8 Throttle Body Intake

[svsgt1]

I was talking with Tony Milla at 1uzquadcam.co.nz about his 8 throttle body setup for the 1UZ. He said the fuel rails can be used but must be reversed and that the lugs need to be re-welded for this to fit. Probably not to bad but definitely not a bolt on item. He also said that a central vacuum tank should be used to accommodate the lose of the vacuum lines that once connected to the intake manifold. Does anyone have any idea what a central vacuum tank is, how it works, and what it hooks up to?



Also, has anyone actually installed this kit? If so could you give me some advice on how easy/hard the install was or if it is worth the time and money.



Also, are there other companies that make an individual throttle body kit for the 1UZ? Any first hand experience with any of them?



Thanks guys,

Adam

 

[Zuffen]

The way the standard manifold is set up is that all cylindes breath out of a common plenum. By doing this there is an adaquate supply of vacuum to operate the brakes etc.

When you use ITB's you need to connect each TB to the brakes to give the vacuum required.

A central vacuum tank could be an alloy tube (say) 25mm/1" in diameter with ends welded into it to make an airtight tank. If you had 8 x 6mm/1/4" pipes welded into it so you could hook each TB to a pipe with a hose you would have created a resevoir of vacuum.

By adding a 9th pipe you can then attach it to the brake resevoir giving you the vacuum you need. A 10th pipe could be used to feed the other vacuum devices needed.

I would think a 50mm x 200mm tank would fit in the valley and work well.

Nothing is ever a simple bolt on item with these engines. Remember we're all pioneers in some way with the 1UZ.

 

[svsgt1]

Wll I don't have power brakes or power steering so do I even need a vacuum tank? I have a couple of lines that run from the manifold to other parts of the car. Like I have a really small tube that when unplugged makes the car run very rich, so I'm assuming this is the vacuum line that tells the LINK ecu how much vacuum there is. There are some other larger tubes that hook-up near the throttle body, but I have no idea what they are. Any advice would be great. Thanks guys.

 

[MacroP]

Wll I don't have power brakes or power steering so do I even need a vacuum tank? I have a couple of lines that run from the manifold to other parts of the car. Like I have a really small tube that when unplugged makes the car run very rich, so I'm assuming this is the vacuum line that tells the LINK ecu how much vacuum there is. There are some other larger tubes that hook-up near the throttle body, but I have no idea what they are. Any advice would be great. Thanks guys.

If you dont have vacuum assisted brakes or PS then I guess you wouldn't need a vacuum tank at all. What vehicle are we talking about here?. It's been a few decades since vehicles had no vacuum braking or is this a racecar of some sort?

 

[svsgt1]

yeah its a race car of some sort. Actually its a street version of a Saker SVS. It is light enough with a mid engine that you don't need/want power steering or brakes. But what are the vacuum lines for that I currently have on my car? Aren't they used by the ecu as ONE OF THE MANY parameters to tell the fuel injectors how much fuel to give?

Adam

 

[Peewee]

You will need at least ONE vacuum line, for the MAP sensor the link uses to guage the amount of air in the motor.
Whether you can run this off just ONE throttle body, and not a collection of all 8, I don't know.

When I go ITB's I plan to use an electric pump for the brake booster vacuum and other things.
Still not 100% sure about the MAP sensor line though.

 

[cribbj]

Peewee nailed it, and you'd probably want a "plenum" type tank that would take an average of all 8 cylinders, otherwise the pulsations from a single cylinder would drive your ECU (and the injectors) nuts.

Alternately, instead of the MAP, you might be able to use a TB position sensor for load input to the ECU. Some ITB vendors offer their setups both ways, and IIRC one has an advantage over the other depending on the application. Have a look at the Jenvey, TWM Induction, and Redline sites. There's some good reading.

John

 

[Peewee]

The advantage you speak of, is that on high lift cams, there is very little vacuum at idle. So its hard for a MAP sensor to guage how much air is being injested.
Most ecu's get around this by saying, if the throttle position is less than x% (around 3%), then it defaults to a specific fuel map, irrespective of MAP.
Once the throttle is open though, you'll want to use MAP all the time.

You are correct though, you can tune in TPS only, but it wouldn't be as nice to drive, or as efficient.

 

[Wobbz]

Or, run your 8 throttles, with a fibreglass/CF plenum over the top, with 2 big filters feeding into the plenum.

Then you have no such problems with vacuum

This is most likely what I will be doing with my 8 throttle conversion (VH45... the 1uz's competition)... I also plan to fire my injectors down the trumpets (there is no way I would run without filters, that is insanity in perth... too much dust).

I'll be using GTR throttles most likely!

Do you think they're large enough?

 

[Peewee]

Yes, easy large enough.

But with the large plenum, you wont get to see them, and I'm still not 100% sure if that will solve the vacuum reading issues.

 

[SCV8]

Some factory carb manifolds used a small (6mm) dia runner joining the intakes downstream of the throttles for signals to distributors etc.

 

[Pro]

the central tank is a great idea - it doesn't even have to be part of the motor. it could easily be mounted anywhere in the engine bay and have all your ECU vaccuum lines and booster line run off the tank.

 

[Anaema]

why not have a local plenum and have the throttle bodies inside the intake runners? instead of having the throttle bodies be intake runners.

 

[rarson]

Or, run your 8 throttles, with a fibreglass/CF plenum over the top, with 2 big filters feeding into the plenum.

Then you have no such problems with vacuum

How do you figure? If the plenum is before the throttle bodies, it won't ever see vacuum.

The easiest way to deal with the vacuum situation, and it's really not that hard, is to just tap a source off of each runner, to a separate container. Then you could even mount the MAP right off of that. Anything that needs vacuum gets hooked to the "vacuum canister" (that's what I decided to call it ).

 

[slyalfa]

I few things with ITB's
one. do not use MAP. use TPS the MAP is not usable in most cases.
two. tune them for the right length and size

now for vac for somthing like the powerbreaks. If you look at somthing like a alfa 4cyl with ITBs
they ran a port only into one cyl. the one close to breakbooster. The thing does not need much and this system was used by alfa for many many years with no problems.
now for easy idle again I think I would go to the 4cyl alfa as that part seem to work all the time and no one have problems with bank sync like other setups do.
on idle you close the buterflys all the way if one bank has any air going at all you adjust the bank to bank linkage untill all are sealed. then on the other side of the butterfly there is a small port drilled with a nipple for each. then you run 4 1/4 tubes to a 5way spliter (9way in the case of a v8) the extra port goes to a valve then to the air cleaner. you adjust the valve for idle speed.

if you look at the alfa you can see where they come together. the big port goes to the air cleaner. it unscrews and is funnel shaped. there is a 'O' ring inside and as you screw in the big nipple it pushes the 'O' ring down the funnel making the hole smaler. there is one more small port that went to a PCV like system.
I tryed hooking a MAP to the part but the readings are useless. The ports get strange reading as it air goes by them at hi RPMS like a venturi in carburetor.

also the ITB runner length on the alfa is in the air/filter box. with the airbox off I lose like 20hp
as the runners would be way to short with out the airbox

 

[SCV8]

Alfas use a mechanical injection system, not like electronic systems where map sensors can be used to help the ecu.
The signal will be choppy on an individual runner, but if a common bypass circuit is created, bypass needle valves can be added to help balance out the throttles. This tends to help maintain a tune for longer than just adjusting the throttles, and also provides a port for a more steady signal.
Look at 70s Ferrari,Fiat factory carb manifolds, on the street cars anyways.

Race cams will require tuning with TPS only, but the map can be neat if you have the patience to tune for it.

 

[slyalfa]

yea that has mechanical injection system. I am working on adding a servo system to it will be controled by the ECU I made.(I am one of the hardware guys that did VEMS) just waiting to get a 2nd pump I can use to to make the parts. I am driving this car right now. The A//F MAP is a 3dcam that is a PITA to change.
but ther is some things that the mechanical injection can do that a normal electric injector can not do.
so I kept it but as soon as I refit it so the ECU can control it I will get the benifits of both.
as for using MAP on ITBs I have seen a lot of different setup and so far all have had to go TPS.
I think the venturi effect on the ports have a lot to do with it. I have not seen a Ferrari done yet.
but someone is doing a Fiat, so the next time I talk to him I will ask how he set it up.
I think at idle the map can be used OK on a lot of them but as soon as the butterfly opens then it get strange.
Also most of the ports are very close to the butterfly as there is no space to get it any farther back. so the flow by a party closed butterfly makes for strange flows in or out of the port.

 

[SCV8]

Yep, lots of variables, I knew a guy who was into Alfas awhile back who had modified the pump by lengthening the connecting rods inside, and a bunch of other stuff. I would like to hear more about the servo setup you're working on, sounds interesting.
I can't remember, but doesn't the Spica intake use a small runner connecting each intake runner for balance?
Or do they use individual bypass screws?
Been a good while since I've tuned one of those, all of our more recent cars had Webers, and that's been a while...

 

[Damien]

I'm in the process of fitting ITB's to my Soarer whihc has been a big learning exercise so far. I bought a set of throttle bodies from CarbonTech about 18 months ago which are the kind that bolt to the lower portion of the standard intake manifold. Initially they wouldn't seal properly resulting in an idle of 1800RPM after lots of fiddling so I sent them to EFI Hardware to have then basically rebuilt (they now have the casts but have improved the design).

Now I get idle around 800-1000rpm which is much better but the vacuum that my MAP-ECU sees is only about half what it should be so it's using values from the fule table that would normally be part throttle so there's way too much fuel going in resulting in rough idle and smelly exhaust. After seeing the pics of the Alfa and GTR intakes on here I think it's because I'm only using 3mm ID tubing so it's restricting how much vacuum can be seen at the collector tank.

So next I'll order some larger pneumatic fittings (5 or 6mm ID) and see how that goes.

OEM throttlebodies like what Tony Miller has put together makes a lot of sense as the quality of workmanship will be very high. I did look at Tony's but thought that making an airbox for filtered air would be more difficult with that design... If I had my time again I'd be doing more investigation before deciding what to go for.

 

[SCV8]

I haven't seen a soarer with the ITBs yet, sounds like a cool project.
I recall seeing the Carbontech setup a couple years ago, and suspected that it used the original runners. I was amazed at how much power it made on a mildly prepped motor, wasn't it around 400 or so?

That is when I began to think about a better plenum.