Bike TB's Cost and Questions about aftermarket ECU?????

[Alex]

Ive been researching into ITB's

as far as i know i would need a manifold for what ever tb's i choose and a low pressure fuel pump????

but i'am lost with aftermarket ecu bit, from what i read you need to use the throttle position sensor instead of the AFM, but you need to use an aftermarket ECU for this...

basically i'am lost from here, do you buy a megsquirt ecu connect all the inputs that usually go into the standard ecu, into the megasquirt one including the throttle position sensor and then get it mapped???????

or can i just get something that just plugs in and changes the signal to something the normal e30 ecu can understand ???????

also what sort of money would i be looking at ???? and can you get carbon fiber airboxes like the m3 has for the sound

sorry if ive got some of that wrong, i dont know much about it

[oakey]

How much have you got to spend??
cf airbox- £500+
ECU- £400+
Mapping- £300+ etc etc etc

[Alex]

forget the airbox then

would £500 be enough for a basic setup ??

[Alex]

are bike carbs easier to do, i read someone doing it for less that £100 on an old ford

or is it a bit of a step backwards ?????

[jaistanley]

Bike carbs will certainly be cheaper. You would need an adjustable fuel pressure regulator, a manifold, the carbs and something to make the spark. You might be able to get the stock ECU to take care of that for you, or buy a mega jolt setup. You'll then need to get the carbs set up and re-jetted by someone who's done it before. Talk to Bogg Brothers. They do lots of bike carb and throttle body setups.

I would personally go for a megasquirt set-up and run bike throttle bodies yourself. You MIGHT just get under the £500 mark if you are very handy yourself and do all the mapping, but I doubt it.

[Alex]

i wouldnt know where to start with megasquirt really

its more for the noise

would i expect much power gains from using bike carbs ?

[UweM3]

a few basics.

removing the AFM and using a throttle pot is called ALPHA-N.
Nothing to do with the number of throttle butterflies you run your engine with. It's a method of running an engine and is used to remove any restrictions in the inlet track (i.e. the AFM)
You can happily run ITB on your engine with the AFM (like the M3 does from stock)

The question you need to ask yourself is, how many bhp do I want to gain? Will fitting ITB's get me there? Or are they other means to achieve more bhp with your current engine?
Cams, exhaust, chips???

Don't bee fooled to think that bike carbs are cheaper/better than injections. They need "mapping" as well, otherwise your engine doens't run to it's full potential. And I do not believe that they can outperform a PROPER injection setup (compare like for like!)

PS ANY change you make to the hardware will require an update of your software. If you fit ITB's and don't map your ECU for it, it won't work. If you fit another cam, you need to map the ECU etc etc etc

PSS the low pressure fule pump is for the bike carbs

[Alex]

so its quite pricey, then

so if i fit ITBS, i could build some sort of airbox that connects to the original AFM

then the original ecu will need mapping?

sorry i'am new to this

what sort of gains would i expect from a setup like this if any?

[m_jermyn]

this makes sense to me and I had a similar idea... But I think the boffins see it different... I dont get the ECU shit myself

[E30BeemerLad]

worth having a chat with a company called Bogg Bros, they are based near York and do a lot of bike throttle body conversions, they can do anything from fabricating a custom manifold to a full turn-key conversion. They have a good reputation for this stuff. A google search will find their details I would have thought

[Alex]

confusing isnt it, ive always wanted to understand it and i love the sound of bike carbs and ITB's

[Alex]

http://www.boggbros.co.uk/

[m_jermyn]

I think with the ITBs the idea is to get crisper throttle response because the butterflies are closer to the head... You also can get a greater volume of air in, this would mean the stock AFM would restrict the gains the ITBs make...

I think if you redesign the inlet manifold to have strait equal length runners with a plenum and a larger Throttle body you might see similar gains to ITBs.. Would still need mapping though..

Does this make sense?

Mike

[Turbo-Brown]

Think the trouble with using the AFM is that it leaves a restriction in the inlet path.

Ideally you want the ITBs feeding from a nice plenum chamber which is fed cold air from the front of the car.

You would need to remap even if you did use the original AFM, both fuel and ignition would likely as not need remapping.

Have a look at Oakey's car.

The ITBs on his netted him something like 60lbft of torque over a similar spec engine running the standard inlet manifold, below 3000rpm (I think!). Headline power figure was pretty much the same though, but all that extra low end grunt should make the car with ITBs faster.

[Alex]

looking at a few videos on you tube a few seem to use some sort of rubber piping as the manifold

could i not cut an exsisting manifold that ive allready got and use the piping ??? or is that the counci way ?

i know its a 106 but it might be better to see what i'am on about

[Alex]

Think the trouble with using the AFM is that it leaves a restriction in the inlet path.

Ideally you want the ITBs feeding from a nice plenum chamber which is fed cold air from the front of the car.

You would need to remap even if you did use the original AFM, both fuel and ignition would likely as not need remapping.

Have a look at Oakey's car.

The ITBs on his netted him something like 60lbft of torque over a similar spec engine running the standard inlet manifold, below 3000rpm (I think!). Headline power figure was pretty much the same though, but all that extra low end grunt should make the car with ITBs faster.

going to have a search for his now

[m_jermyn]

Turbo brown your so moddest...... Who was the master that produced Oakeys ITBs? They are a work of art by the way mate..

[Alex]

just looked throught oakeys pimp my tech 1 thread and the work does look impressive

do you make ITB/and Bike carb setups then turbo brown

had a quick looks at dblias synamic and their kits are just under £1500

[Gunni]

Why are people thinking about fitting ITB´s without telling us what they are after in terms of power upgrade?

That makes no sense to just fit them and hope for the best.

Alex , what kind of performance are you looking really for ? And how much have you got to spend?
With these kinds of answers people on the forum will be much more likely to help out and direct you in terms of what modifications to go for.

[BadDave]

could i not cut an exsisting manifold that ive allready got and use the piping ??? or is that the counci way ?

It can be done

Here's one i made earlier using a std 6 pot mani


The 2 outer runners had to be taken from a spare mani, as the originals bent upwards too early,so I couldn't use them.



There will be a 2nd set of injectors fitted to the throttle bodies as well, with ECU controlled forced switchover

[oakey]

The way I have done mine is probably the cheapest method without having to do any of the complicated work myself.
TurboBrown built the itb's, Ant fitted and mapped them.
You won't get it down to anything like £500 unless you can pick up nearly all the parts for nothing AND map it And fit everything yourself.
More costs involved- Just for the silicone hose 'runners' and aluminium trumpets it was over £120, then you will have to get bigger injectors, then airfilters or filter and airbox.
Then after all that you need to iron out the small issues, which there will be some of. Then you need to get it to pass emissions at MOT time. This is why when you actually consider the price of the Dbilas kit, which comes with everything needed to run them, it really isn't alot of money.

BUT you get an awesome noise and my car will pull well from 1500rpm in any gear and the extra midrange power is great
From 2200-6500rpm the engine makes more torque than a m20b25 makes at peak power and from 3500-5750rpm it makes over 200ftlb

[Alex]

they sound good oakey


more expensive that i thought, so an m50 conversion will still be cheaper lol

[oakey]

^ yup, probably + you'll have a quicker car at the end of it, and the correct no. of cyls

[Alex]

its the insurance

one disadvantage of being young