Ford Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
81 Posts
Discussion Starter #1
Hey everybody I got a EBII I6 4.0...I was wondering how much and what diff would a quad throttle bodied, inlet manifold make...

Thank you
 

·
100 SPEED LIMITED SILVAEA
Joined
·
1,043 Posts
firstly..... you'd need six throttle's not four :p

it would make gains in a worked form, but in a stock application, it may not be worthwile the expense.

also you would have to change to an aftermarket ecu and run a tps (throttle position sensor) instead of the standard ecu running the MAP sensor.

the only way to get the MAP to work would be to tap into each port and run a vaccume line back to a box so the map sensor can get a reading of the running conditions of the engine.

to make most of six throttles... you'd need, massive ported head, big cam, nice extractors and an aftermarket ecu. basicly a hard tuned n/a set up.

cheers.joe.
 

·
Birth, Drift, Death...
Joined
·
3,039 Posts
MAP and MAF sensor setups run a TPS joe...

but yes, you would need 6 if you were going to do it, and the expense is not worth it, there will be minimal HP gain for a huge outlay in $$$, at the very least you would need a specially programmed engine management system as well.

how much HP are you after? Soxx has shown that 161rwkw is possible with stock injectors and Broad band intake manifold/throttle body (you know the EF onwards ones?)
 

·
RIP Sox.....
Joined
·
2,580 Posts
I do wonder how much improvement a 6 TB setup would make to these engines.
I suspect the advantage up top will be heavily disadvantaged at lower revs though.
I might make one some day to play with.....

Rick.
 

·
Registered
Joined
·
529 Posts
Rolin on a MAP based system with multiple tb's you can't use the vacuum signal at idle because it fluctuates and is generally poor. So, the 2 options are to run TPS only or aftermarket ecu which will ignore the map signal at 0% tps.
 

·
Registered
Joined
·
476 Posts
Soxx said:
I suspect the advantage up top will be heavily disadvantaged at lower revs though.
Rick.
i thought this too, but a mate of mine tells me that all the ones hes dynoed have made better power all the way through... im not sure if its possible, but thats what he reckons
 

·
Registered
Joined
·
529 Posts
An example of multiple tb's thats works well is on motorcycles. I believe the Ducatti 998R has twin 63mm tb's. Even though they have little weight their low rpm torque is still excellent.

Although multiple tb's can be very hard to tune, small tps values equates to lots of airflow. This can cause jerkyness on throttle application.
 

·
RIP Sox.....
Joined
·
2,580 Posts
not ford -
A Ducati has good torque for a motorbike at the revs a motorbike typically spins at.
The bike you're talking about redlines at over 10,000rpm.
'Good torque' for that machine is considered to be at between 5000rpm and 8000rpm, so to compare in such a way is meaningless, as a Ford I6 is not realistically going to spin beyond 6500rpm, and 5800rpm if using the standard ECU.

So in actual fact, the low speed (2000rpm - 3500rpm) torque is quite poor.

Rick.
 

·
Registered
Joined
·
1,447 Posts
Ey Soxx can you give us a list of what you've done to your 6cyl and if you dont mind, what kind of money you've spent :)

Nick
 

·
Registered
Joined
·
529 Posts
Actually Soxx good torque for that sort of bike would be about 3500 to 6000rpm, my friend used to road race motorbikes. He raced a friend's 748 once and the guy got shitty at him for going over 10,500rpm just in case it dropped a valve. Most of these bikes idle at about 1000rpm to begin with so you have to be realistic.

Also I don't think the factory would go over oversize on the tb's on a factory road bike, the consumer would complain about it too much. This is also proven by the fact that nearly all the factory superbike teams most run even larger tb's.

The point I am trying to make is a multiple tb setup can be made to work well but for cost boost would be better bang for buck.

V8 supercars run multiple tb's and even with 3.5 gears they toast the tyres from about 3000rpm on the roll (although the motors cost about $100,000 each).
 

·
RIP Sox.....
Joined
·
2,580 Posts
MustangNicko -
There is a couple of threads outlining what has been done to my engine. Search for 'XH DEV5 project'.

not ford -
You're wrong dude. Peak torque for a 998 is produced at 8000rpm, and below 5000rpm they feel very stale indeed, I know, I've ridden several.
My own bike which is Ducati 900SS which is seriously de-tuned compared to a 998 doesn't even produce much torque below 4000rpm and has it's peak around 5500rpm with peak power happening around 7500rpm.
Your mate was also being paranoid as a 748's valvetrain is good for 12,000rpm.

I know the point you're trying to make, but using a bike as a comparison is not relevant as bikes don't make good low down torque.

Are you sure a supercar produces good power from 3000rpm? Sounds suspect to me. These engines redline at 7500rpm, and that would suggest that power would only really start to some on above 4000rpm.

Rick.
 

·
Registered
Joined
·
529 Posts
The reason the guy was paranoid was because he has dropped a valve before, he won't listen that his supposed "mechanic" can't set the cams up properly. Also my friend used to predominately race 2 strokes, proddy and GP which are definitely low speed torque-less.

My friend actually works in a supercar team. They have a ride car which uses the old 18 deg chev heads. Alot of the supercar teams are actually starting to stroke their ride cars to 5.7 to limit the revs and extend o'haul intervals from 1000km to 4000km. The cams in them (race car) are actually not humungous in duration but are very large in lift, they want a broad powerband and obviously alot of it. When my friend rode in the ride car apparently it was like driving on ice, it had no traction anywhere when the throttle was mashed, for fun the driver in the end drifted the last couple of laps (it did have the 5.7 crank). The actual V8 supercars do start to come "on" a little higher but by 4000rpm its already really alive. Even though the rpm limit is 7500rpm you obviously don't want the hp peak to be right there. The aurora heads also flow better then the 18 deg. So it isn't an exact comparison. Also I believe alot from what you and I have written in the past that you and I have very differing opinions.

Also an interesting fact with the multiple tb's all the V8 supercars have a accelerator pump. When they pump the throttle with the engine off (ign on) the injectors squirt raw fuel straight in. Apparently the engine won't start otherwise due to the poor vaccum signal.
 

·
RIP Sox.....
Joined
·
2,580 Posts
If your mate with the 748 is based near Sydney, tell him to have the head shimmed by Gowanloch in Belmore.

Rick.
 

·
Registered
Joined
·
529 Posts
He's not my mate, he and his racing colleage are idiots with too much money. One spent a fotune on his 998 getting aparently superbike cams then dropped a valve and nuked 2 cams. AND guess what, they still go this dogey Ducati mechanic.

Why can't people like this give me the money instead???
 
1 - 14 of 14 Posts
Top