Crossfire to TPI change over.
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Joined: Oct 2013
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From: Utah
Crossfire to TPI change over.
Hello Corvette owners,
I’m new here today. Yesterday I bought a 84 vette. It has a new 350 engine.
He started to change the intake over to a GM TPI. (I have no idea what the TPI came off).
I have the wire harness, the computer, intake, rails everything. I just don’t know where to go from here?
Is there a step by step info page of someone doing this?
Thanks for any help.
I’m new here today. Yesterday I bought a 84 vette. It has a new 350 engine.
He started to change the intake over to a GM TPI. (I have no idea what the TPI came off).
I have the wire harness, the computer, intake, rails everything. I just don’t know where to go from here?
Is there a step by step info page of someone doing this?
Thanks for any help.
Race Director
Joined: Feb 2002
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From: Compound in the Grove, Ga.
2026 Corvette of the Year Finalist - Unmodified
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It can be done, I've done an 80-82 & 84. 80 & 82 were very easy just added after market harness and F-body ECM for the electrical. 84 took a long time you need both 84 & 85 service manuals to run down the wiring if that's what year the parts came from.
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From: Utah
All I want is for the thing to run. I really don't want to put a ton money in it.
I got a box of parts with the car. In the box was the old crossfire intake and carbs. They are in rough shape.
Just to make it simple, I wonder if putting it back stock is the way to go?
It will take some work to get the old carbs clean and looking good.
Ive seen some are porting the intake and they say that helps out on some horse power?
I got a box of parts with the car. In the box was the old crossfire intake and carbs. They are in rough shape.
Just to make it simple, I wonder if putting it back stock is the way to go?
It will take some work to get the old carbs clean and looking good.
Ive seen some are porting the intake and they say that helps out on some horse power?
Safety Car
Joined: Jan 2004
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From: Northern California
Porting the Stock CFI intake manifold, will do wonders for power!...
Race Director
Joined: Feb 2002
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From: Compound in the Grove, Ga.
2026 Corvette of the Year Finalist - Unmodified
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2019 C4 of Year Finalist (performance mods)
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St. Jude Donor '16
CFI Stock VS Ported
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Thread Starter
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Joined: Oct 2013
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From: Utah
That porting looks great! hole size is huge!
Im really leaning toward the crossfire to be put back on.
Is that all the porting thats done? (intake holes)?
Im good with tools do it myself or send it out to a pro?
Im really leaning toward the crossfire to be put back on.
Is that all the porting thats done? (intake holes)?
Im good with tools do it myself or send it out to a pro?
Last edited by Redspider; Oct 21, 2013 at 06:30 PM.
Race Director
Joined: Feb 2002
Posts: 11,619
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From: Compound in the Grove, Ga.
2026 Corvette of the Year Finalist - Unmodified
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St. Jude Donor '16
here is a lot of great info. on the CFI its in the C3 section 82 had the same setup.
http://forums.corvetteforum.com/c3-t...solutions.html
http://forums.corvetteforum.com/c3-t...solutions.html
Safety Car
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Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
Port the runner from it's entrance, to it's exit. Floor, walls, ceilings. The more metal you remove, the more power your engine will make. You can't go too far until your go through somewhere, then that is easily repaired w/epoxy. If a port matching job, as is commonly done to CFI intakes (porting just the end of the runner by the heads) you can get a noticeable gain. With a FULL porting of the runners, optimized base timing and fuel pressure, you can pick up ~30 hp or more.
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Hello Corvette owners,
I’m new here today. Yesterday I bought a 84 vette. It has a new 350 engine.
He started to change the intake over to a GM TPI. (I have no idea what the TPI came off).
I have the wire harness, the computer, intake, rails everything. I just don’t know where to go from here?
Is there a step by step info page of someone doing this?
Thanks for any help.
I’m new here today. Yesterday I bought a 84 vette. It has a new 350 engine.
He started to change the intake over to a GM TPI. (I have no idea what the TPI came off).
I have the wire harness, the computer, intake, rails everything. I just don’t know where to go from here?
Is there a step by step info page of someone doing this?
Thanks for any help.
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
First Congrats on your car.
If your even thinking of tearing all the harness out and ecm just for a TPI set up ..... DON"T BOTHER.. Its a waste of your time and money for the little gain your going to get. Its still a restrictive set up.
Now.. if your gonna go the route of Miniram,SuperRam,HSR on a modified engine then its a different story.
Easiest way to convert a CFI to Multiport Injection
Use the EBL lockers ECM with port mod, Get it Hammed or Repin the ecm connector yourself.
Plug in... Make about 5 min's worth of changes to the some connectors at the engine... relocate one wire at the ecm. And your done.
If your even thinking of tearing all the harness out and ecm just for a TPI set up ..... DON"T BOTHER.. Its a waste of your time and money for the little gain your going to get. Its still a restrictive set up.
Now.. if your gonna go the route of Miniram,SuperRam,HSR on a modified engine then its a different story.
Easiest way to convert a CFI to Multiport Injection
Use the EBL lockers ECM with port mod, Get it Hammed or Repin the ecm connector yourself.
Plug in... Make about 5 min's worth of changes to the some connectors at the engine... relocate one wire at the ecm. And your done.
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
I personally would make the swap to TPI, but I may be a bit biased. The TPI develops more power where most people use it daily than any other intake. Is it restrictive above 4000 RPM? Yes, so as long as you drive above 4000 RPM most of the time then don't use it. Also, the 84 ECM has never been hacked, so any custom programming is out of the question. Either use the 1227165 mass air, or the 1227730 (Camaro) ecm's. To me there's not enough there in the stock 84 to waste your time.
here's a great site for additional support:
http://chevythunder.com/since_its_inception_in_1985.htm
here's a great site for additional support:
http://chevythunder.com/since_its_inception_in_1985.htm
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Joined: Oct 2013
Posts: 57
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From: Utah
Thanks everyone for all you input!
Asking for more input.
Heres my new love hate Relationship with this car:
The previous owner has done the following:
He has taken out the original ECM (I have it) (1226026) out. Cut the wire harness that went with it. And tossed it.
He has a TPI harness and computer that he started to install. From what I can find it came from a 90-92 Camaro/Firebird. It looks to be in excellent shape.
Here’s the shake down: Do I:
A) Just finish what he started? Wire harness engine side will be a breeze. It’s all labeled.
Dash side I’m going to be lost. It will take some research.
B) Put the old CFI back in? Throttle body will need work. It will need new injectors, wire harness that was tossed.
Here’s some pics of my mess.
Heres the old
Asking for more input.
Heres my new love hate Relationship with this car:
The previous owner has done the following:
He has taken out the original ECM (I have it) (1226026) out. Cut the wire harness that went with it. And tossed it.
He has a TPI harness and computer that he started to install. From what I can find it came from a 90-92 Camaro/Firebird. It looks to be in excellent shape.
Here’s the shake down: Do I:
A) Just finish what he started? Wire harness engine side will be a breeze. It’s all labeled.
Dash side I’m going to be lost. It will take some research.
B) Put the old CFI back in? Throttle body will need work. It will need new injectors, wire harness that was tossed.
Here’s some pics of my mess.
Heres the old
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
Go with the TPI without question. Get some valve cover paint, and put the stock ones back on. The TPI is from a Camaro as noted by the fuel line position as it exits the unit. Tell me the fuel rail number on the drivers side rail, and I can tell you what it came off of. You'll need to check everything as you go along. You never what this guy did.
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Joined: Oct 2013
Posts: 57
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From: Utah
Thanks for your help MrWillys!
Fuel rail read 0915 HUZ 17085052
I'm worried about wiring. Everyone says its hard. Looks like plug and play for most of it. (I must not be understanding something)
Fuel rail read 0915 HUZ 17085052
I'm worried about wiring. Everyone says its hard. Looks like plug and play for most of it. (I must not be understanding something)
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
The 17085052 rail is from a 85 thru 87 305 Camaro. The manifold is exactly the same, but injectors, and the fuel pressure regulator spring pressure are not. Choose an injector, and get an adjustable cap for the regulator. You will need a custom programmed memcal anyway to at minimum eliminate the VATS from the memcal. make sure the programmer understands the injector, and let him recommend pressure. hint, look at my website linked in my username.
Wiring is not that hard. You can get the Painless harness which is the best in the business, or go with a cheaper one from a guy like www.fuelinjectionconnection.com (do NOT let him provide a memcal), but if you choose the cheaper just make sure you get every circuit YOU want. Red, or orange wire is a constant hot, and the pink with black strip goes to a key on, and hot while cranking. You'll have to get a fuel pump, so i'll recommend the Walbro 255. You could trace out the harness you have by following these:
http://www.chevythunder.com/199091_c...227727_ecm.htm
http://www.chevythunder.com/fuel%20i...ts.htm#1990-91 speed density (Corvette ecm #1227727)
once you get done you'll realize how easy it was, and have a great running system capable of 400 + HP if properly tuned to a custom build. Or, just a great running stocker.
oh yeah, you'll need to split your VSS wires coming from the trans, and run them to the ECM. keep them clear of ignition wires as much as possible.
Wiring is not that hard. You can get the Painless harness which is the best in the business, or go with a cheaper one from a guy like www.fuelinjectionconnection.com (do NOT let him provide a memcal), but if you choose the cheaper just make sure you get every circuit YOU want. Red, or orange wire is a constant hot, and the pink with black strip goes to a key on, and hot while cranking. You'll have to get a fuel pump, so i'll recommend the Walbro 255. You could trace out the harness you have by following these:
http://www.chevythunder.com/199091_c...227727_ecm.htm
http://www.chevythunder.com/fuel%20i...ts.htm#1990-91 speed density (Corvette ecm #1227727)
once you get done you'll realize how easy it was, and have a great running system capable of 400 + HP if properly tuned to a custom build. Or, just a great running stocker.
oh yeah, you'll need to split your VSS wires coming from the trans, and run them to the ECM. keep them clear of ignition wires as much as possible.