[Hodgdon Extreme]

EDIT: This thread began with me asking what throttle body options are out there for a FFIM conversion using the GTE upper manifold but it morphed into me covering the particulars of the GTE FFIM conversion and overall update of the powertrain.

EDIT 2: After beginning the project, a new product from Dodo Racing became available that makes it easy to mate the GTE upper plenum to the GE head... So the thread changed into an overall make-over of my already-turbocharged IS. New ECU, harness and lots of new features that make a huge improvement over the ancient Haltech.

EDIT 3: Changed thread title from "GTE FFIM Conversion" to "GE-VVTi Makeover" to more accurately describe the nature of the thread.

Before: Toyomoto-built Haltech E6K in parallel with stock ECU, stand-alone PLX devices wideband (not connected to Haltech), stand-alone Greddy Profec E01 boost controller (also not connected to Haltech). Therre was some kind of little "black box" doing something inside the ECU compartment, some kind of MSD thingie attached to an MSD Dis-4 ignition amplifier - all very poorly wired. It was pretty obvious the original build was done professionally, but as the years and different owners passed by, the setup was deteriorating. Overall the system worked ok (better than you'd expect) but was ready for a full control system makeover.

After: Leaving this blank for now. Will update once it's all together and working as intended.

ORIGINAL POST:
Does anyone know if there are some common "go-to" DBW throttles that 2JZ guys typically use?

I'm finally getting around to fitting a GTE upper manifold to my GE lower using the supra vworld adaptor.

The GTE upper I have is from a VVTi engine, but didn't come with a throttle body - so I'm on the hook for finding something suitable.

I'll be using an ECU that is well capable of running a DBW style throttle, and in fact I think I'd like to use DBW so that I can calibrate cruise control, idle control, traction control, throttle blips for downshift, etc...

The easiest option seems like buying an OEM Aristo throttle body, but seems those are rare and expensive. I've seen some used ones on eBay for ~$500 which seems crazy to me when you can buy a perfectly good used GM throttle for $25-50. I'm fine with making an adaptor to mate the throttle to my upper manifold, and fine with using a different connector and pinout.

But... Was hoping I wouldn't have to reinvent the wheel if there is already a common approach that works.

 

[Piggity]

Do a search on here for the Tundra throttle body. Some guys have used them when doing a 1UZ/2UZ throttle body/intake which is larger than the stock 2JZGE size.

 

[Hodgdon Extreme]

Thanks for reply. It seems about any 70-75mm DBW throttle will work fine; I'll likely just go with one for a GM 4.3L V6... No reason for one of the giant 90mm+ ones.

The bigger issue, however, is I'll also need to eliminate my OEM throttle pedal - as any replacement throttle will not have the provision to receive my throttle cable. Instead I'll have to install an accelerator pedal with position sensor built in. Kind of a bummer because I don't want to lose the IS300 pedal with the brushed aluminum face. I guess I'll have to figure out a way to graft the IS300 pedal face onto a GM (or similar) style accel pedal.

Again, any links to info on this already being covered would be very welcome. Hate reinventing the wheel.

 

[Kris OK]

Garagewhifbitz sells a kit to do just what you’re wanting. Not suggesting you buy or don’t buy, but an enterprising guy like yourself could look at the contents and diy the same thing on the cheap.

DBW kit

You’ve pretty well nailed it on the gas pedal, too. Our stock hybrid mechanical/dbw throttle setup forces a swap to a new pedal, like you said. Turning to the Supra crowd again, they use an SC430 pedal. Not cheap though, and I’ve heard Toyota wants a sc430 vin before selling the part. Discourages folks like us.

 

[Hodgdon Extreme]

Thanks so much for that link. Looks like a solid setup and almost exactly what I need. Seems like the direct bolt-in accelerator pedal is meant for Mark 4 and not IS300, but maybe they're the same?

Also, I wonder if this is available elsewhere directly from the USA? A lot of the stuff they sell is USA stuff but their prices are basically same as what you'd expect to pay in USA, except they're in pounds sterling instead of USD - making it far more expensive to buy from them. I'd give $650-700 for a turnkey setup like that instead of needing to fabricate and do it myself, but $1k is getting pretty steep.

 

[Kris OK]

Thanks so much for that link.

No problem man. I’ve not tried it, but I’ve read the SC430 dbw accelerator pedal will bolt right in to the IS300. If you could locally junkyard source the SC430 pedal and Bosch TB, then maybe Garagewhifbitz would sell just the TB adapter? The rest is just wiring/tuning.

Edit: Here’s an adapter that’s a bit cheaper

and This is the garage Whif Bitz piece. Guess it boils down to how much adapting you want to do, to the existing intercooler piping. I imagine the gwb would be cheaper/less headache if you’ve already got the ic plumbing sorted.

 

[Hodgdon Extreme]

You rock. That EFI Solutions adaptor looks nice, and the 68mm throttle will fit the opening in the GTE upper plenum nicely. I suspect that's why they chose to design their adaptor around that throttle.

[Edit: The EFI solutions throttle body adaptor is a well made piece, but unusable because it places the throttle WAY too high and forward to fit under stock IS300 hood. To get it to fit, you'd need to chop a hole in the hood to clear the charge pipe and most of the throttle. I'm moving onto building an adaptor elbow that bolts onto the manifold and provides a ~45º bend to move the throttle down and slightly outboard - pointed directly at the (tight and only) space the charge pipe must come up through.]

[Edit 2: The edit above only applies if you're using an adaptor to mate a GTE plenum to GE lower runners. After switching to the Dodo Racing GE-T lower runners, the EFI solutions throttle adaptor is back in play - and is a great solution]

I did a bunch of sleuthing yesterday for various Toyota accelerator pedals with position sensor (APPS) built in, and then cross referenced the images against the one shown in Garage Whif Bitz kit. It is almost certainly from 2001-2005 Lexus SC430. I found a new one on Ebay for $235 so I ordered. Hope it is a direct fit into the IS300. I don't mind slight modification to fit the brushed aluminum pedal face of the IS300 onto it, but if I'm in for fabricating a bracket and custom fitment - I'll sell/return the SC430 pedal and just get a generic GM Racing one for $95.

Looking at the area where my charge pipe will need to come up from below, to attach to the throttle - there's stuff that's gonna have to move. I've done some searching/reading around about this and understand the need for a remote power steering reservoir and of course the special fitting for the suction side of the PS pump. I've ordered one of those already, but it looks to me like the high pressure line and pressure switch will be in the way of the charge pipe too. Also looks like the PS cooler lines will be in the way of the charge pipe. Am I mistaken? I haven't seen where people have written about this... Any intel or links would be appreciated.

This FFIM upfit is a pretty serious re-arrangement!

 

[Kris OK]

high pressure line and pressure switch will be in the way of the charge pipe too. Also looks like the PS cooler lines will be in the way of the charge pipe.

Yep all that mess is in the way. I bought a gte back when it was like 1700$ to my door, so it had a remote PS pretty much setup already. Didn’t have to bootstrap much. I deleted the PS cooler (been fine 4 years but I do not track race it) so I didn’t have to mess with that either. GTE didn’t have that “idle up” pressure sensor, so I didn’t contend with it. I can take a pic or two so you can see that charge pipe/power steering pump area, if you’d like. I put my maf sensor there, so it won’t look exactly like yours but may give you an idea of what you have to work with.

 

[Hodgdon Extreme]

Update on this:

I tried multiple sources to acquire the SC430 accel pedal and came up empty handed. This included genuine Toyota parts houses and various online salvage shops. I tried ordering a couple times from suppliers on ebay - only to receive an email a few days later they don't actually have one to sell. Some further sleuthing revealed Toyota has these on lockdown and allegedly only releases them to dealers that demonstrate they have an actual SC430 in their shop with all diagnostics and troubleshooting indicating a new pedal is needed...

So I ordered a generic GM accel pedal. Summit sells it as the GM Racing one, but it's basically the same unit GM uses in everything. I ordered mine thru Rock Auto for a 2006+ Corvette. I'll need to fabricate an aluminum bracket that picks up the two bolt holes in the IS300 for its pedal, and then provides new holes for the GM pedal.

I intend to cut off most of the GM lever and weld the IS300 lever on, so that I retain that OEM IS300 look.

Overall the size/shape of the GM pedal looks reasonable for this application.

 

[IS300 2001]

Update on this:

I tried multiple sources to acquire the SC430 accel pedal and came up empty handed. This included genuine Toyota parts houses and various online salvage shops. I tried ordering a couple times from suppliers on ebay - only to receive an email a few days later they don't actually have one to sell. Some further sleuthing revealed Toyota has these on lockdown and allegedly only releases them to dealers that demonstrate they have an actual SC430 in their shop with all diagnostics and troubleshooting indicating a new pedal is needed...

So I ordered a generic GM accel pedal. Summit sells it as the GM Racing one, but it's basically the same unit GM uses in everything. I ordered mine thru Rock Auto for a 2006+ Corvette. I'll need to fabricate an aluminum bracket that picks up the two bolt holes in the IS300 for its pedal, and then provides new holes for the GM pedal.

I intend to cut off most of the GM lever and weld the IS300 lever on, so that I retain that OEM IS300 look.

Overall the size/shape of the GM pedal looks reasonable for this application.

Thats odd that Toyota cares so much about that lol.

 

[Hodgdon Extreme]

Thats odd that Toyota cares so much about that lol.

Not really. Toyota only built about 70,000 of these vehicles and it has a unique accel pedal part number not used on any other package. I'm sure they made extra pedals as service parts, and are not interested in making a new batch of them. When the inventory control system starts showing a depleted supply, they have to ration out the remaining parts to ensure they are only being used as necessary.

Basically, Toyota cares about supporting actual customers in actual need - rather than catering to hotrodders.

 

[Piggity]

I always use Car-Part.com--Used Auto Parts Market for any used vehicle parts I'm looking for.

 

[Hodgdon Extreme]

I'm gonna try to update this thread with progress on my DBW throttle arrangement for the FFIM conversion I'm working on. I have another thread where I was discussing the required flanges and how I'm going to use a generic Bosch 68mm DBW throttle on the GTE upper manifold.

That thread is here: GTE manifold throttle weld flange

But all future updates will be done right here... Mods, if you can sorta merge the threads, that would be cool.

Anyway, I bought a Generic GM accel pedal, which requires fabrication of a mount, as well as modification so that it uses the IS300 accel pedal facing, and puts it in the right spot in the footbox.

So I mounted the accel pedal in the vise, pinching the lever itself with some sockets, just above where I wanted the bend to begin. I wrapped a wet towel over the APS and hinge mechanism so they wouldn't get cooked by the rosebud torch I used to heat it:

Kinda eyeballed it about how it needed to be and this this is what I came up with:

Starting with a 1/4" thick plate of aluminum, I traced and cut out the footprint of the GM accel pedal so that it has something to mount to:

You can also see I've cut off most of the extra pedal lever from the GM pedal, and cut/bent the IS300 pedal so I can weld the two together. The mounting plate will be bolted to the firewall using the original IS300 pedal bolt holes. However the GM pedal base totally covers the IS300 mounting holes, so I'm going to use some M6x1 50mm flat head cap screws, countersunk into the plate. Then two ~1.25" long aluminum standoffs between the firewall and the plate. Still need to do that part, though.

Anyway, here's another shot of the GM/300 accel pedal marriage, ready for weld:

Once it's all fit, I'll do some finish work and paint so that it looks respectable.

Also, I've always hated the position of the IS300 throttle pedal - too hard to heel/toe - even with size 13s. The pedal face is too deep in the footbox in comparison to the clutch and brake, and it is too far inboard. So the new pedal arrangement is moving the pedal outboard ~1", lower in the car ~1/2" and ~1.5" rearward in the car. Hopefully that'll be ergonomically correct. But hey, adjustment only takes a little bending and/or welding. Trying not to overthink this too much - which is a bad habit of mine.

 

[Hodgdon Extreme]

Oh, and I thought of this while using GM parts in my Toyota:

 

[Hodgdon Extreme]

Update:

I've got my DBW accel pedal arrangement finished and installed. Still waiting on flanges from laser cut so that I can fabricate the adaptor elbow for my throttle body.

Here is the accel pedal, bracket and hardware ready to install:

Bracket installed on firewall:

Accel pedal mounted onto bracket:

And accel pedal position in the footbox:

It's not quite as close to the brake pedal as I was planning, but it's def not as deep in the footbox as OEM. I think it's workable as-is. Not gonna modify it until I've driven it a bit.

 

[Hodgdon Extreme]

Update:

Progress has been slow. I did a Marlin fishing tournament for a week, got home and immediately came down with the plague. Took several days to get past it, but it left me with a lingering feeling of general malaise and low energy which lasted about 2 weeks! Never before felt so stripped of the motivation and will to get off my ass to do something. Luckily, that has passed and I'm moving forward with my project.

Got the weld flanges back from laser cut. I'll need to drill/tap the throttle body flange. Also, I am going to machine o-ring grooves into each flange so that no gasket or RTV is required. The throttle body adaptor I'm building will need to be removed to work on a bunch of different things so I don't want to mess with gaskets every time.

This image shows the (slightly) modified power steering cooler lines. I carefully hammered the mounting bracket for the lines to get it as close to the ecu box as possible. This is all in the name of creating clearance for my intercooler pipe to come up from below. The top PS cooler line in the pic has been re-bent so that it points straight back. The stock configuration has this line bent inboard, where it is in the way of the IC pipe.

Next up is the high pressure PS line that runs down to the steering rack. Again, in stock configuration this line points outboard and is in the way. With the new ecu, I won't be needing the PS pressure sensor - so that allowed me to cut the pressure port off the banjo fitting and weld it shut. Which then allowed me to flip the banjo and re-bend the steel PS line so that it goes straight back and then down (just behind the AC compressor).

This last pic actually shows 3 modifications. To make room for the throttle motor on my new Bosch 68mm throttle, I cut off the outcropping on the front of my lower intake manifold (lower right arrow). The outcropping I'm referring to has a vertical stud that serves as a mounting point for the engine harness cable tray, which I decided was not necessary - so I also cut a chunk off the cable tray to make more room (top arrow). Last, the dipstick needed to move. I ground the bracket off the dipstick tube, re-bent and reshaped it a little, and re-welded it to the tube in a new location. As you can see, the tube is now mounted to the boss on the water neck that serves as a mounting point for the VVTi solenoid oil line. The dipstick tube kinda needed to be forced to be in this position and I was afraid that might upset the o-ring where it goes into the pan, so I tweaked/re-bent the dipstick tube itself just a little bit as well.

Hopefully it goes without saying all of this stuff is only in the fabrication stage - it all needs finishing work will be tidied up and re-painted before it all goes together for real.

 

[Hodgdon Extreme]

Some more progress:

The GTE upper requires a remote-mount power steering reservoir. I wanted to modify my OEM reservoir, but I needed to move the inlet to get it pointed in a new direction - but the baffle is small and wouldn't provide the baffling effect for the inlet with it in its new position. Shopped around but settled on the Chase Bays unit because it's so popular and gets so many good reviews.

Most people seem to squeeze the new reservoir between the GTE upper and the shock tower - but the SupraVworld adaptor moves the upper plenum outboard (about 35mm) and the reservoir won't fit. So I chose to install it by the brake and clutch master cylinders. I installed a couple rivnuts into the back of the shock tower (a real PITA) and here is what I came up with:

Although I'm still waiting for CNC time to machine the o-ring grooves into my throttle body adaptor elbow, I got started on the new intercooler piping arrangement. Don't make fun of my aluminum welding - I'm a bit rusty but getting the hang of it again:

I wanted it to fit really close to the car, and wanted to leave the area behind the passenger foglight available for a big air filter that won't have to live inside the engine compartment:

Hard to see, but it dips just below the big TRD front ARB with about 12mm clearance:

Last, here is the clearancing/notching I had to perform to the hood so that it would close on the GTE upper mounted via the SupraVworld adaptor. These pics were taken looking straight at it - so there is no perspective/parallax error in case somebody wants to use these pics as a kind of "template" for notching their hood:

Haven't decided what I'm going to do to metal finish the gaping hole - or what I'll do about the hood liner which I'd still like to use to keep NVH down.

 

[Hodgdon Extreme]

EDIT 03/06/2023: I've since come to learn the only difference between GE-VVTi and GTE-VVTi valve covers is one single mismatched bolt hole (2nd one from front) on the outboard side of the exhaust valve cover. Thus, most of the IGN1A coil brackets meant to jive with a GTE-VVTi will work just fine.

Update:

I'm finishing up the requirement details for my engine harness so I can pull the trigger on getting that built.
Still waiting on CNC time to get the o-ring grooves machined into my throttle body adaptor elbow
Unfortunately, my vision of upgrading my coil arrangement to use IGN1A coils is more complicated than I anticipated:

Basically, the IGN1A coil brackets on the market are all aimed at GTE valve covers which lack the tall humps the GE covers have. Spacing the coil bracket up high enough to clear GE covers won't fit under the hood. GTE VVTi valve covers are expensive and aftermarket covers are egregiously expensive. Also, the coil brackets are mostly aimed at non-VVTi covers and I was not able to nail down exactly what the differences are between them.

I decided I would modify my valve covers as required and simply order a "universal, over-the-valve cover" coil bracket meant for non-VVTi and cross my fingers that it would fit close enough to work. They wanted $12 shipping, which was fine, but when I wanted to add a set of Magnecor plug wires to the order, they wanted $8 more in shipping - which really rubbed me the wrong way. Considering that I can have my own coil bracket design laser cut for $20, I decided to just go it alone.

So I got started on the necessary mods to my valve covers last night:

I'm going to weld in some ~2mm thick aluminum plates into the windows I've created. This will make the valve cover much shorter than original. The coil bracket will sit on standoffs directly above the intake cam cover, and the coils will be bolted to a custom coil bracket I'll have laser cut from 3mm thick aluminum.

My scheme is to harvest the oil filler neck and cap from the intake valve cover, and splice it into/onto the exhaust cam cover.

By the way - those coils are not actually IGN1A's, but rather the 8M0047456 coils from which the IGN1A's are copied. You can harvest these from Mercury Marine Optimax direct injection 2 stroke V6 outboards - along with all the mounting hardware and wiring harness (as can be seen in the rear right of my pics)

 

[Kris OK]

Looks like it’ll be a poorman’s GE-to-gte valvecover mod. I like it. Especially seeing what gte valve covers sell for. 600$ ish a pair is outrageous for some aluminum. I think this is going to look and work great.

That part number 8M004471 for the ign coil clone doesnt return anything on Google, except this thread. I’ve got yaris coils, so I’m prolly not going to pursue this route but future readers will thank you.

Where will you put your AN fittings (or what ever you decide to use) to evacuate crankcase gas?

Also what is that red Chevy? 55? 56? Got another pic of that hot rod ?

 

[Hodgdon Extreme]

I fat fingered the coil part number, but have since corrected it. The correct part number is 8M0047456. I believe there are some later revisions as well - which are also excellent. There were some earlier revisions that were capacitive and are NOT that awesome, but they look different. If if looks like the ones above, they're good. The backstory is when Mercury decided the future of 2 strokes was going to be direct injection, they quickly learned the stratified air/fuel mixture was really hard to light off. So they designed some heavy duty CDI "coils" which did not work as well as they wanted. They tried revising the CDI units, but eventually went back to the drawing board and designed the most badass inductive ignition coil ever devised. My best buddy is a boat mechanic so it's easy for him to source these for me for free.

I haven't decided how I'll vent the valve covers. I think it would look clean if I ran a -10 or -12 line out the side of the intake cam cover, running rearward, and joining the rear "hump" on the exhaust cam cover. Then run a -12 or -16 line from the "hump" to a catch can. This is similar to how a stock GTE is arranged - but they use two smaller lines to joint he two cam covers together - and then vent only one cam cover to the intake (rather than a catch can). However, I'm not sure I'll have room to snake the vent hose amongst all the plug wires.

The red car in the background is dad's 1956 Pontiac Safari. It has had all the chrome refinished and has beautiful paint and interior aside from a ghetto autozone steering wheel in place of the giant wood-rimmed wheel the car is supposed to have. Engine is unknown; it could be a 400, a 421 or perhaps even a 428 - but you can't tell from casting numbers; you can only tell by measuring crank journal diameter, bore and stroke. Heads are high compression units from a 1960's 400. It lopes like it has some cam in it. Aside from a retrofit AC system, the mechanicals and chassis are all stock. The single-channel 4 wheel drum brakes are the worst I've ever felt. Hasn't been driven in a number of years. Next time I'm at the shop I'll snap a few pics.