2012 L99 LSA Supercharger - Almost No Power Gain

[Tzarro]

Hello all,

I recently purchased an LSA Stage 1 conversion kit from Andy over at ADM Performance, and upon completing the installation took it to Alex and his crew over at Carburetor Connection in Kirkland, WA for dyno tuning.

Prior to installation of the supercharger, I had a set of long tubes, a cold air intake, and a tune making 378whp on a Dynojet. Now, with the supercharger on and running about 5 - 6 psi, the highest we could get it was 411whp. The latest stable tune put down 391whp as seen in the dyno sheet. There was some misfiring in the higher RPMs, so I had the shop put in some ZR1 spark plugs to see if they could get anything more out of it as the issue seemed to be ignition-related. Seemed to help with the misfires, but no more power. Pressure tested the supercharger manifold and verified there were no leaks. Thought high-flow cats might be problematic, but running straight headers on the dyno also had little to no effect.

I am running the 52 lb/hr stock LSA injectors that came with the kit, but have retained the stock SS fuel pump. The fuel trims looked good up until around 5k RPM in 4th gear where the car started to get fuel starved. Although problematic, Alex didn't think this should account for the lack of power in the lower RPMs, where there was still practically no gain over my prior NA setup.

Andy, Alex and I are currently going back and forth trying to determine why I am getting a fraction of the power I should be, but in the meantime I figured I'd drop by here to see if anyone had any other ideas. I'm beginning to wonder if perhaps the fuel pump is the source of my issue. I've done my share of reading on this forum and have heard that even if the fuel trims look good that it's still possible the engine is getting fuel starved by the pump being inadequate and the injectors working overtime to compensate. This seems to make sense for the starvation issue in the higher RPMs we noticed, but could this account for the lack of power elsewhere? My shop brought in a tuning specialist to get a second pair of eyes on the situation, and he said that the tune looks good and should easily be making around 50whp more than it is.

Both Andy and Alex have been amazing to work with and have really gone (and continue to go) the extra mile to try and help me get to the bottom of this. However, I know there is also a wealth of knowledge and experience spread out among the members here, so any additional input on the matter would be much appreciated!

On the dyno sheet below, blue is the NA tune from earlier this year and red is the most recent run with my supercharger:

[bayarea408]

SS fuel pump?

Hows the belt drive assembly?

any upgrades to valve train?

have you compression tested the cylinders?

[ADM PERFORMANCE]

Post up picks of the engine bay,Lets get a visual on whats under the hood.

I want to see the Intake setup and install as well as the belt routing etc.

[GenF-GTS]

Have you checked the bypass valve to make sure it is closing 100%

[RealQuick]

Originally Posted by GenF-GTS

Have you checked the bypass valve to make sure it is closing 100%

That was my first thought, second thought is belt slip.

[sscamaro]

Check mods in sig. 546/rwhp. ZL/1 fuel pump and 72# injectors.

[NOLA_1LE]

I have a ZL1 pump that I just pulled out of my 8k mile 1LE if your interested?

[hammdo]

Wow, that is off. Agree need to see the bay and belt routing. I'm an 11 L99, 6 PSI stock LSA injectors and pulley, ported heads, VVT cam and I'm 590 RWHP. I do have the ZL1 fuel pump and ADM FPCM...
I have on my build thread that shows the belt routing and the boost valve adjustment...

-Don

[Tzarro]

Thanks for the replies everyone!

hammdo, I used your build thread as one of my primary references throughout this process. Thank you for your thorough documentation. I found the section you mentioned about the boost valve adjustment. I don't have the adjustment tool but I will order it if necessary. I did come across another thread a while back that addressed this; i assume it refers to the same calibration? Can it be done without the tool?

http://www.ctsvowners.com/forum/93-t...ass-valve.html

The belt I have on the car right now is the one recommended on ADMs website. It took a lot of wrangling to get it on and it felt SUPER tight so I ordered a slightly longer belt. However, having run the recommended for about a week now, the tensioner adjustment indicators appear to be within the proper range as indicated in one of the pictures below, so I'm sticking with it for the time being and keeping the slightly longer one I purchased as a backup.

Throughout the tuning process Alex said he did not see or hear any indication of belt slip at all, so he felt it was safe to rule that one out.

Valvetrain is stock and I do not believe he tested the compression.

As far as checking the bypass valve to ensure it is closing 100%, can that be done without removing the intake/supercharger lid and looking? Can I just disconnect the actuator arm and see if it moves back into the closed position any further and then adjust the controller mounting accordingly?

Hammdo, I noticed in your build thread that you said the bosch intercooler pump could not be mounted upside down (like I have in my picture), but that is how I have it mounted and it seems to be operating fine...will this damage the pump? Is it vital that I reorient it?

Lastly, I just remembered that during my install to make room for the intercooler I disconnected the OAT sensor and left it off. Other than the reading it gives you for your own benefit on the display, does this sensor do anything for the tuning/engine itself?

Thanks again for all of the input, and NOLA_1LE, thanks for the offer on the pump. I will need to upgrade from the SS pump I have now at some point so I'll keep you updated.

[hammdo]

If that is the current setting for the boost bypass, that is way to wide open. It should be just a fraction on the set screw. If that is not closing, you're leaking boost. If you see mine, even without the tool, you can get it close. You'll need to loosen the bolts on the boost valve and make sure the arm is not pulling the valve open, which it looks like it is.

The pump does not need to be reoriented . It appears to be upright

I'd correct the boost bypass valve and make sure it's set correctly.

PM me if you need anything...

-Don

[hammdo]

Mine:



Yours:



I bet boost is bleeding off...

-Don

[Tzarro]

Hey Don, thanks for the input on that. I found the portion of your install that went over that so I went out and tried adjusting it. I haven't done anything with the adjustment screw but I did ensure that the orientation of the boost bypass had the actuator at its default closed position - it would not move any further back. At this point I tightened down the bolts while doing my best to position the adjustment screw just a fraction away from the bracket on the arm as shown below.

I'll have to get to the pump tonight or tomorrow as I will need to come up with a way to drain all of the coolant and fabricate new hoses to ensure proper routing to the pump's new position.

Thanks again.

[hammdo]

If the pump inlet is facing up, your good...
Originally, my inlet on the pump was facing the ground and that was a no no...

Yours looks fine..

Keep us posted! Pm me if you way to talk on the phone...

-Don

[hammdo]

Looks like its still too far away. You need it to be closer to the set screw. I physically hold the valve shut loosen the bolts again and try to adjust the vacuum switch so the set screw kisses the arm on the valve. That will get you close. Then adjust the set screw 1/4 turn in. Do that until you get the tool...

-Don