STP sensors and throttle bodies

[Tiger Racing]

Hi all,
Our team is running with a Suzuki GSXR 600. It has a throttle position sensor and a secondary throttle position sensor for each respective throttle body. To only run one throttle body, how do you wire the STP sensor to still have it work correctly??

[Kirk Feldkamp]

You can't use the blades in the original throttle bodies. Read through the restrictor rules again and you'll see why. You can, however, use the body itself if you'd like. You can pull out the blades (and shafts) and plug any resulting holes. If you want to use the same actual sensors on the throttle body (or bodies) you end up with, that's OK... but you may find other sensors easier to integrate to your new throttle(s).

-Kirk

[Smeller]

If you have the budget, this is an easy solution, it includes the restrictor..

Formula Student - 28mm Single Bore Throttle Body[/URL] http://atpowershop.co.uk/catal...ttle-body-p-101.html (http://atpowershop.co.uk/catalog/formula-student-24mm-single-bore-throttle-body-p-101.html)

[jd74914]

Why do you need to have the second TPS present? Are you going to try to keep the stock fuel injection?

[Tiger Racing]

I dont need the second tps present. Im trying to eliminate it from the wiring but I dont know how the ECM will respond if I remove it. Also I would like to wire the secondary injectors to the primary ones from the ECM. This is my first time doing this and im in ME so electrical isnt my strongsuit lol. Input is appreciated.

[Tiger Racing]

Kirk why cant I use the original blades in the throttle body? I dont really get it from the rules.

[Kirk Feldkamp]

The rules state (on page 45 of the 2012 rules):
B8.6.1 In order to limit the power capability from the engine, a single circular restrictor must be placed in the intake system between the throttle and the engine and all engine airflow must pass through the restrictor.

...and also...
B8.6.2 Any device that has the ability to throttle the engine downstream of the restrictor is prohibited.

In other words, unless you've got some previously unknown method to collect four throttles that are bolted directly to the head and pass them through a single 19mm or 20mm restrictor, then you're going to have to think of another way to do it. http://fsae.com/groupee_common/emoticons/icon_wink.gif

The irony of the path you're about to go down is that it's really unnecessary considering the stated purpose. If the restrictor sat in front of the throttles, it would do the same exact thing, but there are a number of other "lessons" and "puzzles" that The Powers That Be feel are worthwhile, and so they keep them. You can thank the rules committee and their conservative approach to governance for that one. It's better to accept it and just move forward as you're not about to get any rules changed. Trust me, I know. http://fsae.com/groupee_common/emoticons/icon_smile.gif

-Kirk

[jd74914]

Originally posted by LSU Tiger Racing:
I dont need the second tps present. Im trying to eliminate it from the wiring but I dont know how the ECM will respond if I remove it. Also I would like to wire the secondary injectors to the primary ones from the ECM. This is my first time doing this and im in ME so electrical isnt my strongsuit lol. Input is appreciated.

OK, I'm not sure you understood my original question. From this statement, it looks like you are planning on using the stock ECU. You cannot wire the two injectors together; as designed, the stock ECU commands each stage of injection separately. If it all possible, you really want to put together an aftermarket controller. The stock ECU is more or less untunable (unless you are able to unlock it), which renders it untenable for our application.

Don't take this the wrong way, but it sounds like you need to do a lot more research into engine controls. You do not need to be an EE to understand how everything works; in fact, as an ME you are probably better off when working with engine systems.

[Tiger Racing]

Oh ok Kirk I understand what your saying and no im not using the stock throttlebodies. We already have one ready to go on. I was confused on wording but yes im not using the stock ones but using just one before the restrictor.

Jim, I understand how the ECU controls the two sets of injectors seperately and I figured I couldnt wire them together for that exact reason I was just brainstorming a few ideas. I just dont know how to keep the two sets of injectors wired as they are stock while only having one throttlebody instead of the stock two. Also,why I would need to make an aftermarket ECU except for cutting out a few unneeded circuits? Im running powercommander to tune and im pretty sure it tunes fine on the stock ECU.

[Cardriverx]

The stock ECU is not going to be able to compensate the huge changes that a 20mm restrictor and a custom intake cause to the engine. You are seriously very better off going with some sort of standalone ECU with just a single set of injectors. Look up megasquirt.



Originally posted by LSU Tiger Racing:
Oh ok Kirk I understand what your saying and no im not using the stock throttlebodies. We already have one ready to go on. I was confused on wording but yes im not using the stock ones but using just one before the restrictor.

Jim, I understand how the ECU controls the two sets of injectors seperately and I figured I couldnt wire them together for that exact reason I was just brainstorming a few ideas. I just dont know how to keep the two sets of injectors wired as they are stock while only having one throttlebody instead of the stock two. Also,why I would need to make an aftermarket ECU except for cutting out a few unneeded circuits? Im running powercommander to tune and im pretty sure it tunes fine on the stock ECU.

[Tiger Racing]

Ok cool thanks ill do some research on it and see what I can come up with

[Gruntguru]

Originally posted by Kirk Feldkamp:
The irony of the path you're about to go down is that it's really unnecessary considering the stated purpose. If the restrictor sat in front of the throttles, it would do the same exact thing, but there are a number of other "lessons" and "puzzles" that The Powers That Be feel are worthwhile, and so they keep them. You can thank the rules committee and their conservative approach to governance for that one. It's better to accept it and just move forward as you're not about to get any rules changed. Trust me, I know. http://fsae.com/groupee_common/emoticons/icon_smile.gif

-Kirk
A restrictor with downstream throttling would create the possibility of inserting a large plenum between restrictor and throttle, enabling short term power capability in excess of the steady-state restricted liimit.