Ford Shelby GT500 Forum banner

1 - 20 of 27 Posts

·
Premium Member
Joined
·
288 Posts
Discussion Starter #1
Today Jerry and myself got the opportunity to work on a gentleman's brand new GT500. With just over 1000 miles on the odometer the car still smelled like new.



All runs were done on an industry standard Dynojet 224x, you can't fudge these #s like other dynos. 93 octane pump fuel was in the tank.

We ran the car 3 times stock to get the drivetrain up to temp and get a good average HP #. The car made 421/438, then 424/427, and 419/22. I would say the blower and engine are very sensitive to heat soak.

On every run we monitored air/fuel with two widebands, boost after the blower/intercooler, and restriction before the throttle body. We also datalogged a myriad of parameters with the SCT X-Cal2 and Live Link datalogging software.

The stock tune has no timing in it at all, it's really quite disgusting. With the stock tune the air/fuel came in a little lean below 2000rpms, ran 11.5 through the mid range, and hit high 10s past 5000rpm. The car makes about 9psi of boost in stock form, just like the guage on the dash says. With the stock airbox the MAF is almost pegged, reading 4.95v.

Now that we had some good data on a stock car we started playing with the tune. When it was all said and done we arrived at 482RWHP and 477RWTQ, no you're not reading that wrong, that is approximately a 60RWHP gain. This was not a money shot either, the car was ran 11 minutes before and made 481RWHP/476RWTQ on the previous run. This was no ragged edge tune either, the Air/Fuel was 11.5:1. I was not about to blow up a brand new and very expensive car just to be an internet hero. We did not have time to let the car cool for a money shot. I was so excited that I started on the intake install right away.

I whipped up a prototype intake the night before with parts I had laying around. I took a piece of 4.5" aluminum tubing, a 4.5" cone filter, and a little CNCed aluminum flange that I had made a while back. The flange allows you to mount a slot style mass air sensor into a tube. It wasn't much, but it would give us something to play with. We had to retain the stock tube that passes between the Strut Tower Brace and valve cover. The tube is rubber with a plastic insert to keep it from collapsing, I'm sure it's restrictive, just like the stock airbox and panel filter. An aftermarket tube with thinner walls would flow a lot more air and still fit between the valve cover and STB.

The air intake required some tuning because the mass air sensor was installed in a new tube. This totally throws off the air/fuel and requires that the maf transfer function be redone, however an experienced tuner can do this in a few pulls. With the prototype intake the car made 505 RWHP/487RWTQ. Simply amazing, with the new intake the car picked up a slight amount of boost past 3500rpm, about 1psi peak at 6000rpm. The sensors were still measuring a little bit of intake restriction though, so the rubber tube between the maf housing and throttle body definitely has to go. I ordered a piece of 4.75" silicone hose, but it did not arrive until after the dyno testing was done today.

Tune with stock airbox vs tune with air intake, shown with boost.


Stock vs tuned vs tune+intake shown with air/fuel.


This car has a supercharger inlet pressure sensor between the blower inlet and throttle body, this will be handy for measuring various inlet restrictions. In the next few weeks I should have a throttle body to test.

The best part is the car feels just like stock until you romp on it. A quick 1-2 shift can now get you in trouble, even with TCS on.

We disconnected the exhaust after the X pipe, it was only worth a few HP.

I've debated whether or not to post this pic of the intake I made. Namely because its very simple and easy to duplicate. However, since I'm mainly in the tuning business I've decided it does not really matter.


A word of warning to all Shelby GT 500 owners out there. This car has a totally unique electronic control system, not seen on any other Ford (not even the Ford GT). The drive by wire system will take power away if you pulley the car, and then add it back in slowly. The car could be given what is thought to be a *safe* tune on the dyno, but then blow up a few days later.

I am still looking for several more of these cars to work on. If you are in the Central Florida area contact me.
 

·
Registered
Joined
·
257 Posts
[email protected]ks for your post. Lotsa good info. there, with, it sounds like more to follow. Keep up the the good work. I plan on having a tune done on my car once the guys like you get all the bugs worked out and parts start becoming more readily available.
 

·
Premium Member
Joined
·
3,724 Posts
Thanks for the info.I am a little puzzled though.420 RWHP seems to be pretty low even for a stock Shelby.This doesn't seem to be consistant with what I have seen.The total outcome is nice though.
 

·
Registered
Joined
·
2,466 Posts
Thanks for the info.I am a little puzzled though.420 RWHP seems to be pretty low even for a stock Shelby.This doesn't seem to be consistant with what I have seen.The total outcome is nice though.
If you assume 16% drivetrain loss, 420 rwhp equates to 500 hp @ the crank.
______________________

What were the environmental conditions at the time of the dyno? Was it hot and muggy? High altitude?
 

·
Registered
Joined
·
6 Posts
Hey justin, Its been a long time.. I'm actually moving down to the Tampa area in the next month or so. I'm finally leaving the Family buisness, I'll have to drive over to the east coast and see your new setup.

I'm talking with a couple of dealers to get a GT500 Convertible, but I'm at the point where I rather wait and have a later build allocation then paying 15K over MSRP. $55K is the max I'm going to spend on the car, but when I go get it, I'm sure we can find things to try out on it..;)
 

·
Registered
Joined
·
6 Posts
I have given up on getting a GT500 for now. I'll see what they can be had for in a year or so. Best I could find was 10ADM and that was not even local. So I used an Xplan and picked out a 2007 CS/GT Coupe. Hopefully will be signing the papers today X plan was 50 below invoice plus a $500 ford rebate and 3.9 apr and no $100 doc fee. So ineffect it was $650 below invoice.. :)

They let me drive it for the day yesterday so I took some pics while at my office.

What gains have you been seeing with the custom tunes on the GT's..? I figure I'll go the LT with X pipe and a CAI as the first mods. I have also heard that replacing the 2 part drive shaft with a Aftermarket unit frees up some HP n the drivetrain.. Do you have any dyno sheets for cars with the shaft..?
 

Attachments

·
Registered
Joined
·
171 Posts
I asked this question somewhere else. How can you be sure every car will respnod the same way to the same tune. I would think each car has some difference due to the fact that all parts are not perfect and exact. I hope they all work the same since I ordered the tune.
 

·
Registered
Joined
·
22 Posts
I'll be testing an intake tomorrow morning.
Justin,
I am looking forward to your CAI. Please post some pictures on your web site as soon as it is ready. I don't usually modify new cars but this just seems to be too much improvement to pass up.
 

·
Premium Member
Joined
·
288 Posts
Discussion Starter #12
I asked this question somewhere else. How can you be sure every car will respnod the same way to the same tune. I would think each car has some difference due to the fact that all parts are not perfect and exact. I hope they all work the same since I ordered the tune.
Every car is a little bit different, but not enough for it to matter at this level. Ford isn't dynotuning every car that comes out of the factory. With just bolt ons I feel that I can deliver consistent and safe mail order tunes.
 

·
Premium Member
Joined
·
288 Posts
Discussion Starter #13
Justin,
I am looking forward to your CAI. Please post some pictures on your web site as soon as it is ready. I don't usually modify new cars but this just seems to be too much improvement to pass up.
I will actually be testing and developing a tune for the JLT full intake, which retails for $449. My intake is still a few weeks out.
 

·
Registered
Joined
·
2,466 Posts
This is great stuff! Unfortunately, my wife won't allow me to make an mods that might cause warranty issues. :( Since this will be her car, I guess what she says goes.
 

·
Premium Member
Joined
·
867 Posts
I just ordered my SCT about 3 hours ago. I called Justin and we talked about the tunes... warranty issue if something comes up the factory tune goes back on..very simple to undo.. pulley change, gears that can't be un-done in a few minutes so those mods will be further out next year. Tune / Intake than gears..pulley last on the list. No headers, no motor work, just those 4 mods..well maybe different drive shaft :)
 

·
Registered
Joined
·
2,466 Posts
No warranty problems with a tune or intake. The dealer can never tell that the car was flashed.
Really? That seems contrary to everything I've seen from others on this board and other boards. If that is ther case, I may have an much easier time convincing my wife that a tune and CAI is at the top of the shopping list. :D
 

·
Registered
Joined
·
2,400 Posts
rpretzel if you left the CAI on the vehicle and did not reflash the computer you would hava warranty problem. The idea is to remove the CAI and reflash the computer to stock before bringing the vehicle back to your dealer if there were a warranty issue. Takes about 30 minitues for the CAI and 5 minutes for the reflash. What Justin is saying is there is no trail in the computer as to any flashes that have taken place.
 

·
Registered
Joined
·
2,466 Posts
rpretzel if you left the CAI on the vehicle and did not reflash the computer you would hava warranty problem. The idea is to remove the CAI and reflash the computer to stock before bringing the vehicle back to your dealer if there were a warranty issue. Takes about 30 minitues for the CAI and 5 minutes for the reflash. What Justin is saying is there is no trail in the computer as to any flashes that have taken place.
Ah OK. I misunderstood Justin's comment.

I'm still working on my wife. All these driver impressions of the tune and added performance are getting me way too excited. I just can't wait to pick up my Shelby and start tinkering. I'm dying here. Must...get...VIN...soon...before...I...crack.
 
1 - 20 of 27 Posts
Top