Illegal Vette

Lately I've been thinking about how much power you could get out of a crossfire injected motor, obviously the bottleneck is the intake but I'm guessing there's ways of improving the flow there. Anyway have any of you done anything like this? It would be fun to build a high horsepower Crossfire...

cv67

Buccaneer was involved in designing the Renegade CFI his car runs pretty strong.

fishslayer143

BAD *** motor.... breathing thru a crossfire? that's an oxymoron... research Renegade Intake,and.boost your fuel pressure, it will help some.. I believe the tests on it were about 30 HP or so .. then, get a better cam /heads/exhaust/.pistons...... oh hell, just build a real motor

Illegal Vette

Well I've already got an LS, and I'm very happy with it but I thought it might be fun to see how much HP you could squeeze out of a motor that you're not supposed to be able to.

CA-Legal-Vette

The exhaust is your worst bottleneck. I don’t doubt that your intake is second. Probably followed by heads.

Buccaneer

Build a crossfire, why would you want to do that? Nope, can't be done. OK, jus kiddin'. You can, but just how deep are your pockets? It will cost a fair amount, since you have to do a lot of mods, but it will run like a beast.

Nope, the intake is the killer on that motor in stock configuration, hands down. Followed by the heads and the ECM that was never fully hacked like the 84 was. The exhaust really isn't that bad, no more so than most any other 80s smog motor car.

jimco84x

How about a 434 ci small block with and old school cross ram and 2 Holley snipers? We could still let you call it a cross ram if you want to. )

7T1vette

Nothing wrong with asking... You can upgrade nearly all SBC engines, and the CrossFire is no exception. Heads, cam, Renegade intake with larger throttle bodies, headers. Why not? The ECU can still manage it all. Power, good idle manners, fuel efficient; and it would be somewhat of a novelty to talk about at car shows. DO IT!!!

Illegal Vette

The key would be plumbing the intake somehow for multiport injection, with that done you could use the 2 throttle bodies to flow enough air and use a modern fuel management system. With that done you could build the engine anyway you like.

7T1vette

The CrossFire throttle bodies flow air AND fuel. No need to modify a Renegade intake. The stock intake doesn't provide enough air intake area to support significantly higher HP.

Jebbysan

There is a fella here who has a beatifully detailed 383 82' CFI.......his name eludes me.....terrible with names.
I doubt it would take much to search for it......he posted in his thread about three-four months back.....
Anyway...the car in question blows me away with detail......nicest on the planet probably.

Jebby

Illegal Vette

I get that the stock throttle bodies are TBI but I’m thinking lose the tbi and use throttle bodies without injectors, convert the intake to multiport, and no more bottleneck.

jim2527

Holley ECU and probably others will run dual throttle bodies. Has it been down with a crossfire?

htown81vette

I know one thing you can do to add a significant amount of power without even doing anything to the car is move to a lower elevation.

htown81vette

I've got an 82 and wanted to do the same thing. Trouble is I haven't got a round-tuit yet. After the intake and exhaust I'd say the ECM is the bottleneck, or how to program it. There are ways around that too. I read where the NA record for the crossfire is 12.20. I wanted the chase that but too many other priorities....

jb78L-82

Buccaneer...here already posted

Illegal Vette

i love what you did there, looking at the top plate I can imagine how easy it would be to fabricate adapters or a new plate for bigger throttle bodies but it would be tricky to install multiport injectors in the manifold. It sounds really great, I watched your startup video. Nice work!

fishslayer143

to make big power, you need big airflow.. Crossfire intake and heads will never flow big air ..its that simple . put all the throttle bodies you want, the runners are to small , they were designed for 305 cu in.. unless your idea of big HP is in the 300-340 range? .. like Buccaneer said..it can be done by SPENDING a bunch of money on new and better parts.. You might as well just START with better

htown81vette

I thought this was supposed to be the answer to the manifold flow issues. (That is mine btw):

Buccaneer

Our manifold IS the answer to more flow for sure for the CFI motors, stock or modified. It likes more cubic inches, the more it gets, the happier it gets. Highest tested was 400 cu in. Mine runs hard mid and high end, pulls like a freight train. I only have 600 miles on my new motor and ran into a few issues with cooling out of the blue and haven't been to the track yet, but dying to go since this is the time of year in Arizona to do that kind of testing. We made a LOT of improvements to that manifold while in development and flow benches to see how it flowed. Believe it or not, we flowed a stock GM CF manifold and found an issue with the runners which was rather surprising, ours has been corrected. The company that helped us develop the manifold IS a well known manifold manufacturer and they even scratched their head on the GM manifold and why GM engineers let it go out that way.

If you just want to build a good running CF, it doesn't take a lot of cash, just a little know how until you want 400+ and then it starts getting expensive to say the least... Let the modding begin! I don't EVER want to add up all my invoices on motors and parts, I would probably faint. I also probably would never sell my car either. My TBs are 2.13" with no sleeves, you can go bigger, but sleeves are a must and depending how big a cube motor you build, will dictate the TB size. Actually, mine are a tad on the big size, but it runs well with them. Most people just go with 2", which is fine for most motors including mine. Ben73 with his 84 N/A CFI 383 motor is running 2" still I believe and his CF runs 12.20s which is the fastest running N/A CF in the world that I know of. He dropped three tenths after installing our manifold and ran consistently in the 12.20s, not just a one time deal that could not be repeated. He DID have an Xram manifold on his motor prior to ours and ran a 12.52 that he could never repeat and was always in the mid to high 12.50s. Everybody said that the Xram was the bomb and nothing was better...really?! If it was the bomb, that would make ours the super bomb. I wish you good luck with whichever way you decide to go. If you need help with a CF, let me know.

ALSO... Thanks Jebby for the nice comments.