New Camaro Zl1 fuel module

[EFI69Cam]

Just got the latest GM Performance (now Chevrolet Performance?) catalog. On the first few pages they mention the ZL1 fuel pump as an upgrade for the 5th gens.

Got me wondering how does this one differ from the CTS-V module? Based on the pictures it has the gauge sender integrated, does it have dual pumps like the CTS-V?

Not that it matters for my install since my vaporworx tank is set up for the CTS-V module, but it might simplify the upgrade for those who have the 5th gen set up.

[CarlC]

I have one and did some testing this past weekend. It falls between the LS3 5th-gen and the CTS-V modules. It will work well for a mild supercharged build, something along the lines of an LS3 with a Magnuson supercharger with a small camshaft making under 700FWHP and mild boost levels. Anything more than that and it's CTS-V time. The ZL1 is a single bigger pump. The CTS-V is a dual pump.

One nice thing about this module is that it can use the 5th-gen LS3 fuel level sensor. The ZL1 sensor is different and does not lend itself well to working in tanks like ours. The LS3 sensor is a bargain at under $30. It is a single pump so the fuel module plug can handle both the pump power and fuel level sensor. The CTS-V uses all four cavities and needs another method get the wiring out of the tank when using the horrifically expensive CTS-V fuel level sensor (the 5th-gen LS3 sensor does not fit CTS-V.)

The venturi pump system in the ZL1 module is far better than the LS3. There is an extra pump on the bottom of the module, so if the tank has corner pickups there will be four venturi pumps working. With the extra venturi pump 42psi is no problem at full fuel volume.

If the intenet is to never go more than a mild LS3/low-boost build then the ZL1 will work. If a bigger cam, more boost, etc. are a thought on the horizon then the CTS-V module is a better long-term option since a future upgrade won't be needed. It's the ol' "pay me now, or pay me later" deal.

GMPP did their homework on the ZL1 pump. The CTS-V module is not a simple plug-and-play deal. It needs a new fuel controller and a lot of re-wiring. the ZL1 will drop in with no fuel new computer needed, so they will sell like hotcakes for those not doing the real big horsepower gig.

[EFI69Cam]

Carl,

Thanks for the info. I figured you'd probably already got one tested and disected!

[CarlC]

I guess I should have looked around more about the pump. More info here: http://media.gm.com/content/media/us...1_zl1_fuelpump

The flowrate at 65psi measured this past weekend is within 1% of the GM rating. That's pretty close since it is not known what the GM input voltage is. Why is that important? If the GM rating is at 13.5v, that's misleading for 5th-gen owners. The fuel computer in that car is limited to 12v output, so the flowrate(s) will be lower.

At 65psi the pump produces 250lph. At 0.6BSFC that equates to 680FWHP with no safety factor, so 620FWHP with 10% SF.

Bring the fuel pressure down to 58psi and the the power goes up to 705FWHP @ 0.6BSFC with a safety factor if the proper injector is chosen.

42psi fuel pressure at idle + 6psi (atm) + 12lbs boost = 60psi, so 675FWHP with an injector that flows enough at 42psi to support the power level should be OK with a 10% SF.

It will be a nice pump for mildly supercharged engines.

[diesel25lrs]

Carl,
so are you saying that the new ZL1 pump is a direct drop in module for the gen5 & can be run mechanically the same way with a 4th gen regulator just like your 5th gen setup?

I have one and did some testing this past weekend. It falls between the LS3 5th-gen and the CTS-V modules. It will work well for a mild supercharged build, something along the lines of an LS3 with a Magnuson supercharger with a small camshaft making under 700FWHP and mild boost levels. Anything more than that and it's CTS-V time. The ZL1 is a single bigger pump. The CTS-V is a dual pump.

One nice thing about this module is that it can use the 5th-gen LS3 fuel level sensor. The ZL1 sensor is different and does not lend itself well to working in tanks like ours. The LS3 sensor is a bargain at under $30. It is a single pump so the fuel module plug can handle both the pump power and fuel level sensor. The CTS-V uses all four cavities and needs another method get the wiring out of the tank when using the horrifically expensive CTS-V fuel level sensor (the 5th-gen LS3 sensor does not fit CTS-V.)

The venturi pump system in the ZL1 module is far better than the LS3. There is an extra pump on the bottom of the module, so if the tank has corner pickups there will be four venturi pumps working. With the extra venturi pump 42psi is no problem at full fuel volume.

If the intenet is to never go more than a mild LS3/low-boost build then the ZL1 will work. If a bigger cam, more boost, etc. are a thought on the horizon then the CTS-V module is a better long-term option since a future upgrade won't be needed. It's the ol' "pay me now, or pay me later" deal.

GMPP did their homework on the ZL1 pump. The CTS-V module is not a simple plug-and-play deal. It needs a new fuel controller and a lot of re-wiring. the ZL1 will drop in with no fuel new computer needed, so they will sell like hotcakes for those not doing the real big horsepower gig.

[CarlC]

Unfortunately not.

There are two reasons to run the CTS-V pump using the pwm control system. First, there is no good 58psi regulator. Second, even if there was a good regulator, it would pump 18-amps of power into the fuel at all times. That's a 240 watts of heat put into the fuel load whenever the key is on. That's a lot of heat put into the fuel load.

So, it would make sense that since the ZR1 pump has a lower output than the CTS-V it should require less power, right?. Nope. It takes the same amount of power to drive the ZR1 pump @ 58psi as the CTS-V. The ZR1 is less expensive, and quite capable for many builds, but it is not as efficient as the CTS-V.

The stock LS3 Camaro pump needs approximately 10 amps at 58psi. In our case, going from 10 to 18 amps does not result in a similar increase in pumping performance.

The more I deal with the CTS-V pump, the more impressed I am. It's a great piece of engineering.

[LSXfan]

are both the LSA pump and ZL1 pump pwm ?

[CarlC]

Yes.

[chuckd71]

Old thread, but just for the sake of clarity- must a ZL1 pump be pwm controlled? Or is using a fuel pressure regulator and return line an option? I like pwm for radiator fans but would rather not mess with it for the fuel pump on a NA sub-500 hp car if I don't have to

[CarlC]

It's not the amount of horsepower that the engine makes, it's the size of the fuel pump (power requirements) and what the intent of the car is that helps drive the control strategy.

If battery voltage is put to a ZL1 pump with a mechanical regulator the power requirement is 16A. For the 98% of the time the car is running, the full output of the pump is not needed. Running a 750hp NA pump at full speed all the time is not good for pump life, fuel temperatures, etc. We've had many customers that have run the ZL1 with a mechanical regulator come back and go pwm due to heat generation. On very warm days with high pavement temps and soak time, the tank was very hot to touch. The PWM relieved much of that problem.

Also, the current generation of PWM controlled modules are not intended to be used with an external regulator. Earlier module designs were an external regulator type where the return went back into the module reservoir. The PWM modules have no such provision, and hence can run dry under low liquid level conditions. Though not preferable to PWM, it would be better to convert the ZL1 module using the vaporworx fuel pressure regulator adapter and a 60psi GM regulator. This returns unused fuel to the module reservoir.

From a performance and reliability aspect PWM has all the advantages. If there was a way for the OE's to make a better and less expensive system, they have the capital and brainpower to make it happen. Most all of them abandoned mechanical regulation many years ago, especially for vehicles with large pumping systems. Even the current direct injection engines still use a "low pressure" fuel system to feed the DI pump. That low pressure system consists of a fuel module and PWM driver, just like the pre DI systems. The DI pumps simply raise the fuel pressure to the 2200psi+ required.

[chuckd71]

Good info, thanks. I can just grab the vaporworx piece when I order their corner pickups and run it until I find a good deal on a pwm controller. Car is seldom driven, so time is on my side. I had looked on the site before posting that question but I guess I just missed this https://www.vaporworx.com/documentation/fuel-modules/
I guess pwm is the way to go for sure.

[DKz Garage]

Hi Carl,
Looking for some advice on my current/next build. 70 Camaro w/LSA. Not sure what the Hp will be in the end; cam, headers, injectors, overdrive supercharger (top pulley), tune, head porting.... with that said, I've already decided on a Vaporwox tank, so no issue there....just trying to sort out what pump(s) to run. I don't want to "re-do" the fuel system after the car is done.... Your thoughts on the ideal system that will work without any issues/heat build-up ??

Thanks in advance, Dave

[badazz81z28]

Hi Carl,
Looking for some advice on my current/next build. 70 Camaro w/LSA. Not sure what the Hp will be in the end; cam, headers, injectors, overdrive supercharger (top pulley), tune, head porting.... with that said, I've already decided on a Vaporwox tank, so no issue there....just trying to sort out what pump(s) to run. I don't want to "re-do" the fuel system after the car is done.... Your thoughts on the ideal system that will work without any issues/heat build-up ??

Thanks in advance, Dave

That’s the biggest challenges....even when you don’t think so, you end up upgrading. I have a LS7 in my 70 Camaro that Dynos at 555hp to the tires and I run the ZL1 module with the pwm. I was thinking about going CTSV but that pump to ridiculously expensive. If I were to upgrade I would look at dual pump system with the PWM. DSE has an off the shelf dual pump tank for the 70-73 Camaro and Ricks can make one.

[badazz81z28]

Can the same pwm be used with the CTSV pump as the ZL1? I just looked at rock auto and the CTVS pump is shy of $600 while the ZL1 is $198

[CarlC]

For naturally aspirated applications the ZL1 is good for 750hp. We've been supporting some pretty stout LS7 builds on this pump with pwm quite well.

The CTS-V is good for 900+hp NA but there's very few builds like this.

The controller can be used for either pump but the wiring to the pump is different. If the OEM fuel level sensor is not used then a CTS-V kit will work with either pump. If an OEM fuel level sensor is desired then it's recommended to give us a call to discuss how best to do it.

vaporworx has CTS-V pumps for sale with an OEM fuel level sensor for $469 https://www.vaporworx.com/product/cts-v2-fuel-module/

The CTS-V can also be upgraded to use the Deatchwerks DW300C pumps. This upgrade is good for 750RWHP supercharged in Deatchwerks test CTS-V car. If you buy both from VaporWorx we will install the pumps at no charge. https://www.vaporworx.com/product/cts-v2-fuel-module/

If "going big" is in the future the the CTS-V is a great choice. However, if going over 850hp supercharged then going twin fuel modules is usually needed. Steilow's latest green car has twin ZL1 pumps running on E85 with a VaporWorx controller with no issues.

If the build will stay under 650FWHP stick with the ZL1 and save the cash. Mine is a 6.3L LS6, very good set of West Coast Cylinder Heads heads, Lingenfelter GT2-3 camshaft, 9.1psi of boost through a Magnuson TVS1900, 63#/hr injectors, so the overall build is similar to an LSA + cam upgrade + pulley + injectors. The ZL1 is fine for this build.

Feel free to give me a call to discuss (805)390-6423 or email [email protected]

[icemanrd19]

carl some questions please. I bought my vaporworx tank 4 years ago or more with the camaro ss fuel pump. Setup is currently a ls3 hotcam 67 camaro. Now im wanting more power out of my NA motor. Eventually i would like to go with a different cam, and supporting head mods. In the meantime ive bend looking at e85. Would my camaro fuel pump hold up, do i need to upgrade to the zl1 pump or go to the ctsv pump? Im just trying to figure out the correct supporting mods and see if its worth it. installing the dms flex fuel kit is easy. I just didnt know if i need to swap injectors and fuel pump as well as well as it being worth it for a NA build.

[badazz81z28]

^whats the HP goal?

[CarlC]

Sorry for missing this....

Yes, what's the horsepower goal?



If E85 is in the cards the a ZL1 pump will be needed.

Larger injectors are also very likely. E85 is a 30% increase in flowrate.