Need good cam for supercharger app.

[coppergmc]

Got a 94 5.0 mustang stroked to 342 inches. 5.4 rods and forged pistons. Currently running a custom ground Erson roller cam. Car makes good power with about 348hp at the wheels. My buddy wants to go with a vortec S-trim supercharger and change the cam. The current cam chops pretty good and he would really like a smoother idle and a cam that cam still pull to 5500-5800rpm. Not quite up on the supercharger cams and thought maybe someone could tell me what they thought. Need a cam.

[squeeezer]

http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Product_Code=K35-560-8&Store_Code=CC
maybe something like this
im not a ford guy
and dont know what you got now

[squeeezer]

or
http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Product_Code=K35-306-8&Store_Code=CC

[clay]

The Ford Motorsport "E" cam isn't a bad choice. Good lift (0.498"), decent duration (220* at 0.050"). Lobe seperation is 112* I think, maybe 110* - I'll have to find that info. Buddy had one in the 94 I bought, had a slight idle chop, but barely. I believe it was a factory installed cam in some years of Cobra's. Clay

[MufflerBearings69]

I am running this cam in my 95 GT, I am naturally aspirated but this cam is still mild enough to idle fine in gear with an auto behind it... sounds a lil lopey but not bad, says in its description superchargers work well with it...

http://cranecams.com/?show=browseParts&lvl=2&prt=5&action=partSpec&partNumber=444225

http://store.summitracing.com/partdetail.asp?part=CRN%2D444225&view=1&N=700+150+

On the "E" cam- here is a link-
M-6250-E303

http://store.summitracing.com/partdetail.asp?part=FMS%2DM%2D6250%2DE303&autoview=sku

[af2]

Hmmmm, Take the same cam and widened the LSA!?
Just a thought!

[MufflerBearings69]

Stock LSA is 115 or 116 isnt it? I was told thats part of why cammed SN95 5.0s have idle issues, but I dont have the scientific background to say if thats true or not...

[squeeezer]

[96capriceMGR]

[squeeezer]

[af2]

[clay]

I sort of agree with 96capriceMGR on this one. That's why I like the "E" cam. It has a little tighter seperation that a normal "blower" cam but still not a lot of duration. Now I'm about to ramble on about cam theory that I have sort of put together from lots of reading - take it for what it's worth. Following Vizards cam philosophy, as the cubic inch goes up, the lobe seperation needs to get tighter for the same head flow to take advantage of the "fifth" cycle - exhaust scavenging aiding in pulling in the intake charge. Overall duration still needs to be in line with the application or the increased overlap will not be beneficial - for example too much duration / overlap with not enough static compression ratio. The better the heads get, the wider the seperation can get. If he is making 348 at the wheels N/A I would think he has a pretty good setup. For this displacement in carbureted form, I would think 106 - 108 would be good, but this may cause problems with idle quality in a computer controlled situation. 112* seems to be a good compromise and easily available in this situation. Another rule of thumb with centrifugals is to mostly treat it like a N/A setup to increase bottom and midrange since the centrifugal is doing nothing down there. This problem is much worse on a manual transmission setup due to more rpm drop on shifts than a properly stalled automatic. Once everything gets going and up more in the rpm range, there isn't enough time for the intake charge to get blown out of the exhaust which is one reason for the wider seperation. The other is to advance the exhaust event and start blowdown sooner to evacuate the extra exhaust volume. This is more beneficial in a nitrous setup where cylinder pressure rises to a higher level faster and it is beneficial to start exhausting sooner since most of the cylinder pressure has fallen off. Supercharged setups don't build quite as much peak cylinder pressure or as fast, but they maintain higher pressures over a longer period of time. This is a reason to delay the exhaust event slightly to make use of the pressure that is still there. Also why nitrous is harder on parts at the same power level - the more sudden pressure spikes are just harder on parts. I'll stop rambling now and I'm sure this will start a mess, keep in mind this is my opions and ideas to date and am always open to learning more. Clay

[af2]

Clay, Interesting read. I will read a bunch more before I make a statement. It sounds as if you are on track as usual!

[96capriceMGR]

I know NOTHING about the Ford motors. What I do know is 112-114 are the most common off the shelf LSA numbers for the computer controlled small block Chevys. Reasoning, and I use the term loosly, being the computer needs the wide LSA.

I also know my cam is tighter than that and I know of guys running as tight as 106 in an LT1 without any tuning hassles .
Conventional wisdom like this needs to be reexamined.

I know that there are a lot of cars with "better" setups than mine that can't touch me at the track. By better I mean ported aftermarket heads, more displacement, more duration, wider LSA, MUCH more lift etc.

A LOT of over engineering going into cars these days and rarely working.

I am NOT that experianced, I just align myself with those who have great info to offer and listen closely. I am also pretty good at reading 10 pages of garbage and pulling the one paragraph of useful information out of it. That skill does not get to work here because the average poster here is great compared to every other board I have been on, but on other boards it is the only way to learn anything.

[af2]