twin throttle body

[aussie buggy]

I have an off road race buggy that is has a rear mounted 1uz and have seen a twin throttle body set up using a second factory throttle body mounted opposite the original. My car will be running a Haltech e11V2 ecu and the motor is staight from the importers. Will i gain much from the second throttle body alone or do i need to change cams at the same time. I have a spare motor so very little expense if not buying cams. The engine is the cheapest part of the car so far, have posted a couple of pics to give you an idea of what i am on about. Trans is a Mendeola sequential 5 speed from the US. Thanks in advance for your help and advice.

 

[cribbj]

Our member Hypronet had that setup for awhile for his supercharger, and jay-spec has modified a stock intake manifold to have dual TB's (left + right) for twin turbos.

Here's jay-spec's post showing his twin inlet: http://www.lextreme.com/forums/showpost.php?p=109565&postcount=1

Hypronet's pics may have been lost in our forum crash last year, but PM him & I'm sure he'd email them to you.

 

[Zuffen]

Member "Rivmasta" (I think that's correct) has twin t/b's mounted on top of his plenum.

He has a home built buggy also and lives in Sydney.

PM me if you can't find him on here I'll put you in contact with him.

Twin t/b's won't give you much extra power as the lower manifold restricts the air flow more the the t/b.

If you replaced the lower manifold with one like Justen made and did a cam swap you could pick up decent power but given the weight of your buggy you most likely have a good power weight ratio to start with. The cost of cams and new lower manifold wouldn't be less than $2,500.00 and then you would probably need an aftermarket ECU.

 

[Peewee]

A second TB will give you a bit of extra throttle response, and will help it breathe a bit better in the top end, but as far as rwkw are concerned, there isn't much gain at all. Maybe 2-3rwkw at the most.

The lower half of the manifold is the bottleneck in an NA system.

 

[V8Datto]

The lower half of the manifold is the bottleneck in an NA system.

Be careful though, I changed my intake (top and bottom manifold) and lost power through the entire rev range.

I still have standard cams and ecu,

 

[Peewee]

Got a pic of what it looked like?

 

[V8Datto]

You've seen the pictures on here,
I have one of Justin GT8's old manifolds, proven to make more power when under boost

When I re-dynoed my car it made power all the way up to 6100rpm but lost 25nm and about 5kw across the board. In a way you could say It spread the power out more across the rev range but didn't make any extra.

Car is very different to drive, even the induction noise is very different

 

[Peewee]

Ahh interesting.
The stock ecu is obviously very well tuned for the stock manifold, and doesn't like any changes.

Would be interesting to get some back to back comparisons with aftermarket ecu and your manifold.