Dear all,

After researching the net and went to a race shop yesterday to check out my new longblock, I have been told an ITB will result to brake power lost. Tuner said something about the line from the horn to somewhere but I wasnt paying much attention, please if someone can verify me with this issue and why?

maybe it runs vacuum from the intake manifold i thought? so IF i'm not using brake booster then i think problem solved? or? hmm


Modified by sinister6 at 7:53 PM 4/18/2005

 

bump

 

bump! someone got to have a solution,

 

da prob mean u will not have an outlet to supply vaccume for the brake booster

i cant see that being right, or if it were, i would chose another setup

 

ugh? another setup?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">I have been told an ITB will result to brake power lost.</TD></TR></TABLE>

Whoever said this really doesn't know what the hell they're talking about. Yes the brake booster normally gets vacuum from the intake manifold, but no, removing it isn't a good idea. Instead, run a slightly large vacuum line from each runner (after the throttle body) either to a vacuum canister with a large line going to the brake booster, or tee the lines together and run a single large line to the brake booster.

 

most of the time people make a place for vacuum to accumulate, im in the process of fabing a itb set up my self, the brakes will work fine, ur system will need a vacuum log or canister of some sort

 

thanks for infos.
So I just connect a vaccum line from all 4 TB and T them together to one big line and connect it to the booster?

and what about the canister thing? Im building my 16A top 18C1 bottom. Im now holding back my ITB (from a toyota AE101) for the braking issue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">So I just connect a vaccum line from all 4 TB and T them together to one big line and connect it to the booster?</TD></TR></TABLE>

That's one way of doing it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">and what about the canister thing?</TD></TR></TABLE>

That's another way of doing it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">Im now holding back my ITB (from a toyota AE101) for the braking issue.</TD></TR></TABLE>

If there are no suitable vacuum ports, whip out a drill and a tap and make some.

 

Oh.. ok, i think drill 4 holes and a couple T joints is easier for me to work with,
thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ridexstraight &raquo;</TD></TR><TR><TD CLASS="quote">the brakes will work fine, ur system will need a vacuum log or canister of some sort</TD></TR></TABLE>
do this. you'll be happy. and if you're running something other than programmable engine management like AEM's EMS, you can use your MAP sensor on the log too.

 

i had no problems with brakes except after a full throttle run(oh the irony)

but i blame that on a faulty check valev in line with the mast cylinder...if it worked right it should hold enough vaccume for at least 2 full pums before it empties out .

i run 2 vac cannisters ...one small for map(more accurate reading with no interferance from other sources) and a large one for the brakes fpr and what ever else is needed

 

say, how well is your car tuned, machine? i was wonder what kind of gas mileage to expect if i attempted this. i'd love to, but economy for different people (i think because of poor tuning) ranges from 15mpg to over 30mpg.

 

i only had them on the h22 for a few days and considering i bea the crap outta it it was good...but there going on the f20b this weekend if i get my brake set up done

i will let every one knwo

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">Whoever said this really doesn't know what the hell they're talking about. </TD></TR></TABLE>

I disagree. Every ITB engine I have tuned exhibited much less overall vacuum than a multi-runner plenum. Even though you connect all four ports to a vacuum canister, you still have to deal with vacuum at idle of around 11"-12", and closed throttle deceleration at around 17"-18". A stock Honda will idle around 21", with closed throttle deceleration at around 24"-26" vacuum.

You will notice a loss in power assist if your booster is a vacuum actuated diaphragm.

 

ugh, now im start confusing again, so Im having my Power FC+commander and a ITB(modified AE101) sitting in my garage, im sill wondering how to proceed to get them installed.

My car is filled with 1st gen CRV MC/booster and 4040 prop valve. I still dont completely understand what 2 canister thingy means, any pictures can inspire me with the setups?

seems there is lots of trouble with the brake system. ugh..my tuner is out of town and will be back in a month, so..i dont know which route i should go for..

thanks for all the info guys

 

https://honda-tech.com/zerothread?id=947796

check out this guys write up, its helped me figure out some things

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jim Truett &raquo;</TD></TR><TR><TD CLASS="quote">I disagree. Every ITB engine I have tuned exhibited much less overall vacuum than a multi-runner plenum. Even though you connect all four ports to a vacuum canister, you still have to deal with vacuum at idle of around 11"-12", and closed throttle deceleration at around 17"-18". A stock Honda will idle around 21", with closed throttle deceleration at around 24"-26" vacuum.

You will notice a loss in power assist if your booster is a vacuum actuated diaphragm. </TD></TR></TABLE>

My biggest argument here is that the brake booster doesn't require nearly as much vacuum as most people have been led to believe. Most of the early DIY ITB setups were running vacuum off of a single runner and still didn't experience any noticable loss in power assist. Most of the newer setups are running vacuum to the brake booster off of all 4 runners (to maintain equal vacuum in the cylinders) and are pulling even stronger vacuum than the early setups. I don't have an exact figure of how much vacuum it takes for the brake booster to be fully effective, but I do know that what it gets from a stock manifold is overkill (from what I figure is an intentional move by Honda just to be on the safe side).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">

My biggest argument here is that the brake booster doesn't require nearly as much vacuum as most people have been led to believe. Most of the early DIY ITB setups were running vacuum off of a single runner and still didn't experience any noticable loss in power assist. Most of the newer setups are running vacuum to the brake booster off of all 4 runners (to maintain equal vacuum in the cylinders) and are pulling even stronger vacuum than the early setups. I don't have an exact figure of how much vacuum it takes for the brake booster to be fully effective, but I do know that what it gets from a stock manifold is overkill (from what I figure is an intentional move by Honda just to be on the safe side).</TD></TR></TABLE>

I guess it's just me, but I treat any loss in braking power as a significant issue. Yes there is a power loss. Maybe not so much with the larger Integra/ABS booster, but on the small (8" I believe) booster you will notice a loss in assist.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jim Truett &raquo;</TD></TR><TR><TD CLASS="quote">Maybe not so much with the larger Integra/ABS booster, but on the small (8" I believe) booster you will notice a loss in assist.</TD></TR></TABLE>

Again I'm going to have to disagree. I've put together quite a few ITB setups and all but 2 of them have gone on cars with the smaller booster. Even with the single runner setup, no noticable loss in assist. In the last setup I did (using the smaller brake booster) the brakes actually felt better, but it was a fully prepped track car (my daily driver at the time) and I pulled about 40 lbs out of the front of the car during the ITB install.

Here's the link to the write-up:
https://honda-tech.com/zerothread?id=1149532

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jim Truett &raquo;</TD></TR><TR><TD CLASS="quote">

I disagree. Every ITB engine I have tuned exhibited much less overall vacuum than a multi-runner plenum. Even though you connect all four ports to a vacuum canister, you still have to deal with vacuum at idle of around 11"-12", and closed throttle deceleration at around 17"-18". A stock Honda will idle around 21", with closed throttle deceleration at around 24"-26" vacuum.

You will notice a loss in power assist if your booster is a vacuum actuated diaphragm. </TD></TR></TABLE>


i have video of my vac guage reading up to -30hg on decel and -20 to -25 at idle ...
and that running 1 and 4 to my MAP cannister and 2 and 3 gopign to a larger one for brakes and fpr

 

sorry i lied ..the most i saw under decel was about -22
but it did idle at -20

 

Is it possible to upload the video? thanks.

Im still a bit confuse about the setup about the canister thing

 

i use 2 vac canisters...a smaller one for the MAP senor only ..it runs from cylinders 1 and 4

i run a larger one for every thing else i need to run ...i thikn i used 1 1/4x2 for the mad and 1 1/4x 4 or 5 for the larger one ...

the larger one runs off cylinders 2 and 3
ill try to get it up ..i dotn have the one of the idel anymore but im putting my motor in this weekend so by next week i can have new vids up

the reason i used the smaller one for the MAP is cause i didnt want any interuption from the other sources ..plus by keepeing it smaller i was able (or so my theroy goes)to have a faster acting sensor due to not as much volume ...if it was too big i didnt want it to "lag behine" at all .......seemed to work pretty good but didnt have time last year to do a lot of tests ...

 

Im running Golden Ealge vacuum manifold for the brake booster.