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Knurled.
Knurled. GRM+ Memberand MegaDork
1/26/20 12:21 a.m.
A 401 CJ said:

What exactly makes TBI evil?  It worked on GM trucks for eons.  What about it exactly makes it no good?

It has the wet-flow manifold problems that carburetors have, without the benefits of good atomization.

 

A carbureted intake can ice over on the outside on a humid day because of the heat of evaporation and the excellent atomzation.  You'd never see that with TBI and its staccato splurts of fuel blobs.

 

Carbs generally will make more power than EFI because of the excellent atomization, despite the pressure drops required for carbs to work.  They might not be able to make as broad of a powerband, but for peak power carbs are still where it's at.

David S. Wallens
David S. Wallens Editorial Director
1/26/20 9:54 p.m.
Duke said:

And, I believe, the start of GM's weird insistence on putting the entire 'features' list in badging on the outside of the car.

 

Hmmm, didn't think about that, but now that you mention it.... (I'm sure someone will find an earlier one, but that got me thinking.)

OLDMOTORHEADTED
OLDMOTORHEADTED
1/27/20 12:08 p.m.
David S. Wallens said:
feature_image

Cross-Fire injection was new for 1982 and found on Camaros and Corvettes. The setup featured a pair of throttle bodies mounted on an intake manifold that recalled the one found on the original Z28. This was trick-looking stuff that helped user in the modern era of fuel injection. 

Cross-Fire injection performed so well, in fact, that it was gone after the 1984 model year. (Okay, in reality GM’s Tuned Port Injection made its big debut for 1985.)

Photos courtesy RM Sothebys.

 

Read the rest of the story

Crossfire two throttle bodys= junk never ran properly from day one on going problems. Two years only on F&Y Bodys  Single throttle great system lasted years.

Tony Sestito
Tony Sestito PowerDork
1/27/20 12:40 p.m.

From what I've read, one of the biggest issues with the Crossfire setup was the intake manifold itself. It was originally conceived with a different runner design with larger ports, but the production ones got a neutered version of the original. They do make replacement manifolds for them, which wake them up quite a bit.

Another thing to consider is that EFI back in the early 80's was still a relatively new thing. It's easy to blame new technology and call it "junk" when there's a lack of understanding for how it works, and that's something that did happen. Sure, having two throttle bodies upped the complexity, but I still hear people crap on anything with a computer for being "junk" because "you can't fix it" because they don't take the time to learn how. I know people even today that refuse to drive cars made after the 1970's because they say that "computers ruin cars", "they aren't reliable", and that they are "impossible to work on".

All that said, I'd rather have modern MPFI every time. And I still want a Crossfire 3rd Gen Z28 or 1984 Vette just for the weirdness factor!

81cpcamaro
81cpcamaro Dork
1/27/20 1:17 p.m.

Crossfire intakes had the smallest intake ports of any SBC, about haft the size of normal. That really killed the power. Supposedly done for driveability.

Here is a site where someone modified one, you can see the port size Here

Ironically I was researching Crossfire setups years back when I ran across the Offy crossram setup, which I ended up with on my El Camino and then 81 Camaro CP car. I still have the intake/carb setup.

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