Quad Throttle Bodies

[Bluetech]

vac feed, theres an interesting problem too. I've spotted some Quads using nipples off each throttle body running into a vacume canister for the map sensor. Could the brake boost be taken from there too??? or require another device?

[NAspirated]

Originally Posted by Bluetech

vac feed, theres an interesting problem too. I've spotted some Quads using nipples off each throttle body running into a vacume canister for the map sensor. Could the brake boost be taken from there too??? or require another device?

the vacuum for the booster comes of one of the runners. its nothing special as it doesnt need to be.

yes, the vacuum is taken from every runner and joined to a single line running to a vac canister, which is connected to the ecu.

[4 TTL]

Originally Posted by Bluetech

vac feed, theres an interesting problem too. I've spotted some Quads using nipples off each throttle body running into a vacume canister for the map sensor. Could the brake boost be taken from there too??? or require another device?

If you're gonna try it yourself, it becomes trial and error. If you buy a kit then it's up to what they've produced. I've been running 4AGE ITBs for ages, and finally starts, runs, and goes... Just running one balance pipe between ITBs and off to the booster. No vacuum problems, just retuned std ecu with SAFC, and now, Power FC.

[gtierrr]

GTI-R's and levins come with them standard. it does increase fuel consumption but then again f set up right can do wicked wonders. i ran a set on my 2.0ltr NA pulsar, and ran gti-r quads with a link computer, nt only did it sound awesome but ran wicked too

[boott]

the toyota ones on blach tops have a vacum feed off the manifold milled in right as it bolts onto the head which all joins to one then to a canister but looks to be made so they are rellativly even lengths. and the maifold also has a feed out for the brake booster. you could put that all into your own set up as you would have to bake up some sort of system to make them fit a honda head.

doesnt the length from one end of your trumpets on the quads to the valves have to be in some relation a similar length to something on the exaust side? true or faulse?

[rpm]

They will use way more fuel. More power out requires more fuel in at the most basic level. ( all other things equal ) Theres no reason why they should damage the engine if done correctly as stated before. The biggest thing is making sure all the other items required are upto it, esp fueling. It would be nice to change cams at the same time to take advantage of all that extra air. As always it will require lots of dyno tuning to get maximum benefit.

[SiR-Gee]

Originally Posted by boott

doesnt the length from one end of your trumpets on the quads to the valves have to be in some relation a similar length to something on the exaust side? true or faulse?

The lengths of runners in an intake system affect the torque curve, longer ones will give more torque down low, short ones will give more up top.

[rpm]

Your talking about intake resonance tuning. Where by the length of the runner is selected so that the positive longitudinal pressure wave set up in the runners hits the intake valve when its open at a certain rpm. I think there is a upper and lower limit. Essentially where it is too short or too long but between the two the are gains to be made. They dont spend millions researching the the standard ones for nothing.

As far as I know there isnt any direct relationship from the intake to exhaust. Other than you want max pressure on intake valve opening and max scavenging when the exhaust opens. Having said that you dont want your intake charge flying out the exhaust tho, ie to much overlap.

Obivously the timing of this with respect to the piston going up and down is very important also.

[FLYRYD]

i have read.....

that the ITB's will generally lose torque at low RPM because of the short runners on the intake.

and

you generally gain between 20-30hp from ITB's with tuning.

[tysonzane]

I also read on a site, that short runners = more top end torque and power

But longer runners = low down torque

[SiR-Gee]

Originally Posted by rpm

Your talking about intake resonance tuning.

Surely am, when the intake valve opens, air is sucked through at a decent speed, the valve closes, and the velocity in the runner will cause air to pressurize itself against the valve and send a positive pressure wave back towards the open end of the runner (low pressure), when it hits the open end it reflects and inverts itself causing a low pressure wave to come back down the runner and hit the closed valve reflecting itself again (since the valve is closed it does not invert) which runs up to the open end again, where it is reflected and inverted (open end) and sends a high pressure wave back down towartds the intake valve, if the valve opens just before this pressure wave hits again it will fill the cylinders with a nice charge of pressurized air, some people say can be between 2psi to 7psi depending on how well the system is designed. The only problem is as the engine speeds up, the duration that valve is closed shortens, and those pressure charges can only move at the speed of sound, so as soon as this is out of sync, all this resonance will have a negative effect on cylinder filling (unfortunatley). And the high pressure waves will only last over a VERY narrow rev range.

This is how "tuned" runners work

Not trying to show off or anything

[boott]

so really the different length throuts wil create different tourque curves and power curves does anyone know the upper and lower limits of the lenghts?
as ive seen toyota with them almost bolted straight to the block they had them that short.

[SiR-Gee]

The lengths are different depending on the time the valve is closed, the wave has to travel up the length about 4 times, and travels at about 1300ft sec, for high rpms (7000 - 10000rpm) your looking at about 9" (inluding port) whereas right down in the rev range (2000rpm) it can get much longer, usually when the are built for low revs its at about 4000rpm, and they usually need the runners to curve around the manifold to get that extra length.

[SiR-Gee]

Also note: a lot of manifolds arent tuned for these resonations, they are just a way for air to come into the engine, and since the resonations can create a negative effect when not in the narrow rpm range, a lot of manufacturers avoid these types of manifolds, and try to limit the resonating.

[rpm]

i believe thats what the little resonance "bottles" or enclosures that hang of the intake pipes are for. Limiting resonance and sound ( mostly induction noise )

[ek9pwr]

ask dad if i can borrow his btcc honda ????

[4 TTL]

Holy thread revival, batman....

Bit late for 2nd thoughts Dallas.

[Beans]

I have a pretty well worked Nissan SR20VE engine that should make approx 240 - 250hp at the crank according to the engine builder. Been given the opportunity to get some ITBs for it... these are available in 45mm & 48mm. I would look to get a custom plenum made up & still use the MAF though I can run MAP with my ECU if really necessary.

Here are some pics, I would be interested to know what those of you with ITB experience think as we Nissan folks don't have any real experience. Not really interested in running them if they are going to create a heap of problems.

[Sleepy]

N..I..S..S..A..N. What is this Nissan?






Lol, Anyway get them even if just for baller points

[Beans]

LOL... I was wondering if I would get hit with the Nissan thing!

I figure us NA fans have to stick together - we all get hassled by the forced induction peeps for doing things the hard way!