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Making my own EFI intake system


Derek

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Someone who is infrequent on this forum currently has converted SU's with 1000 cc/min injectors in them running on his 3.0L Racer, we were supposed to do a joint dyno day Friday, but everything fell through. So tuning of the final maps and 'decisions' to be made about injector placement of the two injectors still remains up in the air till that dyno testing is concluded.

 

This setup is the 'ultimate quick and dirty' EFI conversion of SU's. The results should prove very educational.

 

Pete, you have 'peripheral knowledge' of his setup. I've no real photos to speak of thusfar, when I do, I can distribute them.

 

Tony,

 

GM TBI injectors?

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Get a hold of some SU manifolds' date=' a fuel rail, and you'll see what I mean. You can do it with some HKS styler injector holders, but they will be firing straight down. I wanted them firing into the stock injector ports. Because the SU manifolds use the other bolt holes on the head, it becomes extremely difficult. If you have a saw, end mill, and you are good at TIG welding aluminum, it is a much easier approach.[/quote']

 

ahhh nevermind. i thought you meant that it's hard in general for all applications. my bad =)

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Well if it will fit in the car then I think I'm pretty much happy with this design.

render6.jpg

 

 

render7.jpg

Thanks for the heads up on the hood clearance Dave. I checked the motor and it tilts 12 degrees towards the passengers side. I had enough clearance at 16 degrees but I pulled it down to 14 degrees in case I end up with an air box.

I put a bell shape on the end with a rolled edge. I also added a step for the air filter inserts. The airfilter insert clamp will be designed to help restore the airflow around the step.

I need to do a little research on linkage designs but this is the basic idea. I may try to do a modification to the end arm and drive it with the gas pedal as opposed to a center bell crank. I'm still going to cast it in two banks of three. I'm going to add a little gusset webbing in between each tube for strength.

 

 

I've got an injection plumbing question. All the injection set ups I've seen use a fuel rail where the fuel is constantly flowing past the injectors. If I use my single line to each injector with a return at the central block layout will this work? I'm in effect dead ending the fuel at the injector head.

 

 

I need to figure out where I'm going to mount the IAT. I'm wondering if I could use a small beaded thermo couple. I could bring it in the bottom of the rear throttle body and epoxy it in place. All I would have sticking into the tube would be a small bead.

 

 

Thanks again

Derek

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I've got an injection plumbing question. All the injection set ups I've seen use a fuel rail where the fuel is constantly flowing past the injectors. If I use my single line to each injector with a return at the central block layout will this work? I'm in effect dead ending the fuel at the injector head.

 

Yes. You can either put a two port FPR (in and out, just like the stock one) on that return line from the dist. block, or you can use a three port FPR (in, out, and return), and plumb the 'out' to the dist. block with no return from the block.

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Z-ya: Do you have a thread going for your progress on this intake setup?? We had discussed it before, and I was curious.. It appears that is basically a flange from a stock intake manifold welded on to the SU manifold in place of its flange??

 

Could you possibly e-mail me some more photos? higher resolution would be nice, but not needed... I am just very interested in this since we had the idea at roughly the same time, and I (like yourself) have the parts laying around. I could actually potentially fabricate a few of these setups, from throttle bodies to flanges, and sell them if there were demand... so you could say that I am somewhat interested.....

 

PM me and I will send you my email address if you have any more photos. thanks man..

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I will have more photos when the smoothing is done. Those are the only two I took, and the manifolds are at the metal shop. I can document the procedure for doing this mod if you like.

 

There is a lot of work involved hear. Not just cutting, machining, and welding. Smoothing the outside (just the top), re-drilling the TB flange, enlarging the TB flange to 50mm, and smoothing out the ports on the inside (the E88 ports are actually larger than the EFI intake ports). Then there is the throttle linkages. You are going to charge a lot of money to make up for your time.

 

I think this setup will look great on a close to stock 240Z that wants EFI. You could modify the stock air cleaner to adapt to the TBs.

 

When I get it done. I will post all the information. I'm thinking it will be done in a couple weeks.

 

This project is part of my 71 buildup I'm embarling on:

 

http://forums.hybridz.org/showthread.php?t=120074

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Derek, on your multi colored rendering of your setup you posted...(I believe )you are going to want to have all of the green actuating arms that are connected to the throttle linkage to all be parallel to each other, due to the geometry they are not going to all have the same rate of opening. The arms that are closer to 90deg. angle to the linkage will open more than the ones that are further from 90deg. Does anyone else agree. It's been a VERY long time since 10th grade geometry.

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A Big block Chevy only pulls 7 CFM per cylinder at Idle! That's not alot of AIR!

 

An L20A with only 1998CC's for Six Cylinders also doesn't draw a lot of air---even quite abit less than the BBC. Best bet for these kind of setups is a balance tube distributed IAC or Idle Air Bypass Screw. Idle is accomplished at closed throttle (with proper t-plate angle at idle, not 90 Deg but offset so as to preclude sticking in the bored or coming back past center)

 

On the Bonneville car, we use an ECU-Driven IAC for idle speed control, and the throttle butterflies (45mm diameter) are totally closed.

 

Synchronisation is done off-idle by linkage length, with a coarse setup to start being a check against the WOT Stop.

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Derek, on your multi colored rendering of your setup you posted...(I believe )you are going to want to have all of the green actuating arms that are connected to the throttle linkage to all be parallel to each other, due to the geometry they are not going to all have the same rate of opening. The arms that are closer to 90deg. angle to the linkage will open more than the ones that are further from 90deg. Does anyone else agree. It's been a VERY long time since 10th grade geometry.

 

Thanks for the heads up and yes you are correct. If the arms are not parallel they won't open the same.

I threw the linkage in just to give an idea of the direction I'm going. Now that I have the clearance issues solved I'll be redrawing everything including the addition of a balance tube and IAC. Thanks for the info Tony D. Kinsler makes 1.523†diameter throttle plates which will give me their recommended

closed angle of 14 degrees.

 

 

I keep vacillating between which injector style to use. Stock 280Z injectors are starting to look pretty attractive because of their clamping system. I could probably machine a fitting to replace the hose at the end so I can still use my hard line idea.

 

Will the stock computer work with a custom manifold? Would you have to move to standalone?
I'm converting a 240 with SU carbs so I'll be using Megasquirt as the control.

 

 

Thanks again for all the help on this. I'll post a final (I hope) rendering of the manifold in the next few days. I hope to start caving towards the end of next week.

 

 

Derek

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Excellent! I cant wait to see it. Are you going to make a few extras or it this going to be one of a kind?

 

 

Thanks!

I'll be making the un-machined castings available. I'm not sure if I'll offer the additional parts or not. My CNC Knee mill doesn't have an automatic tool changer so production work is out of the question.

I will supply all of the cad drawings necessary for the parts though.

 

 

I'm in contact with Motor Man Fuel Injection Supply about the injectors. Man is that guy easy to deal with. He's making up a set of injectors with the stock 280 base and a Bosch o-ring top. For my application I think this is the best way to go.

 

 

Derek

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So how is the bosch top going to work with your hardline idea? or are you going to run a rail instead?

 

MSD sells single fittings with a AN flare and groves for a clip. They're $100.00 for a pack of 8 so Iâ€ll probably make up my own. That price is about the tipping point for me making 6 fittings!

 

 

 

Derek

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damn, i wanna post progress pics of my intake (single tb), but I think I'll bite my tongue until I actually have it back. It's all finished up, just waiting to see the final pics of it coated. My powder coater is supposed to be shipping it out to me today (well Saturday) I hope. It's gonna be a cool surprise for everyone here on hybrid.

 

I've seen pictures and it will definitely be a cool surprise!!!! Jason did an awesome job!

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