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The ZR1 pump is 1000$, and it's a mean pump. Really nice, but not a "smart pump" no diagnostics, no safety's. IT just runs. And runs.
We thought we may have had a flow issue, or boiling over issue, but the duration of the IAT2 increase every session, was exactly 180 seconds, to the T. Every time.
Correct. We edited the post, as we mistyped water for air
The amount of air in the system was in the tablespoons volume. We bled all the systems, as we have been bleeding these systems on various supercharged cars for years.
What we didn't expect, was the pump to shut off. And shut off for not one minute, or even two. But 3 full minutes.
is there anything between the reservoir and the pump? Is there a thermostat kind of device between the pump and the fluid tank? Something that limits the flow intermittently?
in a perfect world the best setup would be having the pump immersed in the tank....covered by fluid...then the only reason for cavitating is the inlet isnt big enough or the fluid level for what ever reason dropped below the pump intake.
GM deserves a bitch slap for this one. Looking forward to your results moving forward.
Bear in mind, that were not running an OEM heat exchanger. We're also running a completely sealed tank, 3x the volume.
However, you can run 5-7 minutes with an angry HX pump (heat exchanger) and you'll never know it. The car just loses power, and eventually reaches the IAT2 temp threshold, and the throttle pedal gets wonky. The Zr1, when this temp was reached, just opened the bypass. It still made 400rwhp. This car, completely disables the throttle, but gives it back, as temps drop, then takes it away, as temps rise. It's a big moving target, then the pump turns on, and you forget about it until it cavitates again....
Did you remove the stock reservoir or is that still there? In the first thread you have this diagram
but it seems to me that you might have two reservoirs now.....plus you made the comment that the pump was below the reservoir...which one? Or am I not thinking this correctly....
I would also double check any clamps you have added.....while the fluid circuit may not be leaking it is possible to suck air in through those hose connections......might want to double check and if you are using just the push on hose type fittings....you may want to add clamps at each junction......
Did you remove the stock reservoir or is that still there? In the first thread you have this diagram
but it seems to me that you might have two reservoirs now.....plus you made the comment that the pump was below the reservoir...which one? Or am I not thinking this correctly....
We have the new fabricated reservoir 12-16" ABOVE the pump. 1.5 gallons.
The stock system pulls from the reservoir, across the lower portion of the stock HX, and into the pump. Not a ton of head pressure, but some. It takes several times to fully bleed the OEM or an OEM style system. This setup we made is self bleeding, but there's air somewhere, where, we don't know yet. We will fabricated a bleeding apparatus in the morning, before we test again tomorrow.
do other pumps that have been used with these type of setups have this built in 3 minute shutdown "feature"?
Should you try one of those in your test setup and put air in the inlet like you did with this one and see if they behave the same?
Any chance of having a bad pump?
We have three pumps here, we will try everything we can! The ZR1 pump is not a "smart pump" that turns off. However, its 1000$, which is motivation for us to fix the issue.
Originally Posted by johnglenntwo
Not as good as the chance that they caused it!
Hey, theres always that chance! And honestly, this is how you learn. We choose to share it, and some of the others out there, dont even know this pump has this capability. This is how you further the platform. By learning, and testing, and hooking up a boiler and doing destructive tesing. You dont do it sittin behind a keyboard, or in the garage.
IF we had not seen this on a stock configuration in the past, Id say we had a good chance of creating the issue.
We have done more to further the cooling and performance development of these cars the last 10 days, than anyone combined in the two years this car has been in consumers hands.
We have done more to further the cooling and performance development of these cars the last 10 days, than anyone combined in the two years this car has been in consumers hands. [/QUOTE]
Keep up the good work guys!!!
Get this thing dialed in by the time I get my Z please...
We have done more to further the cooling and performance development of these cars the last 10 days, than anyone combined in the two years this car has been in consumers hands.
I would say that no one should argue that point....you guys are like a dog with a bone that wont let it go.....I say great job! Asking lots of questions and digging is the only way to move the needle......
perhaps they have this "feature" to avoid having a relief valve...also to have a lower cost pump......I could see a lot of ways that this would have been selected as a design spec....wont be the first time that engineers did a design to avoid other issues that in turn created another issue and the feeling by the team is this wont happen or it will only effect a couple...we will be all right.....
I seriously hope the intercooler pump isn't the same one as the LSA uses. That pump is a royal piece of crap. I went through three of them failing on my CTSV before putting in a Lingenfelter pump.
perhaps they have this "feature" to avoid having a relief valve...also to have a lower cost pump......I could see a lot of ways that this would have been selected as a design spec....wont be the first time that engineers did a design to avoid other issues that in turn created another issue and the feeling by the team is this wont happen or it will only effect a couple...we will be all right.....
thinking about it, this feature is probably a necessary one, for a road car. turning off, and turning on again, allows the bubbles to settle, and start over (on the viscous cycle of cavitation, again) But when you run the car 100%, it rears its ugly head.
Seeing as how the LS9 (Zr1) pump is almost 4x the cost, Im certain cost was a big reason, as the ZL1 uses an identical pump (different GM part number, but physically identical, down to connector and impeller) and there is NO data on this issue, however, that system is easily bled, and those cars are rarely road raced, and have better IAT control than these cars do and does not take throttle away when IAT2 limit is reached (its like the LS9, not the LT4)
Originally Posted by spearfish25
I seriously hope the intercooler pump isn't the same one as the LSA uses. That pump is a royal piece of crap. I went through three of them failing on my CTSV before putting in a Lingenfelter pump.
CTSV has a unique pump. This is not the CTSV pump. This is the ZL1 pump.
Originally Posted by johnglenntwo
Anyway, since this system is failing it makes sense to me behind my phone in my garage (objectively I might add) that it probably hasn't had much to do with your success thus far so why not go back to stock with it?
Dont be so harsh, 1500 miles away. Much too easy to criticize with out knowing everything. Its very possible we could have induced this, however, care was taken upon filling, and the SAME scenario has occurred with a stock configuration.
However, blatently saying were the problem, is a shot from the hip, and a shot across our bow. Were researching and developing, and none of the other heavy hitters share what we are sharing, to further the platform, and help the community. A polite suggestion goes a long way, I can gurantee you that! As evidenced in our other cooling thread, we are sharing it all, failures included, and making big strides this car needed from day one, to enjoy it on track, where it needs to be.
Refresh my memory? What year is the test vehicle? 2015?
I'm wondering if they put a pump Pid and wiring on the network for 2016 or 17.
your assumption would be that the pump could truely control the temperatures rather than just running flat out and reaching a steady state temperature that is acceptable.
From the data collected it looks it would really reach a steady state if it wasnt for the 3 minute pause that the pump does.....that pause is theoretically put there to improve pump life due to cavitation. Pumps will fail premature if they suffer through a continual stretch of cavitation unless they built the pump to withstand that....but it appears that wasnt the case.....
Correct. We edited the post, as we mistyped water for air
The amount of air in the system was in the tablespoons volume. We bled all the systems, as we have been bleeding these systems on various supercharged cars for years.
What we didn't expect, was the pump to shut off. And shut off for not one minute, or even two. But 3 full minutes.
What a great job you guys have done!!!! I realize you have more tests to do, but i find it interesting that Tadge was quoted on this thread as saying some of the problem may be related to improper intercooler fill ie too much air in the system.
A few here have reported that GM TAC has recommended replacing a number of wiring harnesses and pumps and after the dealer did what they recommended the cars ran better and ran cooler. I wonder if they replaced the pumps with ones that don't shut off if such a thing exists. Also recall a thread on making sure the system was vacuum filled properly.
I tried to get this done at MY expense at two dealers last year. One said they didn't have the equipment and the other larger dealer tried to bleed it and said they couldn't get any more air out. I have a lot more air than what you guys are describing but the pump shutting off for that period of time is huge. Looking forward to your tests tomorrow! Your work is excellent.
Last edited by rsilver; 07-09-2016 at 01:31 AM.
Reason: clarification
Does anyone have the proper vacuum bleed procedure and list of required equipment? I trust myself to do this more than my local corvette tech who told me the car has a 10.5L oil capacity. I lost all faith in him immediately after he said that number.
07-08-2016, 09:58 PM
