Cam's Effect on Exhuast Note

[DocBowtie]

I'm contemplating purchasing a true dual setup from Lane's, he's local to me so its gravy gettin it done on one of my off days from school. However, after hearing his setup both w/ and w/o a trex in it, I would like to know how radical an effect a 23x cam would have on the duals compared to my stock cam. Obviously its a big jump, but I loved the way the duals sounded w/the stock cam on my buddy's car, I don't want it to get nearly as loud as when he had the Trex in it.

Right now my plans include an FM-9 from Futral cuz I can get a pretty good deal on one, and its a perfect cam for the D1SC kit I plan on getting in the future. I don't mind losing 5-10rw to the F13 so don't even mind that. How much louder will that cam(specs 232/236 585/600 114) make a 3" true dual system over stock? I'm not sorry for the long post either, I would like some specific answers so get to answerin people!! :whip:

Oh yea, almost forgot. TIA!!

[mySStery_machine]

I think I told you what I thought...or did I? Damn, I've been so busy lately I forget. Did I even get your LS7 email yet?

[DocBowtie]

thats a negative to both of those john. no rush on either tho, lol. let me know if there's any way i can help w/anything around here.

[obseSSed]

My 231/237 changed my exhaust sound through the complete range. I run long tubes with a corsa. If I had to describe it I would say that is was sharper more krisp. Don't know it that will help you but it is input none the less.

[DocBowtie]

did it get any louder tho? across the range?

[obseSSed]

No it did not get louder, just sharper, the only place I would say it was louder was at idle. Hope that makes sense

[DocBowtie]

yea it does. I just don't want duals to get too insane after the cam.

[c6z06]

Duals and a Cam sound AMAZING-jsut depends on what you like- you want a smoothe idle- get something with negative degrees calculated overlap

(IKnt. Dur+Exh. Dur) (divided by 4) (minus LSA) (Times 2)
= Overlap

TR224= -4° Overlap-that has a smooth but mechanical soudning idle-thats probably the biggest i would go if you want smooth-
(also good for emissions

if you want choppy idle- Positive overlap :judge: you will love the sound in the range no matter what!

[DocBowtie]

hahaha, the cam i'm looking at came out with 6* overlap.....FM9. i'm not really lookin for idle quality, its LOUDNESS that i'm worried about. i don't want the duals to get 3x as loud like my friend's did with the Trex. granted, thats a much bigger cam, but still. know what i'm sayin?

btw, 02WS6, if you have any more nifty formula's like that PM them to me or post them up in my formula's thread, i'm trying to write a little program with them all in there that will be able to be integrated here on the site as a popup or something. i'll make sure your name will go on the thank you's ;)

[enisguy]

A 114 LSA cam doesn't sound like a "perfect blower cam" to me...

[DocBowtie]

Let me clarify myself. That cam would perform well enough NA, but would wake up nicely with the power adder. VERY nicely. Allan has said this is a SC/N2O cam himself. If you think otherwise, I'd love to hear why you think so. I'm thinking of purchasing it, so I'd like to hear all sides. :beer:

[enisguy]

Let me clarify myself. That cam would perform well enough NA, but would wake up nicely with the power adder. VERY nicely. Allan has said this is a SC/N2O cam himself. If you think otherwise, I'd love to hear why you think so. I'm thinking of purchasing it, so I'd like to hear all sides. :beer:

114 LSA is a lot of overlap for FI... you are going to blow a lot of boost right out the exhaust valve still open on the intake stroke...

On an N/A engine, overlap works because the vacuum created by the exhaust scavenging helps to pull the intake air into the cylinder... but if it's a FI car, the boost ends up flowing right through to cylinder and out the still open exhaust valve. SO saying that a certain cam is great for an N/A engine, and therefore must be fantastic on a FI motor is compltely untrue...

It's not TERRIBLE or anything... and you can always blow more boost to compensate I think... but it seems like a pretty aggressive LSA number for boost to me.

[DocBowtie]

i get what you're sayin now. and you're completely right, its not a GREAT boost cam. but its a good NA cam for my purposes, and a good starter cam for when i put the D1SC on until i crank the boost up past the stock levels. ideally a 117 or 118 would be better, i agree. but i'm not willing to drive around NA with that kind of LSA for a year or two, so......give and take.

however, right now i'm tetering on the edge of whether i'm going to stick with SC, or go over to the turbo side. in which case i'd instantly switch cams as soon as the turbo goes on, and its a moot point alltogether!! either way FI is at least a year or two out, at the very soonest. poor college kids can't ball like microzon or Nineball with stables of cars :P