Hi everyone
Im Claudio….. and I have not been here in a long time……. Not sure where the CFI section is….. but I’m looking at getting into an 82TA LU5 so I have questions and ideas to bounce off the other CFIers in here……. First I’d like to find that area or section before I start listing questions……. I don’t want to get in any trouble….. I’m also not a stranger to the F Body as I’ve had my fair share…… a few KITTs GTAs TAs and a couple of verts….. not a third gen but I also had a few Transport vans….. ( yes the space ship….. ) a 69 and a few second gen’s….. oh and a few Fieros…….. anyway back to finding the CFI guys….. and gals…..
thanks
i was told I could come here for CFI help and stuff….??

 

TBI is "the section/area" for CFI since CFI is a form of TBI.

You can really post anywhere and not "get in trouble"....but you're in the right place.

 

thanks…..

 

Ok 👌
so what are the exact differences in the two or is it three CFI intakes….? ( maybe some pictures…?? I’ve looked at several and they all seem the same even though they have a different number…?? ) And which one is best for CFI modding….. I’m looking at 1982 Pontiac Trans Am LU5…. And WS6 I think….?? So I want to play around with it…… the dos and don’ts…… I’m hoping to keep the relic ECM happy so that it keeps the CEL off unless it’s going to tell me something useful…. Ha ha ha…. I’m thinking this is enough for my first post or bother you guys with more stuff as we move forward….. if I have CFI Transmission related stuff is that for this section or do I have to go under transmissions if there’s a Transmission section…??
thanks again

 

There are only two that I'm aware of. One has holes in between adjoining runner pairs and the other doesn't. Here is the version w/holes. There is a second hole behind the tape measure, and two more corresponding holes at the adjoining runners at the other end of the intake.





In the 44 years since CFI was introduced, that has not been proven. No one knows what the so-called "Balance holes" are really for...or what effect they have. In MY knowledge of tuned length runners, the holes would hurt both resonant tuning and total air flow....so *I* don't like 'em. The '82 intake would not have the holes. I believe only later intakes had the holes and I BELIEVE it was only on the '84 'Vettes that had them.


Don't think there was such a thing as WS6 in '82 but if there was, it wasn't the same as later cars w/WS6


This is good fodder for arguments, but I had fantastic results w/no CEL's through various stages of mods and engine sizes with my '83 CFI T/A and a friend's '84 CFI Vette. All with stock chips, tunes, ECM....no changes to the stock ECM at all....

*Initially, I put headers, Y-pipe and exhaust on my car, did "free mods" and replaced the 700R4 with a BW T5. In that configuration, it went 14.5@96 at the drag track. It takes about 230hp to do that in these cars. Ran like stock, no CEL's got good gas mileage....there were no drawbacks.

*I replaced the 305 with a 350 everything else remained the same, no CEL, ran like stock, got good gas mileage etc.

*I replaced the 350 with a 400, installed a much larger cam, ported the bejeezus out of the intake runners, bored the TB's ditched the "swirl plates" in the lid, installed larger injectors and fuel pump, tuned it w/fuel pressure and base timing and in that configuration it would go mid 13's/105 -which takes ~300hp to do in these cars. Still....idled/ran like stock, drove great, no CEL, got good gas mileage (24 on hwy trips), and there were no drawbacks.

I sold it in that configuration. It is amazing to me that the car went from 170 hp to ~300...and 305 CID to 401 CID on the stock ECM and tune, with several iterations in between and all of it worked great. To ME, that ECM is quite flexible. I believe it can do that, not b/c it's great, but b/c it's so "dumb" and slow. But it can work and it worked great for me. I think that keep the cam such that the shape of the tq curve remains relatively the same, is key. NOTE: that all of these iterations of engine/cams, etc DID need some kind of tuning of hard parts, to work best. I did play with fuel pressure and base timing throughout, to make the most of each combination.


You can post that in the "Transmission" section. Outside of the intake manifold and injectors, the car and all of it's parts are no different than any other same-year version of that car w/o CFI. Trans is a typical 200C, I believe for 1982. Not great.

 

Thanks for replying
In 1982 the WS six package consisted of a tighter turn steering box stiffer springs bigger sway bars, 15 inch cast aluminum wheels 323 Pozzi rear I believe four-wheel disc brakes and of course it had to have the LU5 and a crappy three speed automatic if I missed any items, please let me know, but I think that was the total package I know in the later years and included more and in the fourth GEN it was a totally different package. I haven’t seen the RPO codes to see if I have it or not. I’ve only seen a couple of key things.

on the intakes was their different year breakdown for the exhaust crossover ports or did they all have them? I heard that some doing some don’t somehow have one and not the other and some have both if I plan on eliminating the EGR valve and all the emissions I think I would want to start with an intake that has none of the exhaust ports and I believe that’s a 1982 but I’m not 100% on that what what part numbers came out in what years my plan was to hunt down an actual 1982 so I can play with it and when I get my car, I’ll have it ready and just swap it out and keep the original on my bench
This 82TA is going to be a weekend cruiser go to a couple of car shows and that’s it the rest of the time it’ll probably live in my garage not a bracket racer not a race car maybe an occasional burnout but I think I can talk to the Transmission guy about that…….. I just gotta work out the kinks as far as the CFI in regards to the porting the hacking up of the inside, removing a bunch of vacuum lines blocking off things cleaning up the engine compartment a bit. I do plan on doing Edmond header kit, Shorty headers with a matching white pipe, probably ceramic coated, shorter plugs and better wires and me personally because I want the noise a gear drive. I want it to sound like it has a nasty gnarly blower under the hood finish that exhaust off with a test pipe and American thunder flow master kit that’s pretty much it. The three speed that’s in it crapped out somebody removed it and the car hasn’t been touched since so I’m gonna put in a newer or later I should say 1988 700 R4 with the matching parts, of course driveshaft torque arm, crossmember, etc. and that’s pretty much it so I leave the 305 bone stock play around with the crossfire intake, what other tips or what are the things you guys do just to get a little like I said I’m not racing it. Maybe I don’t even have to do anything. I just wanna look cool at the car show do a couple of burnouts and tell people yes it does have the crossfire engine. …..

 

Do the stuff I said above. Exhaust, port the runners, then "feed it what it wants".

 

So if a feller happened to have a 350 TBI engine to go into a later TBI RS, wanted to do a very mild valvetrain upgrade, and also had a COMPLETE f-body '83 CFI setup to use just for the heck of it... do you think it would be wise to use the later TBI ecm, or the 'slow and dumb' '83 ecm?

To the OP, if this is too far off-topic, feel free to kick me out of here. But the later ecm and harness may or may not be a worthy upgrade.

 

"Phase II" in my history of CFI ownership above, was actually a 350 TBI long block...which is probably why it was no faster than the original 305 in the 1/4...though it was more fun to drive. As you read above, that was running good on a stock '83 ECM and tune.

Anyway, I doubt that it would matter too much, which ECM you use. All of the combos are going to be close to the same power (fuel use) and a very mild valvetrain upgrade will keep the shape of the tq curve close to stock. It'll need more fuel which you can do with pressure adjustments.....if you think you may want to tune the ECM in the future, then I would definitely choose the later TBI ECM.

 

The balance holes were good for about 10 HP. The ‘83’s with that engine (LU5) were rated at 175 HP, not 165 HP like the ‘82’s. If you use the CFI intake on a 350, you will run into the same issues, or similar problems, to using TPI on a 350. The intake will be a choke point for the engine.

CFI was originally designed from the old “cross ram” intake for the SBC “302”. When they slapped the cross ram derived CFI on the 350 for the ‘84 Corvette, it starved the engine at higher rpms. At the time, it didn’t matter because performance was acceptable (low for the time).

Fuel pressure is critical with CFI, especially on the ‘84 CFI 350. When my uncle owned his ‘84 Corvette, we replaced the fuel pump with an ‘85+ TPI spec pump and the car ran infinitely better. Also, balancing the throttle bodies using a manometer is very important too. Those two things alone made the engine run a lot better (smoother idle, faster in the low to mid rpm range) with no other changes.

 

I think almost all of ^that^ is false or made-up. Can you cite sources for any of that?

*My '83 CFI didn't have the balance holes, but was rated at 170 hp.
*There was never a 175 hp CFI. You could get a CFI with 165, 170, 200 and 205 hp...ratings.
*The CFI intake is a choke point on a 350, a 305....and would also be a choke point on a 265. Fortunately, it's easy to port the runners and doing so produces great results.
*They "slapped the cross ram derived CFI on the 350" in '82, not '84. '84 was actually the last year of CFI on the Vette (and F-bod)
*You're right that most CFI cars like more fuel pressure, but if your Uncle's car ran better w/a "TPI pump", it was b/c the original was already failing....not b/c you installed a "TPI pump". If you had installed a new or properly working CFI pump it would have also, run "infinitely better". If the pump is working correctly (original OR "TPI"), the regulator is what sets the pressure, not the pump. The late great CFI-EFI went mid 14's@96 or so (here in UT's rarified air) probably 500 times or more....and I didn't my 14.5/95 at sea level, both of us with stock pumps.
*You do not need a water manometer to set the throttle plates to get an excellent running CFI

Facts work about the same in this thread as they do in THAT THREAD.

 

They were rated at 175 HP, not 170 HP.

Wrong. In ‘83, the CFI gained 10 HP due to the balance holes which upped them to 175 HP. It’s hard to find, but in all of the literature published about them, they were rated at 175 HP.

I never stated that porting them doesn’t produce great results. I stated that the intake was originally designed for a smaller displacement engine. The 350 was nearly 50 cubic inches bigger than the “302” of which the “cross ram” was originally designed for. Like TPI, CFI starved the 350 of air flow at higher rpms.

Last year for CFI in the F-bod was ‘83, not ‘84.

Nope. The TPI fuel pump ran better at the 13 or so PSI which made CFI run the best. The original pump, whether old or new, just didn’t have the capacity to run at that pressure for the best driveability like the TPI pump. The CFI pumps were marginal at best even when new.

No changes to the regulator. You probably would have run a lot better with the TPI pump, but maybe your budget was exhausted by that time.

You may not “need” one, but it sure made a big difference in idle and off-idle throttle response on my uncle’s Vette. I made my own using the DIY on the old CFI C4 forum.

Whether you like them or not, those are the facts. Oh, since you need something in writing or print about how the ‘83 CFI was rated at 175 HP, not 170 or what ever number you posted, here you go. Enjoy! 🙂

 

Welp...ya did good and finally cited SOMETHING! Now show us the literature that says the 10 hp came from the balance holes.

Even if you can show that, which I would LOVE to see....that doesn't change how ram tunned runners work and the negative effects of drilling holes in the sides of them.

 

The CFI intake shares NOTHING with the 302 intake*, other than that they're both a "cross ram" intake. Saying that the "Cross Ram intake" was designed for a 302 is folly (Cross rams were used on many engines of different displacements). Saying that b/c it was designed for a 302 thus won't work on a 350 is also folly, b/c 1. the Chev 302's intake was designed to run ~7000ROm on a 302...would work GREAT on a 350 at 6500 RPM. 2. The CFI shares nothing with and is in no way related to the 60's 302 cross ram intake so the correlation doesn't work.

You were talking aboug GM slapping the CFI on the 350 'Vette in '84. They did that, actually, in '82. That was the point, there. '84 was the last year...not the first.

YOUR (uncle's) pump didn't have the capacity to run 13 lbs at whatever volume. Mine did. CFI-EFI's did. As I said above:

So...you saw the results that you did b/c you're uncle's pump was failing....a common occurrence

My budget had nothing to do with it...I could set my pressure as could CFI-EFI...where ever we wanted within the realm of what our engine's wanted. What'd your Uncle's Vette trap in the 1/4?

My point was that you can set the TB's with no manometer at all...and realize that "big difference in in idle and off-idle throttle response". People pondering CFI's in today's world, don't need water manometer's.


* @sofakingdom could give you a good skooling on this topic/history, I bet.