Quad Throttle FAQ

[shiroitenshi]

I guess everyone here is limited in the technical know-how of quad throttle, myself included but maybe there's one here that know a bit of each so can accumulate and help discuss the theory behind quads.

So if you came here thinking I'm posting quad throttle info.. sorry you got mislead.

My first question is, if anyone of you has an idea so I can research more on them, is:

The vaccuum log:

Yes, I'm still stuck at this stage, which is why the ITB at the shop is still lying around, so now you know why I didn't call you yet, v8nutter.. :P

One concern I have is about the volume/size of the vaccuum log needed.

At this stage, I know only that the vaccuum log is the replacement (of sorts) for the plenum so speed density setups (using MAP sensor) can get a reading off it.

So far, I've discussed this with one of the SSracing fellas in regard to their AE86 quad throttle which seems to use quite a large sized vaccuum log.

It would seem to me that the sizes affect the vaccuum reading of it from what little information I got from him.

So, how do we actually know the requirements of the vaccuum log sizing?

Try until we get it right, or is there some obsure formula to calculate the needed size?

The lack of an idle valve is also a hinderance for a car that want to retain A/C, though I'm thinking we can actually mount that on the vaccuum log.. (I think)

 

[V8_nutter]

I know some of the ppl here knows how ITB works,,but they dont allowed by thier sifu to reveal much:shades_smile: .

Basically to get a smooth powerband, you have to make map to read smoothly. The reason why some ITB is rough on power delivery bcoz thier map goes crazy onto reading the "pressure". There is no correct size on vacuum, it all depends on the suction pressure that ITB produce,,to stabilize with air/fuel ratio.

Once you get the stabilize power delivery with "almost" smooth idling, that is the correct size.:regular_smile:

 

[V8_nutter]

From the compression test,,,get each cylinder reading first. Then tap the most highest reading with the most reading. For example 252, 255, 260, 248,,,so it will goes 252 paired with 248 to get the smoothest powerband.

 

[chris2000]

Run Hondata and tune with TPS, i think will solve alot of problem. hehe.. Never tried yet, just gues only

 

[J101]

a very good question shiroi.

i never thought u would ask abt this. i asked myself abt the optimum sizing for the vacumm log and indeed theres none. for a start you can copy OERs (japan) or GOLDEN EAGLE (usa). OERs are cylinderish and GOLDEN EAGLE are boxy. the latter model from BLOX are nicer actually.

if you notice the log is to share all the vacuum connection that needs to connect like brakes, FPR, ITBS, NOS and etc. frm there you can tap a vacuum meter or get a reading from your EMS on what sort of vacuum do you need. there is a threshold of level where itbs needs to be at optimum level.

you can run both MAP and TPS sensor on the quads. MAP gives airflow readings to find the correct fuel mixture. TPS tells the ecu where the pedal is to give an idea of if the car is crusing or at full throttle and needs max power. as i mentioned to chris, in the future i would run tps maps on the hondata as it would be accurate since tps dun melt hoses and the volume of air is always fluctuating.

the best way to run aircon is to put 2 holes into the adapter and run a FICD to help you out. quads are meant for racing, but then again u need aircon for daily driving..haha.

im no sifu in this, just that its done and history.

The vaccuum log:

Yes, I'm still stuck at this stage, which is why the ITB at the shop is still lying around, so now you know why I didn't call you yet, v8nutter.. :P

One concern I have is about the volume/size of the vaccuum log needed.

At this stage, I know only that the vaccuum log is the replacement (of sorts) for the plenum so speed density setups (using MAP sensor) can get a reading off it.

So far, I've discussed this with one of the SSracing fellas in regard to their AE86 quad throttle which seems to use quite a large sized vaccuum log.

It would seem to me that the sizes affect the vaccuum reading of it from what little information I got from him.

So, how do we actually know the requirements of the vaccuum log sizing?

Try until we get it right, or is there some obsure formula to calculate the needed size?

The lack of an idle valve is also a hinderance for a car that want to retain A/C, though I'm thinking we can actually mount that on the vaccuum log.. (I think)

 

[V8_nutter]

Run TPS on standard marking and begin with sorting the MAP first. After getting the correct pressure then only meddling with TPS.

 

[shiroitenshi]

Run TPS on standard marking and begin with sorting the MAP first. After getting the correct pressure then only meddling with TPS.

Ok.. will try that.. thanks v8_nutter.

J101, yeah..
got the Golden Eagle Vaccuum log already.. so just use that enough?

I'm asking because it just seems so weird that the local ones I usually see are quite big, then comes the GE ones that quite tiny in comparison..

hmm.. must look for adapters.. and prolly find some way of attaching the idle valve from the plenum.. or must we use FICD from a nissan or something? Aren't they the same? Or does the nissan one have provisions for a hose attachment? Any particular model you used?

 

[J101]

yeah i reckoned its enough.

when u say local ones, u mean malaysia or japan? got any pix u wanna show me how this local one looks like?

actually if u have a aftermarket plenum then its not nice to drill a hole i mean just drive it without aircon :p but if ure willing to drill then its ok.

u can use the nissan or the toyota ones for your personal r&d. i was using denso, rm250 a piece.

J101, yeah..
got the Golden Eagle Vaccuum log already.. so just use that enough?

I'm asking because it just seems so weird that the local ones I usually see are quite big, then comes the GE ones that quite tiny in comparison..

hmm.. must look for adapters.. and prolly find some way of attaching the idle valve from the plenum.. or must we use FICD from a nissan or something? Aren't they the same? Or does the nissan one have provisions for a hose attachment? Any particular model you used?

 

[shiroitenshi]

yeah i reckoned its enough.

when u say local ones, u mean malaysia or japan? got any pix u wanna show me how this local one looks like?

actually if u have a aftermarket plenum then its not nice to drill a hole i mean just drive it without aircon :p but if ure willing to drill then its ok.

u can use the nissan or the toyota ones for your personal r&d. i was using denso, rm250 a piece.

no picture.. but if you want to take a look, it's in an AE86 that I saw down at SS racing.. with apexi livery.. I think they removed the stickers already though. Bloody huge vacuum log.. got a shock when I saw it.

Thank for the hint on the FICD.. will try when I have time to go about it.