stevie1dr

For th past few months I have been building my 89 Vette into a solid street runner and have added several mod's to the motor for that "go fast" feel out of a rather docile C-4 Corvette. They have been notorious for anemic horsepower and although I truly love the body style, I thought the car was capable of far better in the speed and horsepower department. To make a long story short, I had a 383 stroker built from the stock block and then began adding goodies on a rather limited budget, which is why it took a couple of years to get it where I was happy.
Now my idea was not to build a trailer queen and run it only at the strip on the weekends. I wanted performance along with reliability and good street manners. One of the side goals was to chew up as many Mustangs as I could, since I was never really a Mustang afficiando. Opening a large can of whupass on those pesky 4.6 and 5.0 Fords always put a smile on my face, and the more I built, the more Mustangs became a smudge in my rear view mirror.
The last of my project after the initial 383 build was that I just wasn't satisfied with the overall performance with first the stock TPI set up, and then a First Injection system intake set. Although it was respectable with the TPI, and better with the First Injection, it still wasn't what I was expecting. Next, I popped for a set of 195 AFR heads to go with the Hedman headers, and also added a hydralic roller Comp's cam, 1.6.1 Crane roller rockers, 30 lb. Bosch III injectors, a 3.54 rear gear to go with my beefed up 700R4 auto trans and converted to MAP sensor in place of the MAF sensor. I topped it off with a nice Lingenfelter Super Ram.
Well, you guessed it. It still didn't seem to perform up to expectations so I sent the SR off to Ron Kalthoff for some of his porting magic. Man, did he do a job on the intake system! (see pictures).
He hogged out a ton of useless aluminum and opened up the breathing possibilities to the max for this set up.
The nicely ported SR is back on the car and running. Fine tuning will be done this coming Wednesday on the Dyno, and I will finally get to see just what and how much horsepower and torque I will pick up, and if it EVER stops raining here in Miami, I will get it to the local 1/8 mile strip for some comparison before and after runs. The car was a steady 8.1-8.2 @ 85 -87 mph runner before the work, and and as soon as I have new numbers, I will post them on this forum.
I would also like to thank some of the members here who gave me much needed help and advice over the past couple of years like Jim Barth, who advised me on cam selection and the AFR heads, as well as several others who answered many questions too. (The last photo is of the unmodified SR to show comparison of before and after)

Steve Fischer

TA

Wow, that looks great. Looking forward to hearing how it does at the track

John A. Marker

You will loose some of your low end torque after the porting of the SR. But if you have a 2400 stall converter (or higher), you might break even on the low end. The porting should help on the high end. It will definitely help with the AFR 195 heads.

weaselbeak

Very cool! Did you swap to map to get rid of the maf or to use EBL?

stevie1dr

I have a 2800 stall converter and I switched to the MAP to both get rid of the MAF sensor and to use EBL. Now, I guess it's down to the tuning to get the most out of this system. I'm hoping for some serious improvement. I've been running with MT street radials and they hook up really well. To be continued....

cumbercr

I'm interested in your impression after porting the SR. I suspect my 396 SR could benefit from more air. I will also be running a 2800 stall but with a 3.07 rear. I'm not real concerned about losing some bottom end.

cv67

for the words Steve
You did a nice job on cleaning that SR up doesnt look like the same one you sent

And thank you for not mentioning the word "polishing"!

This time sent runners out to be chucked up in a mill to take the walls most the way down rahter than killing the grinder and numbing the hands as quickly
.
Pics tell the story

Steve was a good sport about the whole thing these things happen sometimes when you get aggressive













Stock runners for comparison

cv67

Not bolted up precisely but you get the idea
Fit, trim, fit and trim some more. Still in "some more" mode here








Exhausting amount of time in these
Runner entry wound up about 4 in across or so 2 in where siamese is, 2 in or so in tapers down to a hair under 1.8. pretty close. Obviously the divider wall is now gone and the entire dia increased on the lid

Short of welding more material on the runners/base dont think theres much more you can do here

Waiting to see track/dyno results as is and after a tune.

Caboboy

As usual, a work of art Ron

You say the siamese is about 1.8" deep?

cv67

Hi Tim

Siamese was 2 in or so the dia of the runner where it meets the intake was a hair under 1.8

Think all the cutting of the wall, lid etc just helps the air enter. Unless youre after all you can going down that far (siamesing) may not be necessary. Think an inch if that is plenty suffcient but 2 certainly wont hurt.

383vett

Wow, that's some porting. I had my SR extrude honed years ago. Really clean and works fine for me. Sorry, no pics; the manifold is on the car and the car is running! Picture from last month.

tpi 421 vette

Looks great Steve! Can't wait to hear the results

Nice job Ron, that looks like a work of art

stevie1dr

Booked the dyno for 11am on Wednesday June 27. We'll soon have the end of the story!

stevie1dr

Well, so far I am a happy camper! I picked up 30 hp and almost 50 ft. lbs torque on the dyno!~!! Now, I will run it at the strip this weekend and see just what improvement I get in actual performance. It sure feels good!

More to come....

red L98

Wow , thats great man ... not trying to be a jerk but 8.1 1/8 mile for your set up is kinda slow .. I would think a set up like yours should be easy low 11 sec ride .

Caboboy

Congrats, Ron is the man to be sure!

tpi 421 vette

Wow.. 50 ft lbs is amazing. I would have never guessed it would pick up that much torque. 30 hp isn't bad either. That has to be a huge seat of the pants difference driving it.

GREGGPENN

Nice work Ron...Congrats Stevie!

It does seem a bit reversed of what you'd expect....like 50hp with 30more ft/lbs sounds more like it.

Would be interested to hear if the epoxy repair holds and what kind you used. (Probably won't ever find out though.)

TA

So what were the numbers?

cv67

Cant speak for Steve but think for now hes more concerned with track times and getting his tune figured out. As it is now imo it needs help so #s may not be the "norm".

The gains are there for sure I was surprised myself

Shows how restrictive these are when using a good set of heads the SR was designed when for the wheezy 128 and 113s

Lot of racers/builders dont dyno or use a flow bench at all, their measure is the time slip showing their gains and where they got them >#s on a sheet