THSCC Forums

Okay, so I'm thinking of getting really ambitious and build and independent throttle body (ITB) setup for the Spyder. Anyone here ever done this?

The 1ZZ shared by the last Celica and the Spyder has a plastic intake. The injectors go directly in the cylinder head rather than the intake like many setups. There's one big throttle body on the outside of the intake and a mass air flow (MAF) sensor outside of that.

The PowerFC ECU that I'm using only knows how to talk to MAF sensors and not mass air pressure (MAP) sensors, which are typical of ITB setups. So my plan is to put a plenum on the outside of the ITBs and put a MAF sensor on the intake side of the plenum (and a filter outside of that). The throttle bodies would be something appropriately sized from a motorcycle engine. Hayabusa throttle bodies look to be popular for doing this, but I think they may be larger in terms of what they can flow than my intake ports. Obviously larger is better than smaller, but should larger really be much of a problem?

I don't think I have the room to do independent filters even if I did switch to MAP (apparently it *is* possible to make a conversion circuit and setup the PowerFC for MAP, but I don't have details on that at the moment). Anyway, anyone done anything like this? Any tips to share?


--Donnie

Ahhh one of my favorite subjects. Im no expert but I am currently going down this road and I have done a fair amount of research.

First off dude, ditch the Power FC. Talk about overpriced and undersupported. Unless you are buddies (which you may be) with a authorized HK$ F-Con dealer you cant do jack squat with the Power FC. Im not an expert on Toyota standalone EMS's but there HAS to be something better more flexible.

Some tuners are big on the plenum, some say its a bad thing to run a plenum. Most that I have seen ditch the stock AFM/MAF for a good ole' MAP sensor.

There is a guy on Miata.net (screen name ElyasWolf) who has a motorbike ITB adapted to his 1.8 Miata. There are a TON of ITB (or IRTB over there) threads on Miata.net.

Im using the kit from http://www.fuji-racing.com/



Im not using their piggyback Subcon ECU, I have built a Megasquirt I V3.0 EMS. I tried to get the Megasquirt in and run it at Greenville but ran into some unrelated snags (getting married 1,000 miles away is a bitch).

I hope to have the 'Squirt and ITB's in sometime this year. The stuff has been gathering dust in my shop.

Keep us updated!

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02 Focus SVT
STF 9

Not to snag the thread, but how was building up the MegaSquirt? It really looks like the way to go for a handbuilt setup. Pretty cheap to.

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RedLanternRacing, builders of the fastest cars in last place.
Success is not an option.
1981 Scirocco, "Vera"

I think since you're planning on using a collector, using oversized throttle bodies probably isn't that big of a deal. I think you would be better off erring on the side of too large vs too small.

I agree with Ryan, there are probably better alternatives to the PowerFC. If you really want to stay with it, you might be able to adapt this to get rid of the MAF: http://www.maftpro.com . Although, I think you would be really pushing it, when trying to "tune" two different boxes.

This is another project on my list of things to try with the 240. Others have done it, using the Suzuki ITBs and haven't seen any real gains, so it's not high on my list. Although I think they made mistakes in other areas, like not changing cam timing to help gain high rpm hp.

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In need of car.

On a slightly related note, would there be any gains by switching to a MAP setup over the MAF setup? I believe with the MAP setup, you can get away with sticking the air filter right on the end of the throttle body and not have an intake pipe.

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In need of car.

Ahhh my second favorite topic behind ITB's

It can be pretty cheap if you assemble it yourself. I got mine from DIYAutotune.com and highly recomend them. Everything comes in little "baggies" that are labled what exactly they are, and their spot on the board.

As hard as it may seem, I have a degree in electronics and am no stranger to a soldering iron. So assembly wasnt too bad. Some of the Transistors are kinda small, they were a PITA to not bridge the leads with solder. The MegaManual lays out step by step on how to build it and test it in steps. I think it took me the better part of 6 hours for assembly.

The MegaTune software is pretty neat, and pretty easy to use. There are a TON of parameters to set and adjust. There is virtually nothing you cant control with this EMS.

If money is tight, assemble it yourself. If not, just buy a prebuilt unit.

Helpful hints:

-Dont depend on the MSEFI.com web board as your sole support network. They are kind strange over there. If you do ask questions, BE SPECIFIC. Try and find gurus that have it installed in YOUR car. They are a better resouce.
-BUY THE DAMN STIMULATOR!!! It makes testing SOOOO much easier. I have one and anyone is welcome to borrow it.
-Take your TIME, its all very tedious
-Beware resitor #9 on the stim, it gets HOTTT

Ok, someone wanna talk about cams next? That's my 3rd favorite thing that I want to try

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02 Focus SVT
STF 9

Alright, thread hijacker...

I researched Megasquirt but in all the searching and reading I did, I couldn't find anyone that had done it on a 1ZZ. I also couldn't find a definitive answer on support for VVT control (seemed like a few had done it, but no info on how other than it seemed really hacky). I also couldn't find details on support for Coil-on-plug (COP), which my car has.

So great-local-implementer-of-megasquirt-as-well-as-thread-hijacker, what do you know about those issues? I'm also an electronics guy and not afraid to build a megasquirt and give that a go if it will do what I want. In my ideal world I'd find a source for the Toyota harness connectors so I could switch back and forth, but that's a different issue entirely.

To get back on topic a little, looks like Suzuki throttle bodies are the ones of choice for this because they will come apart from one another into singles so you can get the spacing right for your engine. Honda, in particular, appears to build them in pairs such that you can't do that. Shame. I've got a friend drawing the intake port side of the 1ZZ in CAD so he can use his CNC plasma cutter to cut a plate to mate to the head which we'll then fabricate and weld the tubes to that the TB's will sit on. The intake holes are rectangular with curved corners, so once he draws them I'll have him give me exact dimensions so I can figure what size throttle body I need. I think GSXR 600 TB's may be "more than enough".


--Donnie

Oh, and Jason, what were folks expecting to "see" as a result of going ITB? I don't think you can expect much on the dyno...it's more about throttle response.


--Donnie

That's Mr. Thread Hijacker to you pal!



Ewww forgot about VVT. The 'Squirt has a shift light feature that can trigger the VVT. However, I dont think Toyota made things quite that simple did it? Is the VVT simply engaged by a solenoid (ala VTAK)?

COP? I think that one is pretty simple. All you need is a trigger to the coil right? Sorta like a MSD DIS6?



www.boomslang.us That guy can get ANYTHING.



The GSXR TB's are the weapon of choice for the homebrew ITB guys on Miata.net.

You might wanna give FujiRacing a shout. I bet they have a kit for your car in Japan. That's all he is doing is importing them.

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02 Focus SVT
STF 9

I'm not sure what they were expecting to see, they just all seemed to be disappointed in the response to his. I personally would like to see some improvement in the upper rpm range, where my engine falls flat on it's face. Other than that, he did comment on how well it responded compared to the stock setup. He also used the megasquirt to power it.

I just found his dyno #'s and he dyno'd less than I have. I know that doesn't mean much unless you're comparing results from the same day/location... The important thing I get from his dyno, is that he still has a significant drop in HP/torque towards the top.

If I were looking at the megasquirt, I'd give the microsquirt a good look. I think it has all of the functionality of the megasquirt in a nice fully assembled surface mount version. http://www.microsquirt.info/
I think it's also about 1/3 of the size of the mega version.

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In need of car.

The Microsquirt is still not available AFAIK.

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02 Focus SVT
STF 9

<insert bad joke about Brokeback Autocross here>


--Donnie

You really need some new material...

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02 Focus SVT
STF 9

Nope, that's never gonna get old.

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In need of car.

Megasquirt, eh? Spent a good bit of time with it myself in the Mazdaspeed Protege. A couple things, since I spent quite a good bit of time tuning cars for a living: MAP over MAF, every time. Unless you're willing to spend 3 or 4 times the amount of time to tune, go MAP. No questions asked. There are just way too fewer things to bother with. Its only downfalls are: It's very sensitive to vacuum leaks, and if you make additional modifications, you need to re-tune.

The megasquirt definetly CAN control Coil-on-plug ignition, that's what the V3.0 board is all about. It first came out with the MS II daughter board, but has been fully implemented on the new V3 board. It's pretty cool. If the cam advance crap is actually just actuated by a solenoid then it'd be very, very easy to set up the shift light for it to trigger that solenoid.

Megasquirt is fantastically easy to tune, as long as you have someone get you started IN PERSON. Lots of stuff is very confusing at first, but once you get that little bit started, you're off to the races. Example: My protege made 280 whp at 16psi, on 93 octane gas. That was a street tune. The stock turbo kit on mazdaspeed proteges make around 135whp at 8psi. I was impressed.

If anyone needs help tuning things, especially megasquirt, gimme a holler. I might not be the best resource for building it (too much of a PITA for me) , but I'll certainly lend a hand with tuning and wiring. Best of luck if you go that route!

-Matt