Individual Throttle Body tech

[mikuni]

^ the spacing isn't really ideal and even though they are cheap, it would be a bit of a hassle finding 4 maximas wouldn't it? Also the throttle linkages and sorting tps is more difficult with those. Still good to have another option though.

maybe facelift and prefacelift are different? the entry on the face lift ones have a longer taper from what ive seen, so exit possibly different also ?

Possibly. I had a look at the throttle tonight and its definitely not perfectly round. I'll try and get a pic after this. Hopefully it will show it. Not that it really matters, but just for interests sake.

Not sure what to do with the throttles now. Resining them up and then tidying them up and port matching then to a custom in take might be an option. I got them for a good price and that little bit of effort will mean I still have an extra couple of mm on the intake side, which will be good for higher rpm. Or, maybe I should just sell them and get some early silvertop ones for ease.

[R100]

Theres always at least 4 Maximas at pick-a-part at one given time. The throats on them are about 5mm apart. Another throttle body to try is the Mazda Sentia V6 Its a twin throttle like the Maxima but the throats are more like 10mm apart.

All depends how much room you have to play with. On a 1UZ they work great but unsure how they would go on a 6cylinder in regards to spacing etc.

[Brock-Lee]

Look about perfect for the paired ports of a non crossflow head

keen

[mark105]

probably better again than what R100 suggests is the RB26 ones as they are the same, a straight round 45mm one but you can usually pick them up with the linkages and TPS, just a matter of dropping one of them off for a 4 cyl which is as easy as un bolting an arm.

they look like this

could be difficult finding some one who would part with them though, i picked mine up for $250.

[Spencer]

now thats what I was getting at! seems like a pretty reasonable option.

Doesn't seem that reasonable! seems ok for the UZ for space requirements but on a 4cly it would make for a pretty gay manifold. The whole idea for going throttles for me is to have a sweet intake manifold with a straight taper shot to the port and so you can tune intake resonance. For around ~$100 you could get the aforementioned CBR1000 throttles, you wouldn't have to make a throttle linkage, the spacing is better and it has a TPS & injectors mounted in the throttles. If the CBR spacing doesn't suit I sold my last set of silver top throttles for $80 which you can space to your head with abit of tweaking. Guess it also depends what size you need, biggest bike throttles are 43mm, you pretty much need after market ones over 45mm

Yeah, the facelift Silvertop engines go a lot better because the manifold is nicer, so it would make sense if the throttles were slightly different.

Brendan from Garage Dori/Niteparts told me that the silvertop throttles are better when I was starting the Beams conversion because they are a better shape:

I would def use silvertop 42mm throttles, these will flow 280ish hp with standard throttle shafts- so no restriction there really. Much better shape than blacktop with the kidney backs that stall flow.

.....

Standard cams & adj cam wheels are a good way to go, will be more forgiving wen it comes to extactor design too. A good friend of mine just made 240hp@wheels with exactly those mods & silvertop throttles!! Power was still going at 9000rpm! The dyno reads a little more than the one I use, but it still works out to about the same power as mine was.

Don't get me wrong Brendan is a super GC, but Glenn has the dyno plots of a stock beams making more power everywhere when going to blacktop throttles. More power everywhere again on 48mm throttles and slightly more top end with a bottom end drop off on 50mm throttles and he's pretty much the beams master. The silvertop throttle has less cross sectional area than the beams port, so you have to taper/step down to the port which goes against convention of good manifold design (even though factory they are choked like this). Its not a big deal but if you were chasing every HP I'd be looking at something bigger

[mikuni]

Spence, do you know, or can you find out what Glenn did with the blacktop throttles when fitting them, whether he filled in the kidney shape or just ran with it? I'd imagine a bit of a stall rpm range on a dyno with them tbh.

Another thing you could probably help with - outboard injection. What is the likely hood that the car will run okish with outboard ONLY. Are you looking at doing this with the bike carbs or trying to run 8 injectors?

My car is only a track car, so sub 3000rpm drivability isn't important (the worse the better imo) but obviously mid range is important, would conventional injectors be required for this? I'm not too worried about a minor loss in power, just don't want a massive dead spot till 5500 then a powerband of 2krpm.

Main reason for doing this, staging injection is difficult and getting an ecu that does it, costly. A simple MS2, or G4 Atom could easily run outboards for about $600 or $1500 respectively, but to step up to 8 staged injectors would start at a G4 Xtreme for something around the $2800 mark (until MS3 is sorted), which I just wouldn't be able to bring myself to buying, fullstop (rather take a few months of the mortgage etc).

[Brock-Lee]

outboard only, would you just end up with alot of fuel not going into intake, ie below certain intake velocity it would just fill engine bay with fuel vapour?

How far outboard does injection ideally want to be? or is it just outside throttle plate and be done with it?

[/heaps of q's]

[Testament]

outboard only, would you just end up with alot of fuel not going into intake, ie below certain intake velocity it would just fill engine bay with fuel vapour?

How far outboard does injection ideally want to be? or is it just outside throttle plate and be done with it?

[/heaps of q's]

would be ok if the injectors were in a closed airbox or something. but also in that case enclosed airbox = bomb box?

[mikuni]

Fuel fogging is a problem with outboard injection. Usually the injector bosses are on the trumpets and spray directly into the throttle body. This gets around it but with high overlap cams comes the next problem, where at lower engine speeds some air "bounces" back out the intake and causes a similar issue.

I think with a simple setup it wouldn't be causing to many problems in this respect, I'm just more concerned about being able to even run the thing. I'm going to be ultra cheap and try and get the engine running intially on the original ecu, using the engines TPS on the side of the quad throttles and I was also thinking about using the engines original fuel rail as an outboard only setup and just seeing what happens. The airbox would be the standard toyota 20 valve one and I would put the AFM on this, so the ecu would still see the same air flow. These engines are sequential injection, so at least it would be fueling ok for outboard, just not sure whether it would start or not. Maybe tow start it to get the revs up, or put in a super crazy starter motor that spins it up to 2000rpm or so?

And just back to the problems with outboards, I don't know if anyone watches F1 but in practice 3 (I think it was) Mark Webbers car stalled on track from an airbox fire that starved the oxygen from the engine and cut it out instantly. So, even F1 tech still struggles with these problems.

[Spencer]

You will pretty much loose power with outboards only, even the best setups Ive seen still run 10-20% inboards at high rpm. F1 cars are only allowed to run one injector so they go full outboard, but the revs they run, the awesomeness of there intake design and the quality of there injectors and ECU lets them get away with it. Your car still will be running over a 4000rpm rev range on the track with your normal gearbox etc. You will loose heaps of drive-ability without blending in the outboard injectors. Also if you have the choice move the first set of injectors up the runners, and get some of those ones from those bike carbs like i had, the spray pattern on the new style injectors is awesome.

MS3 is your minimum to run that setup and will set you back less than a atom (or about the same). Its not as nice as the Xtreme, but it will do VVti (not that you need it) and it will do 8 sequential injectors in a staged fashion. I am yet to play with the software and see how the blending map works but there was a thread on the msefi forum to get it added to the MS3 code. Only thing limiting the MS3 for us is that they aren't opening up the code this time for people develop niche bits of the code like the staged injection, so it could be a dog in its current form. I'll look into it, originally it was just there to stage in big injectors for turbo cars, so it wasn't ideal. You can almost do staged properly on the MS2 with 4 drivers, the code needs some tweaks and its out of my league

Glenn used different manifolds for each throttle setup so its not exactly a controlled experiment but that would be impossible with there different shapes. As far as I can remember he used the TRD manifold for the blacktops which would've been matched, and his custom manifolds for the 48's and 50's. Most of the gains could've well been in his manifold picking up the HP. But it doesn't take a rocket scientist to see that a throttle smaller than your port isn't a good place to start. You could actually blend a blacktop throttle to the shape to the beams port quite well, but its still to small. But hey his manifolds and throttles are upward of 2k so 20v throttles are a good start.

Wall of text!

[mikuni]

You will pretty much loose power with outboards only, even the best setups Ive seen still run 10-20% inboards at high rpm. F1 cars are only allowed to run one injector so they go full outboard, but the revs they run, the awesomeness of there intake design and the quality of there injectors and ECU lets them get away with it. Your car still will be running over a 4000rpm rev range on the track with your normal gearbox etc. You will loose heaps of drive-ability without blending in the outboard injectors. Also if you have the choice move the first set of injectors up the runners, and get some of those ones from those bike carbs like i had, the spray pattern on the new style injectors is awesome.

It won't lose power at higher rpm though. The main reason I'm thinking about this so soon is because it would make the intake manifold so much easier to make. I'm not doing it to try and chase figures at the moment, rather ease and cost of doing everything. If it will technically work, or even if it might work, I'm keen to try it. The throttle linkage spins around and creates the same problem as I had on my Chevette engine where you either have to make a long manifold, or turn the throttles upside down, which I don't want to do because of space problems both below and to the rear (firewall side) of the throttles. I should be able to build a tidy little intake manfiold and put the fuel rail and injectors inside the airbox though.

To get the fueling right on a standard ecu I've been reading that you can trim it a little just by using an adjustable fuel pressure regulator. Maybe worth a try?

Can't compare my engine stuff to F1 at 18,000rpm, its an entirely different concept, but I'm sure the super touring engines didn't have staged injection? The manifolds I was looking at last night didn't have scope for injectors near the head, nor a fuel rail, only one in the air box going into the trumpets.

Pretty sure spence will be getting angry with my logic when reading this thread "just buy an ms3" etc

[Testament]

does anyone even have an Ms3 yet? just do it on Ms1 and run it like single point injection for ultimate haggardness/to piss spence off.

[Truenotch]

Also, is it possible to run outboards on an ECU with fewer drivers? a.k.a G4 storm... I realise they would have to be batched to work - is that why they won't work?

[Spencer]

^ you can get away with it if it will run them semi sequential, batch will end up with epic fogging issues. I'm very unsure the software will allow you to stage between 2 pairs of injector drivers

Brad you will loose power at high rpm because you wont be getting the fuel in the engine. Everyone has fogging issues, so at WOT high RPM you will only be able to supply 80% of the engine required fuel and the rest will stand off in the plenum and burn your car down. The fogging down low would be insane, most people are at say 70% inboard because of fogging at low RPM's. Super tourers were only allowed one injector also, they get away with it by having meke injectors with special spray patterns and awesomely timed injection (ie $$$ ECU and tuning). Ever watched a video of how sweet timed outboard injection looks? On a f1 car at idle at ~7k rpm you can see each injector pulsing at the correct time. We have fogging issues because we try and spray fuel into a intake while we have reversion pulses coming up the intake. The tuning time they spend on the dyno timing the injection firing events to balance this out must be amazing, or some clever cunt probably has an algorithm for this. Its something we can't achieve, possibly with a motec and 6 months dyno time. So having inboards is our compromise.

Anyway in short, you will probably burn your car down trying purely outboard injection without at least a decent ECU,

[mikuni]

Pretty sure spence will be getting angry with my logic when reading this thread "just buy an ms3" etc

Success!

The injectors from out of the XE are interesting. Different to the usual generic Bosch ones I've seen in most of the other engines I've played with. Still top feed rather than side feed, but theu have a different nozzle on them. Might research and see how crap they are.

[sentra]

what is the purpouse of outboard injection besides it looking ultra cool?

[EURON8]

Anybody got drawings of the ITBS with measurements of bolt hole spacings etc?

Probably be more acurrate than eyeing up the hole centres with a ruler

[Spencer]

what is the purpouse of outboard injection besides it looking ultra cool?

Better fuel atomisation, also a cooling effect from the fuel, its seen on just about every serious NA race car that allows it. Its easy HP if you have the ECU to run it

[sentra]

bad ass

[Truenotch]

Pic stolen from Toyspeed.