I need more air.........
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
I need more air.........
At least my tuner says I do. I finally got a WOT data log to him. I'm runninga OE intake with a cut lid and a K&N. Here's what he had to say........
Two things I noticed are that your airflow reading is not very high considering your mods. I would think it should be a good bit over 300 gm/s, but yours is just barely breaking that. The other thing is that your MAP reading is not staying close to 100 KPa at WOT, which usually indicates an airflow restriction or valve float (could be related to the low airflow reading).I would check out that in the meantime.
As far as the valve float I upgraded the springs on the AFR's to the next size springs(8019 I believe). I knew I was close to their standard springs with the lift I have plus the 1.6 rockers. Thoughts?
Spring specs
AFR-8019
1.270 OD Size
155# @1.810 Pressure
1.080 coil bind
428 Rate
650 Max lift
Premium Grade
Two things I noticed are that your airflow reading is not very high considering your mods. I would think it should be a good bit over 300 gm/s, but yours is just barely breaking that. The other thing is that your MAP reading is not staying close to 100 KPa at WOT, which usually indicates an airflow restriction or valve float (could be related to the low airflow reading).I would check out that in the meantime.
As far as the valve float I upgraded the springs on the AFR's to the next size springs(8019 I believe). I knew I was close to their standard springs with the lift I have plus the 1.6 rockers. Thoughts?
Spring specs
AFR-8019
1.270 OD Size
155# @1.810 Pressure
1.080 coil bind
428 Rate
650 Max lift
Premium Grade
Last edited by Weav's Vet; Jun 25, 2010 at 01:22 AM.
Race Director
Joined: Jun 2004
Posts: 13,957
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From: WI
You could try a simple air filter mod and see if it makes a difference. I read some posts from d48mclain about using two air filters. One with the filter media removed and used as a spacer. I was really skeptical of it working but give it a try. Here is what he said about it in email: "The single stock filter sits real close to the bottom of the intake and there isn’t much room for air to come up from the bottom. All the second filter is a spacer to open up the area so air can flow."
Safety Car
Joined: Sep 2001
Posts: 4,157
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From: Glenbeulah Wi
My estimate is that 300 gm/s is close to 475 HP at the crank. When I look at the mods in your sig this does not appear to be out of line. How low was the MAP reading? If the MAP reading is real low that would indicate an airflow restriction. The valve spring appear OK to me, how high do you rev the car?
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
My estimate is that 300 gm/s is close to 475 HP at the crank. When I look at the mods in your sig this does not appear to be out of line. How low was the MAP reading? If the MAP reading is real low that would indicate an airflow restriction. The valve spring appear OK to me, how high do you rev the car?
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 553
From: Glenbeulah Wi
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
I've been looking at after market air intakes but the pickings are slim for anything that looks like it may help. There's a C5 twin filter one I may get and try. I'll have to do some kind of piping though to get it up to the MAF sensor.
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Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
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From: Sandhills of North Carolina
I can do that
Race Director
Joined: Jan 2005
Posts: 10,641
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From: Slidell Louisiana
What was the highest AFGMS you saw on your datalog....
Mike
Last edited by aboatguy; Jun 24, 2010 at 06:45 PM.
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
Could it something on the other end, the exhaust? I had the cutouts closed when I made this WOT run. How about cats? Partially plugged maybe? Headers 1 5/8, maybe 1 3/4 would be better. I mean the air has to get out as fast as it's coming in, right?
Race Director
Joined: Jan 2005
Posts: 10,641
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From: Slidell Louisiana
A while back I was looking for intake track improvements and I had lower MAF readings (at speed) with the airfilter removed so the filter was not a restriction on my car.
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
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From: Sandhills of North Carolina
Team Owner
Joined: Mar 2001
Posts: 30,847
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From: Boston, Dallas, Detroit, SoCal, back to Boston MA
how old are they
what did you install? (I see longtubes in you sig)
Melting Slicks
Joined: Feb 2008
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From: Palm Beach
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
Down at the track last year in one of my moments of total stupidity I ran about 3 gallons of 112 octane through them. I was lower on gas than I had thought so I got that to make my runs and make sure I made it home. I guess there might have been 3 gals or less in the tank of 93 octane so it was a 50/50 mix more or less. I ended up replacing the O2's because of the lead and after that and it seemed to run ok so I didn't really question the cats anymore. (Lesson learned!) Now I am though since they are being put to the test here with exhaust flow.
Safety Car
Joined: Sep 2000
Posts: 3,524
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From: Hinckley Ohio
really stupid thought, maybe your throttle body is not going fully open??
..for sure your problem, based on drooping MAP, is on the intake side
