GT350 Throttle Body on Stock GT Manifold?

Type550 · Mar 13, 2018

So I had a GT350 Throttle Body (& adapter) fitted to my S550 GT 5.0 with a Steeda CAI, and I've noticed it runs like a dog down low.

Lost a tonne of torque when pulling away from the lights as if the tune is running way too lean. Driveability and throttle response has been adversely affected.

Any of you guys noticed the same issues with the GT350 TB?

I'm looking to get my OEM TB fitted back on to resolve the driveability issues.

Advice appreciated.

Kahboom · Mar 13, 2018

Did you get a retune? If you did did you do any data logging afterwards? Probably be better off just porting your stock one and selling off your GT350 throttle body. I had one for a little while on my boss manifold and it just never ran right even after data logging.

Type550 · Mar 13, 2018

Yeah the workshop who supplied and fitted the exhaust, CAI and GT350 TB did the "re-tune". Just seems down on power/torque under light throttle conditions. It's fine at WOT but around town drivability sucks. Hesitates and bucks and struggles :(

wildcatgoal · Mar 13, 2018

The GT350 TB is notoriously difficult to tune and I'm sure your shop has not done the extensive amount of work it's taken to get throttle and power smooth like Lund and Steeda have (and surely others). Not to mention, the GT350 TB is near useless on the stock GT intake manifold. I highly suggest putting the stock TB back in and, if you want a tune, getting one from Steeda, Lund, AED, Palm Beach Dyno, VMP, or Livernois with at least 3 revisions allowed so you can data log and update the mapping specific to your car.

gameovergt · Mar 13, 2018

I had mine ported/bored by http://www.maxbore.com/ , took it from 80mm to 85mm. No problems with it.

EFI · Mar 13, 2018

Sounds like a poor tune, as it's been clearly shown that the GT350 tb and adapter can be done so they idle and drive 100% like stock.

That being said, I do agree you should just stick with your stock tb.

Braski · Mar 13, 2018

Mine along with the rest off the pp2 runs like a beast!

Stang8psi · Mar 13, 2018

gameovergt said:
I had mine ported/bored by http://www.maxbore.com/ , took it from 80mm to 85mm. No problems with it.

Any idea on the power gained with the new TB and did you need to tune update for it?

gameovergt · Mar 13, 2018

Stang8psi said:
Any idea on the power gained with the new TB and did you need to tune update for it?

I don't know about HP #'s. Throttle response seems faster, no tune update is required. I opted for the port & shaft trimming. Cost me $160.00. Turnaround time was 4 days.

AZStang · Mar 13, 2018

wildcatgoal said:
The GT350 TB is notoriously difficult to tune and I'm sure your shop has not done the extensive amount of work it's taken to get throttle and power smooth like Lund and Steeda have (and surely others). Not to mention, the GT350 TB is near useless on the stock GT intake manifold. I highly suggest putting the stock TB back in and, if you want a tune, getting one from Steeda, Lund, AED, Palm Beach Dyno, VMP, or Livernois with at least 3 revisions allowed so you can data log and update the mapping specific to your car.

My dyno tuner and the speed shop that handles installs both said stay away from 350TB, so I did. Now, that doesn’t mean it can’t be accomplished, but the overall opinion was it’s not worth the hassle.

Monty17GT · Mar 13, 2018

I believe Ford is the only one who has really been able to put out a canned tune with this TB which is on their PP2 kit, they have access to the vehicle computer in ways regular tuners don't. Other tuners can tune the TB but it won't be a canned tune which then makes it cost prohibitive if you ask me.. I have the PP2 kit and I'll put it up against any canned tune and I bet it will be just as good if not better and I still have warranty

AZStang · Mar 13, 2018

Monty17GT said:
I believe Ford is the only one who has really been able to put out a canned tune with this TB which is on their PP2 kit, they have access to the vehicle computer in ways regular tuners don't. Other tuners can tune the TB but it won't be a canned tune which then makes it cost prohibitive if you ask me.. I have the PP2 kit and I'll put it up against any canned tune and I bet it will be just as good if not better and I still have warranty

The dyno should tell the story. I’d love to see a comparison all bolt ons equal and Ford canned tune and a dyno tune. I would be shocked if the Ford tune made more power.

AlmostFamous · Mar 13, 2018

Monty17GT said:
I believe Ford is the only one who has really been able to put out a canned tune with this TB which is on their PP2 kit, they have access to the vehicle computer in ways regular tuners don't. Other tuners can tune the TB but it won't be a canned tune which then makes it cost prohibitive if you ask me.. I have the PP2 kit and I'll put it up against any canned tune and I bet it will be just as good if not better and I still have warranty

Correct me if I'm wrong but I believe AED is the only aftermarket tuner who's reliably been able to get good power out of the GT350TB without any drivability issues?

texasboy21 · Mar 14, 2018

AZStang said:
The dyno should tell the story. I’d love to see a comparison all bolt ons equal and Ford canned tune and a dyno tune. I would be shocked if the Ford tune made more power.

There are quite a few FPPP2 dynos floating around, which can be easily compared to the number of intake+tune dynos and the numbers are quite similiar (as are the trap speeds).

Why does the forum (for the most part) assume the Ford tunes are weaker than a third party? Ford has a tremendous leg up on any of the tuners in terms of R&D budget, access, and knowledge of the systems.

V8EATR · Mar 14, 2018

texasboy21 said:
There are quite a few FPPP2 dynos floating around, which can be easily compared to the number of intake+tune dynos and the numbers are quite similiar (as are the trap speeds).

Why does the forum (for the most part) assume the Ford tunes are weaker than a third party? Ford has a tremendous leg up on any of the tuners in terms of R&D budget, access, and knowledge of the systems.

They also have to maintain warranty standards as well so they have one hand tied behind their back in that aspect.

GT350 Throttle Body on Stock GT Manifold?

Type550

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Kahboom

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Type550

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wildcatgoal

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gameovergt

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EFI

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Braski

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Stang8psi

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gameovergt

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AZStang

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