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Discussion Starter #1
I've been wanting to put a solid Comp cam and better intake on the 396, decided to just try the manifold and see what it'll do. The current cam is supposed to have a 1500-5800 RPM powerband, but it really drops off after 5400. So, taking it one step at a time, see if the Action + is what is holding it back and the RPM Air Gap makes a difference.

Main motivation is to get under 13.80 consistently at 5800' Bandimere. That's the max allowed dial-in for a Fall Series non-box class that has a pay-out. They're also running a Sportsman class that allows slower dial-in, but it's trophy-only.

Summit says it's been shipped, I paided the ransom for 2nd day delivery, hopefully it will be here by tomorrow so I can get it on by Friday. The 1st race of the Fall series is Saturday, but there's a Club race on Friday, and I'd like to be able to make some passes with it before it counts.

The other choice is to remove weight, such as the front passenger seat and front bumper (and I would consider bumper removal a "drastic" step).
 

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Hopefully the intake works well for you. I have one on my 406 and it definately makes power above 5400.

What are the cam specs; current and proposed?
 

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Discussion Starter #3
The current hydraulic is 270 advertised, 220 @ .050", .510" lift (single pattern). The proposed solid lifter cam is a Comp Xtreme Energy XS274, 274/280 advertised, 236/242 @ .050", .568/.578" lift, 2000-6400 RPM powerband - recommended by Comp knowing what the car is, what it has or I was willing to get (like the intake manifold), and it's intended use. Obviously a lot more cam than I have now.
 

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Discussion Starter #5
I've had several 13.7x time slips this year, and one wind-assisted 13.68. But, 13.8x has accompanied the others every time. In the fall, the density typically stays below 9000', sometimes getting into the 6's. Lowest I think I've run so far this year is 7500'.

It will be interesting to see what effect the manifold has. I've always accompanied such changes with others, so never have a manifold-only change to make direct comparisons.

UPS says the package is out for delivery this morning. Should be at the doorstep soon. I'll get started on it tonight (actually started last night by draining the coolant), have the day off tomorrow, should be ready to go Friday afternoon.
 

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Hopefully UPS doesn't let you down. :) Let us know what happens.
 

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Discussion Starter #7
Brown delivered, about 12:30 p.m. Thursday. I got the Action+ off and the RPM torqued down last night, I need to get to the parts store for some brass fittings (block off the rear coolant passages, which the Weiand didn't have, and get a different vacuum fitting for the rear runner - the hose nipple interfers with the runner now), and a coolant by-pass hose - the RPM sits up higher in that area.

Will also have to eliminate the thick carb gasket that goes with the Holley heat shield. The air cleaner nut kisses the hood brace with it now.

Should have it back together and will have results after tonight. If things go as expected, I'll have to sandbag tonight, as the class I run in for this series has a 14.00 minimum dial-in. Then see if I can cut it for the 13.80 max dial-in class Saturday.
 

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Discussion Starter #8
After getting it running and things adjusted (timing, mostly), took it out to the track. It felt and sounded different on the street, but you never know if that's just what you think it should be like, or if it really is different.

After getting to the track and mounting the Hoosiers, it started raining. That lasted about a half hour, humidity was up, took them another hour and a half to dry and prep the track. The car never likes longs waits like that, or humidity, but at least the wind was calm. Previous best without wind assist was 13.733/97.16 shifting at 5400 RPMs, first TT was a 13.706 @ 98.36 shifting at 5600. I was in the 2nd pair to report to the staging lanes, they gave us first 4 an extra pass (usually only get 2 on race day), so 25 minutes later it ran 13.659 @ 98.36. The last TT traction went away, so it was back to 13.76.

So, better on all three ends of the track - 60' (about 2 hundredths), half track (almost a mile an hour), and top end.

Funny, it actually felt "lazy" going down the track, although it reved to the top end much more smoothly. I guess the difference is that it just runs "flatter" now.

The exhaust tone difference is probably due to not having blocked off the cross-over passage on the Action+. I thought I had, but discovered when I pulled it off that I hadn't. The Air Gap doesn't have the passage at all.

Overall, I think I'm happy.
 

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Discussion Starter #9
It pulled off a couple of 13.62's Saturday, even though it was hot out and my radiator fan motor burned out after the 1st time trial. I cheated a little, pulled the passenger front seat out, which was good for about 45 pounds. But, it ran solidly under the 13.80 requirement.
 

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Discussion Starter #11
The DA was pretty high (thin air) for the fall. I was a little surprised at that.

Next race is Sept 23rd. Hopefully I'll have time to get the fan fixed, adjust the valves (I'll be replacing the adjusting nuts, they aren't locking very well), after getting the wife's Bonneville running, of course.
 

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Some have said the AG intake was concieved as a marketing gimmick...I don't care though...I run one (ceramic coated even) and I love it.
 

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Discussion Starter #13
My electric radiator fan motor failed after the first time trial last weekend. I was having to point the car into the wind in the pits to cool it down between runs. I don't have any clue if the Air Gap contributed to it, but I never had any trouble getting it cool enough for the next run. Normally, getting it cool between rounds has been a task that requires my attention, even with the fan operating.

The vast majority of factory manifolds that I've seen make some provision to isolate the runners from the valley oil. There must be solid science behind the effort.
 

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five7kid said:
My electric radiator fan motor failed after the first time trial last weekend. I was having to point the car into the wind in the pits to cool it down between runs. I don't have any clue if the Air Gap contributed to it, but I never had any trouble getting it cool enough for the next run. Normally, getting it cool between rounds has been a task that requires my attention, even with the fan operating.

The vast majority of factory manifolds that I've seen make some provision to isolate the runners from the valley oil. There must be solid science behind the effort.
The proof (or lack thereof) is that several folks have dyno'd the AG, and found no appreciable difference between it and a Performer RPM unit.
 

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Discussion Starter #15
Whether or not it makes more power than a non-AG RPM isn't the issue, as far as I'm concerned. Getting consistent power round-to-round is the issue. When the rounds start coming closer and closer together, it becomes critical.
 

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I run an rpm air gap on 2 cars, the monza and the chevelle. When I built the chevelle motor I went with alot of suggestions and help from AFR. I purchased their CNC ported aluminum heads and from there we built the engine around that. With a somewhat large custom ground roller cam and heads that flow over 370 cfm on the intake side, AFR knew the engine would make most power with a single plane victor jr but since my chevelle is mainly street driven and weighs a hefty 4,108 lbs. they thought the rpm air gap was better suited. It's their dual plane intake of choice so I went with it. Although mine runs better et's with a 1 inch open spacer on top of it, my motor loves to rev and I generally shift in the 6,300 rpm range where the motor is still making great power. I can stretch it a little more for about .05 or so, but not worth the abuse though. I am very happy with the intake. So much so I installed one on the Monza with it's 406 sb and love it. Glad to hear you are liking yours. Larry.
 

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Discussion Starter #17
Well, my last post on this thread was over a year ago. Since then I've also added a Comp XS282 solid flat tappet cam. That has produced a best of 13.30 at a tick over 100 mph shifting at 6200 RPMs, with 13.4's very common. Other changes are keeping the passenger seat in, about 30 pounds more in the driver's seat, and converting to E85. The Air Gap part of the last mod probably is a contra-indication, as the ethanol in E85 tends to need heat to get it vaporized by the time it gets to the combustion chamber. I never got a full run at sea level when I was at Topeka last month (a couple of factors there, one being only being able to dial 13.00 and slower in my class, the other being not trying that hard to tune it for the elevation), but it would probably be capable of 12.5's at its 3900 pounds running weight.

It would probably do better with a single plane as well with this cam. So, we'll see how long it takes me to decide to go with the Victor Jr.
 

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Thats, cool. You are widdling away at the time.
You will really have to increase the jetting to run that E85 to get the car back to where it is.
Is that something that is being forced on the public where you are or just something you want to try? We don't really have much of that where I live but I have heard some states are really taking hold of it.
Larry.
 

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Discussion Starter #19
The E85 was something I wanted to try. There are two stations currently in the Denver metro area that carry it. One big advantage to it is the engine has to be warmer for it to run right, while I was having issues keeping the engine cool enough to get it to run right on gasoline.

I definately tuned for E85. You can see the improvement in times I was running last year vs. this, even with the handicap of additional weight this year, due to the cam change. It probably would have been a little quicker on gasoline with the new cam, but it was plenty quicker with E85. All of those comparisons were at 5800' elevation; what I was saying is I didn't spend a lot of time to get it tuned on E85 at sea level for that one weekend of running. It ran fine, just probably not as quick as it could have at sea level with more fine tuning (I was having to slow it down for the class I was running in, anyway, so running quicker would have been for bragging rights only).
 
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