Ok then I retract my statement. Trying to make CFI go is a WASTE OF TIME. See how much work you have to do to go reasonably fast? I also never said TPI was good, we all know it runs out of breath in stock form. And keep in mind my first post WAS talking about in stock form with porting, not making your own custom intakes. Telling people that there are better systems to start with is not a waste of time, the guy who originally posted doesn't sound like the type to be fabbing his own intakes and dynoing the results. Don't mislead the poor guy by saying his CFI system is good, it's not because it's stock and there needs to be a lot of improvement that he would have to undertake to make it equal to better setup.

again we have done nothing to this car that you would not have done to any other fuel system. with the exception of porting the intake. he doesn't have to make his own intake. he can have it done. or buy the x-ram. you don't think for a minute that he can't or doesn't want to change his intake set up. just changing the exhaust and doing a tune up netted a 1.13 sec gain. then the porting gained another .3 over that. so again thanks for wasting out time.

Not a problem here, The CFI guys are using a TBI ECM (749??) to run the injection and spark. I know a guy that has a transplanted CFI in an El Camino, it runs good and is trick looking.

There are individuals doing their own proms for the stock ecm (the one used in 83 f-bodies and 84 corvettes (I'd need to check, but I think its the '6026, I don't think there is a good map for the '5550) or you can easily convert to either a '7747 or an '8746 ecm. There is now an aftermarket harness adapter so that the new ecms plug right into the car's harness - Harness Adapter Info

My '8746 cost about $135 including the adapter (It is not yet installed)



The same people that built the harness adapter are also building an eprom emulator with programmer built in - Prominator Info

This is the site dedicated to Crossfire cars - Crossfire Injection Forum

You will also find people discussing custom proms for crossfire cars in the DIY-PROM forum right here on thirdgen.org....

Tom84L69,
you are wicked annoying. What is most annoying to me about you is that I knowyou have never owned a CFI car, and therefore, have nothing to contribute but hearsay, annecdotal information, and misguided opinion.

Here is the main thing here that you can't seem to grasp; you REPEATEDLY claim that a CFI is
1. not the best place to start
2. too costly
3. takes too much work

1. The guy already "Started". He already has the car, and it's got CFI. To go to a carb/intake as you suggest, would be a similar amount of work as porting (remove intake, install carbed intake, carb, fpr, linkage, different cable, kickdown airfliter etc. vs remove intake, port reinstall) yet it it would cost WAY more, not have the advantages of injection, and put you in the same place as porting. Porting this intake is VERY EASY. And cheap. To tell us that you "should start w/carb" is a mute point, because he already has a CFI car. The shortest, cheapest route from point "A" to "power" is exhaust (same as every other F-bod), porting, and tuning. Not dinging w/a carb.

2. It costs just about, hmmm... SQUAT to port the intake. A gasket set. That's a far cry from a gasket set, and intake, a carb and requisite hardware, air cleaner housing, cables....

3. After the exhaust had been replaced (something that you would need to do on ANY F bod), one Saturday of work, and a day at the track will get you in the low 14's. Whoa, I don't know if I can handle that! lol.


How do I know all this? Because I HAVE a CFI TA, and I've DONE IT. FWIW, I also had a carbed '83 ta prior to this car so I've "done that" too.

I don't believe anyone ever said that he should "fab his own intake". We recomend porting, AFTER exhaust, "free mods" and tuning, which alone will get him in the 14's. Porting the intake is easy and cheap. It's not "fabbing". Got that?

And don't YOU mislead this guy into spending $500+ on a different induction system, that will put him in the same place -performance wise- as an afternoon of work, while hurting drivabillity, fuel economy, and emissions.

Hey man...those were alot of posts...most said it was pointless to mod the CFI.
Well I have a modest budget. and something I forgot to mention was the previous owner put aftermarket headers on the car with Rhino exhaust. I through a Jet chip on the car and now I have a bog whenever I matt the gas pedal. I think it's trash...I'm gonna take it out...but buddies think it's just my 20 year old ignition system. I'm only a 305. but I'd like to eventually love to Run 13's...even 12's...I wanna stay different from the rest and yet smoke all the rustangs in my city...and hand some of my buddies their TPI asses

I've never tried one, but on the CFI vault, there is a general consensus that the hypertech and jet chips are junk(for the CFI application). Certainly any problems with your ignition system are going to cause the car to run poorly, so make SURE you have everything functioning properly before we venture any farther.

Again, read the post in this very long thread written by the people that actually have CFI cars. There is PLENTY of good info to go with.

Also "beating rustangs" and "handing TPI's their asses" is kind of an ambiguous goal. You should set a solid, objective goal to achieve and achieve it. With out that, you won't get a reward. There'll ALWAYS be a Mustang somewhere that'll beat you. A goal if 13.999 in the 1/4 of a CFI injected 305 is a good one. Shoot for that with a well ported intake, apparently you have the exhaust, tuning, and maybe a cam. Should be pretty easy, IMO, and you'll shock a TON of people when you open the hood.
-Tom

just keep checking at www.crossfireinjection.com right now we are building a 350. was going to stay 305, but the #4 cylinder had excessive wear in it.

I know Edebrock makes TBI units... would those fit the CFI manifold? Just a thought.

Even if I was pulling bad times... I'd love to have a crossfire! It's just so.... cool!

Good luck with it

I think the Edelbrock part you're thinking of REPLACES TBI with MPFI. They don't make TBI units that are compatable with CFI, to the best of my knowledge.

The stock CFI TBI units aren't restrictive until you have many mods, AND more cubes. The stockers seem to work and flow fine up to around 300 hp. Plenty for any NA 305.

Don't waist your time and money, boring or buying TBI's until you have do then other mods listed above.

The LU5 (5.0 liter, 305 cid cross-fire fuel injected V8) will not go down in history as one of the fastest V8s ever produced, however it does have its place in automotive history .There was a fuel crises which hit in late 1979. Efficiency and fuel economy were the buzz words that every manufacturer was reciting. And to make matters worse when the federally mandated C.A.F.E. standards hit in the late 1970s, it looked like it could be curtains for the V8 all together by the mid 1980s. A few persistent folks at GM insisted that the 3rd generation f-body (Camaro/Firebird) platform which was release in 1982 have available V8 power propelling the rear wheels.

What you see here with the LU5 is what the engineers at GM came up with when their hands were tied. Considering this they came out with a masterpiece. From a performance standpoint the early 1980s was the lowest point in the last 40 years however the LU5 helped keep the Trans Am in 1982 and 1983 at the top of the heap of the performance cars for the early 1980s. From 1982 to 1983 the LU5 equipped Trans Am was among the fastest and powerful American production cars. Even the 1982 Mustang GT and its H.O. 5.0 liter (302) V8 produced 8 less horsepower than the 1982 LU5 Trans Am.

So the LU5 might not be the fastest engine, but if you still have one that is unmolested you have a peice of history. Some people like bragging about how much HP their engines put to the rear wheels. I like to know that i have something special.

At a car show the other day, I saw a mint condition, early eighties (I assume) "cross-fire" Corvette. Is this a rare or special car in any way? Just curious.

Build a 350 when you get the money. If you have no intention of building a 350 in the future, then do this....Right now go for the World Products heads mentioned above. Stay mild on the cam if it's in a 305, nothing more than the 89 L-98 cam. Go with a 2500 rpm stall converter and a trans cooler in the Turbo 350 (or is it a stick????). Port your intake and leave it alone.....

When it's time for the 350:

Get a low-rise twin carb tunnel ram (from Holley I believe) and get a couple of adapters to mount a Throttle body on a standard holley squarebore carb pattern. Then you get a twin carb linkage to tie them together. That will support any cam you will put in the 350... Buy a good set of aftermarket heads and put a ZZ4 cam in it. Purchase an aftermarket computer like the Accel DFI VII or convert to the latest factory TBI computer you can get. You will also need the injectors from a 350 Crossfire engine.

You should be able to kick some 'Stang with that combo....

Bottom line: TBI of any make and model is only a highly efficient carb....... You still have a wet manifold. But it's different than everybody else and that's a good thing in it's own right!!!!!

I personally wouldn't use a crossfire, because I don't know much on it. I know it ain't great stock in regular form, but hey, do what you want to do. It's your dream man. You want to make a fast Crossfire, go ahead. Screw these people who say you can't do it. It may take a lot of work, but go for it. Don't let anyone put you down because it's a crossfire man. It's a Camaro man, and what is this? A Camaro forum. Dissing another Camaro (skipping the camaro ricers) is just wrong. I say go for it man, I would love to see a FAST CFI.

For all the guys who were able to give usefull information, I thank you.

As the recent purchaser of a CFI car, I now know where to start with my mods.

No problem. Good luck, have fun, and don't be afraid to ask questions again.

Just remember that you'll always have to "weed" through those that know (have one) and those who don't but love to bash.

-Tom

I've also worked with a cross-fire camaro. It had a 383 transplanted into it. It was also equiped with a 299(1992 truck, van, suburban) TBI ecm. The 299 has an identical pinout to the 7747 but is easier to tune due to the single VE table, etc. The car eventually ran a 12.79@112 on a ported intake. Holley used to carry a 1 bbl TBI that was oversize for the GM 4 cylinder engines. This car had 2 of them from Ebay. The fuel pressure regulators were hooked in parallel instead of series though. The pressure was set at 16 psi on both(tough to achieve).

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intake porting is next

next up is intake manifold porting

A couple things:

When I ran a 14.5 @ 95 my car had the stock 305 long block, and CFI intake (un-ported) the car had the following mods:
*Edelbrock "headers" and Y pipe with '86 and up catalytic converter (larger than the '83 cat. SLP cat back
*160 T-stat
*Optimized "physical tuning": Fuel pressure and timing
*No cooling fan (Eventually "fixed" w/an electric fan)
*Borg Warner T5 transmission in place of the original 700 R4
*No air filters installed during passes, (BUT filter housing in place), and cowl induction wired open all the time
*AC compressor removed
*Stock 3:23 rear
*Car weighed 3150 lbs on NED's scales at that time, w/a 1/4 tank, no driver.
^That's it. Basically headers and exhaust, a 5 speed and "free mods"/tweeking got me a 14.5 at 95. That was on a 2.0ish 60' time and powershifting.

My recomondations to you are:
Put the stock aircleaner lid back on. It's not a restriction, and it feeds cool air to the engine. Right now you're sucking hot air from your engine compartment. Made worse by the headers. Ditch the Hypertech. I've only heard about poor results from those, and here's what the chip CAN affect: Timing and fuel. Both things that you can control on your own as you've already learned.

Your exhaust sounds good but just to make sure, you DO have some kind of aftermarket Y pipe...right? The 4.10 gears are questionable for a motor that quits making power at about 4500 RPM, but might be O.K. for the 1/8 mile.

With regard to fuel pressure, you need to "feed it what it wants". I didn't have access to (or money for) a dyno so I "tuned" by making many, many passes and adjusting timing and FP until I got the best results. The important thing to this though, is that first you need to make enought passes to make your driving consistent. Once you know what your car will run, then make small changes to just one variable, until you reach the best performance. Then try another variable. Fuss w/it until you reach the BOTTOM time the car will run. Then when you make a "big" change (like porting) you'll need to do it all again.

Hope this helps. Let me know if you have anymore questions.

-Tom

nice time

to thanks alot for the reply , now that you mentioned porting i just finished porting my intake manifold, i have pic of it on the crossfire.net forum under "people who have successfully ported...please" i know i might sound a bit persistent and very info hungry but i really apreciate your time, first off, theres a place called cassicindustries.com, they have a package #222008D wich consist of a comp cams camshaft part #(12-389-4)
which is .425 intake and .440 exhaust with valve lift at 252 deg on intake and 260 deg on exh, what do you think about this combo and what type off rockers should i use?, in regards to the t5 transmission how difficult was it to change ? any computer adjustments needed?, how about drive shaft length?, interior adjustments? im debating wether to go with the five speed or the 200r with overdrive and trans brake with a stall converter the performance shop charges me 2400 for the tranny (200r )............tom thanks for your time http://www.thirdgen.org/techboard/at...1&d=1197436266

It looks like you've gotten a good start on your porting, but you need to go further. Due to the OD dimensions of the CFI runner, you CAN'T PORT IT TOO MUCH....even on a mild 305. It looks like you haven't touched the floor of the runners. You need a looooong bit that will reach through the entire runner so you can remove metal from the floor walls and ceiling of each runner to the point of breaking through the walls. If you break through, you can repair a breach w/ PC-7 epoxy, and it will hold. Don't forget to modify or remove the "swirl plates". I removed mine completely, and only had "issues" -if you could call it that- in cold Park City winter mornings for about 1-2 minutes after start up. The "problems" were a slight stumble at throttle tip-in unitl the engine generated a LITTLE heat.

W/regard to that cam kit, that part number brings up three options, and I can't tell what the difference is between the three. They all seem to have the same "specs" but different text describing them. I'm not "down" w/that cam kit, mostly because of the price for what you're getting. You can buy a siimilar Summit Cam & lifter kit, roller timing set, springs, retainers, and seals for about $240. For $60 bucks more, you could ALSO get a set of stamped steel 1.6 ratio rockers, which would get you more lift and quicker action (while maintaining similar duration). With that combo, you'd have 4.53" intake/4.69" exhaust lift while saving about 70 bucks compared to the Classicindustries kit.

OR you could buy this kit:
http://store.summitracing.com/partde...2&autoview=sku
...and save about $50 over the classicindustries kit, and end up with more lift, less seat to seat duration, and more power, better idle, low end torque, and fuel economy...in theory. Either way, it's a much better cam, at a better price.

Trans: The trans is a direct bolt in w/the proper stock parts: bell housing, pedal assy, flywheel, clutch etc. If you have the 700R4, your stock drive shaft will work fine. The only "mods" that you need to make, other than R&R'ing the related parts, is cutting a hole in the floor pan, and drilling holes in the firewall. All pretty easy stuff to do. I used a Jig saw w/a metal cutting blade to cut the shifter hole in my floor pan. I used a hole saw for the master cylinder pushrod and of course a drill for the master cylinder mounting bold holes. You can see the spot on the fire wall where the mater cylinder should go; it's stamped w/a spot. As for interior, I used the shifter bezel/boot assy from a junk yard car, and it looked completely stock and original when I was done. I did nothing to my ECM to accomodate the 5 speed, and it didn't seem to mind. I think it's too "dumb" to "know" that there isn't an auto there anymore.

I have one of these motors in my 82 vette .... Yea it's dog but who cares it's vette .... The best thing I ever did to mine was install 90 vette dual electric fans and run them thermostatically (on 228 off 208) It actually made the motor run smoother in almost all conditions (not really sure why) ... Once it's warmed up it has excellent throttle response and a much smoother idle when it hangs out around 210 degrees. And yes I'de drive this cfi anytime before even a LS-1 f-body.

tom, jproz where can i get one of those electric fans?, what additional hardware do i need like thermal switch or something?, also proz on your post you said the car had excellent throttle respoce around 210?, i always thought that it would run better if it had 160 or what i mean to say is if the engine is cooler doesent it run better?

I ended up using the "Taurus" electric fan; if you do a search on the cooling boards for "Taurus fan" you'll find posts about it, but it's a 2 speed, pancake style fan that moves a LOT of air, quitely efficiently, and reliably. Late '80's and early '90's Taurus' have the desired fan and they fit the f-body radiator really well. Since the fan has two speeds, you need to aquire two temp switches that actuate at the temps of your choice (should be chosen w/your selected T-stat in mind), and two relays. Back then, I ran a 160 T-stat, and used a coolant setich that closed at 180* and the second that closed at 195*. Even w/the SBC 400, the fan only went to it's high speed once in the time that I owned the car. I selected the switchs by desiding on the temps I wanted, observing the NPT ports that were available in my cylinder head/intake and t-stat neck, and calling a parts store and asking them to look up OE replacement coolant switches that met that criteria.

The EASIEST swap would be a factory F-body fan and shroud assy., but those fans aren't as powerful. FYI, Hot Rod did a dyno test of various fans years ago, and the factory style clutch fan, when engaged, consumed 45 hp at 5000 RPM.

As for what temp to run your motor at, that could turn into a 5 page debate. Hotter temps generally result in better milage, lower emissions, and less cylinder bore wear. Cooler running (in this engine) can result in more hp, because the intake and heads are cooler, allowing more timing. I ran mine at 160* because that gave me the best results at the strip, I still got OVER 23 mpg hwy w/the 400 at that temp, and I didn't care much about "excessive engine wear". At the time, I was changing engine configurations so much that the questionable wear caused by cooler running was unimportant. T-stat/engine operating temps is a decision that you need to make for yourself. BTW, the throttle response in my car was obsurd. My girlfriend at the time didn't like the car because "it gave her whiplash". IOW, coolant temps aren't going to make or break "throttle response" -there are other factors that have a much, much greater effect.

thanks tom i think thats my next mod!

I dont think a taurus fan pulls more air then these 90 vette fans sounds like a hurricane under my hood when they come on .... I did some reading near as I can tell my hotter temps result in less fuel puddling in the intake. Which is why it probably idles better and has a better throttle response.

All I run in my vette is a single pass f-body aluminum radiator with plastic tanks and I can let it idle for a hour without a problem it seems to be a good combination.

you cant see them the greatest but they cool this 82 vette just fine.

hey tom where can i get a stock prom in order to compare the differences between the hyperthech and the stock chip,

lost mine
----------
going to irwindale to test the intake and the fuel pressure mod from 11 pounds to 15 pounds previous track time 10.02

hope to do at least 9.5

GM has them for about $45 dollars IIRC. I put an '84 Corvette chip in my car at one point years ago, bought it new from a GM dealer and it was about $40. FYI, that didn't work, so don't try it.

Also a junk yard. I'm not sure where else.