hi guys. gathering parts to do a engine swap in my c4. switching to a carb, as i posted in a previous thread. anyway, im pretty sure a performer will clear the hood, not sure if the rpm will. will the manifold feed a 383?? i figure the engine will top out between 5500 and 6000, so its in the right rpm range, just wondered if it would move enough air. thanks. regards, j.d.

 

I'm using the Performer, with Vortec heads, on my 383. It seems to flatten out above 5500, but that could be due to the cam also (see sig.) Hope this helps.

 

With the right set-up a small block can make 400hp with a Performer ... I've seen it .

Here's what a Performer 180 degree manifold flows

Edelbrock Performer (not RPM, not Air-Gap) .....
There are two sides, one "low side" which has smaller runners, and one "high side" that has larger runners.

Low side - 238CFM @28" H2O
High side - 278CFM @28" H2O

Section out some of the plenum divider for a gain in top end power w/o negatives to the low end , if done right .

 

Yes, the 2101 is good for over 430. Have posted that several times since some here have low rise hoods.
(The 73-79 med. rise can handle the RPM.) :cool:
Also, the divider can be cut or use the air gap Performer (+ about 1/4" over 2101) depending on your setup & clearance. You might want to state cam & carb.
While I would not expect you to use an early one, it is said the originals were smaller.

 

i doubt you could pull to 6000 with the performer

 

MM could you email me as I lost my addresses and phone #'s. :banghead:

 

I am running a Performer manifold on mine. The carb is an Edlebrock Q-Jet (Performer Series too) flowing 795 CFM. Very strong right up til my cam's limit which is 5500 RPM.

 

Curtis (mountainmotor) has posted several times over 400 on a 350 & I have said over 430 on a 383,

recently WA 2 FST posted:

... It was performed at Westech Performance Group, and used an engine dyno. You can find the results in the Oct. 2003 issue of Corvette Fever. Sometimes the mag is full of fluff, but sometimes they actually have some interesting reading.
The engine was as follows:
355ci
10.0:1 CR
AFR 190 heads
"mild Comp Cams hyd. roller cam" (no specs listed)
BG 750 Mighty Demon carb
MSD ignition

Performer
Avg. TQ: 406
Avg. HP: 365
Peak TQ: 430 @ 4500rpm
Peak HP: 438 @ 6100rpm

dewcustom
A good estimate on your part.

 

I'll take a 'mild hyd roller cam' that puts puts out 430hp/438tq on a 355 sb.

:skep:

 

Here is a dyno graph of Comp Cams XR288HR-10 on a 356ci sbc with high rpm goodies, it is down 50tq and on only giving 408hp at 6100 rpm's.

http://compcams.com/Technical/DynoSh...8HR-10_001.asp

 

thanks guys. appreciate the info.

ganey/mountain motor. any tips on where and how deep to cut the center divider??

thaks again fellas. regards. j.d.

 

It'll feed it.. but depending on your built - it'll cost you between 15 and 30+ horsepower compared to performance intakes..

 

I agree on the 15 to 30 hp - on a bunch of dyno reports I've seen,
with 220 to 230 / 500 type cams and decent heads, the RPM & AIR Gap
RPMs gave about that much extra power along with more torque pretty
much from 2500 rpm on up, surprisingly.

Back in 67, I had a 396/375 hp Camaro - swapped on an L88 intake
w/950 3bbl dbl pump mech 2nds, the intake had the center milled down
I think over an inch if not most all the way out. Really woke the engine up over
about 4000. Also had a hopped 426 Street Hemi with the factory SS carb &
intake package - the intake also had the dividers milled down I think
to only about 3/4" high - course both these were relatively higher cubes and had fairly high torque and hp peaks. With more of a daily driver street rpm engine with less cubes, you might want to try 3/4" at first, and maybe try it 1/4" or less at a time from there - at some point you're going to level off and then start losing low/mid range torque at the expense of your higher rpm hp. You'd probably want to target the torque peak of your cam/head combo.

I'm in the same dilemma - trying to see if there's a way to fit an RPM type
under a stock 81 hood. I've read about drop base air cleaners (I suppose
if you drop too deep you cut off airflow anyway) - I'm going to post to see
if anyone has used thicker body mounts to get the body up maybe an
inch or so - just to make up the difference on the height difference between
the 2 intakes. New to Vette's, so not sure if that's even workable. I'll find out.

I'm sure there's lots of posts in the archives, too - guess I'll also try that.

 

You get another 10 peak HP when using a ported Victor jr... I personally wouldn't go with a dual plane intake for a performance application... The loss of bottom end torque isn't all that much that it wouldn't be worth to run a single plane.. I would only consider a dual plane intake for pure street applications...


[Modified by GrandSportC3, 5:25 PM 1/11/2004]

 

the engine thats going in will have almost exactly those cam specs. 222/230 duration, 509/528 lift. its the zz383 from scroggins dickey. it was dynoed with a gm single plane and 1 3/4 headers. the website says a dual plane will lose 20 to 25 hp. not sure about the torque loss. probably consistant with hp. hp peaks at about 5400. tq at 4500.

my thoughts are that even with the loss of hp with the dual plane, i should still get 300 hp to the wheels and maybe 350 tq, maybe a little better.

" I would only consider a dual plane intake for pure street applications... "

point well taken. in fact it will be a street app. possibly a few runs down the strip to see what it will do, but basically a daily driver. complete with a/c etc. im hoping with the 1 3/4 headers, it will breath well enough to get me 300 hp at the wheels. if i can get low 13s.high 12s ill be a happy vetter. at least ill have some kind of prayer against my bosses c5.

thanks again for all the input guys. some interesting and informative reading. gotta love this forum :D regards, j.d.

 

Well - on those few passes down the strip - you could be 3 tenths or more faster with a Victor Jr. :D :D . That's HUGE in Drag Racing.. but if you don't care - the Performer will work just fine...

 

I'm running an Edelbrock Performer (EGR dummied for emissions visual insp.) on my stroker motor. I defaulted to this manifold because I wanted to use the OE dual snorkel air filter housing and the '80-'82's are short on hood clearance.
All in all, it does somewhat OK for my daily driver, I suppose, but lately I've been wanting to extract a bit more power from my engine so I'm considering swapping to an Edelbrock RPM (or similar). Several forum members have done it, you just cannot run the OE air filter housing

The euphoric effects of HP soon taper off, leaving you needing MORE... That's where I'm at..... I'M IN NEED of MORE HORSEPOWER! :reddevil

I'll probably play with trimming the divider plate before purchasing a new intake.

My 388 combo...
SCAT stroker crank
.060 over
5.65" rods
~10:1 compression
Comp Cams 280H w 230/230 duration and .480/.480 lift. Using 1.6:1 roller tipped steel rockers.
Edelbrock Performer EGR intake
Headman 1-5/8" headers
Trick Flow heads
Edelbrock #1904 replacement Q-Jet carb (#73 jets and #50 primary rods)
OE style HEI ignition

It's a decent running budget engine. :yesnod:

 

Those specs might put you up a bit over your 300 rwhp figure - check out some of the linked dyno tests, and some of the articles. Sounds like you for sure need
an RPM (or if not an all-weather driver, an RPM air gap). I'd been wondering the same, but have been told that even an 81 will work with an RPM if you use a drop base air cleaner, or you can be real sneaky and shim the body up a tad on the frame.
http://www.corvettefaq.com/c3/goodwr...20part%201.htm http://ryanscarpage.50megs.com/combos2.html http://www.chevyhiperformance.com/techarticles/76178/

 

Why take a chance?
Use the weiand 8004 :cool:

 

My '74 would bounce off the 6000 RPM rev limiter in first, second, or third gear (never tried it fourth) when I had the Performer on it, even with the old 882 Chevy heads. It didn't wrap quite as fast as it does with the Performer RPM Air Gap and AFR 195s on there now, but it would pull hard all the way up.

As for the Comp Cam dyno sheet, I think that cam was poorly matched to the rest of the setup. Needed more compression, for one thing. I really think it should have made more power.
Jeff
Jeff