How To Install The GT350 Intake Manifold

spiller · Nov 11, 2017

What's the approximate time to install the IM if doing a first time DIY using the JDM harness extension and other bits in their kit? Some are saying one of their hoses did not fit properly?

MikeyPee · Dec 14, 2017

So....

I have a Paxton. All I need for the install is the adapter (gonna run the stock TB), JDM install kit, and the manifold? My Paxton JLT intake will work with no issues??

:hail:

MikeyPee · Jan 12, 2018

Ordered the kit, and all I used was the evap harness extension. Didn't use the manual once. Def a waste of money, in my case. Kinda disappointed the brake booster reducer, and the 3/8" and 1/2" hose sections weren't included in the kit. There was no way the stock 3/8' hose was gonna work.

If you have a Paxton, just get the evap harness

MustangGuy · Jan 13, 2018

MikeyPee said:
Ordered the kit, and all I used was the evap harness extension. Didn't use the manual once. Def a waste of money, in my case. Kinda disappointed the brake booster reducer, and the 3/8" and 1/2" hose sections weren't included in the kit. There was no way the stock 3/8' hose was gonna work.

If you have a Paxton, just get the evap harness

Unfortunately already ordered the JDM kit. Does a definitive list of what is REALLY needed for the installation exist? Doesn't seem like anyone's kit includes everything. Looking to install this Spring.

MikeyPee · Jan 13, 2018

MustangGuy said:
Unfortunately already ordered the JDM kit. Does a definitive list of what is REALLY needed for the installation exist? Doesn't seem like anyone's kit includes everything. Looking to install this Spring.

To be fair, I’m running PCV breathers, and I did use the purge and evap hardware, but $80 wasn’t a good value for my build.

This is pretty much all you need: (taken from page one of the thread)

Purchased a 6mm x 31mm long threaded stud from Ace Hardware along with a 6mm flange nut to use on the driver's side to hold down the purge valve. The GT350 factory hold down will now slide onto the exposed threads. A 6mm x 30mm flanged bolt will do for the passenger's side. The ones from the OEM manifold won't work - they're self-threading. The GT350 manifold has inserts with M6 x 1.0mm threads.
Hose clamped tee fitting end that feeds the charge motion control valve diaphrams at the rear of the manifold - just to be sure.
1/2" hose from manifold port to 1/2" x 3/8" reducing elbow. 3/8" silicone vacuum line to existing power brake booster hard line.

MustangGuy · Jan 13, 2018

MikeyPee said:
To be fair, I’m running PCV breathers, and I did use the purge and evap hardware, but $80 wasn’t a good value for my build.

This is pretty much all you need: (taken from page one of the thread)

Purchased a 6mm x 31mm long threaded stud from Ace Hardware along with a 6mm flange nut to use on the driver's side to hold down the purge valve. The GT350 factory hold down will now slide onto the exposed threads. A 6mm x 30mm flanged bolt will do for the passenger's side. The ones from the OEM manifold won't work - they're self-threading. The GT350 manifold has inserts with M6 x 1.0mm threads.
Hose clamped tee fitting end that feeds the charge motion control valve diaphrams at the rear of the manifold - just to be sure.
1/2" hose from manifold port to 1/2" x 3/8" reducing elbow. 3/8" silicone vacuum line to existing power brake booster hard line.

Sounds like I need to visit Ace Hardware. What about the 25mm offset cable ties for the back of the manifold? Thanks MikeyPee

MikeyPee · Jan 14, 2018

MustangGuy said:
Sounds like I need to visit Ace Hardware. What about the 25mm offset cable ties for the back of the manifold? Thanks MikeyPee

They don’t come in the JDM kit. You’ll have to get them separately

MustangGuy · Jan 14, 2018

MikeyPee said:
They don’t come in the JDM kit. You’ll have to get them separately

Only found in packages of 500 on line so far. I'll have to stop by dealer so they can tell me they have no idea what I'm talking about. :frusty:

Andrewg · Jan 15, 2018

This seems like a more comprehensive kit https://lmr.com/item/M9424M52-HDW/15-17-mustang-gt350-intake-installation-kit with the hoses and studs. Might save you a trip to Ace.

Edit: Just realised it's pretty much exactly the same as JDM's kit only a bit cheaper.

v8hgt · Jun 5, 2018

Have any of you guys noticed increased brake servo assistance after doing this install with the vacuum lines routed as per the pic on page 1 of the thread?

I don’t have the pp vacuum gauge but the digital engine gauges show warm idle vacuum is approx 16.6Hg. If I route the vacuum lines the other way I get 17.3Hg and more stock brake servo assistance.

Dragster · Jun 6, 2018

I installed my GT350 manifold at the same time that I also did some cams. The dyno results weren't what I expected (lower), and Comp blames the tune. The tuner says everything looks good. So now I'm wondering what, if anything, else it could be. Could someone check to make sure I installed the manifold correctly?

Thanks for the help!

Schu · Jun 6, 2018

^hate when that happens...

Type550 · Jun 6, 2018

Dragster said:
I installed my GT350 manifold at the same time that I also did some cams. The dyno results weren't what I expected (lower), and Comp blames the tune. The tuner says everything looks good. So now I'm wondering what, if anything, else it could be. Could someone check to make sure I installed the manifold correctly?

Thanks for the help!

OUCH! That must hurt after all the time and expense! Hope it's resolved soon. Just doesn't make sense you'd be making LESS power. Maybe the CAMs haven't been dialled in properly?

Type550 · Jun 6, 2018

djpheer said:
You might pickup 5 hp by running the TB. Just risk of driveability issues/money outweigh whatever small gain you might pick up IMO.

I think AED have ironed out all the drivability issues with the GT350 TB on the Coyote motors, whether one runs an OEM GT manifold or a GT350 manifold.

I'm considering this swap on my car (GT350 IM + GT350 TB) with an AED tune. Fingers crossed. If it doesn't work out, I'll just throw the OEM TB back on with a Blowfish adapter, and get a re-flash :thumbsup:

Dragster · Jun 6, 2018

Type550 said:
OUCH! That must hurt after all the time and expense! Hope it's resolved soon. Just doesn't make sense you'd be making LESS power. Maybe the CAMs haven't been dialled in properly?

Yeah, it pretty much sucked... The car did make a very small peak gain of 11 hp, but that includes both the cams and the intake manifold. It actually lost hp and torque all the way up to 6,000 RPM.

How To Install The GT350 Intake Manifold

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