SGT with Shelby Paxton SC

[savage1969]

Hey Cuda, why didn't SAI put the "Shelby GT/SC" striping on your ride? I thought that came with their install? Great looking package. Do you wish you had the big brake package?

 

Thanks for your input.

[blueshawk]

I hope for good results. My work schedule comes out on Wed for the following four weeks. I hope to find a date in there and an open appointment with one of two tuners in my area. I am now taking it very easy on my car because I am VERY concerned that the Paxton tune that is on the car is running lean. If I press down too quickly on the gas in any gear, except 1st, I hear what I think is detonation. I am not a car expert but used to have the same problem on a EFI motorcycle.

 

 

This is what worries me about getting a S/C. I have a hearing loss for high frequencies and I DON'T hear pinging. S/C's and even just agressive tunes w/o S/C's can have conditions (poor gas, temperature, etc.) that tend to cause dentonation and need to be addressed with the proper tuning adjustments. I'm not sure how to handle that other than have a tuner check it out every so often to make sure the tune is safe.

 

Anyone else have any ideas other than just your hearing to determine if there is a problem?

[savage1969]

Maybe an a/f monitor guage in an instrument pod. It would let you know rich and lean conditions on the fly and in real time.

 

Not the same, but just a thought.

[ShelbyPilot]

....I have an appointment next Thursday for a tune on "Precious." I hope to back up Cuda's numbers but I am more concerned about reliability then getting to a specific HP number. I do have a detonation problem that is pronounced when I try to add throtle from a cruise on the freeway. I am now being very careful with my inputs.

[Hot Pony]

Well it’s been a good week for me and #259. Went over to Stangfest in Daytona and met up with some fellow Shelby GT owners. Then to top it off I got a 3rd place trophy in the new Shelby class up against a couple of other Shelby GT’s, a few CS6’s and CS8’s, and a bunch of GT500’s. And I wasn’t even planning on showing the car.

 

Today I took the car for the final custom tune and dial-in on the dyno and it rocks! Pulling 448 RWHP which is well over 500 HP at the flywheel (~527 HP using the 15% rule). This is with the stock Shelby Paxton supercharger kit and a fairly moderate custom tune in terms of timing and A/F ratio.

 

There was a huge thunder and lightning storm while we were tuning on the dyno, it was like bringing Frankenstein to life – so I’ll call it FRANKENSTANG.

 

It is AWESOME to drive… like a freakin' rocket ship!!!

 

Video of dyno runs… (turn up the volume):

 

 

 

 

 

 

 

Cuda, It was nice meeting you at Stangfest. I'm the owner of the other black SGT in Oviedo. Congratulations on the 3rd place win and the dyno run. Maybe I'll catch you riding down Lockwood some day. Emphasis on "maybe". Take care.

Joe

[CudaFly]

....I have an appointment next Thursday for a tune on "Precious." I hope to back up Cuda's numbers but I am more concerned about reliability then getting to a specific HP number. I do have a detonation problem that is pronounced when I try to add throtle from a cruise on the freeway. I am now being very careful with my inputs.

 

socal,

 

Hope you resolve the detonation issue, that is definitely not good. Any good tuner should be able to figure it out. It will be very obvious on the Dyno data capture.

 

I have had zero ping/detonation problems with the SC and tune. Very smooth through the entire power band. I've run nothing but 93 octane from the beginning, even before the SC install. I assume based on being in CA you are running 91 octane which could be a factor.

 

Probably could have easily squeezed another 20-25 HP from the SC with more A/F and timing adjustments but I was also looking for good, reliable mid-range performance. Gas mileage with the supercharger is at least as good as or slightly better than with the CAI, except when you stomp on it of course.

 

Good luck...

[ShelbyPilot]

I too hate long post and this one is that so beware.

 

Well my dyno day has come and gone and I have mixed results. I am actually a bit disappointed and it started right from the base run. I'll start by saying this is a new experience for me and I might be misunderstanding somethings and if I am please feel free to correct. Maybe it will make me feel better.

 

If you read through this thread you saw I thought I had a problem with detonating. The problem would occur at tip in from a cruise around 2000-2500 RPM and between gears under a hard shift. The tuner was able to duplicate the problem on the dyno during the base run. Then he opened up the car for the base run and was so surprised by the results he did an second base run to back it up. If you look at the chart below you can see the base run produced 351 RWHP and a 311 Torque number. Using 15% adjustment that is 413 at the flywheel, only 399 if you use 12%. I was very disappointed.

 

SAI, where is my advertised 462 HP?

 

That isn't what surprised the tuner. What surprised the tuner was that the A/F mixture didn't even show up on the graph it was well below 10. Me being a dummy, I said that maybe the intent was to keep the engine real rich and safe. The tuner said but it could be too rich and cause another set of problems. He did his thing on the laptop and Preadator handheld and ran it again.

 

This time the results gave me a smile and was the only part of the session where hope was on the rise. After another two passes, the numbers came up to 390 RWHP. I thought wow cool, a 40HP jump for a half hour of tinkering with the computer. The tuner showed me the A/F and it barely broke above 10 around 4000 RPM. I was thinking cool maybe there is more left in, maybe I can back up Cuda's and another owners numbers. Back to the laptop and back to the dyno.

 

The tuner ran the car up and came up with final results (perhaps). As noted below, a max RWHP of 403.6 HP and a Max Torque of 370.1. If I do the math right using 15% loss that is 474.8 HP and a torque of 435.4 (458.6 & 420.6 if you want to use 12%). Iwas still disappointed thinking about Cuda's 500+ number and another owners 485 HP number. However, I came home, took a nap and looked at those numbers again and perhaps they are fine. I told the tuner my number one priority was a healthy engine. If we could improve, on the 462 in my mind, then great. Looking at it now I think we did. Maybe?

 

I do consider that Cuda is running 93 octane (I think) and that his A/F is a tick higher than mine but it certainly wasn't 98 degrees, probably more like 80. Below is the chart. Those that know, anything you see? My feelings aren't easily hurt. That isn't the end of the story, look for more below the graph.

 

 

After the tuner was done with final run he poked around the engine some more looking at the set up and noted the intercooler was really hot in his opinion. We, looked at the reservoir levels for both the radiator and the intercooler and thought they were low, not dangerously low but not what they should have been. He topped them off and then noted that the coolant for the intercooler wasn't circulating. He trouble shot and discovered the fuse for the intercoolers circuit pump was missing. :o Now I was disappointed in SAI, concerned for my car (1000 miles without an operating intercooler) but relieved he saw that, otherwise dummy me would have just thought the intercooler was always meant to be that hot.

 

He located and installed a fuse. The intercooler began circulating and cooled off. He made one more pull on the dyno after that. The results showed about a 11.5 A/F ratio but the numbers fell about 5 HP.

 

Finally, I left the shop tired, I work nights and had only a few hours sleep for my morning appointment, and disappointed in the final numbers. However, just a small turn onto the street and straight line to the first stop light showed me the positive. A new found 50 HP and no detonating were much appreciated and made a big difference. All in all after a few hours rest and contemplation, I am satisfied with the results........at least for a little while.

[RogerS]

Wow,

I don't know where to begin. Looking at the graph the initial run IS dissapointing.

 

Here is what concerns me

The initial A/F ratio

The intercooler issue (no excuse for that SAI!)

Fluid levels again (no excuse)

 

I guess overall just the state of tune and installation and apparently lack of tight quality control before releasing the car. I still need to think about the graph. On the high side that 50 extra HP. But it still confuses me on such a difference from Cudafly's numbers. I need to think about this.

 

It just confirms that when I do receive my car it is going to be delivered straight to the tuner. I am thinking there is more in your car with a safety margin. I'm going to call my tuner in the AM and have him look at your graph.

[ShelbyPilot]

....thanks.

[ShelbyGT/SC]

Socal, I just sent you a PM.

[ShelbyPilot]

A follow up question for somebody who really knows. If it is a stupid one forgive but I need it answered. If the A/F mixture shown in my base run was too low since I picked it up, 1000 miles (shouldn't have changed recently), could it have caused fouling or damage to my spark plugs or anything else? Will it self correct? Do I need to have them checked or replaced? I suspect the tuner would have said something since he did with the other stuff but just in case.

 

Who knows maybe I am getting tired and paranoid again.

[CudaFly]

Well my dyno day has come and gone and I have mixed results. I am actually a bit disappointed and it started right from the base run. I'll start by saying this is a new experience for me and I might be misunderstanding somethings and if I am please feel free to correct. Maybe it will make me feel better.

 

 

socal,

 

Sorry in advance for the long post. I’ll PM you my phone number and you can give me a call if you want to discuss the details.

 

403 RWHP with the Shelby Paxton kit is a totally respectable number. That is about what I would have expected if I had used the Diablo Predator tune. But I don’t understand the initial run numbers and the end result. I really don’t want to cause you any additional stress but my concern would be that if nothing was changed mechanically (other than the missing fuse) you probably still have the original problem(s) and they are now being masked by the custom tune.

 

The 450 RWHP I’m getting is not anywhere near the upper limit with this kit and you should be able to get there fairly easily. There are many other 2005-20007 Mustang GT’s that are well over 500 RWHP with the Paxton or Vortech versions (and custom tunes) and are regularly run hard on local tracks without any internal engine or drive train issues.

 

There must be a lot of really good speed shops in southern CA. First thing I would do is take your car and leave it with a good mechanic familiar with these kits (yes I know you shouldn’t have to). And then have it re-dynoed and re-tuned (yes I know you shouldn’t have to).

 

Things to check for:

 

 

- Go back to the Diablo Predator tune that came with the kit. See if the original performance issues (pinging, etc…) return.

 

- Air Flow leak – Check all of the SC blue neoprene fittings, the SC bypass valve, vaccum lines, etc...

 

- Boost pressure – Verify with a good gauge. Should be about 8-8.5 psi at 6000 RMP’s. Make sure there is no belt slippage.

 

- Try disconnecting and bypassing the Diablo MAFia sensor plugged in to the Mass Air Flow (MAF) sensor (near the air filter). This comes with the kit; I didn’t need it to get to 450 RWHP.

 

- Fuel pump/fuel pressure – Verify with an accurate fuel pressure gauge. The auxiliary fuel pump that comes with the Paxton kit is a bear to install. Could be a fuel leak (inside the fuel tank) or the auxiliary pump is not on.

 

- Change plugs… probably not an issue but just in case.

 

- Blood pressure monitor – for you… Relax, breathe deep, and think happy thoughts. I’m sure this is ultra-frustrating but it’s just a car and it can be fixed.

 

I’m sure lots of people will say that you should send it back to SAI and have them check it out and fix it under warranty. But if they do not have the ability to monitor/change the tuning software and a Dyno then you would still need to independently verify the performance.

[RogerS]

Socal,

 

My tuners is looking at your graph as I write this. His initial comments were, if you compair Cuda's graph with yours and the A/F ratio is not the same where he makes his max HP. Yours is too rich. What Cuda states are also critical to check also. It's good advice.

 

The other noticable issue is your timing. It is cutting in and out. Max timing should me no more than 17.5 degrees. I will PM you my number and his also if you would like to contact him.

 

Just a note on his background. He was the head Master Tech of the performance division at Tasca Ford and personally built all of the Tasca Families performance cars. A Shelby 427 SC, from the ground up and when the 03 Cobra's hit the market with the SC's he developed with Amazon Racing the 500 HP kit which became extreemly popular nationwide. His last car built for Tasca was the KR700. The 700 for RWHP. I think he is one of the better, more knoledgeable tuners in the North East.

 

He is calling me right now, got to go. I will be in touch.

 

Roger

[ShelbyPilot]

hmmm, thanks guys. I appreciate the help. I guess its time to find a good shop around here. My first option lead me to the place I went.