Throttle body and Plenum upgrade on 2004 GT.

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
Hello. I'm looking at ordering a new larger throttle body and plenum for my 2004 GT. It has the stock 4.6L V8, and the only mods I currently have for the car are exhaust (Pypes off-road H pipe, M80 mufflers), and a Cold Air intake. I've been looking at the BBK assemblies that incorporate both the throttle body, and plenum into one unit. I see they offer it in two different sizes (73mm, and 78mm). Everyone thinks the old saying "bigger is better", but I've seen reports of the 78mm unit actually hurting performance on lightly modified motors. After finding that out I think maybe the 73mm model might be a better choice. I don't plan on adding forced induction to this motor (that's where a 78mm TB would shine).

I can get the 73mm (Part #17801) brand new in box for around $200 from an online supplier I found. Worth it? Or can HP be found else where with that same money?
 

Cpotts13

Well-Known Member
Joined
Mar 11, 2012
Messages
1,594
Reaction score
36
Location
Biloxi, MS
Yes. Bigger isnt always better. For stock application I would go 70mm or close to that. I noticed a slight increase in throttle response but for the cost i'm not to sure its a good mod.
 
OP
OP
P

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
A buddy said I'd be better off with a tuner first. I will eventually have both mods done to the motor.
 
OP
OP
P

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
I decided to keep the stock throttle body and plenum for now. Maybe later this spring I'll change it up.

Current setup...

3a89db48c87d2902665bb7fcfe9c23a1.jpg


Airaid cold air intake. Poweraid throttle body spacer.
 

DropTopPony

Post Whore
SN95 Supporter
Joined
Jan 12, 2006
Messages
15,376
Reaction score
203
Location
South Jersey
look for them used I have seen them half price when guys swap on superchargers.
 

ttocs

Post Whore
Joined
Oct 9, 2009
Messages
32,383
Reaction score
5,557
Location
Evansville Indiana
How big is the opening on the plenum? I ask because I was surprised to take my pushrods intake off and measure that it was only 70mm. I thought this was a little strange since everyone I know with a pushrod that upgrade the tb goes to 75mm.
 
OP
OP
P

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
I didn't measure it when I had things apart. I've been driving the car this week since I installed the new parts. Car seems to pull harder now. I also installed a Steeda Tri Ax shifter. Getting use to that also. Overall very happy.
 

Burninriverdiver

Well-Known Member
Joined
Jan 1, 2014
Messages
2,770
Reaction score
234
Heck yeah that's why I got mine, dressed up the engine a little and was on sale. I did pi cams, pi manifold and a tuner at the same time as the tb/plenum upgrade, so I can't tell you how much it helped overall. But my car pulls much harder with all of the above added to the npi motor. The thing I like about the bbk is the noticeable whistle it makes under throttle lol
 

chris91

Well-Known Member
Joined
Apr 20, 2007
Messages
3,761
Reaction score
200
Location
Cincinnati, OH
Cant go wrong with the BBK setup. What are the future plans for the car? You might lose some low end with it being a 78mm.
 
OP
OP
P

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
After supplier issues and my BBK 78mm throttle body plenum assembly being placed on backorder through bbk I ended up cancelling my order.

I reordered the SVE 75mm throttle body and plenum combo. Hopefully it ships Monday.

Customer service from late model restoration was excellent and this wasn't a fail from them. BBK on the other hand...
 
OP
OP
P

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
Finally after nearly a month after I ordered the BBK and then cancelled it I got my SVE 75mm throttle body and plenum combo instead. Installed it in about 30 minutes. I'm happy with it. Pulls harder than the stock unit that's for sure.

Before

e7ab3449cb99c7e56726ee1d2140d43f.jpg


After

cc3aa6e10076a6997bce61449d5182a5.jpg
 

96blak54

Moderator
Staff
Joined
Feb 21, 2011
Messages
9,977
Reaction score
2,806
Location
In the shop
Oh yea! Looks good, nice work! Was you making a bunch of engine rev sounds while you worked?....lol
 
OP
OP
P

PHATSPEED7X

New Member
Joined
Feb 7, 2015
Messages
43
Reaction score
0
Location
Northern MN
I'm really impressed how this really woke the motor up. Everyone says a 75mm throttle body is too much for a n/a motor. I think it's just right.
 

ttocs

Post Whore
Joined
Oct 9, 2009
Messages
32,383
Reaction score
5,557
Location
Evansville Indiana
well don't keep us hanging... Get your friend with his best fossil watch and you with yours to get some times on this *****!:laughing4:
 

Latest posts

Forum statistics

Threads
77,435
Messages
1,502,106
Members
14,917
Latest member
virocanah

Members online

Top