For those with ITB's (Lip, Cheetah,Christian, others) , I am aware that some of you run vacuum log canisters to provide sufficient vacuum for a motor with such a conversion.

How do you go about sizing the vacuum canister in accordancer to engine size, fuel management system, throttle body size, etc etc.

Cheetah mentioned the GSR IAB box being a perfect candidate for the job, but ive seen pictures from Christian's (h-t username) set up and his log is longer.

Is there a guide for whats too small or whats too big?

 

Maybe that vacoum block that GE makes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J2turbo21 &raquo;</TD></TR><TR><TD CLASS="quote">Maybe that vacoum block that GE makes.</TD></TR></TABLE>

i thought that was more for turbo users to clean up a few vacuum lines instead of using a bunch of tees.

what are you guys like cheetah running on chipped ecu's and afc's?


Modified by JaeOne3345 at 11:19 PM 6/6/2003

 

i would also love someone to share some info on this. Not asking for a free handout but just helpfull insite would be great.

 

Yeah, I was curious how Cheetah was running the vacuum on his car and still being able to run fine off an ECU with the afc....

 

i tried running diffrent vacume log's and never got good enough vacume out of them. it's extreemly hard to tune itb's off vacume, expecialy since every thing after 1/4 throttle there was no vacume.

 

We also tried to use a canister for our race car but we were not succesfull. We were running vtec eliminators so we didnt have very much vaccum to begin with. We eventuall turned off the map sensor on our stand alone unit and used the tps only. If you are unable to pull enough vaccum for your map and brake booster both you could always use an electric vaccum pump to run your brakes and use the canister for your map only. just a thought

 

I have TWM itb's on my allmotor nonvtec. I just run all 4 of the vacuum lines together( T'ed) one goes to my map and the other to my brake booster. As far as tuning, I have tec2 ems and i dont have any prob. at all on my tune up.

 

I thought some of the itb set ups came with a vacuum canister?

 

WE justed capped of the nipples on each runnner and were using TPS to run the car. WE also didn't have a brake booster.

 

thanks for the replies guys

in essence (here me out, it may sound stupid), the honda ecu is made to run with the amount of vacuum that a normal honda intake manifold creates correct?

well if this is so, if you found the volume capacity of the intake manifold, and you made your vacuum log have a similar capacity, it should work a bit better no?

im curious because OER sports injection from japan has basically "bolt on" kits that people claim can run off the stock ecu. i have pics of the manifold and the manual from katman. one way uses all sensors including iacv with a vacuum block and theres an option vacuum log configuration, no idea on what size it needs to be. perhaps i should attempt to contact OER in japan.

thanks for any more help guys.

 

i ended up reprograming my stock ecu to run off the tps insted of the map sensor.

 

but on a street car, isnt map good for changing in load?

 

bump

 

jay the guys at the shop really enjoy your towley avatar. i think they want to make him our new mascot.

 

max, its Jared (Flipwon).

LOL..towelie says "you wanna get high?" "thats my last j *******"

 

I would be kinda tough to run straight TPS with a race car...you have to make the distinction tho.

Suprdave

Edit: I meant street car...


Modified by Suprdave at 8:40 AM 6/11/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JaeOne3345 &raquo;</TD></TR><TR><TD CLASS="quote">well if this is so, if you found the volume capacity of the intake manifold, and you made your vacuum log have a similar capacity, it should work a bit better no?

im curious because OER sports injection from japan has basically "bolt on" kits that people claim can run off the stock ecu. i have pics of the manifold and the manual from katman. one way uses all sensors including iacv with a vacuum block and theres an option vacuum log configuration, no idea on what size it needs to be. perhaps i should attempt to contact OER in japan.

thanks for any more help guys.</TD></TR></TABLE>

Hook up the pics!! I wanna see how this thing is set up with the log and running all sensors. I get what you're saying about making the canister close to manifold capacity, but I think the problem would be that there just wouldn't be enough vacuum to keep it steady, some say that the logs "surge" at partial throttle due to inadecuate vacuum. But I'm a ITB newb so I'm just throwing out ideas here, feel free to give it to me.

 

anymore help?

 

if you run off the tps you wont be able to account for the changing load the engine sees in different gears (this is what cheetah has said from his own experience). if you go to a MAF setup using aem ems or similar its alot easier to tune but the most cost effective is still to try nd get the map to work.

im sure you already know this though since ive seen you in the older ITB posts

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rolow &raquo;</TD></TR><TR><TD CLASS="quote">I thought some of the itb set ups came with a vacuum canister?</TD></TR></TABLE>
I am assuming he is doing DIY ITBs.

ttt, good thread.

 

my "log" is at the top of the firewall. 4 itb vaccum lines and one brake booster all to one canister. I'll see if i can find a better shot of the T'ing off the sensor...but the DFI did the rest after that





found them

 

Lip, im most gracious for those pics, thank you very much.

So you are running the dfi system. the dfi system only takes the tps into account right? do you have any experience running different management systems prior to the DFI with the itb's? thanks.

 

Also, is there such a thing as too big of a vacuum canister?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jeff C &raquo;</TD></TR><TR><TD CLASS="quote">Also, is there such a thing as too big of a vacuum canister?</TD></TR></TABLE>

ive talked to one person who said the vacuum seemed to "lag" when running a log with zdyne. so im curious on this as well. man im really waiting for yoshikatu to fill us all in. he says hes got all the answers for drivability with hondata, something import builders did not. (im sorry but not being able to floor it under 5k without problems isnt really streetable to me).

cheetah has custom programs made to runon itb, and seems like a very helpful guy. maybe one of his customers can give us some insight.