Is the crossfire injection on my car really all that great or is it a horsepower robber in disguise? I want to to keep the car as a reliable daily driver for college, but still want the power to put you in your seat. Is there any benefits from a crossfire setup as compared to TPI or carbs or other???

 

I would think a ported crossfire flows about same as my XRAM with plenum. i went to xram as i falsely assumed the crossfire was a dog. i later found out ithe crossfire issue was lack of flow. base design OK. just tiny runners. no flow. the XRAM is a cold weather problem for me(wis). now i am losing the plenum(in spring) leaving the single plane in place and installing a 454 670 GM.. in fact ups should bring today along with adapter. my engine is modified so needs the increased air fuel....

 

i hear from alot of people that crossfire was horrible .... maybe thats why it didnt last 2 long... then again i never owned/or worked on one... im not knockin them.... im just sayin wut i heard.... i also heard sumthing about how they are too good in bad weather(rain/snow..etc)?!? i dont no... maybe someone can clear this up ....

 

I don't like it much but the design is pretty cool. Equal length runners, long runners, and relatively low profile. Definatly a bit air flow limited in stock form.
What I would like seen done is a nice mild vortec 350 build with removed CFI and replaced with two 2 barrel TBI's like a crossfire only more like the old school xram. I would REALLY be interested in seeing the flow differences between the older crossfire with standard vette heads vs the newer intake with vortec heads. That would be a very useful test. Then maybe some AFR 210cc heads with the xram.
I didn't think of it right away but that cold start problem does look like an issue. There is a LOT of manifold there. The long runner wet flow never worked well enough that I could ever consider it's application in a sports car.
Does anybody know of anybody that's converted a vortec EFI intake to carb or TBI? I doubt anybody has done TBI but there's got to be some guy out there that's done a carb swap....

 

like most stuff GM did, the design was good, the parts solid, but the way the finished product came out leaves much to be desired.

the crossfire came out in the dark ages of the smog era... its ports are absolutly TINY. i couldnt find it on a quick search, but theres a pic on here of the ports next to a aftermarket carb intake.... BIG diff...


luckily, the CF can be ported to be much better.

i really like the design, but it needs soo much work.

 

Keep it while you are still in school. It's TBI so it's cheap & reliable. It can be ported to allow better breathing (see the Crossfire Vault website for details).

Remember that the engine group at GM, under Roy Midgley, did the Crossfire development using parts borrowed from the Caddy 8-6-4 TBI system, and they used them to inexpensively develop fuel injection for the Corvette (to raise the fuel economy). It also boosted the engine output slightly, and the big torque gain at mid-rpms made the car an excellent (for its day) performer.

Midgley knew that they had a problem with fuel distribution with the flat plenum but they had already told the C4 chassis people that they could have the low hoodline, so they had to stick with the CF manifold until 1985, when the CF was replaced by TPI. The TPI was developed, again, by the same people that did the Crossfire. And the designs are very similar. The big difference is that the TPI has 8 port injectors (to solve the fuel distribution problem) and the CF has two. That's why the CF has the swirl plates to help spread the fuel around more evenly inside the plenum.

I laugh when I see TPI people trashing the CF design. The two designs have more in common than they realize.

Go to the CF Vault website to get more info on cheap/simple mods. HTH.

 

i am a prior crossfire. now not sure what i am. XRAM gone. dual TB 454 sitting on a single plane....

 

Every one told me when I bought my car that cross-fire injection was total crap, and at first it was crap to say the least. I put a new GM 350 in the car instead of the old 305 and it made it worse. I took the car to a local budy of mine who owns a shop and owned cross-fires himself to see what he could do. He told me the car needed fuel injectors from an 84 vette with the same setup because they had 350's and I guess bigger injectors to handle the bigger motor. Then he got me a prom chip from an 84 vette with CFI and 350. After that you wouldn't believe the difference in performance, I couldn't describe it if I wanted to. It was night and day, it now drives like it should with a new 350. He says it drives better than he remembers his cars driving new. I would recommend doing this to your CFI no matter what engine size you have. The original injectors are just to small and the prom chips are known to have problems. I love the car now. It's very reliable and gets great mileage, around 21 average with city and freeway. Lots of power too, even more so with the right mods.

 

Wow.... A thread on CFI that hasn't ended in bashing! Amazing!

I just installed CFI on my '82 a few weeks ago. It had it originally but by the time I got the car it was long gone and replaced. I really like the setup and I am still thinking if I should build a CFI 350 and surprise people at the track.

 

better replace that 200C

I LOVED my '82 Z28. Never ever really gave me that much trouble except for the weak tranny. On cold days, like any wet intake system, it would be a little hesitant. There's a lot that can be done to the stock intake to make it flow better. I had an extra manifold that I chopped out the EGR channel, trimmed back the swirl plates, and shortened and cleaned up the runners. Then I was going to send it to be extrude honed to finish it out. There's a guy on the CFI forum that bores out the throttle bodies, I think I've even seen him around on this board as well. If you can avoid it, don't get a 700 R4 when you replace the tranny (for those of you with 200C). The closer gear ratio of the 200 4R really woke up my crossfire car. After a few engine mods the need for fuel will surpass the stock 305 injectors. So plan on replacing them. One last thing... if you haven't done so... get a couple cans of carb and choke cleaner and clean the HELL out of the throtle bodies. Make sure you get down inside the IAC ports real good... probably wouldn't hurt to open the TBs up and spray some down in there. The last few intakes that I've come across have been all carboned up. TBs too.

 

hey thx for the advice from everybody. I do plan on putting a 350 in and will use the greater majority of the mods you have revealed to me. couple of questions though, does it matter what year the 350 is? a buddy has one out of a monte carlo(no computer) that he will sell me and I was curioous if it would work. Second, what is the 200 r4 and where will I find one? I have access to a TH350 tranny but like the extra gear that a 700r4 has. thx again for all the help.

 

200 4R is an automatic overdrive transmission. These can be found in older chevy caprices, buick cars, oldsmobile cars, cadillacs, some where even put in a few pontiac firebirds

 

i think the issue with crossfire is the size and flow numbers of the stock intake. i am not certain what they were but i will guess 180 cfm. the single plane flows around 250 cfm. with a port mod/extrude hone i believe the stock crossfire flows about 230 but that too is a guess. so any mods that were attemped to the crossfire never reached potential due to the stock intake flow #s.

 

If you upgrade to the 350, you will need injectors from any 89-93 LO5 9C1 (copcar) Caprice.

If you don't opt for the 350, then you can keep your stock injectors but alter the FPR to raise the fuel pressure to supply more fuel to meet the needs of any engine modifications you make.... especially the exhaust.

Edit: the stock manifold flowed approx 150 cfm (per runner), per Ken73's measurements on his flowbench. With the manifold ported (ported at the end that meets the head - where the restriction appears), it flowed approx 190 cfm. This is almost the same as flow measurements taken on a stock TPI runner. There are other measurements made, in various configurations, on the CF Vault website.

 

maybe someone can chime on in BUT if you plan on any future mods you may be better served going to a 454 injector. at 12 lbs of FP the 65 lb injector was matched to a 205 HP engine. i believe that is at 80% duty cycle. that leaves little room for more HP.

 

After I put in my new 350 in my cross-fire I used new injectors for 84 vettes with CFI and 350. What a difference it made! Although I don't have any mods to the motor yet, so I don't know if it's good enough for future mods and more hp.

 

Anyone know or have any ideas on what injectors I should use if I want to build my motor up to 350-400HP?

 

350 HP = 90 lbs. 400 HP consider a 4 injector holley or edelbrock system. IMHO i think 90 lbs factors to max about 360 HP...

 

I thought there was only 2 injectors. I didn't think holley or edelbrock made stuff for cross-fire cars anyway. What do you mean by a 4 injector system?

 

the holley/edelbrock "system" has a purpose in that it is for changing over carb cars to EFI. speed density TBI. has its own ECU. can support 500 HP. not specific for any specific car/truck. i assume can replace the TB EFI on any TB equipped car that needs more CFM's due to mods. fits standard squarebore intake. look on their web site for all the details....

 

Thanks for the info. I will look into it on their websites.

 

FINALLY people are seeing the light through the dark crossfire tunnel.
I have a crossfire injected 305. When I had it in my T/A it was slower than a snail. HOwever when I did some work to the tbi's and added headers, dual open elements, took out the cowl tunnel and gave it a straight cowl scoop,,,man was there a difference. I at the time I thought that if I port the intake and heads to match flow and put a better F.I. cam that I would stomp new x-fire records. However until 3 months ago the 305 was running like junk. I didnt know what it was. However yesterday I took it apart and believe it or not,,,THERE WAS AN INTAKE BOLT STUCK BETWEEN ONE EXHAUST VALVE AND ITS SEAT!!!
Wow,,was I shocked, and nooo it wasnt me because I did no unbolting of the mani..

ANyways since last month my freshly swapped in 350 (see sig) which is carb. sufficed my craving for speed.
However Now I am currently porting the x-ram intake and gasket matching everything. I also cleaned up my tbi's and did the ultimate TBI mod, I still have all of the wiring to the crossfire system tucked away in my engine bay with most wires running to the tbi's CUT but still in my possession. I feel that with my 350 and its decent cam, I will swap the carb/intake with the system, will work better. THIs is all including the previous members idea of taking an 84 vette's injectors and chip.

My question for anyone out there is if you know the exact wiring needed(correct routing and locations) to make a crossfire I.System work properly..


P.s. Correction
I will not be using the 350, I will use the rebuilt 305 I have lying around with the crossfire's original heads(9.5:1 comp,decent), and other components..The Vette' chip and injectors should work fine on the 305 right?...
Also how much fuel pressure will I need, can I use a holley electric pump with 7 to 15psi????

PLus,,should I keep the stock cam..its about .390/.410 lift, if i should chuck it,,then what is a good F.I. cam for the C.F.I.?

 

The vette chip and injectors will work just fine with the 305. This is exactly what I did to my 83 cross-fire, except mine has a 350. A buddy of mine who has owned and worked on cross-fires for years recommends this to anyone with a cross-fire no matter which size engine you use. You won't believe the difference. I love my car now. As for fuel pressure my car is running at 14psi. Factory recommneds 9-13psi I believe. I have talked to a lot of people with cross-fires and they all recommend you have 14-15psi, and absolutly no less or you will run to lean and have a loss of power. That's the problem I had with mine at first also. Anyway I hope I have helped you out a little. Good luck.

 

thank you soo much..thats all i wanted to know

 

the vette chip wont work on a 305. the injectors should work on a 305 but will require tuning of the ECU to accomodate the significant increased flow vette injectors provide. that is what i did but i ran 90 lbs (9 lbs FP) on my 350 instead of the 65's that are stock. BPW needs to be changed in chip for 65's. i have 4132 210/216 @.05, that i think requires chip tuning. the 4122 204/214 may get by with no chip tuning but these are crane 350 applicattions not 305.. so ??? i agree 13-14 lbs will work well.

 

Sorry about the bad info. Guess I should have looked into it a little more before recommending it to someone. I think I will ? my buddy and myself a little more from now on.

 

I was running mid 13s with a 355 Crossfire 7 years ago.

I used the early BBC TBI injectors, bored the throttle bodies out for 2" butterflies, replumbed the TB so they were in parrarel, and a 1227747 ecm. Lots of work and playing eith chips, but, when it was done it was sweet. I was doing 13s with it for ALOT less then what 13s cost with a TPI.

 

so pretty much what is the final say here?
Can you use an 84 vette ecm and 350 injectors on a 305(bored to 310)
fully ported and gasket matched intake manifold and cylinder heads but stock bore tbi's.
If the size of the tbi is the issue, how hard is it to bore out exactly 2.00'' and get necessary butterfly.

If the whole corvette ecm thing is out of the question, is it easy to just install 350 injectors or will the ecm(stock 305 x-fire) be confused.
I guess I will see decent gains with my mods while still using the exisiting ecm for the 305. Will a cam with .443/.465 lift be too much for the stock comp?
How difficult is it to get a chip burned?

Thanks for any input because im like this guy when it comes to fuel injection:lala:

 

Hey matt_82transam, you said you did some mods to your air cleaner intake and hood, what exactly did you do? Could you explain it in more detail please? I have been looking all over for some ways to modify the air cleaner intake and hood, and have found nothing from anyone. Can't find any articles to read either.
Could you post some pics or suggest some things for me to read?
I would greatly appreciate any help. :hail:
Anyone else with some info or opinions on what to do would be awesome. :hail:

Thanks!:hail: :hail: :hail:

 

i have no experience with fbody but i think the injectors in 305 is 55 or so. the vette is 65. that is 18% larger. for this to work the engine at idle to WOT and ALL map will need to see a demand for more fuel like 18%. what is point of larger injectors unless the engine needs more fuel? i needed more fuel so i install 90 lbs. i could have and did use vafpr but found lean at low map(check engine light). could have worked with higher fp at idle and did but after blowing 2 diaphragms(?) decided the vafpr was not the best route to go for me. my ecm (vette) i believe was not hacked so i needed to replace with 7747 and did. just swapping the vette ecu with vette injectors and bored TB i think will result in engine that wont run worth a dam. and mine ran poorly after mods. if you want to consider burning read Trax article and every post on tuning on this forum. pick and chose the postings that apply to you. many will not as i found out.

 

hi will
Just like you, when I got my x-fire powered 305 I too wanted to do as much as possible to use the cowl induction effectively. THats true, you cannot find many articles on the subject without looking around extensively.
Well on to my mods.....at first I though that the solenoid that actuates the cowl flap was burned out( it was), so I proceeded to take of the flap assembly, that way there was always cold air going in regardless of throttle position. And yes, there is a greater chance of water getting into the air cleaner through the cowl however if you notice inside the tunnel there are 2 holes that you can route a rubber line to drain water from the tunnel.

THe next mod I did was making a crossfire open element system.
The process was started with tapping a small screwdriver at the tac welds on the two air cleaner hats, to separate them from the huge lid.

Make sure everything is smooth so you can put a washer on each of the lid tops where there are small holes(from factory tac welds)
.You can at this point take the base plate that the two filters sit on the clean it up (remove old vacuum ports and other emissions junk stuck to it)
Then set the cleaned base plate over the tbi's......set the air cleaners in(any 10'') and line up the 2 air cleaner hats to where there is a perfect seal over the filters and the tbi stud goes through the hole(you might need to elongate..i cant spell: ...the hole for the aircleaner stud with a small file rather than a drill).
Install a wide washer to seal the holes, install your nuts, and your off.

**honestly,I noticed a big difference in power(and sure there is a lot more warmer air coming in then the cold from the small cowl flap that usaully works at WOT,,,,but it is still MORE..and I definately felt the improvement)

You can combine these two mods in that you will have dual open elements plus an open cowl tunnel that is an escape route for engine heat and as you increase in speed, a greater amount of cold air flows in. Some people on the board have argued that there is close to no real gains from taking off that big lid to making the dual open element. I do not have track records to prove them wrong(I never did a track run in my life

However I did many tests where I had 2 fresh k&n filters in the lid and there was a huge bog at WOT. Sort of like something was holding all the power back greatly..hint..lid).
Then in the same weather,,25 degrees celcius...same engine temp..I had the dual open element on with the plastic cowl tunnel removed..and I dont know what everyone who said this sucks was smoking..but I sure know my rubber was.

if anyone doesnt believe me just try these mods and give me some track data..if there is no good gain give me the description of your total setup, maybe mine is slightly different from yours, thus changing outcome of mod

try and everyone is happy:lala:

 

Thanks for the help and info. :hail:
I am for sure going to try this out and see what happens. I know what you mean when you say at WOT something is holding the power back, the engine is bogging down. The air intake and cleaner system is a nice idea, but it just doesn't work at all. The system totally lacks air flow. Good luck with your car, and again thanks for the help. :hail:

 

just recently finished swapping out 350 with '84 vette crossfire into my '91 3.1 rs, can't complain at all about low end torque, this thing pulls strong to about 4000 rpm's and then runs out of uuumpf, it's perfect for stoplight bashing, best thing to do is to upgrade to later model ecm and ignition and mfi pump, it really wakes the crossfire up.......i'm happy with it....as usual the saying applies "dont knock it 'till you try it".

 

What later model ecm do you think is best? As far as ignition I plan to upgrade to an MSD system with 8.5mm plug wires, etc. When you say mfi pump, are you talking about the fuel pump? Which one do you recommend? I have put a 350 in my car with 84 vette injectors and a prom chip for an 84 vette so far. Off the line it's fast until about 4000 rpm or so, than dies off like you said.
I am looking for any advice on making this car faster, especially in the 1/4 mile times. Thanks for any help. :hail:

 

1227747 ECM out of a late model truck with TBI

350 TPI fuel pump

get another intake manifold. You can usually pick one up off of Ebay for less than $40 if not check the local wrecking yards. The one up here had 4 of them complete with TBs. Once you get your spare intake, take a close look at it and see how you can easily gain a little air flow by doing some work to it here and there.

 

have you given thought to adding a single plance and adding a truck 350 dual TB on top with adapter plate? or better yet a 454? i suspect the flow #'s will surpass a ported CF intake by quite a bit. all those flow #'s we posted on CF forum if you do a search. now as a prior crossfire owner i can assure you the extrude honed CF manifold is allowing more flow but doubt it is flowing the #'s the single plane can.also consider the injecors spray in relation to the bottom of plenum. the CF plenum was designed not for performance but to adapt a dual single TB system within a hood clearance that is nil. FFT.

 

for the challenge of working with what you got no matter how bad or "not as good" others say it is. I know you're not knocking CFI and I'm not flaming you for your comment. For me it was something very different than what everyone else was running and for me it worked very good. It's a project I'll always wish I could have finished.

 

Thanks for the info guys. Everyones opinion is greatly appreciated so I can make a good decision. The only problem is that most people have such different opinions. oh well, I don't mind. I am getting closer and closer to making up my mind every time I read more opinions, so it really does help. Thanks. :hail:

 

hey wills83, just got back on the machine, in response to your earlier post i'm running a '89 firebird ecm from the tbi engine with stock chip and factory 91 camaro 3.1 fuel pump, as for ignition i'm using a 92 dizzy and coil for now, will prob go with 6al box as funds become available....noticed your sweet ride, too bad your so far away 'cause i've got an almost complete '83 z28 crossfire parts car to part out or sell, just don't have the title.

 

Thanks for the reply Crossfire "RS". I wish I was closer too, that would be a nice car to have to just pick parts from it. Thanks again for the info.

 

It's generally right around 1/2 lb per hour, per hp. So for 400 hp you need 200 lb/hr. Two 90 lb injectors with the presure 16-17 PSI should do it.

The CFI intake runs out of potential at about 320hp though. To keep it "Crossfire" and also maintain some economical modding, you can buy and Edelbrock SY-1 intake off ebay, or get an Offenhauser Cross-ram intake from Jegs for about $280. Fab a lid, use bored TB's crank the fuel to it, and you'll have all kinds of flow, fuel and power.

 

I think I want to keep it cross-fire so far. Tom 400 CFI, I have read about the other intakes you have suggested from other sites including the CF Vault. However, I can't seem to find if that would be smog legal using one of the other intakes. Do they have egr provisions or a way to hook one up. I live in CA, my car has to pass the visual test as well as tail pipe test. My car is my daily driver, do you think porting the current intake or switching to another intake would be better for gas mileage? When you say the cross-fire is only good up to 320hp, are you talking about it in its stock form, or can it go up to more hp if you port the intake? Thanks for the info and help.

 

i think the reference is an extrude honed CF manifold. in stock form i believe it is 210 HP. it is strangling the engine but good drivability and nice torque out showroom door.
TOM: do you think the 90 lbs can be run at 17 lbs of pressure and not go static with subsequent early failure? also at 17 lbs would not the idle or off idle be extremely rich for a 350 cid. i dont think the VE tables can manage all that gas down there. DOM stated that he can run no more than 9 lbs(90lbs) as way rich which is where i am at now(9 lbs but idle very good). i am going to 10-11-12 this spring to see what happens as the cam will need more fuel at WOT(12.5/1).

 

Wills83, I mean fully ported, the Stock manifold is good for about 300 - 320 hp. Keep in mind that AT THAT POINT, the manifold is again a huge restriciton, and changing it would net you huge gains.

In other words, to get 320 hp you need to "build" a 400 hp engine get to that 320 horse. At that point, a manifold swap would net you huge improvements. I'm at that point in my sig. There used to be a guy on the CF Vault that had a 350, Trickflow heads, Marine cam (210*/210* IIRC), Roller Rockers, headers and exhaust, ported and extrude honed intake, and LOTS of chip tuning. He was turning 320 horse, but he had built a 400 horse engine. Had he swapped to an Offy, SY-1, or an RPM Airgap and carb, he would have seen a HUGE jump in power.

The manifolds I listed are not emissions compliant. However, I do believe that they look stock enough that it'd pass the visual. Just rig up a dummy EGR for the visual. What state inspection kid now days is going to know EXACTLY what a real CFI vs an aftermarket Crossram intake looks like? Not too many I bet.

Ronny the bone box stock intake will support more than 210 horse, IMO. When my car was stock YEARS ago, I replace the entire exhaust (headers, Y, cat, & cat-back), replaced the blown 700R-4 with a T-5, removed the smog pump, adjusted the timing and FP, and I got that thing to run a 14.5 @ 95 at New England Dragway (Epping NH). It takes about 230 hp to do that. That was with the stock swirl plates and everything. I believe you could "draw" up to 250 horse through that intake with some effort.

As for 17 lbs, I've heard of folks running 19 lbs and that working fine. I haven't tried it though. I as for idle, I used a Vacuum refferenced fuel pressure regulator to pull out fuel pressure at idle and any high vacuum situation. With my set up, at my elevation, it was running 15 lbs at WOT, and 10 lbs at idle. I don't know about Dom, he has some odd issues, and I think you need to address each engine seperately. "Give the engine what it wants". That's what I did.

 

Great info from both of you guys, now I just have more to think about. Sounds like you can make a cross-fire fast, but it will take a lot of time and mods to do it. If I am going to build a 400hp engine and only get 320hp or so, forget the cross-fire, I would rather switch to something that will give me full potential from that engine. This is exactly the problem I am having now. I used to have a 84 Z28 5.0 HO. I miss that car more and more, I used to hate the carb, now I want it back. My 84 with the stock 305 will still smoke my 83 cross-fire with the new 350 anytime. Well, enough complaining. Thanks again guys. :hail: :hail: :hail:

 

Keep in mind that it will cost you LESS to get all the potential with a OFFY etc, than switching to a carb/intake. It'll give you ALL the potential the carb/intake route will, be cheaper, and run/start etc better. Plus, no WAY you'll pass the visual w/a carb. You can fake it pretty easy with an aftermarket CFI intake.

 

True, but I can switch to a carb and still pass all emissions testing as long as I do it right. I have already look into it. All I have to do is go to a referee station and have it approved and they give me some sticker to put on my door for future reference. I guess the law says you can always take a step forward but never backward when you mod your car, wether it's intake, engine, etc. I think I will try to mirror the setup I had on my 84 camaro. As far as carbs not running as nice, etc, I never had a problem with that at all. I had the carb rebuilt when I bought the car and I swear it started and ran way smoother than this cross-fire.

 

On a 355 84 Firebird, with a Crossfire, I ran mid 13s. Yes, it took some work, but 13s with any TBI is going to.

Bored out the Throttle bodies, cut the runner roofs back, replumbed the fuel. Went to a different ecm. Built a 1/4" spacer to raise the lid. Lots of detail tuning.

And that was 7-8 years ago. With the newer cams, and ecm info. there's no reason not to get signifigantly faster.

 

What Grumpy said about newer cams etc.

I didn't mean that carbs aren't good. I used to have an LG4 that ran GREAT. What I meant was the (IMO) hassle of a choke, setting it, high idle, kick down, accel pump, etc on cold mornings... you can't just turn the key and it's running. But no biggie, carbs can work great too when set up properly.

 

I know you were not bashing carbs, sorry if I sounded defensive. I am sure with all of the new technology out there it's easier to mod a cross-fire, but I keep hearing opinions from both sides of the tracks. Some say no matter what the CF will always choke my engine, others say it's not true with the right mods. Who the hell knows , I have to try to make the decision myself using everyones opinion.