ITB's info/projects [Archive] - M42club.com - Home of the BMW E30/E36 318i/iS

tim_s

02-03-2007, 04:53 PM

OK, my setup used modded 50mm bodies, new fuel rail and a custom vacuum rail, fibreglass plenum (this was the bulk of the work and a real pita), 3" MAF, 24lb injectors, M3 IAT sensor, 76mm K+N, S14 throttle clip, veedub aux air valve controlled by MS , and prob a load more stuff I've forgotten.
For management I used Msns-e with wasted spark on the factory coilpack, and MAF, not Alpha-N or MAP unlike most with MS. Many reasons for this, not worth getting into here. Mapping with a wideband took the best part of 6 months, and still in traffic (esp coming off throttle), warmup and idle my MS setup is not proving as good as the factory motronic; i do run a performance inlet cam which doesn't help I guess.
I used m44 timing map for reference and as the basemap for timing. Fuel economy on motorway runs and in traffic is about the same as with motronic/standard inlet, contrary to what some people will tell you regarding big throttle bodies and driving in traffic. I cruise at 17:1 and on WOT use 13:1, hasn't been optimised on the rollers yet. I'm actually back on the standard inlet and motronic (with budget mods to make it work with the 2.1!) for the moment, weighing up whether to keep the ITBs or not.
When I built them the car was mainly a toy and MS was great, whereas now i'm doing a lot of miles in traffic and on the motorway where the factory injection and throttle are actually better than the ITBs (quieter at 85mph+ and smoother in traffic/better idle). Most of my problems lie with me not being as happy with MS as with motronic for daily use, not with the ITBs themselves, which worked great. throttle pedal feel was a bit vague compared to the standard setup, but the throttle reponse, noise, and the power delivery esp at higher rpms was brilliant.
Will find some more recent pics when I get a moment, here are some old ones.

http://i2.photobucket.com/albums/y30/ts295/DSCN3009.jpg
http://i2.photobucket.com/albums/y30/ts295/bmw/DSCN3000.jpg

cecotto

02-03-2007, 05:08 PM

Tim.

Very nice looking setup, cant wait for the extra images.

Your setup looks cool with the airbox. I have been thinking about fabricating one for my setup... But i need to finish the engine before taking on any tasks...

Do you know how long your setup is from tract entrance to valveseat ? And how is your low end torque ?

My Dbilas setup is 27cm as i remember, measured crudely with a carpenters steel measuring band. I'm a bit concerned with the length so i might have tofigure something out about this..

tim_s

02-17-2007, 01:06 PM

hi steffen,
I'm going to have to re-measure my inlet for you. I did know its length but I've forgotten. I just got a tape measure on the bodies and the trumpets the total length there is (very approximately) 25cm, so yes it's much longer than the dbilas setup. The trumpets are probably wider though, of course.
low end torque is very similar to factory, but it feels better because of the throttle response and the noise!

dino245

02-19-2007, 12:53 PM

I am sure may people have heard of using the Hayabusa throttle bodies and wondered what they would look like spaced to the BMW bore centers of 91mm and not the Suzuki factory 80mm.

Well I have purchased a set that I will be using with my new engine and Haltech E8. Here are some picture of just the throttle bodies. I still a long road ahead and much to fab. I am using 26.85lb/hr @3bar injectors from a VW 1.8t At the 4 bar I will be using thay flow 31lb/hr enough for 200hp

mike85-325e

02-20-2007, 05:02 PM

definetly a n00b question but what are the advantages for using ITB's?

dino245

02-21-2007, 11:34 AM

More air capacity and better throttle responce.

silverblades181

02-21-2007, 05:07 PM

definetly a n00b question but what are the advantages for using ITB's?

What Dino said. At higher rpms it permits more air to go into the engine and therefore fill the cylinders more efficiently.

1991 E30 M42

02-24-2007, 04:50 PM

http://www.gttechnic.com/catalog.html
about 2/3 of the way down

steve321

03-04-2007, 05:53 AM

well it all started about 18 months ago, when i brought a set of E36 M3 evo ITB's off ebay, but had a nightmare when it came to trying to fit them, what did'nt help is that i worked everything out using gaskets and not actually matching the ITBs to the head, (becuase i did'nt want to take my inlet manifold all off in case it all went tits up and did'nt work, lol) so i machined my self an aluminium adapter plate to match the S50 itbs with the M42 head, and that went fairly well, but i was never happy with having the adapter plate, one reason among other was that the ITBs and plenum sat quite high in the engine bay and stoped me from using my strut brace,

heres how i was first going to have the itbs
http://i34.photobucket.com/albums/d117/stevemitchell321/throttlebodies10small.jpg

and heres the aluminium adapter plate
http://i34.photobucket.com/albums/d117/stevemitchell321/throttlebodiessmall.jpg

time went by and i had the itbs fitted for about 8-months, then just recently i was browsing through ebay for a cylinder head, and found one for £30, so i brought it with the intention of practicing headwork on it, and making the itbs fit properly,

heres the main problem with the itbs, the ports are the same size, just dont quite match
http://i34.photobucket.com/albums/d117/stevemitchell321/Photo-0029.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/Photo-0028.jpg

so i started to grind out the head and itbs so that they matched each other, that was only about an hours work, with a drill and tungsten carbide bit.

now its a case of bolting them to the head when the bolts do not all line up, you can see in this pic that there very very close, and i did even have to file a small ammount from either end so that the itbs sqeeze in around the studs,
http://i34.photobucket.com/albums/d117/stevemitchell321/ITBsonhead4.jpg

so with most of the obsticles out of the way i got on with making some little brackets up, and very luckily i happened to have some 2" aluminium angle thats about 3-4mm thick so i used that for some little right angle brackets.
http://i34.photobucket.com/albums/d117/stevemitchell321/18small.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/17small.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/Photo-0037-1.jpg

and thats about it really, then got them bolted to the car
http://i34.photobucket.com/albums/d117/stevemitchell321/PICT0005small.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/PICT0009small.jpg
its still abit of a mess and needs some more tiding, but slowly getting there, i am working now on the spare cylinder head, the porting is going very well indeed, i am fitting bigger 34mm inlet valves and the inlet and exhaust valve seat/throats are being machined out to the maximum they can be,

heres some of the head work
before
http://i34.photobucket.com/albums/d117/stevemitchell321/M42small.jpg
after
http://i34.photobucket.com/albums/d117/stevemitchell321/port11small.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/portbeforeandafter.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/port10small-1.jpg

once all this is done then i will start on the bottom end, making it 2 or 2.1 liter, and a silly high RPM :D

steve

romkasponka

03-04-2007, 09:12 AM

looks very good!

I found this few days ago http://www.homemadeturbo.com/tech_projects/itb/

Alpine003

03-04-2007, 09:29 PM

looks very good!

I found this few days ago http://www.homemadeturbo.com/tech_projects/itb/

This is what I did with my Acura 4 years ago. I recently acquired another set of GSX-R ITB's but they are going on the 2002.

IMO, ITB's are only good for track cars that have upgraded cams/headwork and constantly sees above 4000 rpms.

The itb's on the 2002 will more or less be for curiosity sakes and experimental with no intentions of leaving them on in the long run.

It seems that Carbon Fiber and ITB's are so overrated these days and it's usually the wrong people that adds to the hype. :rolleyes:

As for the above poster, definitely an "A" for effort. Curious to know the outcome on whether it was really worth it or not.

tim_s

03-06-2007, 09:58 AM

i kinda disagree with the above (ITBs just for track cars). ITBs on my M42 made it have fantastic throttle reponse throughout the rev range, and (ok particularly at high rpms) it really went very well. It was pretty driveable in all conditions, it was the aftermarket ECU that let it down. I could not map megasquirt so that it would drive as well as factory.

My concerns with Steve's setup are how he's going to get MS to run well enough, although Steve's car is mainly a toy, whereas I had to use mine to drive around cities etc.
I will resume hostilities with my setup later in the year if I can pluck up the energy

Alpine003

03-06-2007, 11:28 AM

It was pretty driveable in all conditions, it was the aftermarket ECU that let it down. I could not map megasquirt so that it would drive as well as factory.

Your sentence seems confusing saying it was driveable in all conditions but the ecu let it down. :confused:

The term "driveable" imo is a relative term for everyone. The issue that I have with ITB's is that most of the diy itb's looked niced and performed nice within a certain rev range but as for daily driveability, it was far from optimized.

I'm sure if someone spent enough time on tuning, they could get the driveability and refinement close to a factory tuned M car but I've only seen 5% of ITB cars that exhibited this trait. There is just too much r&d and tuning time involved to get the kind of refined ride that factory cars have for daily street use.

Of course if you're riding around on 800lb/in springs on the streets then ITB's will probably suit you and offer you that good "driveability". ;)

tim_s

03-07-2007, 06:32 AM

i said it was 'pretty' driveable, which is probably a term that's used more in the UK. Lots of people have been in my car, and more or less everyone said that i was being really fussy over how it drove, but i didn't really want to accept any compromises. I have to spend quite a lot of time in slow-moving traffic and I could never get megasquirt to respond to IAT properly with MAF, and also i wasn't using the new hi res code and was never happy with the idle. Having said this, when I wasn't living in london, the car drove great, so well the girlfriend could drive it; it was only when I moved to london and had to spend loads of time in traffic that I found the ITBs tiring.
It all depends on definitions I guess. I'd say my car with MS and ITBs drove as nice if not better than factory in most conditions, apart from slow moving traffic and idle, especially when the inlet temps hiked up.
With MS improving all the time, especially the hi res code, and with some more improvements to the ITBs, I may be back with ITBs later on in the year.

Alpine003

03-07-2007, 09:32 AM

I'd say my car with MS and ITBs drove as nice if not better than factory in most conditions, apart from slow moving traffic and idle, especially when the inlet temps hiked up.

I would say this is a definition of a street car as most people that live anywhere near a major city will most likely experience some amount of slow moving traffic and idle. Hence, I stand by my original statement that itb's are great for the track.

In my experience, I've noticed diy itb's are easier to tune for steady state cruising or higher rpm operation. Not necessarily the case with lower rpm and rock steady idle.

Are you using a Vacuum canister? If not, I found using one can help with the idle situation of ITB's. Really easy to construct out of PVC pipe, end caps, and some fittings from the hardware store.

As for the lower RPM driveability, I might try to utilize the secondary butterflies of my ITB's on my next project to see if those would make any differences.

tim_s

03-07-2007, 12:32 PM

The idle and traffic issues have absolutely nothing to do with the ITBs. I would still have these issues if i were running MS with a single TB.
The idle seems to be due to the (lack of) resolution of msns with the normal code and fairly large injectors, and the traffic temperature problem is due to not fully understanding the relationship of inlet air temperature to the output of my MAF. You simply cannot blame the ITBs for both of these megasquirt issues. Megasquirt is a big undertaking, and is improving all the time; bottom line i've just not been good enough or had the time to get it perfect, especially as I'm running it in an unusual configuration. When I took on megasquirt, I was aware that this was likely to be a big project and that i'd have some small issues. Had I paid a lot more money and had the car properly set up and mapped on a more expensive standalone, I daresay I wouldn't have had those problems. Theoretically traffic and idle were not a problem with ITBs; it was my implementation of MS that caused the issues.

In my experience, I've noticed diy itb's are easier to tune for steady state cruising or higher rpm operation. Not necessarily the case with lower rpm and rock steady idle.

Are you using a Vacuum canister? If not, I found using one can help with the idle situation of ITB's. Really easy to construct out of PVC pipe, end caps, and some fittings from the hardware store

When I was running MAP i experimented with small plenums and with restrictors. I found MAP had more fundamental issues with ITBs than getting a stable vacuum reading. This is why I ran MAF. I've not found ITBs any harder or easier than a single TB to tune for steady cruising or high rpms. In fact especially when using MAP ITBs are really easy to tune at light load and low rpms.

I just don't really see many issues with running ITBs on a daily driver car; the difficult bit imo is getting the management right. Which in a roundabout way i think is similar to what you're saying, but i think its an important distinction.

Alpine003

03-07-2007, 01:28 PM

I just don't really see many issues with running ITBs on a daily driver car; the difficult bit imo is getting the management right. Which in a roundabout way i think is similar to what you're saying, but i think its an important distinction.

Yes this is what I'm saying and tuning is obviously the key in making ITB's suitable for the streets if done right. It's just that I haven't seen many able to achieve or put the time into tuning a really refined map on ITB's that can rival the refinement and driveability of factory itb cars. Most usually lack either time or proper knowledge to fully achieve this. Hence why I say that itb's generally belong on the tracks.

That is not to say that no one should be using these on the streets. I would say do what works for them and their situation.

I would easily recommend itb's to a "street car" if by definition, you are riding around in a stripped out interior, 800+ lb/in springs, no a/c, race seat, straight pipe as a street car and are perfectly fine for using it as a daily driver. ;)

nobrakese36

03-09-2007, 03:06 PM

So you eliminated the spacer?

steve321

03-10-2007, 09:45 AM

yep, dont have it anymore, i did in the end actually need two spacers, there was another 10mm one in between the head and the adapter plate.

bmwman91

03-12-2007, 01:47 AM

Has anyone looked into slide throttles for this instead of butterfly valves? Although the way they open could lead to odd air flow vortices, and subsequently odd air-fuel mixing, they seem like a pretty neat concept. I have a lower M42 intake manifold on its way to me, and I hope to make some real design ideas for a sweet new manifold...then I just neet to get my Megasquirt working again!

dino245

06-01-2007, 11:10 PM

I put my Hayabusa throttle body adapter up for sale in the clasified section. Check it out.

Boyracer

06-07-2007, 08:58 AM

I am not quite sure how essential ITB's are for making big power on M42 :confused:

Honda S2000 makes 120 hp/l and first Integra Type R around 110 hp/l without ITB's, also Ferrari seems to be content running their current engines with one TB per cylinder bank (2 for F420 for example).

So clearly big power (for our cars atleast) can be achieved without ITB's. It is different matter for race cars that need to utilize every advantage they have. But we cannot go that far because of emission regulations anyway.

Why ITB's on BMW M cars then?

I think the reason might be in number of cylinders and driveability. 4 cyl inline engine fires once at 180 degrees of crank rotation and 6 cyl inline once at 120 degrees. So power (and induction) pulses come more often in 6 cyl engine.

Both 4 cyl and 6 cyl engines have common intake system for all cylinders but but with 6 cyl engine the induction pulses are closer together in time and they might overlap meaning there is less air going to cylinders. To avert this you could increase size of STB the cylinders share but that is not good for low speed running.

When you have ITB for each cylinder on 6 cyl engine there is no pulse overlapping between cylinders if the plenum and it's intake are large enough.

At low revs the overlapping intake pulses are not a problem because amount of air is not that great and time between pulses are quite long. But when you start revving the engine higher it is different. 6 cyl inline running at high revs (yes, M3 S5x...) have pulses close to eachother and they can affect eachother if you use STB. Solution is to have ITB's.

4 cyl inline running at *same* revs will have intake pulses further away to eachother and ITB's might not be needed because there is less pulse overlap.

So that's why 4 cyl Honda can run well on high revs without ITB's. And Ferrari V-8 plenum is split in two so it is basically two 4 cyl inlines, one TB per cylinder bank.

Does that make any sense or did I talk utter bollocks? :o

kowalski

06-07-2007, 11:56 AM

Boyracer

06-07-2007, 01:13 PM

the s14 has ITB's. and while the s2000 might now have itb's it just have a better designed intake system. rather then redesigning a full intake system to utilize just one throttle body why not use 4? Better flow, better throttle response. Everyone pics the mods that they feel like doing, whether its building a stroker motor or a forced induction motor, some people want to build ITB's some go other ways for the power. However i see no downside in making your engine more efficient, Plus, the m42 needs all the help it can get for power.

Yes S14 does indeed have ITB's BUT:

1. It has 0,5 (0,7 in EVO sport) liter larger capacity than bog standard M42
2. It has rev limiter set (over?) 7200 RPM
3. It was designed to go racing from the factory -> even higher revs were in plans so ITB's made sense.

I am not saying anyone should not put ITB's to M42 if they want to, far from it! Throttle response will likely be better... I just think the effort and money could be put on better use elsewhere on street car. ITB's will help with radical cams producing strong intake pulses on high revs, something that is not present on many M42's.

But I think people should atleast consider custom made intake runners (perhaps lower part of E30 M42 intake?) and plenum with single throttle body perhaps from 2.5 liter M50 engine which flows nicely up to 192 hp from factory :)

I think it would be quite bit cheaper than ITB setup (german ebay: 300€ for S50 ITB's vs 10€ for M50 TB, same amount of money for plenum for both) and if you design TB system correctly is should flow ok up to 190 - 200 hp, just as in Integra Type R or S2000. That is if you can get the M42 to rev up to 8000-9000 RPM :D

m44power

06-09-2007, 09:03 AM

hey guys do a little search about brandnew yamaha R1 ITB's they have a solinoid to make the Tubes longer for low end torque and high rpm power AWESOME!!!!

Boyracer

06-09-2007, 05:40 PM

You must mean this :)

http://r-world.yme.com/images/YZF-R1/preview/spec02.jpg

It is a neat system! Problem is that those bike engines rev about double M42 does. Also they do not have to have any low rev torque...

I calculated optimal runner lenghts for M42 that revs upto 8000 RPM and has two positions. Lengts were 30 cm and 60 cm, those will give good top end power and low end torque. So basically at high revs you would have 30 cm runners but on low revs another 30 cm of runner would be stacked on top of that so it's then 30 + 30 = 60 cm.

That is quite difficult lenght to fit to a engine bay sensibly on DIY tech. But if you look at E36 M42 it has been done for you by BMW :) Ok, there is only two "extension" pipes for four short pipes but only one cylinder is sucking the air at the time.

If you are willing to sacrifice low end torque then shorter pipes bit like that R1 pic could work well on high revs :o

Alpine003

06-10-2007, 01:34 AM

hey guys do a little search about brandnew yamaha R1 ITB's they have a solinoid to make the Tubes longer for low end torque and high rpm power AWESOME!!!!

Suzuki does something a bit different by offering two butterflies sequentially in each intake runner opening at different times.

Alot of people recently seems to be addressing intake and exhaust enhancements but I think a lot of them often overlook the headwork and/or more agressive cams needed to really make any intake/exhaust mods worthwhile.

It doesn't make sense to me on why someone would spend the money/time/effort/frustrations on an ITB setup if they don't even have headwork or cams to end up with minimal gains.

Boyracer

06-10-2007, 06:21 AM

Alot of people recently seems to be addressing intake and exhaust enhancements but I think a lot of them often overlook the headwork and/or more agressive cams needed to really make any intake/exhaust mods worthwhile.

It doesn't make sense to me on why someone would spend the money/time/effort/frustrations on an ITB setup if they don't even have headwork or cams to end up with minimal gains.

I completely agree!

What ultimately defines engines capability to produce power is intake path on cylinder head (intake port, valve seat and valves). It is the largest restriction. You can improve every other area (ITB's, exhaust manifold etc.) but because they really are not the restriction, gains are small.

As on discussion on other thread, stock TB is good for atleast 210 hp (Metric Mechanics use it as it is). They use around 260-270 degree cams so apparently there is no problem yet with intake pulses. It might be different when you have 300 degree cams but I think there is no way in hell that would be road legal from point of emissions...

I think I will start thread about my project plans :)

steve321

06-30-2007, 06:41 AM

what i have always been told tho, (by kent cams and piper cams) that with the standard TB and a really wild cam the car would be terrible, really rough ect, but they said with ITB;s you can run virtualy a race cam and still be ok for road use.

steve

ose30

07-01-2007, 04:42 AM

Yes S14 does indeed have ITB's BUT:

1. It has 0,5 (0,7 in EVO sport) liter larger capacity than bog standard M42

320IS S14 is just under 2.0L and has ITB's. It produces 193hp. I suppose S14 block is more or less M10 block, so only the head is "special" stuff.

dino245

07-03-2007, 12:36 PM

Here are the ITB,s that I will be using for my set up. I was going to use the Hayabusa set up but after much thought I chose to get some Euro E36 M3 ITB,s like the ones Tim_s has and make them work on my engine. It was a good decision I think.

nickmpower

07-03-2007, 12:55 PM

MAF or MAP?

Alpine003

07-03-2007, 01:04 PM

I was going to use the Hayabusa set up but after much thought I chose to get some Euro E36 M3 ITB,s like the ones Tim_s has and make them work on my engine. It was a good decision I think.

Care to expand your reasoning?

dino245

07-03-2007, 02:16 PM

Although I have been preaching the use of MAF's I think I will be switching over to MAP. I have realized that the Haltech system was designed as a MAP based system so the load grid and fuel grids are designed around this.

I chose not to use the Hayabusa stuff because it looked less than stock. I am all about form following function but when you open the hood of a modified car and it looks stock, that is a big deal to me. Its more ego than anything. Ironicly if I had not gotten the adapter made and just went for the Euro stuff it would have been cheaper for me. I paid 775 for the adapter and 100 for the throttle bodies and 150 for the trumpets. I then paid 550 for the throttle bodies shipped form Germany and 150 for the plenum shipped from Germany and 75 for the factory ceramic spacers that go under the trottle bodies. All in US currency. So I live and learn.

The next step is the carbon fiber plenum. I will keep yall up to date as I make progress.

Boyracer

07-03-2007, 05:01 PM

Cool photos and plan Dino! I think that is the way to do the ITB setup :)

General problem with bike ITB's is the throttle plate angle which is larger than in M3 ITB's. This means small throttle opening on bike ITB's will increase air going to cylinders very fast, not ideal.

Boyracer

07-03-2007, 05:58 PM

Dino, can you measure the intake runner dimensions of those ITB's? It would be very interesting to know how closely they match M42 intake port size and shape and if there is need for adapter :eek:

tim_s

07-03-2007, 06:46 PM

nice one! Guess what's fallen into my lap recently? Bagged myself another free set of TBs :)
Don't know when I'll get around to using them again, been there done that with ITBs and happy with a single TB for what I'm using the car for at the moment. Tempted to build some as a trackday special though! what kind of plenum are you going to make?

steve321

07-04-2007, 05:51 AM

will it work with the trumpets cos there the the as i had to start with,
(on an E30 it may be different) but the trumpets where usless on my with M3 evo ITB's cos they just hit the alternator

its quite close see, cos the angle of the inlet ports on the head is different to the M3 heads, http://i34.photobucket.com/albums/d117/stevemitchell321/PICT0010b.jpg

idealy i would of thort an easy plenum design would be this

http://i34.photobucket.com/albums/d117/stevemitchell321/enginein3.jpg
http://i34.photobucket.com/albums/d117/stevemitchell321/enginein2.jpg

steve

steve321

07-04-2007, 05:54 AM

you can see in the pics that the itbs on the m3 are pointing up in the up (so the curved trumpets fit ok) but on my M42 the itb point (almost perfectly) sideway,

steve

tim_s

07-04-2007, 06:58 AM

steve, i think the zoom motorsport plenum is rubbish - unequal length runners, and the 'plenum' bit isn't really acting as one. must lose loads of power. yours is much better, as was my old one!
the trumpets don't work on the e30 either. the e30 has less room to play with than yours mate.

dino245

07-04-2007, 12:17 PM

As for the plenum, I want to duplicate the the stock e36m3 set. I had wanted to reposition the alternator so that I can install an oil cooler, but that is a project in its self. I will be making the plenum from carbon composite and use the stock trumpets. The length of the runner through the trumpets and through the throttle body is about 12 inches, which is long but this is the correct leght acording to the pipemax software I am using to design the header and the old Hayabusa set up lenght.

By using the stock stuff it will look clean and be more reliable. The added benifit with moving the alternator to the location of the old A/C compressor is a lower CG, HA HA.

Alpine003

07-05-2007, 12:23 AM

I applaud your efforts on the ITB's. I hope you can find the proper tune to make these work good.

dino245

07-05-2007, 09:29 AM

Haltech standalone.

AL GReeNeRy

07-07-2007, 04:12 AM

how about incorporating this with a maf upgrade or possibly reusing the stock afm.

http://store.666fabrication.com/m42-short-runner-intake-manifo.html

luigginator

01-04-2008, 12:36 PM

hey boy im new here and i have a e36 318is stock but i dont know what to do with it i want to run fastttt!!!! waht i shut do????????

haledj

01-04-2008, 01:06 PM

hey boy im new here and i have a e36 318is stock but i dont know what to do with it i want to run fastttt!!!! waht i shut do????????

Start by making your own thread in the member profiles section; tell us about yourself, your car, and what you want from your car.

Also, please use real words.

Welcome!

Febi Guibo

01-04-2008, 02:02 PM

actually, can we get an update etc where everybody is at with this?

over at bf.c, gizmo318i has a pic of his euro S5x based itb setup... and there's a rumor of a dbilas kit for sale somewhere near me, I think...

anyway, any ITB updates please post! thx!!

haledj

01-04-2008, 02:29 PM

I am trying to get a ITB project started. I want to run 2 banks of injectors, one right at the ports and one right after the throttle bodies. I need to figure out what sportbikes use throttle bodies that are not one piece, but come apart like these (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=160193394255&rd=1).
Original equipment EFI systems are configured to meet very stringent emission regulations and to provide "soft" driveability characteristics. Positioning the injector as close to the inlet valve is beneficial in this respect. Maximum power however, is usually obtained by moving the injector away from the inlet valve, some racing engine manufacturers going as far as to mount the injector high in the velocity stack and others installing two injectors, designed to operate at different RPM. When TWM designed the throttle bodies our engineers were not in favor of having high pressure fuel on the atmosphere side of the throttle plate, although this could have resulted in some power increase. We compromised by mounting the injector as far from the cylinder head as possible while still maintaining the safety afforded by keeping the fuel downstream of the butterfly.

swiss318is

01-07-2008, 10:53 AM

why you dont use something like that?? direct bolt on for the 318is e30/e36! they also have the enginemanagement and the maps.
http://i244.photobucket.com/albums/gg19/swiss318is/db10010005.jpg

hoevesruperd

01-07-2008, 11:05 AM

actually, can we get an update etc where everybody is at with this?

i had posted a thread a few weeks ago about a set of M3 itbs i had found. i'm still in the research and development phase. i decided to take my time with this. i'll prep the car this summer (complete new paint, suspension overhaul and other maintenance and mods) then by december 2008 i will be ready to start working on an M42B21 ITB that hopefully will be dropped in by summer 2009.

the goal is to have a reliable 100hp/liter stroker by the time i finish university
this thread will be very helpful. as Febi said, any updates on your projects will be appreciated

hoevesruperd

01-07-2008, 11:12 AM

why you dont use something like that?? direct bolt on for the 318is e30/e36! they also have the enginemanagement and the maps.
http://i244.photobucket.com/albums/gg19/swiss318is/db10010005.jpg

for those interested
http://www.dbilas.de/dbilas_eng/index.htm
1453 euros seems a bit pricey tho.
throttle bodies from GSXR can be found on ebay under 300$, then the adapter has to be machined. i'm sure someone you know knows someone that works in a machine shop so it should be too pricey, or get it machined at your university's faculty of engineering. then the airbox can be made out of fiberglass insted of carbon fiber i guess by building a mold and laying down the fiber. (which IMO is one of the interesting parts, to make different prototypes and see how to tune the plenum and runners)
then the engine management being megasquirt
the total is probably under 1500
what are you guys thinking?