ITAC News.

[JeffYoung]

Numbers here:

http://members.shaw.ca/corvette.84/crossfire.html

Pictures here:

http://users.swko.net/~lionsden/crossfire.htm

About halfway in is a comparison of the manifold "blocked" (on the right) and "unblocked" (on the left). Look at the unblocked one. The runner drops away quickly from the port. Appears that block really couldn't extend much into the manifold given the sharp taper down.

[Chip42]

jeff - 28"(of Hg/Mercury, about 1atm or of water/H2)/wc, about 1psi or ~0.07atm) is a barometric pressure reading, indicating the test pressure differential applied to the measured item (i.e. head or manifold) which induces the flow of air. kinda like voltage for amps, temperature for heat, etc...

the "numbers" page you found shows 182/137 cfm in/ex at 28"Hg and 0.400" lift, which is close to the max valve lift also shown on that page. based on the pictures you supplied, I'd say you're right about the potential for significant flow gains.

Andy, my admittedly limited experience with the CRB has been one of good cooperation and support. I know you have had bad experiences. I hope that maybe you got them to see the light, so to speak, but no matter, I appreciate your efforts, help, and jaundice.

[JeffYoung]

Got it on the 28" -- thanks.

jeff - 28"(of Hg/Mercury, about 1atm or of water/H2)/wc, about 1psi or ~0.07atm) is a barometric pressure reading, indicating the test pressure differential applied to the measured item (i.e. head or manifold) which induces the flow of air. kinda like voltage for amps, temperature for heat, etc...

the "numbers" page you found shows 182/137 cfm in/ex at 28"Hg and 0.400" lift, which is close to the max valve lift also shown on that page. based on the pictures you supplied, I'd say you're right about the potential for significant flow gains.

Andy, my admittedly limited experience with the CRB has been one of good cooperation and support. I know you have had bad experiences. I hope that maybe you got them to see the light, so to speak, but no matter, I appreciate your efforts, help, and jaundice.

THe other thing with these era FI systems - the fuel and timing curves are all screwed up for economy and emissions. You'll see big gains once you start correcting that.

Agreed on the CRB -- since about February of 2010, we have all worked well together. Jim Wheeler, Bob Dowie, Chris Albin, Peter Keane, Jim Drago -- all supportive and helpful.

[Ron Earp]

the spreadsheet shows -50 for brakes, -50 solid axle, and +150 torque on the 89-93/94-95 mustangs, same without brake adjust on the 87-92 camarobirds. they all use a 30% gain and all match the GCR. mustang weight difference is the result of 10hp: (10*1.3*11.25=146.3)

the only +100 tq adder in there is for the V6 94-98 'stang

this is the doc from Kirk Knestis, created march 2008 (thanks to KK for this)

V6 94-98 Mustangs are in ITS. They shouldn't appear on a ITR sheet.

IIRC, and I'm pretty sure I do, they all have a 100lb torque adder. The 50lb difference on the one line is due to lousy brakes.

94/95 V8 Mustangs have good brakes in Pony car land, four wheel discs. They shouldn't get a deduct for poor brakes. Was the ITAC giving deducts for poor brakes?

[Ron Earp]

Numbers here:

http://members.shaw.ca/corvette.84/crossfire.html

Pictures here:

http://users.swko.net/~lionsden/crossfire.htm

About halfway in is a comparison of the manifold "blocked" (on the right) and "unblocked" (on the left). Look at the unblocked one. The runner drops away quickly from the port. Appears that block really couldn't extend much into the manifold given the sharp taper down.

Interesting.

I see a cam duration that is somewhat okay at .050" lift, about what I'd expect and what I have to deal with on my own car. Valve lift isn't bad at all on a per cylinder basis and given the size of the valves, 1.94" and 1.5", typical Chevy sizes. Stock the throttle bodies flowing around 572 cfm isn't too shabby at all. If those head flow values are worth a damn then that is pretty good stock, quite good. I suppose we'll never know if the flow values are with the intake in place or not. Those boys are doing some trick work boring those throttle bodies out. Clearly illegal on the latter but I'd also say unnecessary based on the stock flow and other components in the engine.

All in all, impressive. I'd build it!

[Chip42]

V6 94-98 Mustangs are in ITS. They shouldn't appear on a ITR sheet.

it's an IT sheet. just making a point.

94/95 V8 Mustangs have good brakes in Pony car land, four wheel discs. They shouldn't get a deduct for poor brakes. Was the ITAC giving deducts for poor brakes?

yes. the spreadsheet has a -50 in the brakes column, ops manual calls out the same (+ or - depending). I suppose that they were seen as small or ineffective - we'll have to keep digging for that justification.

[Andy Bettencourt]

There are some conspiracy theorists that Chevy intentionally screwed the heads and kep the intake crappy so that the revision with TPI would look that much better. Not sure how much I buy into it but the heads are CLEARLY blocked. A new upper to that intake would have done a world of good to...it was developed...just not used.

This car will be interesting for sure. Not worried about torque at all. It's revs and HP...and brakes.

[quadzjr]

I ams sure it has been explained before, but search is failing me. How come a strut suspension on the powered wheels of a FWD car gets a weight break but a strut suspension on the powered wheels of a RWD does not?

The problems inherit with the strut suspension are consistent no matter which wheels are driven.

What was the percentage diffference/standard deviation from the norm of the class to warrant a torque increase/decrease adder?

Also why are all these adders only applicable to ITR but not ITS-ITC?

[ShelbyRacer]

There are some conspiracy theorists that Chevy intentionally screwed the heads and kep the intake crappy so that the revision with TPI would look that much better. Not sure how much I buy into it but the heads are CLEARLY blocked.

My information points to emissions as the impetus. Given the inherent issues of a wet manifold design, I'd think the keeping port velocities up and inducing some swirl and tumble would be an attempt to address that.