drive mostly out of boost ... on the flip side, with any forced induction you are putting more oxygen into the motor and it simply uses more fuel, but only when in boost. One more thing to consider is drag on the motor caused by the supercharger ... but i dunno how much of an effect that has.

good luck mate, hope that helps
akaryrye is offline  
Old 05-12-2008, 09:05 PM
Junior Member
Join Date: May 2007
Location: Toronto Area, Ontario
Posts: 168
Total Cats: 41

Also, you do realize that the RRFPR does nothing until you tip into boost right?

unless you have a very heavy foot, your gas mileage is probably more related to condition of plugs etc.

what kind of mileage are you getting?
oreo is offline  
Old 05-12-2008, 10:21 PM
Senior Member
iTrader: (7)
Join Date: Mar 2005
Location: VT
Posts: 939
Total Cats: 0

Do yourself a favor and invest in a WBO2.

I have both the LC-1 and the Zeitonix ZT2, both are excellent units.

I'm running a smaller pulley, and heat is a concern (my intake takes it from lower rightside of the car), (near ambient, more of a direct shot into the intake, which on my car is against the passenger firewall).

What plugs and gap are you running?
Jefe is offline  
Old 05-13-2008, 02:22 PM
Senior Member
steelrat's Avatar
Join Date: Jul 2005
Posts: 513
Total Cats: 0

Have you got a fuel pressure gauge? The JR AFPR normally is adjusted to increase the pressure in the rail to around 50 or 54 psi (without the vac hose connected). So you might be spraying a little more than stock @ idle/off boost, but not much.

Have you retarded the timing too much with the BTC?

Also as a thought, check your by-pass valve. Make sure it's still working, otherwise, the blower could be producing boost more of the "idle time".... and it will heat the charge a lot more, so you'll need to retard the timing more.

steelrat is offline  
Related Topics
Thread Starter
Last Post
Insert BS here
03-03-2013 03:00 PM
Insert BS here
01-27-2010 07:16 PM
Engine Performance
12-17-2009 12:52 PM
General Miata Chat
04-22-2009 04:06 PM
Insert BS here
04-10-2008 11:43 PM

Thread Tools
Search this Thread
Quick Reply: Here's a thought...

Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.