I didn't realize your old throttle bodies on the 924 were that big. Mine are 42mm on my 924. It definitely makes it more of a pain at low rpms to drive lol.
I didn't realize your old throttle bodies on the 924 were that big. Mine are 42mm on my 924. It definitely makes it more of a pain at low rpms to drive lol.
Yeah, I got a great deal on them via eBay years ago and they sat around collecting dust until the 924 came along.
Found a set of 40's similarly and I was working on getting them ready, but I swapped back to the stock intake for the sake of adding a turbocharger (though I might still make a plenum for the ITBs and go that route, but that would be more for fun than anything else).
Well, with the engine making such good progress, I've been working on getting the interior back together. Though dyno time is set for november, my coworker is going on paternity leave and my boss is going on vacation. So... I'll be running the place on my own as our other person working there is retiring.
So I was told to burn my PTO asap. I've taken all of not this week but the coming week off just so that I can devote it to crunch time on the Lambo. Will post lots of pics and progress as it comes together. Excited!
bgkast wrote:
definately
Air boxes are completely taken apart with new parts to rebuild them. Sandblasting them tomorrow and am having a hard time deciding: Do I go with repainting them? Or do I just leave them as is, aluminum color.
I'll post pics when they're finished. For now want to keep the fun of before and after.
In reply to corsepervita:
Was it just paint or was it a thermal coating of some sort to help keep the air cooler? Something to think about.
corsepervita wrote: Air boxes are completely taken apart with new parts to rebuild them. Sandblasting them tomorrow and am having a hard time deciding: Do I go with repainting them? Or do I just leave them as is, aluminum color. I'll post pics when they're finished. For now want to keep the fun of before and after.
Powdercoat has always served me well in the past. The place where I take my stuff actually does it cheaper than for me to blast and paint with professional quality automotive paint.
Well, I attempted to get it off with media blasting and that E36 M3 is really stuck on there. I don't know what they used, but wow. It's really really on there. I did get the insides of the boxes cleaned, as well as the runners and everything else. So that's ready to go.
Currently running everything through the washer (because no wife to tell me no) to clean all the glass beads out of the intake bits.
I did go ahead and pop one on ever so gently though to make a tiny previous. Will put the boxes together tomorrow. Either way.... like a kid at christmas at the moment.
Pretty ........ !!!!!!
Alright so the machinist called me today. The carbs he was going to use for the dyno WILL NOT WORK. So I am now faced with hooking up and getting my EFI system ready way before I thought I needed to.
I'm facing a dilemma which is that I am having a hell of a time finding the right injectors. These ITBs use Bosch EV14 injectors. According to my calculations on the injectors I should be using 25-28lb injectors if I want to keep my duty cycle at 60-80% or 250-280cc. All I'm finding is 600cc injectors or 1000cc injectors or something ridiculous like that.
Does anyone know where I can find some normal EV14 injectors in this flow rate? I've found that apparently MX5 Miatas and Subaru STI cars use these injectors. The flow rates that I've found on them are more like 205cc injectors, not enough.
Anyone who has any sources for injectors at good rates and prices would be greatly appreciated. I have a friend who has an auto shop and repairs a LOT of subarus with parts to spare so I'm bringing one of the ITBs tomorrow with me to see if we can find a flow rate and injector that will fit.
Worked on the intake runners last night and tonight to clean them up and patch up the weird corrosion issues they had. Nice and smooth now.
Air boxes cleaned up really really well, everything did. I haven't posted up any pics yet but will get to it when I get a chance.
I'm waiting on 8 o-rings which I apparently missed for the sleeves. There are actually 2 grooves for the sleeves, but the factory manual calls for only 1 o-ring per sleeve. I'm terribly confused by this. The logical side of me says, "Why the hell would you make 2 grooves and call for 1 o-ring, and why would you leave 1 failure point on an o-ring if it fails." I'm half tempted to order another set and tell my machinist to put both sets in, should 1 ever fail. The other part of me wonders if there is a legitimate reason for it (barrier between oil and coolant, no air pocket, etc).
There was only 1 o-ring stock when I took it apart, and I can't help but feel there must be a reason. Still, confused on it.
Interior is stripped and ready to be sealed up but with me having to order everything for the ignition system and the fuel system, my concentration needs to be to get the engine ready for dyno day and tuning for the engine dyno. The good news is that he can put the motor under load so I can actually get a baseline tune while I'm there, so once the engine goes in, I'm good there.
I have ALL of the parts to rebuild the airboxes. I'm not sure though if I want to paint the inside or leave them bare since they're aluminum. They're super clean, and I may just leave them that way, though part of me says "sealing that up would be a good thing". Will definitely paint the outside. I might just drop them off and get them powdercoated.
Ordered some bits to rebuild the distributor. Idea is, for now, to drive the ignition off of an MSD6AL and will run Fuel ONLY for dyno day. Once that's done will end up moving over to coil on plug setup for the car since it would be far more efficient on MS3.
If anyone has any feedback on injectors you'd be forever my hero.
Rx8 injectors may get you close.
I remember reading that not all injectors are equal. A certain 1000cc may do a duty cycle of 10% better than a 600cc at 16.67% duty cycle. It may have been Keith Tanner that mentioned it with turbo miatas?
Are you sure you need that big? what is your target power? I thought a stock Jalpa only made 240ish actual, not 80's Italian hp. I know your doing some work to it, but lets assume you have a great engine with potential for 300hp.
300hp
8 injectors
Let's go for 0.5 BSFC
80% max cycle
Fuel pressure (adjustable I assume) between either 40 or 50
That looks like 230 to 260cc injectors
According to this http://miataturbo.wikidot.com/fuel-injectors 94-97 1.8 NA Injectors are right in your sweet spot unless I'm reading it wrong. Keith will know for sure.
Stefan (Not Bruce) wrote: Yeah, I got a great deal on them via eBay years ago and they sat around collecting dust until the 924 came along. Found a set of 40's similarly and I was working on getting them ready, but I swapped back to the stock intake for the sake of adding a turbocharger (though I might still make a plenum for the ITBs and go that route, but that would be more for fun than anything else).
A guy finds a deal on ITBs on ebay, snaps them up...because racecar, then waits years to afford a car to put them under...Only at GRM 
4cylndrfury wrote:Stefan (Not Bruce) wrote: Yeah, I got a great deal on them via eBay years ago and they sat around collecting dust until the 924 came along. Found a set of 40's similarly and I was working on getting them ready, but I swapped back to the stock intake for the sake of adding a turbocharger (though I might still make a plenum for the ITBs and go that route, but that would be more for fun than anything else).finds a deal on ITBs on ebay, snaps them up, then waits years to afford a car to put them under...Only at GRM
Heh, yeah kinda. To be honest I had bought a DCOE intake for the Chrysler 2.2s I had been playing with and had plans to put them on my Rampage with MegaSquirt to control them.
Then I bought a Direct Connection/Mopar Supercharger kit and I bought a 4-bbl to DCOE adapter to use with MegaSquirt on the Rampage.
It all fell apart when I lunched the transaxle and set it aside to work on other projects. Eventually the page went away and the parts sat on the shelf. I found and bought the 924 off eBay for $600 (about twice what I paid for the ITBs, heh) and the DCOE intake for it wasn't too expensive and the rest is history.
Adrian_Thompson wrote: Are you sure you need that big? what is your target power? I thought a stock Jalpa only made 240ish actual, not 80's Italian hp. I know your doing some work to it, but lets assume you have a great engine with potential for 300hp. 300hp 8 injectors Let's go for 0.5 BSFC 80% max cycle Fuel pressure (adjustable I assume) between either 40 or 50 That looks like 230 to 260cc injectors According to this http://miataturbo.wikidot.com/fuel-injectors 94-97 1.8 NA Injectors are right in your sweet spot unless I'm reading it wrong. Keith will know for sure.
I guess I figured it'd be easier to go with bigger injectors to run a smaller duty cycle than it would be to go with smaller injectors and plowing out the duty cycle close to what they are at max.
I suppose it wouldn't kill me to run bigger injectors on a small duty cycle, but I feel like it'll be more efficient to go with something closer to the recommended size, maybe just slightly larger.
Might Car mods mentioned some method of modifying stock miata injectors to get a higher flow rate. (when they turbo'd theirs.)
Mad_Ratel wrote: Might Car mods mentioned some method of modifying stock miata injectors to get a higher flow rate. (when they turbo'd theirs.)
I briefly remember that, I think they uncapped them. I'm leery of doing something like that since I don't have anything like a flow bench to ensure there's no variance in doing something like that. I think I'd rather just find some injectors at a specific flow rate so I know exactly what cc they are, etc.
Look at ford injectors - 2007-2011 crown vics, some mustangs (v6s and GTs). They run ev14 style injectors at about 260cc and around 80-85% duty cycle. It's what I used in Mrs. Oldtin's 928. Often called the ford 24# injectors
corsepervita wrote: I guess I figured it'd be easier to go with bigger injectors to run a smaller duty cycle than it would be to go with smaller injectors and plowing out the duty cycle close to what they are at max.
Bigger injectors don't do as good a job spraying fuel at lower duty cycles though - this will have a (small) impact in idle quality and drivability.
But not sure if this is entirely true given the reasonable sizes you're looking at. It's certainly more of an issue with big injectors...but the market has come a long way in recent years. This isn't nearly the issue it once was.
oldtin wrote: Look at ford injectors - 2007-2011 crown vics, some mustangs (v6s and GTs). They run ev14 style injectors at about 260cc and around 80-85% duty cycle. It's what I used in Mrs. Oldtin's 928. Often called the ford 24# injectors
This design? http://www.ebay.com/itm/26lb-Ford-Racing-Fuel-Injector-Set-Ford-F-150-E-150-F-250-4-6L-V8-4-Hole-03-09-/232091500776?hash=item3609bb40e8:g:tHIAAOSwgZ1Xubns&vxp=mtr
Alright, during lunch dropped by my friend's shop. Picked up a subaru manifold and injectors, along with some ford injectors. Going to bring them home and test them out. Will report back.
Mazdas and Fords with the 2.0L FSDE use 280 cc injectors with the same Bosch connector. I'm running STi 565cc injectors in my mazdaspeed protege and have a couple sets of stock 280s kicking around someplace. If you want them let me know.
In reply to thepope540:
Are those EV14 style, and normal size not extended size?
Call FM and talk to Jeremy. He's our injector nerd. 230cc is indeed a stock Miata size, I've probably got a set or two I can donate if they work. I'll check tonight.
Modern injectors work much better at short open times than old ones did. Stock NA injectors are not modern 
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