damm you have alot of free time on your hands......make me some custom 4-1 headers w/a 3.5' collector.....hahahhahahhahaha good Sh.T

 

Warning: serious reply here!!

Hi. I might be of some help to you if you are trying to build your own ITBs. I run a Lotus Super Seven with a 1600cc Ford xflow motor. for induction, I use the Dual Webber DCOE sidedraft carbs. This is basically just like ITBs, except no fuel injectors. it uses 4 separate butterflies; my engine runs the DCOE 40 carbs; that is, 40 mm throats. The engine was dynoed and broken in on an engine dyno, and produces about 150 hp. The engine builder told me that the 40 mm throats are good to 175 hp or so. The next step up is 45 mm throats; these are suitable for 2 liter engines up to 230 hp. The biggest size I have heard of any of the Lotus guys running is the 48 mm; these are good for 280 hp engines!

I think that 50 mm would be too large for you; look at 40 to 45 mm throats.

hope that helped some...

Todd

 

Once the BBS on theoldone.com comes back up, you'll be able to find some very in-depth conversations about this topic. I'd watch for that to come back up then do a search over there. Then post if you still have questions.

 

HAhahahhahahahahha yea I'm waiting for the header also..

 

hahha oMG, yes i got an idea for ma FINAL for art class! hahahhahah

 

Good stuff man, you got some skills. Next thing you know, there will be aftermarket paper performance parts.

 

So for 250whp 50mm would be on the small side.

 

46mm is stock on E30 M3's, and they are rated new at 195 hp. 2.3L 4 banger. Just throwing in more info.

Warren

 

Awesome, thanks for the input.

So I guess it would be safe to assume you are speaking of WHP. I'm expecting maybe 200fwhp.

The idea would be to use small enough throats to keep some airspeed for the low end torque, but big enough to provide more than enough volume at the high rpms. There's a little happy medium in there.

I think 45mms would probably be a little easier to work with.

 

Hello again.

My engine was dynoed on an engine dyno; not a chassis dyno, so it was flywheel horsepower....

I agree that 45 mm would probably be best for you to look at....

A friend of mine has an E30 M3 with the stroker kit (2.5 liter) head work, and custom cams. It makes in the neighbor hood of 275 horsepower (flywheel). He is still using the stock ITBs (46 mm per Warren). Don't think you will be needing the 50mm units....

The smaller throats will give you better low end response and less "off cam" feel. The trick is to size them correctly so as not to hurt your top end, and to also not seriously affect your bottom end...

good luck and keep us abreast of developments!

Todd

 

I'm rolling....

 

Hummmm

RX7 Club is laughing at us....
http://www.rx7club.com/forum/showthr...threadid=48646

 

haha..don't pay any attention to them..they are just a bunch of post ******.

They are just laughing at the carboard IM and LSD


[Modified by martini, 6:09 PM 1/27/2002]

 

i thought about using the poor mans itbs i found a couple sets of carbs 40-50mm weber, solex, mikuni but the intake manifold is 340 from twm and also you run in limp mode do to the tps sensor not being there but all you have to do is advance the timing to get it back properly timed i still might go this route for my d16 it might be fun or it might be a nightmare who the hell knows the carbs would be hard as hell to drive on the streets poor as mpg but it would sure scream up top but the cold winters here would be hell are hell on carbs from what ive experienced but i still might go that route.
thanks
chris

 

hahhahahahaha ...who makes it Rota? haahhaha

 

bahahaha!

 

that is some of the funniest thing i have seen, i almost poo poo

 

The stroker kit is nice, but it's insanely expensive

The EVO3 version of the E30 M3 had 48mm itb's and I think it put out right around 225 hp @ the flywheel. So there may be some more top end power to be had if you friend went to 48's, but again $$$.

Warren

 

Hi Warren.

I recall that he sent the motor to California somewhere (or parts of it). I think final assembly of most parts and tuning of car was done at ERT (maybe)?

total cost somewhere in the neighborhood of $15k or so.

its a nice car...

Todd

PS i crush him at the Glen in my Seven. its a battle of cornering vs straightaway speed. he will pull 30-40 lenghts each straightaway section; i pull more in the corners!!!

 

here is my idea on my turbo zc

i was going to use 4 hf crx tb on a modified 89 teg manifold.

how does f/i effect the use of multi tb set ups?

and what size are the hf TBs?

 

I've got dual DCOE40 Weber sidedrafts on my built CRX as well, So I have some comments:

People that comment on the "loss of low-end power" usually don't even have ITB setups, or are still driving them like they would any other car. You can't just stomp the throttle and expect to go, instead you have to feed into the throttle rapidly without killing the intake velocity. It takes some practice, but it works, once you're rolling, it doesn't matter.

For displacements under 1.8L, 40mm throats are plenty, to use anything larger effectively you need a wild cam grind.

As for the open element filter, use mesh backed foam, or the throats WILL suck them into the engine once they get dirtied much at all. I made a fiberglass backing plate to use with an airbox I also fabricated to use a remote filter.

Also, when you go with a forced induction method, you cancel out the gains of ITB's, might as well use a Skunk or Venom manifold.

 

1stgen: you say you have to feed the throttle..I can live with that, it isn't a street car. And it doesn't matter when rolling? Even better...in that case, it should work well with the hondata full throttle shift?

my displacement will be slightly above 1.8l. So I still haven't decided what size I'm going to get. I may try and find 45mms, and if they don't work, I'll just sell the whole thing to my buddy with the CRVTEC integra. And build myself another set.

As for the filtering system. I don't yet have the ***** to run it open air...So it will be filtered for the time being. I haven't figured out what I'm going to do yet. I know that just a foam filter will get sucked in. I'd like to stay away from foam elements if at all possible. I'm also planning on cuting the fiberglass front end up to put a hood scoop in. I have a ton of extra fireproof fiberglass left over. Perhaps an airbox is in order? Perhaps even make one out of some sheetmetal.

I dunno, it's all still in the planning stage. But the more and more I look at it. The easier it seems like it would be.

I've been thinking about how I'm going to link together the throttle rotors. I would like to change the rotational ratio for more sensativity. And I would like it to be adjustable...in case I'm off a little in my initial linkage lengths....but that may not be a good way to go, because there is always the chance it will become "uncalibrated".

so there are a few things yet to figure out.

 

How much of the stock manifold do you plan on retaining? I would definately want to have equal-length runners to go with the ITB's.

 

so how bad would they be on the street because if i go through with this crazy *** idea it still will be driven everyday? and also what about the tps sensor and ecu going into limp mode how can this be avoided with carbs?
thanks
chris

 

Hello again.

if you are talking about using the DCOE carbs for street use; I'd try to talk you out of it....

Again, my Lotus is 1600 cc and has the DCOE Webber 40 carbs on it. It was proffessionally set up and dyno tuned (exhaust gas pyro sensors on each exhaust outlet, etc.). It runs very well. The car weighs 1100 lbs and engine makes around 150 hp. Carefull street driving (shifting around 3500 to 4000 rpm) gives me between 14 and 16 mpg. Race track mileage (very hard driving shifting around 7500 rpm) gives about 8 to 9 mpg.

Cold starting the engine is tough, when temps are below 40 degrees. I usually have to use starting fluid. These carbs don't have chokes on them, and the cold start valves are not connected. You need to be careful when starting, because it is easy to flood the motor and then the spark plugs need to be removed, cleaned, and dried.

I would never consider changing my street/track driven Honda over to carbs; way too many concessions made. It would be fine for a track only car, but I think you would not enjoy street driving it every day....

just my opinion....

Todd

PS I think that the ITB fuel injection setup would be better than the carbs because you could run different programs, etc.