individual throttle bodies

[madmonkey]

im going to be running an after market on my 1uzfe and that got me thinking

i have heard that you can get a lot more power from using separate throttle bodies

im just wondering if it is worth going to the effort of doing this mod

 

[rivmasta]

There are much less expensive ways to make power! Exhaust and a good tune.

From my own searches on here Ive often read that you cant really reap the benefits of ITBs without dropping in cams and maybe even doing a bit of head work.

what other mods have you got done/doing?

 

[madmonkey]

re

have made new exhaust manifold and exhaust system
thinking about getting a link computer but might use standard ecu
not really sure any ideas on getting good power with out spending heaps and heaps of money
wanting value for money alone with power increase

 

[rivmasta]

you'de be much better off putting the money into a decent ECU and dyno time than the money you put into ITB's... they can be horrendously expensive.

And if you do have a bit of disposable income to splash out on it later I'd consider cams and a bit of head work including upping the comp before ITB's.

 

[rms]

ITB's can make a large difference, but not with the original manifold.
http://www.a1turbos.co.nz/eight.html

Agree it is not cheap.

Dyno figures are from our STANDARD engine with 50mm ITB's, dry sump and open exhaust headers.

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[madmonkey]

re

from what i understand the factory manifold is crap
so is it possible to change the factory setup to a new type using the existing v8 throttle body to achive a similar increase in power

 

[rms]

Wouldn't say the factory manifold was 'crap'. It meets the requirements of the market the engine was meant for. Not meant for 'rev heads' like you and I.

Major problem for performance is the abrupt angle change at the manifold/head interface.

A single plenum will not give the same or close results. Air pressure at the valve will be lower, and when one valve is about to close and needs to ram the last bit of air in, another valve opens and lowers plenum pressure.

So far as cost effective ?

'How fast do you want to go ?' - 'How deep are your pockets ?'

 

[madmonkey]

ok well ill go with the individual throttle bodies can't think of a better cost efficient way to increase power

 

[rms]

The other point I forgot to mention.
ITB's need a GOOD aftermarket ECU. They MUST be mapped from throttle position, be sequential, and have variable injection timing.

 

[cribbj]

ok well ill go with the individual throttle bodies can't think of a better cost efficient way to increase power

Probably the most cost efficient way to increase power is nitrous, as long as you don't overdo it. ;-)

 

[Almac_Sabre]

i have heard that you can get a lot more power from using separate throttle bodies

im just wondering if it is worth going to the effort of doing this mod

Yo Mad Monkey, I'm currently doing the same thing. You may like to follow the thread I just posted regarding fabricating a cold air box for an eight throttle body manifold. It may be useful for you too.
Cheers, John

 

[Almac_Sabre]

ok well ill go with the individual throttle bodies can't think of a better cost efficient way to increase power

Hi Again Madmonkey. Don't know if you have definitely decided upon the individual throttle bodies, but if you are still looking for a more cost effective alternative check out http://www.trademe.co.nz/Trade-Me-M...buration-induction/auction-107657620.htm?p=20
This setup off my racecar is being sold because I'm fitting the 8 individual throttle bodies. They look great, but are going to end up costing me NZ$3500 ... I'm starting to wonder if I've done the right thing!

 

[Tomasberkut]

The other point I forgot to mention.
ITB's need a GOOD aftermarket ECU. They MUST be mapped from throttle position, be sequential, and have variable injection timing.

tuning via TPS is good in race conditions where the engine runs in almost constant full throttle position and the load varies by a small amount... As far as i know this system wont work in daily driving conditions beacause the system wont work correctly with part throttle settings (at least thats what im told). In the megasquirt software there is sucha w thing as Hybrid Alpha-N wich uses TPS as the base signal but has a correction factor via the MAP sensor.

 

[rms]

tuning via TPS is good in race conditions where the engine runs in almost constant full throttle position and the load varies by a small amount... As far as i know this system wont work in daily driving conditions beacause the system wont work correctly with part throttle settings (at least thats what im told). In the megasquirt software there is sucha w thing as Hybrid Alpha-N wich uses TPS as the base signal but has a correction factor via the MAP sensor.

Have mapped Porsche Carrera 2.7 (std factory ITB's) via TPS for road use. The MAP sensor goes to atmosphere and corrects for barometric pressure changes. Fuel economy, response etc were excellent.

Setting up on dyno requires all throttle/rpm points to be held constant (not ramped up) during tuning, you set fuel and ignition at these points as well as injection timing relative to intake period.

Road tuning is then only for acceleration enrichment and you need an ECU sophisticated enough to allow you to set enrichment by throttle position, rpm and rate of accelerator movement.

The problem with ITB's and/or big cams is that even with a vacuum canister you can not get a signal stable enough or large enough to map correctly. With enough restriction you can get it stable, but then it lags behind engine response.

Setting up a customers 1UZ with ITB's and 280 deg cams for road use at the moment. It will be mapped from TPS via Autronic ECU.

 

[Damien]

My ITB setup is mapped via TPS and it also uses a MAP sensor to account for barometric differences and the 2 tables are combined (TPS x MAP). This is with an Adaptronic ECU.

Drivability on the road, in traffic and on the track is excellent and when in closed loop the fuel economy is fine.