Started work on a individual throttle body project today, so I thought I would start a thread to keep track of progress and to collect ideas and suggestions as I go.

I have looked at a number of ITB setups for inline 6's, most use DCOE webber type throttle bodies, with a small length manifold, great for power up top but not too good for low to mid torque, so my plan is to fabricate a longer length manifold and run the throttle bodies upright.

Starting with the flange from the bottom half of a BBM manifold, ban sawed off. Monday I will bolt it to a plate and mill them flat.



Intake runners will carry a similar curve as that of the bottom BBM runners, this will allow enough room to create the optimal length of the runners, calculated based on my cam specs as 45cm from centre of the valve to the top of the ram tube.

I have found some 6061 alloy tube with the right ID and thickness, however I can't find anyone in Adelaide with a mandrel bender with the right dies to suit. I have a regular pipe bender at work, so a bit more research found a product called "cerrobend" it is a very low temp melt alloy used to fill the centre of a pipe before bending, it melts at 70C degrees, so boiling water melts it, pour it into the pipe quench with water and you basically have a solid pipe to run through the bender, no chance of creasing the pipe. Once bent to desired shape, reheat in boiling water and it pours out.

These will be TIG welded to the manifold flange as well as some TB mounting plates from EFI Hardware


Throttle bodies 48mm from EFI Hardware


The benefit using single once piece TB's over the DCOE type is EFI Hardware can make the butterfly rod to suit, meaning I only have the one rod running through all 6 throttle bodies, no problems with linkages or butterflies out of whack.

Another benefit to running the throttle bodies upright is cold air intake, if I have worked it out right the ram tubes should finish roughly at the same height as the existing BBM top, quite easy from there to create a surround and run an air feed from the bonnet with a scoop of some sort, sealed off with foam to the bottom of the bonnet = no hot air from the engine bay.

Just in case anyone wants to know why I want to do this, a number of reasons:
Because I can
I haven't seen one done like this before
I love making and fabricating things
I love a challenge
I want something different than the regular turbo etc
But most importantly because of the sound of six ram tubes on full song at 5500rpm

Some things I still need to work out:

ECU to run it
Throttle position sensor, shouldn't be too hard with only one butterfly rod
Manifold vacuum for brake booster


Please feel free to add advice and comments (except for "just turbo it" see list of why above)

I will update as it progresses.

for the ECU check out the EMS range. The 6860 is the 6cyl version of the the 8860 that have been doing for a long time. can do 6cyl sequential injection and 6cyl direct fire ignition, duel maps that are switchable on the fly. and a bunch of other useful stuff that will come in handy.

Have you ever though of just using the bottom half of the BBM instead?

you can fab a blocking plate to either block the short or long runners?!?!?! sorry I can't recall if the snail shape continues to the bottom half. I'm to lazy right now to walk out side and have a look.

Cool, will check them out, I think Bruce Heinrich Performance Tuning in Adelaide uses and sells the EMS range.



I did have a good think about that, but I think using custom runners gives me a bit more flexability with runner size and tapering, plus I want to compact the length slightly, the gap between 1,2,3 and 4,5,6 where the throttle body enters is a bit too wide for how I want it to sit.

yeah, I just had a look and it appears the runners are to close together to be of any use to the ITB's.

which order are you tuning too and at what rpm are placing it?

Grea project, looks like you've done your homework which is important. Good luck. I'll be watching keenly!

Very interesting.

Will be following your progress.

BenJ

I'm watching with great interest to see how this develops.

Cheers

ToranaGuy

The EMS 6860 looks like it will be perfect for the job, the EF's are already wired for sequential if i remember right?, got a couple of quotes to supply only, $800 difference between the highest and lowest prices I guess some places like to have plenty of mark up.

Got the pipe extrusions today, 50mm OD, 44mm ID 6060.

I figure by tapering from 48mm at the throttle body, down to 44mm then to 40mm at the manifold should create a bit more air speed entering the head.

Forgot to call AAA to see if they can mandrel bend the pipe, otherwise will order the cerrabend low melt alloy this week then make up a jig and bend them at home.



Have also just started reading up on porting the I6 heads, I have done a couple of hemi 6 and pinto 2l's in the past so the principles should be the same, just need to modify to suit the ford head I guess, there is a couple of nice ones in the porting bible on here so that makes it easier.

tickford_6, do you mean the tuned length? If so I used and cross referenced some of the intake calculators using peak torque RPM and intake area to get the tuned length of the runners, as the cam is a new custom grind I had to rely on the calculators to find peak torque RPM which works out at 4500-4700 RPM. I figure that the manifold is only $100 worth of metal + my time, I can always make another one with adjusted length once I finish and get it on the dyno, same with the cam, once I see what the ITB setup can do.

I have a spare motor sitting in the shed waiting for a bore and balance, and if the $$$ can be found some forged rods so it can rev safely.

for vacuum, to run the brakes, heater controls etc, you need a shared chamber that runs off all 6 ports. you can either drill and tap fittings to the ports and run them all into a vac cannister or similar, or fabricate a shared chamber into your intake. This will also help balance the cylinders slightly as you may have play in the linkages between each T/B.
Also take your map sensor feed off the shared chamber, and you can use the MAP signal to alter your fueling (ie cruising and decel)

an EMS will probably run it ok, but your best option is using an MSII/e ecu as you have a lot more control over the injection parameters. The MSII's have a few features that will give better drivability with ITB's than an EMS will

TPS, you can easily adapt a Haltech TPS to the end of the shaft.

If you do decide to use MSII ecu or want more info, give me a call/PM

the reflections keep going. back and forth the intake runner, each time getting weaker and weaker.
You can make use of the 2nd, 3rd, 4th and 5th reflections. Most of the calculator programs tune for either the 2nd or 3rd reflection and ignore all the others. And most of the programs don't tell you what which order reflection they use.
You could tune it to have the 4th order at peak power and use the 2nd and 3rd to help boost the bid range.

what features does the MSII have that would be of benefit of other ECUs?

Ahh, do you know the formula for how fast they diminish? or which program might list them and let you choose? I was thinking maybe a fluid dynamics flow simulator might be more accurate?

Interesting Idea mate, Ill be watching with interest.

Cheers