Winter Project- IS throttle bodys

[appletree]

Right theres been much talk about people running a IS on throttle bodies but with the exeption of Tim_s i dont know any one whos actualy done anything.

A while back when i started my Superchager conversion i bought this adaptor plate from a bloke on a ebay who had made it for his IS.

The adaptor is a one peice item machined using a state of the art CNC milling Machine and machined from solid billet ally.





love the detail in the ports going from round to oval!!




I did try and sell the adaptor and trumpets but no intrest so ive decided to build it up as a project with the idea to sell the hole lot at the end as a running set up, or i might just keep them who knows.





any way some pics to start with

Heres the throttle bodys from an early hayabusa.



One problem with the throttle bodies i bought was the ebay ad never side they had a one bent butterfly, but it should bend back ok and they are all individualy able to be adjusted.




Started off by splitting the TB's and sitting them on the adaptor plate to measure the distence i need to split them and make up some spacers

Love how they look already!





Just need to get these little tabs extended there used to balance each butterfly and are to short now ive spaced the TB's differently!



The injectors are Peco ones i beleive and was just woundering if they would be ok to use as is far as i know bosch type dont fit!

I've also sold a second incorect set i bought to my freind who has a MK2 golf GTI 16V and i'am doing the machining on that for him on that set up but ive got to make a manifold to adapt them first. joy of joys !

[hammoj28]

Wow. Iv always wanted to do this to mine but iv not had the money. This is going to be good. Looking forward to seeing what it does.

[Dan318-is]

Dude were did you get the trumpets? Exactly what i need!

[Auto_X]

Hi, any idea how to do it ona 6 cylinder Motor?????????????????????????

[agreen]

wow i wan them they look so good a adaptor group buy anyone lol

tell us is lovers more how do we do this

[appletree]

Dan the lad who i bought the adaptor and the trumpets off livd in the states and had hem made from a plate in austrailya.

There not just any old trumpets ( so the guy said) they were made to size using a special program that suposidly calculated the optimum length and tayper using valve diameter, stroke, bore and so on.

not sure if ther wil be much gain or even if i will actualy go all the way and get them set up and my ecu re-mapped.

I would also like to build a carbon Air box for them like the M3 DTM box think it would look mint and sound pritty cool.

to fit them to a 6cyl motor you'd need an adptor plate and 6 ITB's,you might be able to fit some sort of e36 bodies

[BadDave]

Hi, any idea how to do it ona 6 cylinder Motor?????????????????????????

I'm in the process of doing just that for the M20B25 thats currently in my tourer
I've got 2 sets of Suzuki GSX600R 38mm bodies



Going to use the Keihin injectors thats fitted to them

Having the inlets machined now and having a 2nd set of injectors fitted to them(for future turbo upgrade)

Using the std Suzuki throttle pot and controlling it with a DTA ecu(no megasquirt for me)




Got the spacers made and the extended threaded rods to keep them all together

Just need the manifold finished and the linkages extended and a fuel rail made up

Got to make a few alterations to the loom
Then everything should be ready to fit

[agreen]

so suddenly it is seeming more comilicated to me than an adaptor and trumpets lol

[BadDave]

so suddenly it is seeming more comilicated to me than an adaptor and trumpets lol

Not really complicated
More time consuming

[agreen]

how so diffrent injectors etc so by the time al said and done what are you lookin ng£Â£Ã‚£ for 318is itb

[appletree]

Only in the way that you need to extend everything.

i dont need to bore anything out. as far i can see if they can flow enough air and inject enough fuel for a 1.3 at 16,000rpm then that should be ok for a 2.3 at 8,000 rpm so my Is should be no trouble.

so also will need aftermarket ECU, should have already said that i'am using an emerald ECU.

Baddave -any pics of how you did the manifold? looking for some inspiration of how to do my mates with out using CNC, just anormal lathe and milling MC.

thinking of welding some internaly tayperd stubbs on to a plate then mill a oval fom the backso thers a smooth transition then maybe finish off with a flap wheel??

[maxfield]

Sweet

[agreen]

so gsxrinjectors and itb's then

[appletree]

Thought you' like that Max!

The manifold and trumpets cost me £250 which i think is pritty cheep considering the cost and the labour that would go it to making such a good adapotor but if you had the skill and the milling machine you could make a lesser quaity version for the cost of some materials and a few beers for a weld hear and there maybe £50

Then you need some TB's mine were £100 off ebay.

Then some kind of ECU to run them £300-700 depending on type

Theres also the other little things to think about like cam breathers and brake vacume pipes, throttle cable linkage, plenum and clearences.

All little but all eat money.

I'd say to fit them to a bog standard IS with no other mods it would probably be best part of a grand depending on what parts you could do on your own!

seen as i've got the machinery avalible and the ability to use them its only realy gonna cost me the cost of the materials and a remap as ive got lots of things from my S/C set-up.

Just incase any ones intrested i'm not getting rid of my S/C set up just having a play! think the S/c going to be replaced with a new manifold and a larger supercharger over witer to, still positive displacement type though loving that low down torque!

[agreen]

whats a s/c set

[appletree]

Agreen

The throttlebodies are suzki hayabusa ones or GSXR there just different because of the different years of the bikes IIRC

[appletree]

Supercharger!!!!

my car is currently supercharged

[agreen]

ohh so way out of my leauge though sadlluy

[maxfield]

BadDave, how much was the DTA?

[BadDave]

Agreen

The throttlebodies are suzki hayabusa ones or GSXR there just different because of the different years of the bikes IIRC

The early(K1/K2/K3) throttle bodies are individual units all bolted together
IIRC the K4 - current K7 are all twin sets(like a weber 40/45 dcoe)
The 600cc ones are 38mm dia
The 750cc ones are 40mm dia iirc
The 1000cc ones are 44 mm diaa
and i think the busa ones are 45mm dia
Most of the other bike manufacturers use the twin castings instead of individual ones
For a 6 pot you might get of with 2 sets from a speed triple??

[BadDave]

Baddave -any pics of how you did the manifold? looking for some inspiration of how to do my mates with out using CNC, just anormal lathe and milling MC.

thinking of welding some internaly tayperd stubbs on to a plate then mill a oval fom the backso thers a smooth transition then maybe finish off with a flap wheel??

No pics as yet
Mines not going to be anything "fancy"
Just this

I'm not happy with it so gonna do another one

Just a 1/2" thick adapter plate and 6 inlets approx 2 3/4" long for the tb's to mount on to
1 set of std bmw injectors mounted on the inlets with std fuel rail and pressure reg
1 set suzuki injectors in the tb's with a fabbed up fuel rail
Aliminium plenum chamber with the inlet ready for the turbo(in the future)

[BadDave]

BadDave, how much was the DTA?

£400 delivered with a pro built loom
So comparable with a built up MS and complete loom
Plus it's got extra features

[maxfield]

My Dad paid about 5 times that

[appletree]

Is two sets of injectors a good idea?? heard some horro storys of the second set failing but the engine still being able to run and melting pistons!!

Atleast with on set you would feel/hear a miss fire??

only a thought

[BadDave]

Is two sets of injectors a good idea?? heard some horro storys of the second set failing but the engine still being able to run and melting pistons!!

Atleast with on set you would feel/hear a miss fire??

only a thought

Will only be running one set with the tb's
The second set will triggered to come on when the boost level increases once the turbo's fitted(Garrett T04E)

[BadDave]

My Dad paid about 5 times that

Your dad might have the P8 Pro version tho

[Andy335Touring]

Have you thought about chopping the mounting flanges off a standard manifold then weld an inch or two of pipe to which you can mount the TB's ?

May be join the TB's to the pipe with some silcone hose if practicable ?

[BadDave]

Have you thought about chopping the mounting flanges off a standard manifold then weld an inch or two of pipe to which you can mount the TB's ?

May be join the TB's to the pipe with some silcone hose if practicable ?

It was an option i considered
Going to use some silicone hoses as suggested anyways

[Dan318-is]

Dan the lad who i bought the adaptor and the trumpets off livd in the states and had hem made from a plate in austrailya.

There not just any old trumpets ( so the guy said) they were made to size using a special program that suposidly calculated the optimum length and tayper using valve diameter, stroke, bore and so on.

not sure if ther wil be much gain or even if i will actualy go all the way and get them set up and my ecu re-mapped.

I would also like to build a carbon Air box for them like the M3 DTM box think it would look mint and sound pritty cool.

to fit them to a 6cyl motor you'd need an adptor plate and 6 ITB's,you might be able to fit some sort of e36 bodies

Dam that sounds good! If you ever feel the need to sell them please message me! I have given tim his old plenum back as ideally i didnt have time to perfect the setup and also socks and trumpets are so much easier to get right! Bigkev on here is pretty handy with carbon fibre i think; i know tim is going to be in the process of getting some copies etc made of his first plenum so might be worth giving him a messgae if you are interested!

Any posisibilities of some measurements of the trumpet sizes etc so i can try and get some as close to that if possible? Your car rules!

so suddenly it is seeming more comilicated to me than an adaptor and trumpets lol

Not really complicated
More time consuming

Couldn't agree more! Its getting the little things set up and perfect that take so long.

[Jhonno]

Dan - be an idea to try and get some info bout the S42 engine for your plenum spec surely?!

[Andy335Touring]

I forgot to post this link up, shame it's in the US but looks good ?

http://www.velocity-of-sound.com/

[tim_s]

Nice one Matt, i'm still surprised David got rid of those! Thought he paid a load of money for that manifold too. How about going throttle bodies and turbo?! You've done S/C now

Dan, your trumpet size/length will not be the same as Matt's, because Matt is using TBs of a different diameter and manifold of a different length etc. You've got to think about length from valve seat to end of trumpet as well as dia. if you do sums, you also have to do it based on where you want peak power etc - on top of all that, trial and error works pretty good!
S42 plenum shape is no good for an e30 as the brake servo gets in the way. if you get rid of the brake servo then you can then do something similar.

[tim_s]

so suddenly it is seeming more comilicated to me than an adaptor and trumpets lol

Not really complicated
More time consuming

Couldn't agree more! Its getting the little things set up and perfect that take so long.

lol, you would say that! you didn't have to build that sodding fibreglass plenum or mod the throttle bodies, or port tune the damn thing etc.
The little things are not that time consuming compared to that stuff, but i know what you mean!

[jkarran]

thinking of welding some internaly tayperd stubbs on to a plate then mill a oval fom the backso thers a smooth transition then maybe finish off with a flap wheel??

Sounds like a good idea. You may also get away with making a positive form of the port shape you want from steel (its always easier to work the outside of a shape than the inside ) then press/hammer annealed aluminium tubes down over it. If you keep the circumference of the form pretty constant (you might not be able to depending on port size/shape) it should work fine. Finish off by hammerforming the fine details like the injector boss relief then weld them to a plate in the form of the inlet gasket and finish with a die grinder.

I've also seen the original manifold used on a Suzuki Swift engine, cut off to leave stubs, ground to a nice taper and just joined to the throttle bodies with silicone hose. Ok it's a bit agricultural but it works fine.

If I had a milling machine i'd do what you suggested, cut them from bar and finish with a diegrinder.

jk

[ed325i]

Have you thought about chopping the mounting flanges off a standard manifold then weld an inch or two of pipe to which you can mount the TB's ?