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I installed an LS3 430HP Crate with GMPP wiring harness, GMPP ECU, Dry Sump, electric water pump, Headers to 3" X pipe (no mufflers or cats) in my tube chassis Nissan 350Z. After making some small changes to the ECU on the Chassis Dyno we made 410HP and 408TQ at the wheels. In the past this drive train loss was around 80HP 17% which is typical, that would put me at 350RWHP This suggest one of 2 things.
1) GMPP is underestimating HP and TQ numbers
2) Summit Racing sold me the 480-490HP version
Any way to tell what version I have ???
GM understates power numbers a lot, but so does most other manufactures. I’ll say this, you will ALWAYS pick up power over the factory tune, with a good, patient tune session. GM tunes their stuff for fuel economy, not max power. I’ve been saying this for years on here and other forums also. It’s been proven before, and your experiencing the same thing.
I expected to pick up some HP with a better tune, dry sump and exhaust but 60HP seems like a lot. I am running the car in a power to weight ratio class so the unexpected extra 60HP means adding 350LBS to the car so it looks like I will need to detune the engine. Going backwards on HP does not feel natural LOL
I ran the car at Mid-Ohio this past weekend and had overheating issues.
Mezeire 333 electric water pump flows 55 GPM
Any idea what the stock LS3 crate motor water pump GPM at say 4000 RPM?
I'm at 3,500 to 6,500 rpm's all the time on track with sealed air shroud to the radiator
92 Sq Inch opening feeding 384 Sq Inch radiator (No Fan)
I'm trying to figure out if the water is moving to fast or to slow thru the system.
I don't know what the GPM is for the stock waterpump, but from what I remember, I think the Mezeire electric waterpump moved the same amount of water as the stock pump does around 2500 rpm. I could be wrong about that, but I know it doesn't move nearly as much water. Put a stock pump on it and I bet your cooling issues all go away.
I'd go back to the OEM mechanical water pump, electric doesn't move enough water above ~5000RPM. Some snippets from FFRAX (F-body road racing forum):
* Electric has consistent water flow because the pump is rated at a constant GPM.
* You can run the electric pump and fans while the engine is off if you choose.
* There is not much to be gained at the tire. The LS1 sees about 7 peak HP using an electric pump, I have heard people claim a bit more.
* A few less pounds compared to stock
* "We both run the LG motorsports "Supercool" or whatever radiator. I have the stock W/P and he has the electric Meziere. Everytime his rpm's went above 5000 rpm in 5th gear his engine would start to heat up and he'd have to back out of it. Electric pump owner told me that they are setup to flow the same as a stock w/p at 4700 rpm. His Meziere is now for sale. My setup worked perfectly even running continuous 6000+ rpm at 170+ mph. This pump might work for most applications, but it sure isn't up to the job of handling ORR."
* "The various electric pumps are rated for "free flow"--as in dumping into a bucket. With that in mind, I sure wouldn't bet on a Meziere 55 gpm to push any more than 40 or so through the system if my engine depended upon it and I think even that's being generous."
384” square is smaller than an oem 4th gen fbody radiator. Granted yours being aftermarket should have a better core design, it may end up being on the smaller side of adequate.
I’d look into and consider the edelbrock pump. Its flow is not only higher than an oem pump, but more even bank to bank.
What is your steam vent setup like?
Any engine tilt?
Possible trapped air?
Do you have a loop on the heater hose outlets?
Are you running a de-gas bottle?
I'm running the electric pump because of space issues. The dry sump systems sits the motor so low in the chassis I only have room for 2 things on the front of the crank. ATI damper and the Dry Sump pulley.
The alternator is on the diff.
If I have to go back to mechanical pump I would need to loose the ATI Damper and I'm not sure I want to do that. I know they are "internally balanced" but an a motor that only runs between 4,000 and 6,500 RPM's ???
Is the ATI Damper necessary or overkill ?
I have optimized all of the cooling system and added a larger Oil Cooler. I will find out if it works on the next test day.
Terry
I've always been curious if a second EWP in series would resolve this issue? I have the large Meziere EWP on my car.
I know there is a PWM bmw electric pump out there that is extremely powerful. Might be what we need to start switching to if the Mezieres can't keep up.
Pierburg CWA400 is the model. It came on many BMW's and can probably be found cheap.
I tried to post a facebook link but I'm not able to on the forum. There's a video of the thing running it is really insanely powerful.
08-07-2024, 04:24 PM
Road Racing LS3 
