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Discussion Starter #1
hey guys, I was reading over my car craft mags and saw a bunch of cars using turbo / belt driven superchargers with the carb in the box system hooked up. it got me thinking, I could definately make a preassure box to go on top of my crossfire manafold.

so do you think the crossfire throttle boddies on my car can deal with a verry minimal amount of boost? or do the tb. injection units have some pieces on them that will not allow them to function if they are preassurized past the point of 14.? atmospheric preasure?

I have been all over the web trying to lern more about the crossfire system im blessed with having ( :rolling: ) and have found that it realley lacks flow. - so if I can increase airflow with some minimal boost ( like 4 pounds or so ) then that would take care of the inadequate flow, id just need to upgrade the injectors to higher flow units, and upgrade the fuel supply system to match acordingly.

it seems some what logical in my head.:smack
besides, raid isnt the only one allowed to have a supercharger in a c4 on here :thud:
 

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DC Crew
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I don't know about the TB on those cars but I do know that the carbs used in blow applications are blow through carbs and are set up a bit different than a normal carb. Just throw a Holley stealth Ram on there and forget the Cross fire. All you need to do is cut your hood and change the computer.:laughing: Better yet buy the Stealth Ram and send it to me, I already have the hood for it.:smack
 

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Couple of items:
1) You'll waste part of the boost advantage just trying to stuff the extra air mass through the restriction of the lower part of the manifold. I'd definitely get it extrude honed if you are considering turbocharging.
2) Bigger injectors may not be necessary. If you pressurize the box, you'll pressurize the FPR reference diaphram. I'll bet it goes pig rich, not lean. (Ask me how I know. :laughing: )
3) If you run a low boost level, you probably won't heat the intake air too much. Remember, the injectors and regulator will be sitting in this extra heated air.
4) Your MAP sensor (and ecm) goes stupid after one atmosphere. You need to deal with the injector pulsewidth issues and the need to pull some spark out when you get into boost. (You could just let it knock, and rely on the ESC to retard the spark, but that's sloppy.)

There's other issues, but these are just a couple items that come to mind. Don't let the technical stuff stop you. Part of the fun is overcoming the technical problems. The other part of the fun is the look on guys faces when they get dusted by a lowly '84.

Go for it!
 

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Discussion Starter #4
I just spent the better part of 5 hours reading about ths guys setup.
http://www.joby.se/corvette/

only thing that scares me is his crossfire never ran right, then agian he was pushing for alot more power. and plaigued with other ailments

I was almost half thinkig about making some kind of ajustable boost preassure escape that would bleed off extra boost past the point of what I want in the engine. maby an ajustable blow off valve in the side of the box would allow me to dial in max preassure I want in there, allowing me to run true 4psi max preassure or something alont those lines, and extra boost made at higher rpms would be bled out of the system.

hmmmmm.:crazy:
 

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Discussion Starter #5
1) You'll waste part of the boost advantage just trying to stuff the extra air mass through the restriction of the lower part of the manifold. I'd definitely get it extrude honed if you are considering turbocharging.
!
what do you think of the xram manafold ?
http://www.x-ram.com/xramdesign.html

looks like a improvment over stock,
 

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I was hoping you'd find Joby's setup. He gave up on the crossfire in search of more power, and now has a stealth ram and a really wicked turbo project (He's one of the most talented people I can think of, so his projects are good examples).

As for the X-ram, any of the really fast Crossfire cars I know of run one, so there must be something to them. Their design is very poor looking, but they seem to do the job, so at this time I would reccommend it, and if I stick with crossfire, I'll run one as well.
 

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DC Crew
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For that price you could damn near carb. the thing with much better results untill you could afford to put a better intake system on there using FI.
 

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DC Pit Crew Boss
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I believe grumpyvette just did a nice write up on how to increase HP on an 84 by up to 100RWHP for about $1200. Basically it was geared around letting the X-Ram really do its job by increasing its "breathing" around the intake manifolds or somehting of the sort.

I just did a quick search but couldnt find it, hopefully he'll chime in
 

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I just spent the better part of 5 hours reading about ths guys setup.
http://www.joby.se/corvette/

only thing that scares me is his crossfire never ran right, then agian he was pushing for alot more power. and plaigued with other ailments

I was almost half thinkig about making some kind of ajustable boost preassure escape that would bleed off extra boost past the point of what I want in the engine. maby an ajustable blow off valve in the side of the box would allow me to dial in max preassure I want in there, allowing me to run true 4psi max preassure or something alont those lines, and extra boost made at higher rpms would be bled out of the system.

hmmmmm.:crazy:
I wouldn't rely on a blow-off valve for continual use. My recommendation would be to use a wastegate, and then a small pop-off valve. The wastegate will reduce your exhaust backpressure, and also reduce the intake air heating, as there's no need for the compressor to pump an excess amount of air that's just going to be dumped overboard.
And remember, boost is load dependent, not rpm dependent.
 

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Discussion Starter #10
I was thinking a small belt driven supercharger off the front, im kinda leary about turbos, not scared of them, but it seems like alot more work and money to get one setup, and custom making exaust headers scares me :laughing: seriously tho, the belt driven supercharger just seems easier to set up, as for the waste gate, who knows, maby I can install one along the pipeline from the sc, to the boost box over the tb's.

do you think a waste gate could be used to bleed off extra preassure on a supercharged set up? I realley dont know anything about turbos, as a whole system
 

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I was thinking a small belt driven supercharger off the front, im kinda leary about turbos, not scared of them, but it seems like alot more work and money to get one setup, and custom making exaust headers scares me :laughing: seriously tho, the belt driven supercharger just seems easier to set up, as for the waste gate, who knows, maby I can install one along the pipeline from the sc, to the boost box over the tb's.

do you think a waste gate could be used to bleed off extra preassure on a supercharged set up? I realley dont know anything about turbos, as a whole system
I won't try to persuade you against a belt driven supercharger, but I'm sold on turbos. They're more efficient, and the boost is not rpm dependent. You'll have similar fueling and spark changes to make with either system.
The reason I don't like pop-off or pressure regulating valves is that you are using valuable horsepower to pump and compress air, that you then dump back out to the atmosphere. But, I believe you would have no choice but to use one with a belt driven supercharger. (Supercharger guys, please correct me if I am misunderstanding your system.)
I support either system you try to implement. I like modified Corvettes, and I and a large portion of the forum group are willing to help answer any questions you might have during your build. Go for it. You'll be amazed how much you learn during the process.
 

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Here's what redmen031 was talking about I believe:
http://www.digitalcorvettes.com/forums/showthread.php?t=2264&highlight=crossfire+run

The SY1 is a terriffic intake in theory, but you need a lot of motor to make it worthwhile and in several applications it did not clear the hood.

The offy is another option, but the amount of customization to make it work is mind-blowing.

The X-ram, in my opinion, is your best option for high performance from what I've seen

For stock performance, port the stock intake, as it can take about a second off your ET.

As for price, remember, if you go with crossfire injection and high performance, you need to upgrade the ECM and have some way of tuning it. That will add to the cost, but is very worthwhile.
 
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