MPG with Radix?
11-09-2005, 08:20 PM
#11
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Originally Posted by Naked AV
There are very few hills where I live, so in general I don't go into boost unless I want to. I can set the cruise control and get 17.5 MPG (or so) all day. With 3.73's that number was closer to 20 MPG.
what do you have now...4.10's with 32" tires
11-09-2005, 08:57 PM
#12
Originally Posted by CHarris
Have you guys considered inclines in your driving areas? I have a lot of hills in my local area and a heavy vehicle so I end up in boost a lot. PE fueling AFR ratios are not conducive to good mileage!
I was in bremerton for 3 years...he's definitely right there. I didn't even think of that...my ride to work is 49 miles and I bet at least a 1/3 of it is in PE! 
11-10-2005, 02:58 AM
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MJHoward, I think a lot of your gas mileage problem may be the small pulley. I noticed in going from the stock 3.7" to a 3.25" that the engine goes into boost much more often, and that fuel economy does suffer. This is with the stock radix tune, just letting the pcm adjust itself (hasn't blown up yet 
). I can imagine that with a 3.0" pulley and a richer (proper) tune it would be worse. Also I know zip about cams, but if you are running a lot of overlap, the blower may be just pushing a lot of fuel/air right through the cylinder and out the exhaust.
Lastly, just to hijack your thread, I notice you have a manual transmission. I thought you weren't supposed to use radixes w/ manual trannys, something about the cooling system overheating ??????
). I can imagine that with a 3.0" pulley and a richer (proper) tune it would be worse. Also I know zip about cams, but if you are running a lot of overlap, the blower may be just pushing a lot of fuel/air right through the cylinder and out the exhaust.Lastly, just to hijack your thread, I notice you have a manual transmission. I thought you weren't supposed to use radixes w/ manual trannys, something about the cooling system overheating ??????
11-10-2005, 04:54 AM
#15
I Get 18.2 Highway.
With the 3.7 pulley I got a solid 18.2 all interstate going on a 500 mile run.
I do not know about the Joe Gibbs kit and the GM tune, but the Radix kit and tune it self will not hurt much if you leave it alone and control you foot accordingly.
The 20" tires, cam, smaller pulley and such are nailing you some for sure.
I do not know about the Joe Gibbs kit and the GM tune, but the Radix kit and tune it self will not hurt much if you leave it alone and control you foot accordingly.
The 20" tires, cam, smaller pulley and such are nailing you some for sure.
11-10-2005, 10:12 AM
#16
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My Joe Gibbs did not come with the radix. I installed it and purchased it from Magnacharger. It is the same kit you all have. 15mpg is all I got with the stock pulley and the stock tune. The stock tune with the 3.25 & 3.0 pulley was much richer than I am running now. That is why you can safely run a smaller pulley with the radix tune on 93 octane anyway. It is way fat! I try to keep it out of PE as much as possible but it is hard to do with this pulley. As I stated before, I have my fuel tables set at around 12.5:1 below 2800 to help out my gas mileage when it goes into PE at cruise, with the stock radix tune it would jump straight to 10.2:1 then creep up to 11.5 with the more rpms. I'm sure the cam doesn't help but it really isn't a large cam at all IMO.
11-10-2005, 07:31 PM
#19
I'll Give You My Timing @ Cruise Number Tomorrow.
Originally Posted by mjhoward
So back to the original question...Does anyone know what their timing is at cruise? Custom tune, Maggie tune?
I have 3.42 gears. Any particular speed or RPM you want me to look at?
11-10-2005, 07:55 PM
#20
Originally Posted by mjhoward
So back to the original question...Does anyone know what their timing is at cruise? Custom tune, Maggie tune?