C4orce2

Only new issues I've run into since my last update two months ago both concerned hoses. Had one came off from the top front part of the engine and one came lose from the lower right part of the new radiator. I've had all the connections and clamps tightened so this type of problem should not re-occur. This weekend we have 5 or 6 auctions in the Phoenix area including Barrett Jackson. This Saturday there will be over 1,000 cars at the Pavilons shopping center in Scottsdale. Every Saturday there is an informal car show there with around 200 cars from 3 to 9 pm. But on the last Saturday of BJ sellers who have not sold their cars at the other reserve auctions take their cars to the Pavilons and try to sell their cars their with no commission and no sales tax. Of the over 1,000 cars that will be their, 50% or so will be for sale. Always a great weekend here in the Valley of the Sun. Temps tomorrow will be in the 70's and I plan on being there with C4orce2 from 8 am till sunset. Then over the next several months, one car show after another. I'll continue to update any issues with the build.

STL94LT1

^^ Sounds like fun!!

ch@0s

Take some pictures for us brother

C4orce2

Sorry about the pics. One of our other ACE members was going to show up and usually takes great videos. However, I think he bailed out and never showed. I got to the Pavilons at 8:05 and the best spot I could get was in the 7th row (each row holds 60-75 cars). By noon there had to be around 1,000 cars and when I left at 3 there were still cars coming in and trying to find spaces. They finally started parking cars between the rows. Weather in the mid 70s, not a cloud in the sky and no wind. Great day for cars and sun tans. Wish you all could have been there.

aboatguy

Thanks for the periodic status reports. Its good to see reports on a projects long term reliability

C4orce2

Quick update. I now have over 30,000 miles on the build which was completed in July of 2010. Have not had any problems with the build for a long time. I attend car shows most weekends and now have won 57 awards with it.

C4orce2

Thought I'd give a quick update on the build. I now have over 133,000 on the car and about 36,000 on the build. No build related issues for a long time. During the summer there are very few car shows I attend here in Arizona. As of now, 67 awards won and will start up with shows again in September. Car is running great!

ch@0s

That a lot of awards bud

dizwiz24

Cool! congratulations on a successful project.

How is fuel economy? Was it improved?

Did you notice any improvements in handling taking weight off the front end?

C4orce2

The fuel economy is actually better even though the hp has been increased from 300 to approx. 535 SAE net (429rwhp on a loaded dyno). I drove it last year from Phoenix to Wichita (about 1,100 miles) non stop both ways. Going across New Mexico I got over 22mpg running about 85 mph without the air on. Not bad since I have 3.73 gears in the rear. I know that is better mpg than with the LT1. As far as handling, I cannot tell much difference. The builder guessed that the LS3 and alum rad probably weight about 150 lbs less than the LT1 and stock rad. I can tell that the front end rides just a little higher than before. But since I have never tracked it either before or after the build, I have no way of really knowing.

kg4fku

You have a great build up there.

I have a some questions concerning the interface module you used to interface the LT1 (OBDII?/OBDI?) ECM to the LSX ECM. These may have been addressed already and I probably missed them. I am good at that sometimes but this is one project that really interests me.

First, what can you tell us about the interface module? Is it a separate computer module using a computer OS for operating value conversion or is it a processor chip that just reroutes incoming signals to its counterpart. Do you have any pictures of it?
Second, what stopped you from being able to use the cruise control module and fuel consumption averages?
Third, are these units available for purchase or can the schematics and OS be purchased to build a unit?

Again, this is an awesome build. Being able to integrate two completely different technologies is no small feat.

C4orce2

OK, I'll give it a try. First, let me warn you that I'm an IT guy at all. My builder here in the Phoenix area (who has passed away) was put in touch with Wes Burch who designed all the electrical aspects of the build. The computer that came with the kit for the GMPP LS376/480 was an E67. Wes built the computer board that connected the two computers together and did some functions on its own as well. I have attached the best picture I have of the unit. Wes felt that if I really wanted to save the cruise control and traction control features he could have done it given more time. Of course going from the cable driven features of the LT1 to the drive by wire features of the LS3 would have taken some more engineering. I told him not to bother with either. He had no idea what is wrong with the MPG but that is the only feature that we tried to save and could not. My interface was only the 3rd one Wes ever built. He had one for his own C4 and one for another hot rod built before mine. I'm not sure how many he has built since my build. He told me eventually he will build a new computer that will combine the old C4 computer and the interface together since many of the old C4 computers are going bad. I have not seen that new computer yet but I'm sure when he develops it he will make it available to me. If you want more information about the interface you will have to get it from him. If you'd like to, send me a message and I will give you his cell number in Fla. Hope this answers your questions at least in part.

PS: for more pics of the build, google "C4orce2" and look for the photobucket. It has an album on the build with over 30 pics.

85MikeTPI

Having done the swap myself, I can tell you that the interface module would just be emulating Analog sensors/data for the Dash. You have the option of deploying the stock sensors (CTS,Oil pres/temp, RPM, etc) along with the LS digital sensors or building a Digital (+5V) to Analog (+12V) conversion circuit. I run all the stock C4 sensors in my LS3/L92 along with the engine sensors and the only electronics I had to add was a pull-up resistor for the Tach. You need to retain the stock ECM to feed data to the CCM for the other dash and internal functions, since they communicate using the OBDI data.

The MPG is difficult because the CCM needs the Injector pulse widths along with the VSS to calculate. You would basically have to feed false cam/crank/TPS/RPM/etc. data to the stock ECM to fool it into believing it's running the engine and delivering a pulse width, and even then it won't be correct unless the stock ECM is programmed. Alternatively you could build a small controller (CPU) circuit to intercept the OBD2 data stream, pull out the real PW, and inject that back into the OBD1 data stream. Again, pretty difficult for little value added.

Annoyed

I'm not running the standard C4 computer in my '85 C4 LS1.
Engine senses go to the cluster connector/plug wires and that's about it.
Tach wire connected to LS1 ecu tach wire. I need to do what 85Mike said above to get it working accurately, but I'm not fussed. It's a useless gauge really. And my MPG doesn't work, but I don't really care about that too.