I have to laugh a bit. What did i just write on the TBI 400 spec thread last night on SV.


Your not talking apples to apples there and you are exactly right
TBI to TPI- nothing really gained.
TBI to Mini Ram, HSR, Stealth is a much more worthwhile investment.

and remember my HSR was free and the engine managment system I use is the EBL/Flash which I already had. So my cost are minimul and in all honesty this project could be done in a weekend.
I'm in no rush since its sitting till spring

 

I have been following your thread here. You do some awesome work there on your corvettes. I realy enjoy your threads.

So what kind a power would you guess-timate? Your motor looks good.

Corvette Mike

 

The 1984 L83 is rated at 205 HP. The 1985 L98 has the same long block, except for the camshaft, and is rated at 230 HP. One might presume that some (all?) of the additional 25 HP in the early L98 is due to the cam. Even as produced by Chevy the difference in the 1984 and 1985 performance is small. Without the 1985 camshaft, and without the faster, more sophisticated 1985 ECM, who knows which may make the greater power and by how much? I have always considered the move from a Crossfire to a stock TPI EFI, a sideways move, at best.

Also, it has been pretty well documented that small, cheap, modifications made the the Crossfire will show greater results then similar modifications to the TPI. Generally, effective mods the the TPI are not cheap.

Good to hear from you, Mike.

RACE ON!!!

 

Did I make a Boo Boo?

RACE ON!!!

 

[QUOTE=qws;1572263682]I have to laugh a bit. What did i just write on the TBI 400 spec thread last night on SV.QUOTE]


What is SV?

 

In case I didn't make myself perfectly clear, my comments ONLY refer to the Crossfire vs a factory L98, TPI. It might not have been MY choice, but I think your project has much merit. And on second thought, with what you paid, yours probably would be my first choice.

RACE ON!!!

 

SmokinVette

RACE ON!!!

 

Thanks Mike, but I'm just a wanna be mechanic. Thankfully I have an engine builder and a real back up mechanic close by if I need help.
Honestly I don't know what it will make in the end for power. All I can due is guess and right now I won't. I can only go off of what I've read.
My cam is only mild and I do have a new cam and heads sitting here waiting. I was going to put them on BUT, my goal is to get in the 12's and I want to compare the Xram that I had on this engine with the HSR. Just to see the amount of gain and be able to YES it gained this much.
After that I will throw in the Heads/cam I have and do the same with that.


Nope....you did ok... LOL

I should have quoted the previous post, I was actually referring to what I stated about the first thread I ever posted on CF....

 

Thanks. That is once in a row, for me.

RACE ON!!!

 

Being a total Nube to the vette scene, I always thought the hp gains were bc of the multi point and the intake design. I know it was actually designed for a 305, but the CFI always gets such a bad rap, I just assumed. I also did not know about the cam change. This has been VERY informative, and it makes me appreciate my CFI more.

THANKS!

 

You hit the nail right on the head! That happens often with the CFI

There is a number of things you can do easily and better yet FREE to improve your peformance. Search out how to port your CFI and you'll find a lot of threads about how to do it and the results....

 

Actually, the multi point has little to nothing to do with the power output. Technically it is a better method of introducing the fuel, but as a practical matter for producing power, it make little difference. I don't have the specs on the cams, but I doubt there is much difference. The manifold is the most significant difference in the two. And the difference isn't what you think. Of course there is the obvious difference in the whole design layout and theory, but take a look at the port openings at the head in the base of both manifolds. It quickly becomes obvious they there is a 25 HP difference. If GM had made both manifolds similar in port opening size and cross section, they would have been hard pressed to ever sell any of the slower TPI cars.

Half truths, rumors, and idle chatter by those that never owned one are the cause of the Crossfires bad rap. A perfect example is what you posted, "the CFI always gets such a bad rap, I just assumed."

RACE ON!!!

 

Well said. We the early C4's take a beating dont we? I still like mine no matter what anyone tells me.

Corvette Mike

 

Update for you guys.
Small Cap distributor is in place, Fuel line connectors are on. I'm using the Pushlok fittings. They're pretty nice and easy to work with. The water neck is in place. I used a 61-84 Pontiac V8 water neck. I had to reem the holes just a little bit but worked out nicely. Also replaced the knock sensor with a 90 GM Van unit. Its coming together. Again I'm in no rush. I'm also doing some other stuff along with the project. Such as cleaning up all my harness,new heat shield protection on the wires. Speaking of that one thing I did find is in the harness for the starter there is also a vac line. Even though I had it protected the headers did run hot enough to melt that vac line. Just a note to you guys. I'm also coating the headers and the front Y-pipe since it has been removed as well. If you want to see the entire build and all the pics check out SV in the C4 section. Or if you want the link just PM me.

 

Just wanted to update this for the guys that may be following.
Headers are coated and done and reinstalled. Remember I'm also doing some other projects while doing this.
Small cap distributor is in place.
Now for fuel lines
About 2 hours worth of work.
The push lok fittings are nice but getting the hose on is a real PITA!!! I used lube where I could and also heated the hoses if needed to help slip it on. I also picked up a box of Fuel injection fuel line clamps and used at every connected
Left Side of HSR


Right Side of HSR
Notice I change the FPR out to a Kirban regulator. Quality is awesome. Well worth the money.


Bare with me on the next 3 photos. I'm upside down taking them.
Here what I did
1) Routed the lines up over the tranny, I also sleeved them in "thermac" heat shield. Figured since they were near the headers I'd rather be safe.
2) Return line I reused the coupling and bought a brass flared hose barb to connect to the blue fuel line. I also bent it to aim in the direction I wanted.
3) clamped the hoses so they will stay in place.
4) closet point to headers is about 4 inches. I think it came out nice.




Since I had the fuel line apart I also took the time to replace the hoses at the fuel tank, once again I used clamps that were rated for the higher pressure. I should be alset now to run 4x psi in the fuel system safely.

 

I know some may be waiting for this part. OMG this is so easy took me an hour. I left the wire loom off.
With the EBL/Flash ECM there is NO NEED to run or add any wires
First lets go through the connectors
IAC connectors notice that there are two? Crossfire has 2 IAC's only one is needed

TPS sensor connector is the SAME and will slide right on

Air Switch Solenoid and Air Divert Solenoid
A.S.S (lol) is not used but you will use the A.D.S wires

Ground Wire

The 2 injectors for the Crossfire


Now I laid out my IAC wires and TPS wires and made my connections. Just remove one of the IAC set of wires and connect the 4 remaining to the new IAC.
TPS is color for color, take note of how I connected my butt splices. I did this so in the future when setting up and adjusting for voltage I have a point to probe with my DVM


Coolant sensor connector stayed the same, just rerouted. Took the one injector wire and paralled to the new injector wires on the drivers side.
Very Important: Use the A.D.S wire and cut connector off and install new sensor(IAT or MAT) connector to that wire. Move the A.S.S wire aside. (not used)


Passenger side just wrap up the injector wires


Now for the real tricky part
Go to the ECM harness. Black plug as shown in pic and remove the wire/pin from number 16 (A.D.S) and reconnect to number 21 of the same black connector and your done! Go back put some wire loom on
[IMG]Mod Removed image. I accidenty held the black ECM connector up with the wrong finger. I was to worried about getting in there and getting a educational photo for you members rather than how I was holding it up.[/IMG]

Thats all there is to the wiring. This is why I believe the best way to go is by using the EBL/Flash as the fuel managment system to run multi-port injection for a TBI system...:thumbsup:

 

unreal man!
BRAVO, great inf here.

 

if that is a MSD distributor, drill a pair of 1/4" diameter holes in the side of the ca, 1870- degrees apart to prevent oxidation

congrats

 

Thanks guys. Its just about done. The cap is a MSD....LD85 but not the distributor itself. Good info!
Down to just finishing up some other winter project stuff, but for the most part the HSR is just a few hours away from completion. As I start it up for the first time I will document that as well.

 

Excellent pictures and documentation.Can't wait to see how she runs.