Mine is up and running, but my tach is only reading 1/2 the RPMS. Actually idles around 900 RPM's, but tach is only showing 450 RPMS. Anyone have any clue. Emailed Mike, but I see on the site they're closed until April 12th, I don't know if he'll respond or not. I hope so.

 

Your tuner needs to change the tachometer calibration data in the PCM. EFILive lets you change...

• Tacho Pulses High
• Tacho Pulses Low
• Tacho Pullup Enable

The logic of these values is not clear to me. According the the explanation in EFILive, the tach output for an LS1 Camaro/Firebird is 2.

"The number of output pulses P is calculated as P=24/(N*2) where N is the value of this calibration (Tach High and Tach Low)." The LS1 values are both 6...which result in an output of 2. But 2 pulses per what?

The LT1 instrument cluster has a different tach than the LS1 instrument cluster. Have your tuner (trial and error) try different values to fix the tach. Or ask one of the guys on the forum who have already done this conversion in an LT1 F-body. We don't have an LT1 F-body to provide the correct numbers.

 

Whats the best way to install my drive by wire pedal? (I figured I would put it here in case others need to read about it, even though I emailed you.) I noticed the brackets are not the same. It seems the existing throttle pedal is attached to the clutch/brake pedal bracket. I will post answer here if you email me first.

 

You'll have to fabricate some sort of mount. I've never mounted an electronic pedal in a 4th gen.

In case this comes up...the 98 and newer V6 F-body has an electronic pedal. It is NOT COMPATIBLE with the LS1 PCM. I have personally tried this while wasting about $100.00.

From what I recall looking at a 4th gen pedal assembly for my 3rd gen, I'll end up cutting off the gas pedal to retain the brake and clutch. It will be quite awhile before I make a custom mount for the accelerator pedal in my 3rd gen project.

 

My car is a 97, so the cluster looks the same, but I guess could read differently, would a 98+ cluster fix the issue? It would fit with no issues.

 

Yes, the 98+ cluster will fix the tach issue...but will introduce a bigger problem of rewiring for the newer cluster. It's not worth going through the trouble of a cluster swap when you can change a few values in the calibration to fix the tach.

 

That sucks I am somewhat lost on what to do about a bracket. Am I the first one with a LT1 f body going drive by wire? I would be even be willing to pay for a bracket. I just dont have the fab equipment to come up with one. I honestly thought the kit would have come with something like this.
What do you recommend I do?

 

The only other drive by wire 4th gen F-body swap I'm aware of is Christian of AutoXDyno.com. He's a member on the forum, but I don't know his screen name. He has a YSi supercharged LT1 with a 24x conversion using a monoblade throttle body and I seem to recall a Corvette pedal assembly. You received an 04-05 CTS-V pedal assembly. He has not yet finished his conversion.

• The Corvette pedal assembly is about twice the price of the CTS-V pedal assembly.
• They use different connectors.
• They use the same TAC module.
• They mount differently. In other words the Corvette pedal will not mount to the firewall of the CTS-V.
• The Corvette pedal has a spring at the pedal's pad; the CTS-V pedal pad is fixed.

When you consider the wide variety of vehicles getting fuel injected V8 swaps, each having a different firewall (pedal mount), we can't possibly provide a specific pedal mount solution for every application. Unfortunately it's impossible to make a universal solution.

 

Drive by Wire conversions also require a location for the TAC module (throttle actuator control).



The 4th gen F-body does not have a bolt-on location for this module. The convenient location for this module is above the PCM. In this location it is hidden from view. This requires a custom mount as GM never made a bracket for this module in the 4th gen F-body.

The problem with mounting this module inside the vehicle is that it will require too many wires to pass through the firewall grommet. The grommet inside diameter (ID) is not big enough. Delphi does not make a larger ID grommet for this application.

 

GM does make an LS1 PCM bracket for the 4th gen F-body (99-02). This bracket is not the same as the LT1 PCM bracket.

The LS1 PCM bracket has been discontinued by GM, so we can not offer it with a 24x conversion going into a 4th gen F-body.

The LS1 Camaro/Firebird PCM bracket is often on ebay and can also be pulled from a 98 and newer V6 Camaro/Firebird. It is a direct bolt on solution.

 

Ok I am wondering if the other corvette pedal will fit better for my application. Do you have any pics of the pedal bracket. If it is closer to the factory setup it might work better despite cost. Maybe you can pm me details. I appreciate the extra info, and have already got a gm pcm bracket out of junkyard.

I am excited to almost have this build ready and will be going to get the base tune on the PCM soon at G-force.

 

Sorry, no pics. But search for "Corvette pedal" on eBay and you'll find a few.

 

late to the convo, I know. to conclude you're saying the express van ECM (pt# 12200411) runs an old school SBC/LT1 firing order. so it sends fuel and reads O2 sensors appropriately bank to bank and knows what cylinder?
the van didn't run COP but has the capability, so you just assign the ignition to spark in the right firing order via efilive?

Just want to make sure I understand completely.

 

Yes

Yes

Yes, based on the 4x crank reluctor.

No, this will require a 24x crank signal and a calibration from an engine originally equipped with a 24x crank signal.

No, you cannot change the firing order with EFILive. HP Tuners supposedly supports this, but I don't know of someone who has tried this. The firing order (injectors and coils) are changed in the harness. The injector to bank assignments for closed loop fuel trims are changed in the calibration.

 

Just thought I would let everyone know that I finished converting my 93 and it fired up the 1st time!!

Have to know your stuff when doing the late ones because I had to move a bunch of wires to get everything to line up with the LS harness.

Thanks Mike & EFI Connection!!!

 

Awesome would like to see some dyno numbers from a built 383 with this setup.

 

Unfortunately I made a cam swap with this setup, but no missfires, and that's the best thing.

I'm making 394 rwhp / 358 rwtq with the setup in the signature except it now has a LE custom cam and a Strange 12 bolt w/4.10's.

One thing I did want to ask if anyone experienced yet, was my tuner said something about the dwell being different on LS2 coils vs. LS1 coils, but when he loads the LS2 dwell, it missfires. Any thoughts on this? It does run fine with the LS1 programming, but was only able to put 25 degrees of timing on it before loosing power, but this could also be due to running to hot of a plug which we're about to find out. I'm guessing it's more the plugs.

 

I just double checked the final calibration for the 396ci LT1 we helped with for (Street Thunder magazine). That engine made maximum power at 33-35 degrees timing with the LS1 dwell tables (I don't recall changing the values) and LS2 ignition coils. I wish I knew what plugs we had in the motor during the dyno test, but I'm not sure.

 

We are in the middle of doing the conversion on a 97 Z28 and have a few wire related questions. We appreciate any information from those who have done this already.

1. Where is the LS1 PCM red 15 "Alternator L" wire supposed to come from?
2. What are the 2-12" black wires and 5 extra pcm pins in a bag labeled "PCM Terminals" intended for?
3. Does the wire from LT1 PCM Blue 3 "PCM Ignition Positive Voltage" get transferred over to anything on the LS1 PCM?

Thanks in advance for any help.

David

 

^^ I would also like to know the answers to thiese questions plus what you guys did with the second knock sensor? Can it be tuned out of the computer or did you have to install the sensor on bank 1?