Crossfire to Holley Sniper
Thread Starter
7th Gear
Joined: Apr 2018
Posts: 7
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From: MN
Crossfire to Holley Sniper
has anyone converted a 1984 crossfire over to a Holley Sniper system? what would all be involved, i know the intake but what about the old ecm and other engine sensors
Le Mans Master
Joined: Aug 2017
Posts: 6,942
Likes: 1,490
From: New Jersey
Most of the sensors are on the throttlebodies. The only engine sensors are the lone o2 sensor, knock sensor and intake coolant sensor. The rest are standalone for the dash and fan. The map sensor goes into the rear tb. I've never seen someone do it but you'd need an intake for sure. The trip stuff in the cluster won't work but I believe you'll still have a tech, fuel gauge, oil pressure and temp and speed as they all are taken care of by the ipc? I'm not too sure on that though.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
You don't need an intake for sure. You could run the CFI system, intact with the Holley Sniper controlling it, if you so choose to. However, if your goals are to increase power, you should port the stock intake.
Only thing you'll lose with an aftermarket ECM is fuel economy read out on the IP. Everything else should continue to work fine.
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Only thing you'll lose with an aftermarket ECM is fuel economy read out on the IP. Everything else should continue to work fine.
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Last edited by Tom400CFI; May 11, 2018 at 10:08 AM.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
You will need a different fuel pump crossfire uses 15 lb pump. IDK about using original intake you will at least need a new top. The bottom should be reworked, as it is not as good as the original 1968-69 version. A single 4 barrel carb on a box intake was hard to tune. It would be nice if the efi can compensate for a " Smokey Ram" type intake. A more conventional 4 intake would be more cost effective. The kit has all necessary sensors so the oem fuel system sensors can be removed. Cooling fan switch has to stay. The intake selection will depend on if you plan to use hood scoop.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
You will need a different fuel pump crossfire uses 15 lb pump. IDK about using original intake you will at least need a new top. The bottom should be reworked, as it is not as good as the original 1968-69 version. A single 4 barrel carb on a box intake was hard to tune. It would be nice if the efi can compensate for a " Smokey Ram" type intake. A more conventional 4 intake would be more cost effective. The kit has all necessary sensors so the oem fuel system sensors can be removed. Cooling fan switch has to stay. The intake selection will depend on if you plan to use hood scoop.
You guys are right; I thought the Sniper was a stand alone controller. But it's actually a 4bbl TBI so to speak. Yes, at the minimum, you'd need a new lid w/a 4bbl flange in the middle. Probably not worth it.
Pro
Joined: Jan 2003
Posts: 706
Likes: 47
From: Denver Colorado
I looked at doing a single 4bbl tbi onto a stock Cross-Fire base a while back and decided the limiting factor was going to be the partly blocked intake manifold passages on the stock intake. Looked like porting the intake would not gain enough to make a 4bbl tbi operate anywhere near capacity. Look at a Renegade set up or a Smokey Ram (hard to find) or a pair of single 4bbl tbis on an old Offy Cross-Ram if you are going to go crazy.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Wouldn't that depend on the "4bbl TBI"? A fully ported CFI intake is enough to run with many a intake that people might put a "4bbl tbi" onto. Properly ported, it should be good for ~300hp. Not that I think making a custom top lid is worth it...but it should work fine, of someone wanted to go that route.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
The problem was it takes a "big pump shot" to accelerate or it stumbles badly. The 11 in runners were thought to be the ideal length. Fabbing a " box top " isn't that hard. Will the sniper tune itself to a " box intake" is an unknown. Holley most likely has a few recommended intakes,
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Pro
Joined: Jan 2003
Posts: 706
Likes: 47
From: Denver Colorado
Wouldn't that depend on the "4bbl TBI"? A fully ported CFI intake is enough to run with many a intake that people might put a "4bbl tbi" onto. Properly ported, it should be good for ~300hp. Not that I think making a custom top lid is worth it...but it should work fine, of someone wanted to go that route.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Tom is probably right here, I've only done a couple Cross-Fire intakes and got too ambitious on one and broke thru on #3 cylinder on the first one. The second one I was more conservative on so it probably doesn't count as "fully ported". The stock tbis were good for it. The difference between it and an Offy cross ram port is huge.
Melting Slicks
Joined: Jan 2008
Posts: 2,054
Likes: 120
From: AZ
[QUOTE=1984Z51auto;1597187844]broke thru on #3 cylinder[/QUOTE ]HotRodRoy has a great running CFI, plus another expert/pal who ported his (beat a factory '87 TPI), both had to add material during the porting process.
This is not for non-experts, IMO.
This is not for non-experts, IMO.