anyone running this cam?

It sounds like you don't know what you are talking about! After thousands of hours of research and development on high horse power engines and you come out saying they are junk. Why didnt you tell them that years ago. they might have made a new design just for you... since you do know it all...
 
BB71Mopar said:
It sounds like you don't know what you are talking about! After thousands of hours of research and development on high horse power engines and you come out saying they are junk. Why didnt you tell them that years ago. they might have made a new design just for you... since you do know it all...
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Well lets put it this way. I have done a bunch of testing with mufflers. Flowmasters typically work the worst and due to the nature of how overlap works in the scavenging and filling cycle of the engine,and can be a poor choice on a badly designed exhuast system with a camshaft with alot of overlap.

Thats from raw experience.

If someone is willing to due some AB testing with a set you can find power. But if you just slap them on a car the odds of them working "as Advertised" are slim.
 
I agree with Sean. Flowmasters "generally speaking" hurt power. Go on the bullet and read all the stories about picking up 1 to 3 tenth when going to a straight through design. Don't get me wrong I have flowmaster outlaw bullets on my white notch. Heavy as hell but you can lighten them up if you wish.
 
foxbodydave said:
sorry..lol its gonna be a 306 with ported gt40 heads.
10:1 comp
1 3/4 longtubes.
c4 trans with 4k stall (or what would be better?)
3.73 gears
performer rpm intake
650 proform
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what cam are you running now? IMO...this is too much cam. You're running about the right amount of minimum compression but NOWHERE near enough gear or intake. Best combo I ran on the street was GT40Ps w/ a heavily ported Weiand Xcelerator intake, XE274H, 650dp, FRPP shorties, stock shortblock w/ the pistons reversed, and 4.56 gears w/ a T5. I eventually morphed this up to Pro Topline 180cc heads, Vic Jr intake, and this same XE284H cam you're asking about. Was too much cam for the combo. I was a little under your combo on compression and header but even w/ the 4.56 gears I wasn't supporting the cam well enough IMO. Car ran 13.0s @ 111 on a street tire w/ the small combo. 12.8s @ 113 on the same tire w/ the "big" combo (w/ a shot Trac Lok). It definitely picked up at the track but had valvetrain harmonic issues and it never made the power it should have and I used good parts. Small combo made 270+ to the tire w/ power steering and 290 by pulling the belt completely. "big" combo made about 303 w/ a manual rack.

That much cam in that CID needs to spin some RPM and you're gonna need to lose the current intake and gears IMO to make the most of it and you'd be better of going solid lifter. Better bet...bump the gears either way and knock down to that 274 stick. You'll have a monster of a combo. 3.73s are for a toolin' back and forth to work car. 4.10s minimum, 4.30s better if running 26" tire. The 4.56s if running a decent sized tire track/street (275/60 is what I ran)
 
I have a 2.5 inch X-pipe along with super 44 flowmasters on my car and it runs pretty much the same with or without it. Not sure if thats due to the low compression or not though.
 
wow thanks for the info!! its greatly appreciated
motorcitymustang said:
what cam are you running now? IMO...this is too much cam. You're running about the right amount of minimum compression but NOWHERE near enough gear or intake. Best combo I ran on the street was GT40Ps w/ a heavily ported Weiand Xcelerator intake, XE274H, 650dp, FRPP shorties, stock shortblock w/ the pistons reversed, and 4.56 gears w/ a T5. I eventually morphed this up to Pro Topline 180cc heads, Vic Jr intake, and this same XE284H cam you're asking about. Was too much cam for the combo. I was a little under your combo on compression and header but even w/ the 4.56 gears I wasn't supporting the cam well enough IMO. Car ran 13.0s @ 111 on a street tire w/ the small combo. 12.8s @ 113 on the same tire w/ the "big" combo (w/ a shot Trac Lok). It definitely picked up at the track but had valvetrain harmonic issues and it never made the power it should have and I used good parts. Small combo made 270+ to the tire w/ power steering and 290 by pulling the belt completely. "big" combo made about 303 w/ a manual rack.

That much cam in that CID needs to spin some RPM and you're gonna need to lose the current intake and gears IMO to make the most of it and you'd be better of going solid lifter. Better bet...bump the gears either way and knock down to that 274 stick. You'll have a monster of a combo. 3.73s are for a toolin' back and forth to work car. 4.10s minimum, 4.30s better if running 26" tire. The 4.56s if running a decent sized tire track/street (275/60 is what I ran)
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Solid cam, victor jr, 750dp carb, C4 w/ 4000 stall, and a 4.30 gear should run very well! Or a 4.56 with 28 inch tires as "Motorcitymustang" stated.

I had a 306 with a similar combo (higher compression though) and it ran very well. It was a 5 speed though...
 
well i am going back and fourth on the c4 or a t5 setup. its gonna be 80% street car so im thinking a stick would be fun. and i can row gears very well for when i do race it.
 
Do the T5 and get yourself the OD. Run 4.30s or higher and it'll still be completely streetable & be an absolute blast to drive. I drove those combos daily all year long w/ the only change being jetting and a switch to skinny, siped M&S's.
 
foxbodydave said:
well i am going back and fourth on the c4 or a t5 setup. its gonna be 80% street car so im thinking a stick would be fun. and i can row gears very well for when i do race it.
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I do miss the 5 speed but I love having the C4. I don't drive my car a whole lot so going to an auto made more sense.
 
Sean said:
that where things get interesting with a reflection design muffler. If you attenuate the muffler correctly "nearly impossiable with most floor pan layouts" the flowmaster can actually become a scavenging device.
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FYI - attenuation is defined as a reduction of something using something else - you can attenuate a value (like sound pressure or sound power) but you can't attenuate a thing (ie a muffler). Now you could use a muffler to attenuate something like sound by say tuning it for a certain frequency but it would be silly to try and promote scavanging this way. If you are trying to tune for scavanging and you are tuning for it in the muffler you are in the wrong place - the opportunities are much more in the header/manifold than anywhere else in the exhaust system.
 
when you attenuate "tune the length of the pipe" you can use ,If you have room "most cars don't", the length of the pipe to put the muffler into a placement whereby it actually sets the exhuast pulse and exhuast pulse timming into a place where the muffler starts to scavenege. This only applys to systems that use Flowmaster or similar sound reflection design mufflers. If you want some really good science on this contact CORSA they do alot of work in this area.

Treat the Pipe like a port on a band pass. If the port is to long or to short the box will not perform well and in most cases performance will suffer. Get the port length just right and you get a nice boost in a certain frequency band.

The exact same effect happens in a engine. If we are running at a frequency of roughly 400-500hz across the power band "wild number thrown out there, I don't feel like doing the math" and we have a bandpass designed muffler the port length on both the input and output side must be right or we can put the tunning outside of the bandpass's effective tunning range.

Engines have accoustic properties and if we get them wrong power will suffer. If we get them right power is increased.

I absolutely agree however that there is alot of be had in the collector but if you put on a accoustical tuned muffler and ignore the accoustics of the system it Could hurt power.

Hence why I siad. Striaght through mufflers. They don't really have any effect on header behavior that worth noting unless they are louvered in design and thats just bad overall.



90blknotch said:
FYI - attenuation is defined as a reduction of something using something else - you can attenuate a value (like sound pressure or sound power) but you can't attenuate a thing (ie a muffler). Now you could use a muffler to attenuate something like sound by say tuning it for a certain frequency but it would be silly to try and promote scavanging this way. If you are trying to tune for scavanging and you are tuning for it in the muffler you are in the wrong place - the opportunities are much more in the header/manifold than anywhere else in the exhaust system.
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I run a Edelbrock rpm Cam # EDL-7122 with damn near what you are running and it runs good and is very street friendly, BTW it likes spray to, check it out
224/234 @ .50, .496/.520 112 ls
 
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E'bok cams a nice bang for the buck. I had the small Performer cam in it b4 I freshened the shortblock and did the piston reversal. That ran mid to high 13s w/ the P heads & the intake only port matched. You'll get nicer ramp profiles (.200 numbers for example) on those Comp X grinds though.
 
im gonna run the comp cam i listed. although i did manage to scoop up a windsor shortblock. its just a 357 and ill still be using the p heads, and a rpm cam still. i am planning on spraying this motor too with a 150-200 shot
 
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