20 PSI

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
Hi All,

I just recently purchased a 2014 GT500 (track pack) from a dealer across the country.
It's got 5500 miles at the moment and the dealer was a little limited on what they were able to tell me it had...

From what I can see it has a JLT CAI, VMP 68mm Twin Jet TB, Idler pullies...and this is where I get lost.

It looks like a 100% stock pulley on upper and lower (I know VMP makes a stock looking upper so maybe it has that...)

car1.jpg


car2.jpg


car3.jpg


Anyway under full load im hitting 20 PSI and 10.9/11.0 A/F ratio (I'm running 93 octane here in NY)

My question is...is this a safe setup? I plan on taking it to an actual tuner to confirm everything but I just want to be able to drive it without thinking it's going to pop...

for the record...it absolutely rips and won't even hook up in 2nd gear from a punch.
 

Attachments

  • car1.jpg
    car1.jpg
    622.5 KB · Views: 163
  • car2.jpg
    car2.jpg
    651.8 KB · Views: 131
  • car3.jpg
    car3.jpg
    605.2 KB · Views: 149
Last edited:

96gt02

Well-Known Member
Established Member
Joined
Jan 21, 2015
Messages
1,465
Location
NJ
You would definitely need some upper and lower pulleys to get 20 PSI out of a stock trinity if your measuring it accurately
 

PhoenixM3

Hello Kitty Slayer
Established Member
Premium Member
Joined
Jul 31, 2012
Messages
6,343
Location
Colorado Springs
My thought is that you should be very careful at that boost level because it doesn't sound like you know anything about the existing tune. These motors are very costly to bend. High RPM is (one of many) killers of all things rotating, so consider limiting yours to about 6K. The stock rods in this motor aren't very robust, but this motor lives comfortably at 100HP over stock, many owners have gone higher.

My guess is that you're right regarding a previous owner changed the upper pulley. Someone will very likely post the diameter of the stock pulley, but you should measure yours to better understand what you have and/or post photos of the upper and lower pulleys (I'm not sure if the boost gauge is all that accurate, or if you could even reach 20PSI on only an upper pulley swap). To lower the boost a little, you could install some LTH, or swap back to a stock pulley.
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
My thought is that you should be very careful at that boost level because it doesn't sound like you know anything about the existing tune. These motors are very costly to bend. High RPM is (one of many) killers of all things rotating, so consider limiting yours to about 6K. The stock rods in this motor aren't very robust, but this motor lives comfortably at 100HP over stock, many owners have gone higher.

My guess is that you're right regarding a previous owner changed the upper pulley. Someone will very likely post the diameter of the stock pulley, but you should measure yours to better understand what you have and/or post photos of the upper and lower pulleys (I'm not sure if the boost gauge is all that accurate, or if you could even reach 20PSI on only an upper pulley swap). To lower the boost a little, you could install some LTH, or swap back to a stock pulley.

thanks man- pix posted above but yeah I think I need to get to a tuner ASAP and maybe try to get back to a safer 17/18 PSI max.
 

PhoenixM3

Hello Kitty Slayer
Established Member
Premium Member
Joined
Jul 31, 2012
Messages
6,343
Location
Colorado Springs
The lower pulley (although a bit blurry) appears stock, so that means the upper has been swapped and is probably as small as you can get, hence the aftermarket idler pulley used to help prevent belt slip. I'd still suspect the accuracy of the stock boost gauge, and re-emphasize the need to have a reputable shop examine the tune and get a good read on actual boost levels. Good luck!
thanks man- pix posted above but yeah I think I need to get to a tuner ASAP and maybe try to get back to a safer 17/18 PSI max.
 

decipha

Well-Known Member
Established Member
Joined
Jul 12, 2008
Messages
1,019
Location
New Orleans, LA
20psi is fine I've done several of them with no issues.

It has to have a tune on it since the gt500s have a max load limiter table. If that hasn't been adjusted in the tune then it would make stock boost no matter what pulley you put on it.

It would be best to find a tuner that can read the tune out and evaluate it rather than paying for a re-tune.

Did the car come from the new orleans area by any chance? We do quite a bit of shelbys at my shop here.
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
20psi is fine I've done several of them with no issues.

It has to have a tune on it since the gt500s have a max load limiter table. If that hasn't been adjusted in the tune then it would make stock boost no matter what pulley you put on it.

It would be best to find a tuner that can read the tune out and evaluate it rather than paying for a re-tune.

Did the car come from the new orleans area by any chance? We do quite a bit of shelbys at my shop here.
good to know-

the car came from Washington State but was originally bought in Canada.
 

RBB

Well-Known Member
Established Member
Joined
Jul 3, 2013
Messages
1,354
Location
Stephens City, VA
How are you getting that 20psi reading? If you're using the stock boost gauge, it's not accurate once the car has been tuned, and this one clearly has been.
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
How are you getting that 20psi reading? If you're using the stock boost gauge, it's not accurate once the car has been tuned, and this one clearly has been.
yah i was just reading the stock boost gauge. looks to peg 19 and then just touch 20 at upper RPM
 

decipha

Well-Known Member
Established Member
Joined
Jul 12, 2008
Messages
1,019
Location
New Orleans, LA
yeah the boost gauge on the dash is inferred by the ecu. It will read whatever the tuner set it up to read.
 

biminiLX

never stock
Established Member
Premium Member
Joined
Jan 17, 2003
Messages
13,253
Location
Toledo, OH
I would most definitely NOT even go WOT without going to a shop or learning to datalog it yourself.
If you don’t have a local tuner/shop you trust, go mail order.
You can buy a mail order on these as they have dual wide bands and datalogs are really accurate.
Congrats on the purchase, I ran 19psi with a stock upper and 15% lower.
-J
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
I would most definitely NOT even go WOT without going to a shop or learning to datalog it yourself.
If you don’t have a local tuner/shop you trust, go mail order.
You can buy a mail order on these as they have dual wide bands and datalogs are really accurate.
Congrats on the purchase, I ran 19psi with a stock upper and 15% lower.
-J
i hear ya. ive put on about 800 miles now with a good amount of WOT pulls but I am scheduling time with def a reputable tuner soon to check everything out.
 

tomshep

Another R Addict
Established Member
Joined
Feb 9, 2003
Messages
4,372
Location
Republic of Texas
I would try contacting the dealer and let them know you have determined the car has been modified and has a custom tune. See if they will try to get the turner. It is worth a couple of phone calls.

Tom
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
just dropped it off at a very reputable tuner so he can diagnose/log/tune.

It's in his hands now so I def feel a lot better.

Will let you guys know what kind of #s she makes and what he finds installed.
 

biminiLX

never stock
Established Member
Premium Member
Joined
Jan 17, 2003
Messages
13,253
Location
Toledo, OH
Good call man!
Money will be well spent knowing your investment is safe while maximizing what you have and also learning what can be improved.
Where did you take it? Some members here may know the shop.
-J
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
Good call man!
Money will be well spent knowing your investment is safe while maximizing what you have and also learning what can be improved.
Where did you take it? Some members here may know the shop.
-J
took it to Bill at pro edge tuning in Connecticut
 

Jam421

Jam421
Established Member
Joined
Sep 15, 2010
Messages
480
Location
Long Island NY
Pro Edge has deep experience tuning GT500's. I'm on eastern LI and have only spoken with Bill at Pro Edge. My guess is he will observe the bolt ons then write you a base tune near those parameters then start tweaking on his dyno. You should already have a tuner ( or he will sell one) that will store the Pro Edge tune forever. Pro Edge uses a Mustang Dyno so expect not to see #'s guys pull on Dynonometers. I had my car on both dynos 10 days apart at shop Open Houses. MANY factors can effect what the car makes on different days. But FWIW the difference between the two was about 8%. That means nothing other than belly to bar talk.
My mods are below . PSI Boost at the shops was 16.5psi with headers, 2.4 Upper, stock lower & KB Mono Blade. Looks & sounds as though you have a 2.4 upper. In my car the dash gauge at WOT always pins at 20psi. In other words reliable but NOT accurate.
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
Pro Edge has deep experience tuning GT500's. I'm on eastern LI and have only spoken with Bill at Pro Edge. My guess is he will observe the bolt ons then write you a base tune near those parameters then start tweaking on his dyno. You should already have a tuner ( or he will sell one) that will store the Pro Edge tune forever. Pro Edge uses a Mustang Dyno so expect not to see #'s guys pull on Dynonometers. I had my car on both dynos 10 days apart at shop Open Houses. MANY factors can effect what the car makes on different days. But FWIW the difference between the two was about 8%. That means nothing other than belly to bar talk.
My mods are below . PSI Boost at the shops was 16.5psi with headers, 2.4 Upper, stock lower & KB Mono Blade. Looks & sounds as though you have a 2.4 upper. In my car the dash gauge at WOT always pins at 20psi. In other words reliable but NOT accurate.

good to know- thanks man
 

darksykal

Active Member
Established Member
Joined
Sep 5, 2019
Messages
108
Location
NY
got the car back and couldn't be happier! Bill is hands down the best in the business.

My only complaint is how useless my tires are now in 1st and 2nd gear. lol

I capped at 17.3 PSI and she made 660 rwhp and 619tq on mustang dyno.

my IAT2 temps got to 140 so he mentioned long tubes are in my future.

 

Users who are viewing this thread



Top