Calling all Modifed CFI Owners
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
Calling all Modifed CFI Owners
Here we go again. I am so confused. I am talking about head slesction here. When modifiying a CFI car and using the STOCK computer, what is the best head to use that wont freak the computer out. Im torn between a 64CC head and a 72CC head with 180cc runners. You guys that have moded your motors chime in and tell me what you used please.
I am going to port the intake
use the Comp Cam # 12-249-4
Not sure to go with dished or flat top pistons. jury is still out untill the heads are selected.
Install headers connected to a 2.5" dual exhaust with a highflow Cat (already installed on the car).
Change the rearend gear to 3.73 (already purchased ring and pinon)
I will probably leave the smog stuff on the car
I am going to port the intake
use the Comp Cam # 12-249-4
Not sure to go with dished or flat top pistons. jury is still out untill the heads are selected.
Install headers connected to a 2.5" dual exhaust with a highflow Cat (already installed on the car).
Change the rearend gear to 3.73 (already purchased ring and pinon)
I will probably leave the smog stuff on the car
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
The 64cc heads are a good choice in aluminum because you get a nice bump in compression and alum. is lighter also help with pinging but if your using cast iron go with a vortex style head (best bang for the buck). CFI will accept performance parts as long as you don't lose your vacumm!!! meaning no large duration cams under 218 duration @.050. Go have some fun!!!!
Advanced
Joined: Sep 2007
Posts: 77
Likes: 0
From: Walker LA
From what I read on the Cross Fire forum, a lot of guys use the Dart s/s heads and the Crane 2040 cam with the stock ecm. That 84 fuel pump seems to be a dog and not give you reliable pressure, cahnge it out for an 85 and bump the pressure up to 12psi.
Mitch
Mitch
Race Director
Joined: Jan 2003
Posts: 15,175
Likes: 86
From: State of Confusion
when I frequented the Cross-Fire Forum, I thought guys suggested using 58cc heads from L89s?????
Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
That is exactly my first thought. His bottleneck is still going to be the intake flow. Go with smaller runner heads. The L98's are 163cc I believe. The 1.95 valves will flow more than you will need.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
LOTS of room for porting in the CFI manifold. Someone posted a pic of one next to a carb manifold, the runners are only about half open.
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
Im in the process of negotiating the purchase of a ported manifold, bored TBI units with 80# injectors and a programable computer. If this goes through....The sky may be the limit.
Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
I doubt someone would port one of those things for less than what a new manifold would cost him. My time is worth more to me than trying to do it myself too.
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
$630.00 was te first quote...jury is still out at the other shops. I think I found a used one that has been ported. Its of an 83 Z28. If the guy is reasonable I will buy it.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
Race Director
Joined: Jan 2003
Posts: 15,175
Likes: 86
From: State of Confusion
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
If I Had Some Cash To Spend!
I would splurge for the aluminum in 62 or 64 cc chambers. That should put you around 10 to 1 compression. Also I agree with what was said before about manifold flow. You can HOG it out but with stock TB you still only have around 700 CFMs max flow. 700 cfm is not bad but I wouldn't use any larger than a 2.02 intake valve. The basis of the crossfire manifold is air speed through the small long runners to produce massive torque right off idle
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
Small runners..gotcha. Im working out a deal with a guy to buy a ported manifold, bored throttle bodies with 80# injectors, external fuel regulator, and programable computer (early prominator version). This should give me some cam and head selection options that the stock ECM and throttle bodies dont allow for.
