Author Topic: ITB's info/projects (Read 147045 times)

kowalski · « **Reply #30 on:** June 07, 2007, 10:56:20 AM »

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.

Boyracer · « **Reply #31 on:** June 07, 2007, 12:13:33 PM »

Quote from: kowalski;27307

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

m44power · « **Reply #32 on:** June 09, 2007, 08:03:26 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 · « **Reply #33 on:** June 09, 2007, 04:40:52 PM »

You must mean this

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

Alpine003 · « **Reply #34 on:** June 10, 2007, 12:34:18 AM »

Quote from: m44power;27450

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 · « **Reply #35 on:** June 10, 2007, 05:21:47 AM »

Quote from: Alpine003;27495

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 · « **Reply #36 on:** June 30, 2007, 05:41:29 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
________
LUPUS ADVICE

ose30 · « **Reply #37 on:** July 01, 2007, 03:42:58 AM »

Quote

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 · « **Reply #38 on:** July 03, 2007, 11:36:27 AM »

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 · « **Reply #39 on:** July 03, 2007, 11:55:42 AM »

MAF or MAP?

Alpine003 · « **Reply #40 on:** July 03, 2007, 12:04:25 PM »

Quote from: dino245;28998

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 · « **Reply #41 on:** July 03, 2007, 01:16:44 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 · « **Reply #42 on:** July 03, 2007, 04:01:03 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 · « **Reply #43 on:** July 03, 2007, 04:58:07 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 · « **Reply #44 on:** July 03, 2007, 05:46:00 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?