If 389 is the highest rwhp with a 383, manual transmission and ported version of these heads, how does the OP get 392rwhp with a 358, unported, and automatic?

Hmmm.....

 

Variables we dont know.....

 

OP says his are ported
"They were flowed @ 270cfm's."
Puts them ballpark but not maybe as good as the LE ported ones

 

This is the same Dyno that Edmonds uses when they did the testing with the New Camaro, Mustang, Corvette and few other new cars you see on youtbue.
Heres the video1 http://www.youtube.com/watch?v=24KJe...8&feature=plcp

http://www.youtube.com/watch?v=17nKp...3&feature=plcp

 

400ishRWHP is what the 280XFI is capable of. Depending on how good the heads are, how much compression it has and how much timing your tuner can squeeze out before it starts detonating, it can go 10-15HP in either direction.

Different dyno's do read differently so comparing numbers from different people really isn't the best thing to do... espc with such a small window on power output. One mans 420 is another's 380.... I don't know why people are so hung up on comparing RWHP numbers that they don't even know where they came from....

Then again.... Yes I do. It's because 90% of the dyno racers out there never put their junk on the track so they can't do anything but speculate about how they have a 10 second car because they fanagled XXXRWHP out of it....

As for cam grinders. There are 3 guys I'd use today. These 3 guys will hit your combo dead on the first try.

Mike Jones did the cam in my 92. I'll let the motor speak for itself. Actual track results in my sig....

I have used cams from Harold Brookshire (UDHarrold) in the past. He designed alot of lobes for REED and Bullet cams bought what was left of UltraDyne Cams. 2 of his lobes (very similar to the 280XFI) are in a 383LT4 I built for blackharleyman (well documented engine build on this forum).

Chris Straub. This man went out of his way to help me fix a set of Morel lifters that got contaminated and damaged. I've bought a lot of valve train parts from him in the past couple of years and his stuff is top shelf. Very knowlegeable and good fellow to work with.

To the OP -

If you want a 12second 400RWHP car, with a good lick at idle and decent driveability and want to have what everybody else has then the Comp 280XFI is what you want.... If you want the same driveability and more power then call one the 3 cam guys I listed.
Will

 

11.45 at 121 in a A4, 2800 Vigilante, 3.73 gears with DR's. Consistently. My dyno time was to get WOT AFR, which ended up at 12.7 as I had a little over 11 to 1 Comp

 

Is this with the 280XFI or something else? What is your engine combo?

 

Yes 280 XFI, LT1 383 old AFR 195.

 

Thats about right. I'd agree, that cam is good for those power levels. Its a nice cam for a shelf piece and EFI in mind. Wide LSA does make it easier to tune with and run closed loop. I've had that cam in a 360" motor idle at 775-800 rpm all day long in closed loop. Aggressive lope to it but worked well. Motor was a high 11 second combination but had valve float and only hit 12.2's. Old AFR 190 heads and stealth ram. Budget combo that worked well for the goals.


For cams, I've used Jones for my turbo car combo one. Worked well. I have a friend who used Harold Brookshire...406 single plane EFI car that went 10.41 at 132 all motor! Drove 5 hrs from the track too. Near 20mpg. Bad **** car.
I've used Bret Bauer for my old 383 and loved it and now have his cam in my new turbo combo. I expect it to work well.


But the XFI series seem to work well with good heads. Most agree the wide LSA hurts power. YOu can always order it on a tighter LSA for no extra charge I believe.

 

I've seen this cam run High 11's in a 383 6speed C4. Trick FLow CNC 195 heads & all the goodies. It never pulled quite as hard as my 383, AFR195 / CC306 setup but it was pretty damn close and was SOOOO much nicer to drive day to day.

 

Nice to hear some positive feed back besides this cam will pass Ca. smog. It has done it so far in 4 engines including a 406 cu.

 

I would have thought that the more cubes the easier smog would be. This cam in a 350 would probably struggle.

 

http://www.youtube.com/watch?v=ss8ynx4478I

 

As long it's tune right it would not be a problem. It passed in a Super Ram and Miniram 350-406. Seen it for myself

 

Bringing this back from the dead. The IROC Z is up and running. Trickflow Heads fully ported flowing 303/217@.600 lift, Miniram 388cu and 280XFI Cam with 114LSA. 3.42 gears. Its just a dyno run for now. Will get track times sometime in January if the weather permits. 439whp@6300-399wtq@5100.

 

Congrats!

Those are good numbers and your HP and TQ peaks are where they should be considering the wider 114 Lobe centers.

You should have no trouble getting solidly in the 11's.... your a little light on rear gear with only a 3.24 ratio, but depending on tire and low gear in your tranny - It will proballly work OK.

Nice looking IROC... don't see too many clean tastefully modified 3rd Gens these days.
Will

 

Thanks!

 

Ok! Finally went to the track tonight. E.T. Sucks at 12:24 but the MPH was 119.62.
http://www.thirdgen.org/forums/south...times-san.html