Built LS3 - use Warren PCM & cable throttle or DBW setup??

[Vega$69]

The 24x is for 3 bolt and limits cam selection.

LS3 design is 58x reluctor so going 24x is a step backwards.

Dyno tuned on an engine stand and then dropped onto you car with a different intake and exhaust should have a retune. With a MAF over SD it is not as important.

[Nativefx]

Hi Tom, thanks for providing some input. Hopefully i can answer some questions and also make note of questions I should ask Kyle at Thompson.

As I mentioned above, if I decide to go with DBW, it will come with a custom built harness but I don't know for sure who they use. If I remember correctly it would utilize a GM E38 PCM with a 58x reluctor.

The drive by cable option would utilize the 24x Warren PCM and set up with a cable operated TB. The harness would also be custom made for this application.

As for the information listed in the link, I believe this was the options for the BDW setup using MAF and IAT. I'm not sure whether speed density would be the option with the drive by cable 24x setup, I would have to ask.

Forged may not be completely necessary, but they are running a special on their turnkey packages for the first setup of the 10 options they have. I was able to get the FI LS3 option at the discounted price. For the power level I was hoping to achieve, it made more sense to at least look at going to forged pistons, which is where my initial conversation started with them. It will mainly be street driven but at some point I hope I can do some autox and maybe large track.

Just for background, I took my car to bare metal to start my build and it includes RideTech Level 2 AirRide suspension with TruTurn and Musclebars, Baer Tracker full floater rear end on a 9" with 3.89 gears and TruTrac posi, Baer 6P brakes front and rear and Forgeline 19 x 11.5 (335/30/19) rear and 18 x 9.5 (265/35/18) front. The trans will be switched out to a T56 Magnum close ratio to go with the motor.

Let me know if there is anything else I should be asking or if you have any further input. I really appreciate anyone willing to take the time to share knowledge, even if they may have different views. Its great learning experience!

thanks, Jake

Originally Posted by TomM

Thanks for the link. It doesn't relate much as to what the harness and computer consist of at all, so it will be hard to give you an answer unless we know what you are specifically getting.

Reason being is there are many options.

I see they state it uses a MAF (Mass Airflow Sensor = no speed density) and IAT, so does that mean for both 24X and 58X, DBC or BDW?

If not, are they running Speed density on 24X and not on 58X.

Who made the harness?

Who made the computer if it's not OEM?

What about replacement parts, should you have a failure?

A lot of companies make very different applications, Some use what is know as MEFI, or Marine Electronic Fuel Injection, which eliminates the MAF and uses Speed Density.

Sounds to me like the 24X DBC setup may be the Speed density type, hence the "custom" "Warren" computer.

If it is speed density, and I am not saying it is, not every "tuner" can tune it. They better be reputable and proven and they need to know their s**t or they can toast a 15K motor setup real quick.....you should find this out for sure. This means if you need a tweak here and there, there are few who can effectively do this for you. Not the case with closed loop tuning...(MAF)

Then there is the MAF system, which is still good for big HP, but is a little more street and tuner friendly for around town driving...

So you see, there are a lot of options, depends on what you are going to do with the car.....as to what is actually "better"...

Forged is good, but do you really need it? Is this just an around town car with occasional romp on the gas or a big smokey burnout?



T,

[andrewb70]

Originally Posted by Nativefx

Hi Andrew, I appreciate your input and you have been a great help even earlier on when I was thinking about buying a used "refreshed" motor. Once I decided to go with a new motor I have been doing a lot of research and considering the GM crate motors and other options. In the end, I guess it's never "enough", so I wanted something a little more custom. If I was going to run a different cam, even a different GM cam, it would have voided any warranty which kind of tilted me towards a custom motor.

Thompson Motorsports seems to have a great reputation not only for the product they sell but also for taking care of any issues should they come up. This set-up comes with a 24 month unlimited mileage warranty, which Kyle was kind enough to work with me on. As I mentioned, I do have the option for DBW, which I believe he said would come with a GM E38PCM to go along with a a 58x reluctor. The harness is custom made, but i'm not sure who they are using but he did say it is farmed out.

I've just seen too many people choose "custom" this "custom" that and in the end be unsatisfied because their car doesn't run right. I know that it is tempting to get the biggest, baddest combination that you think you can afford, but in my experience, less can be more.

If you want a little extra power, choose the LS3/525 and the matching GM harness and ECU. That cam is gentle on valve train parts, sounds great, and has an excellent torque curve. You'll save a bunch of money, and have an engine that makes more power than the average person can handle.

Or...for that same (roughly) money as that "custom" LS3, I would do a LSA. Again, with the GM ECU and harness.

That's just my 2 cents on the subject.

Andrew

[Vega$69]

Originally Posted by andrewb70

I've just seen too many people choose "custom" this "custom" that and in the end be unsatisfied because their car doesn't run right. I know that it is tempting to get the biggest, baddest combination that you think you can afford, but in my experience, less can be more.

If you want a little extra power, choose the LS3/525 and the matching GM harness and ECU. That cam is gentle on valve train parts, sounds great, and has an excellent torque curve. You'll save a bunch of money, and have an engine that makes more power than the average person can handle.

Or...for that same (roughly) money as that "custom" LS3, I would do a LSA. Again, with the GM ECU and harness.

That's just my 2 cents on the subject.

Andrew

X2

I ran a built LS7 in my last 69 approx 640 HP with a T56

My new car is an LS3/525 with a T56 Magnum F9 with 3.70 and 335/30/18s

It runs better on the street at lower rpm (taking off from stops and cruising) then the LS7 with the big cam and honestly feels just as strong.

Plug and play with the GM Performance and ECM.

I just added a Holley Mid Rise intake more for looks then power.

[TomM]

Makes it a little clearer now. For what you describe as your use, and to echo what Andrew said, try to stay with the GM parts. The E38 is a good ECM, and can be found anywhere at a dealer or online should a replacement be needed. The 58X with a MAF and IAT combo is much "friendlier" as it were, for street driving and occasional track use, and the part throttle driving experience is very linear. Speed density is an option with just about any setup, but no real need for speed density for what you are doing....IMO...

Sounds like you have a good plan and are using some quality parts in your build...keep us posted...

T,

[andrewb70]

Originally Posted by TomM

Makes it a little clearer now. For what you describe as your use, and to echo what Andrew said, try to stay with the GM parts. The E38 is a good ECM, and can be found anywhere at a dealer or online should a replacement be needed. The 58X with a MAF and IAT combo is much "friendlier" as it were, for street driving and occasional track use, and the part throttle driving experience is very linear. Speed density is an option with just about any setup, but no real need for speed density for what you are doing....IMO...

Sounds like you have a good plan and are using some quality parts in your build...keep us posted...

T,

To clarify, the GM ECU and harness kits come with the E67 ECU, which more advanced than the E38.

Andrew

[Vega$69]

Originally Posted by andrewb70

To clarify, the GM ECU and harness kits come with the E67 ECU, which more advanced than the E38.

Andrew

GM Performace E67. PSI and others use the E38 as well