GT350 Throttle Body on Stock GT Manifold?

Aubrey · Mar 14, 2018

I just bought a GT350 TB and the seller recommended the VMP tune over Lund.

Type550 · Mar 14, 2018

Thanks for all the feedback/responses guys.

I took the car back to the workshop this morning outlining all the issues I've experienced since they did the install/tune for me (i.e. intermittent stalling in traffic, hunting RPM's @ idle, lethargic take off and severe hesitation when dipping into the throttle).

They said they may just need to tweak the tune as it might have gone "out of whack" after everything bedded in over a few days, and that's what's caused the poor running/performance. They did say they've done numerous S550 GT's with the exact same mods as mine, and have never had such reported issues. Not sure I'm convinced, but we'll see! :(

I'll report back with my observations when I get the car back this afternoon. Fingers crossed it's all resolved.

freight dog · Mar 16, 2018

I feel certain that Ford knows a thing or two about its cars. Consider that they include the GT350 TB with the PP2 and PP3 and that the production Bullitt will come with the GT350 CAI and TB paired with a stock GT IM on the showroom floor. Tuners that say its a waste or can't get it to run right are full of it IMO. OP, best of luck with your setup!

AZStang · Mar 16, 2018

freight dog said:
I feel certain that Ford knows a thing or two about its cars. Consider that they include the GT350 TB with the PP2 and PP3 and that the production Bullitt will come with the GT350 CAI and TB paired with a stock GT IM on the showroom floor. Tuners that say its a waste or can't get it to run right are full of it IMO. OP, best of luck with your setup!

Well then, lots and lots and lots of tuners around the country are full of it.

The real question is what are the benefits? The HP difference is minimal at best, but I do agree that Ford knows more about it then Dyno tuners.

MikeyPee · Mar 16, 2018

Lund won’t tune the GT350 t/body, even with the matching manifold. At least, that’s what I was told. On a n/a car, it’s not worth the hassle

AlmostFamous · Mar 17, 2018

MikeyPee said:
On a n/a car, it’s not worth the hassle

If you're dead set on going with a tune from Lund.

MikeyPee · Mar 17, 2018

AlmostFamous said:
If you're dead set on going with a tune from Lund.

I’m not. I’d rather not buy another tuner or pay to unlock the NGauage tho

Type550 · Mar 19, 2018

OK, so I took the car back to the Tuner last Friday and he spent some time re-calibrating the tune. Overall drivability seems to have improved somewhat, but there are still some annoying light-throttle flat-spots which need to be ironed out, and a couple intermittent stalls whilst in slow moving traffic.

Taking it back again this week and I'll leave it with him for two whole days so we can fine tune the cold and warm running maps a bit better. It's getting better, but seems to be a lot of back and forth to get it right. I was hoping he'd have a fully calibrated tune for the setup he sold me, so it ran mostly right post upgrade.

I'll report back this weekend, so "stay tuned"...

Vancity5oh · Mar 19, 2018

I actually just made a new topic on this as my car started throwing the p061b code after tb install and ive seen limp mode on cold starts a few times
Anyone else see that code before? The surging and drivability are pretty rough it seems if you dont have the ford procal but im going to see if my local tuners can do anything with it
Could there be a gt350 throttle mapping of somesort we can bring over to the gt tunes? Im talking out of my ass but if someone knows what i mean than i got the point across*

Type550 · Apr 6, 2018

So I just thought I'd update on the status of this saga.

Took the car back to the tuner to iron out the annoying flat spots and cold start running issues. Almost 4 days later, got the car back and it's even worse than before.

I've decided to rip out the GT350 throttle body and fit the OEM one back in and retune it again. Not worth the hassle with the GT350 TB for such minimal gains and adverse impact to driveability of the car. Very disappointing.

Monty17GT · Apr 6, 2018

Type550 said:
So I just thought I'd update on the status of this saga.

Took the car back to the tuner to iron out the annoying flat spots and cold start running issues. Almost 4 days later, got the car back and it's even worse than before.

I've decided to rip out the GT350 throttle body and fit the OEM one back in and retune it again. Not worth the hassle with the GT350 TB for such minimal gains and adverse impact to driveability of the car. Very disappointing.

Per motoiq

Ken from Palm Beach Dyno said the factory torque demand tables for the S550 are a lot more complex than the Gen 1 Coyote, so it takes far more knowledge and understanding how the factory parameters and tables interact to make a car have good drivability when using the larger GT350 throttle body. Keep in mind that drivability makes up 90% of the tune, and most tuners just work on the 10% full throttle maps for dyno bragging rights and ignore the real time-consuming work that actually matters (part-throttle tuning). They bank on the customer’s lack of knowledge and ability to give feedback to save them the time from doing a proper, inclusive tune.

Most tuners try to plug and play the stock tables to the larger throttle body and it just doesn’t work, so it’s much easier to just use the stock throttle body even if it costs power for the sake of drivability, since they don’t know how to work around the factory programming. Apparently, that’s why you sometimes hear the GT350 throttle body “doesn’t work” -not because it doesn’t work, but because they don’t know how to make it work.

Take it for what it is...

Type550 · Apr 6, 2018

Monty17GT said:
Per motoiq

Ken from Palm Beach Dyno said the factory torque demand tables for the S550 are a lot more complex than the Gen 1 Coyote, so it takes far more knowledge and understanding how the factory parameters and tables interact to make a car have good drivability when using the larger GT350 throttle body. Keep in mind that drivability makes up 90% of the tune, and most tuners just work on the 10% full throttle maps for dyno bragging rights and ignore the real time-consuming work that actually matters (part-throttle tuning). They bank on the customer’s lack of knowledge and ability to give feedback to save them the time from doing a proper, inclusive tune.

Most tuners try to plug and play the stock tables to the larger throttle body and it just doesn’t work, so it’s much easier to just use the stock throttle body even if it costs power for the sake of drivability, since they don’t know how to work around the factory programming. Apparently, that’s why you sometimes hear the GT350 throttle body “doesn’t work” -not because it doesn’t work, but because they don’t know how to make it work.

Take it for what it is...

Couldn't agree more! I've learnt the painful way! :(

Curious, if they fit the OEM throttle body back on and leave the CAI and full exhaust in place, would an OEM tune map work, or would they need to re-tune all over again manually?

I'm not confident my car will ever run right again after this ordeal.

Monty17GT · Apr 6, 2018

OEM tune will not work with headers

MaskedRacerX · Apr 6, 2018

freight dog said:
I feel certain that Ford knows a thing or two about its cars. Consider that they include the GT350 TB with the PP2 and PP3 and that the production Bullitt will come with the GT350 CAI and TB paired with a stock GT IM on the showroom floor.

Just an FYI, re: the bold

https://media.ford.com/content/ford...03/29/summer-blockbuster-mustang-bullitt.html

The new Mustang Bullitt delivers even more power, thanks to its performance open air intake, Mustang Shelby GT350 intake manifold, plus a larger 87-millimeter throttle body and unique powertrain control module calibrations delivering 480 horsepower and 420 lb.-ft. of torque* and deliver a top speed of 163 mph

Type550 · Apr 7, 2018

MaskedRacerX said:
Just an FYI, re: the bold

https://media.ford.com/content/ford...03/29/summer-blockbuster-mustang-bullitt.html

Yes, Ford has the engineering resources to develop a proper tune for all load and RPM points for the GT350 intake on the 5.0 Coyote motor.

The issue is these aftermarket tuners only tune it for WOT and not normal light throttle driving conditions, which a daily driver is used for. Not everyone drives around at WOT everywhere.

GT350 Throttle Body on Stock GT Manifold?

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