Jump to content
HybridZ

SU EFI Manifold Update


z-ya

Recommended Posts

The Cosworth Vega is a very *neat* car. Kind of reminds me of a 1/2 sized Chevelle. The header (my friends is Jet Hot coated so it looks sweet), and the EFI, very high tech for it's time. The Vega block without iron sleeves is POS. The Cosworth head is a beauty. It's got Muncie 4-speed in it!

 

C2409-0021.jpg

Link to comment
Share on other sites

  • Replies 116
  • Created
  • Last Reply

Top Posters In This Topic

Z-YA awesome work.

 

What made you splice an efi intake and mate onto the SU intake, when you could have just drilled and welded injector bosses into the SU intake?

 

SDS sell these .. newboss12.jpg

 

Just wondering, that's all.

 

Keep up the good work.

Link to comment
Share on other sites

Z-YA awesome work.

 

What made you splice an efi intake and mate onto the SU intake, when you could have just drilled and welded injector bosses into the SU intake?

 

SDS sell these .. newboss12.jpg

 

Just wondering, that's all.

 

Keep up the good work.

 

Just because I had the parts, the means, and access to the equipment to do it. Something new I guess. Yes, there are many different injector bosses you can buy out there. The nice thing about this approach is the injectors fire into the head port directly like the stock EFI manifold. You would be hard pressed to do that with weld in bosses.

 

Pete

Link to comment
Share on other sites

I agree Pete and qudos to you, I am just trying to find an easier way for me as I'd like to do this to a triple manifold.

 

I found this little gadget during my research and I had never seen it before, it may help fire the injectors directly into the head port even if the injectors were mounted vertically.

 

yamaha_vmax_fuel_injector_cv_car.htm_txt_DSC00792.gif

 

Anyway, I am digressing now..

Link to comment
Share on other sites

I agree Pete and qudos to you, I am just trying to find an easier way for me as I'd like to do this to a triple manifold.

 

I found this little gadget during my research and I had never seen it before, it may help fire the injectors directly into the head port even if the injectors were mounted vertically.

 

yamaha_vmax_fuel_injector_cv_car.htm_txt_DSC00792.gif

 

Anyway, I am digressing now..

 

To be honest, I don't think there will be any noticable difference between directing the spray into the head port versus angling the spray towards the port using one of these bosses. Just mount them close to the head on the manifold. The tricky thing about welding these bosses is getting them aligned if you want to use a fuel rail.

Link to comment
Share on other sites

The tricky thing about welding these bosses is getting them aligned if you want to use a fuel rail.

 

That was my thinking. The advantage of grafting the EFI manifold flange on is that one can use readily available o-ring fuel rails. I think that'd be a cleaner look than welding in all those big clunky injector holders.

Link to comment
Share on other sites

I found these on Ebay ($10 for pair!). 48mm IDA stacks. Almost slide into throttle bodies. Too thin to turn down in a lathe. I think I am going to build a cold air box with these inside, kind of like the stock 240Z air box.

 

P1010002.jpg

 

When the stacks are welded into the airbox, it will clamp on with hoses and clamps.

 

P1010001.jpg

Link to comment
Share on other sites

OOOoooOOOoooOOOO!!! SO not fair!

 

 

 

Them thangs sher are purdy!!!

 

Have I mentioned my idea with a manifold like this, to use the TB flanges off of stock EFI manifolds (with the egg-shaped hole) and find the dual stage TBs that were sold in JDM market (little guy for low throttle and a big guy that opens on high throttle)

 

I was thinking that it COULDNT be too hard to build an SU-type airbox that had horns for the larger bore (about 40mm?) out into the main plenum area, and then pipe the smaller primary butterflies into long skinny tracts going around the outer circumferences of the airbox/plenum, and then opening out into the main volume... thus giving you a nice loooong airway for low throttle application and then transferring to a short shot in for WOT application.... The biggest problem I could find with this idea (if it were set up by someone who could do the engineering and math to establish proper length tuning) was the air entry into our plenum area in the Z car engine bay. Ideally I would think a centered entry coming from the top would be best, and it MIGHT be do able but it would be such a trick piece by the time you were finished..... impractical to say the least.

 

Another filter thought that just occurred would be even more of a mimicry of the stock SU "airbox..." which is just a plate on the carbs, a round filter, and then a covering box. Make a backplate that includes the horns and piping as I described, then set the filter cartridge around it all and then a top plate, just like stock... Hmmm...

Link to comment
Share on other sites

 

Another filter thought that just occurred would be even more of a mimicry of the stock SU "airbox..." which is just a plate on the carbs, a round filter, and then a covering box. Make a backplate that includes the horns and piping as I described, then set the filter cartridge around it all and then a top plate, just like stock... Hmmm...

 

Yes, this is what I am planning. I might use part of the 240Z airbox. I want to get cool air from in front of the radiator support. This seems like the best way to do it.

 

 

Pete

Link to comment
Share on other sites

I found these on Ebay ($10 for pair!). 48mm IDA stacks. Almost slide into throttle bodies. Too thin to turn down in a lathe.

 

But putting the TB in the lathe backwards (lathe jaws gripping 'out' to the bore) and trimming just a little out of the throat would let you shrink/press them into the bodies with some loctite and be done with it....and not have the hose look and clamps out front... Not that Tony would know anything about boring that damnable square bore to round in 73/74 Flat Tops....oh, you can do it on a Bridgeport with a rotary table and mill, or a simple boring bar once you find center of the bore...not that I've ever witnessed that being done or anything...snarfk!

 

XNKE is correct on the cowl, ths Japanese do it all the time as they are not confined with the Master-Vac and linkage being in the way of a reverse-mounted airbox.

 

The issue with longer horns is packaging them with proper clearane inside an air cleaner for proper flow. More clearance is needed meaning a fatter filter housing...or one with a 'dome' and open mesh element surrounding the mouth of the pipe.

Link to comment
Share on other sites

But putting the TB in the lathe backwards (lathe jaws gripping 'out' to the bore) and trimming just a little out of the throat would let you shrink/press them into the bodies with some loctite and be done with it....and not have the hose look and clamps out front... Not that Tony would know anything about boring that damnable square bore to round in 73/74 Flat Tops....oh, you can do it on a Bridgeport with a rotary table and mill, or a simple boring bar once you find center of the bore...not that I've ever witnessed that being done or anything...snarfk!

 

XNKE is correct on the cowl, ths Japanese do it all the time as they are not confined with the Master-Vac and linkage being in the way of a reverse-mounted airbox.

 

The issue with longer horns is packaging them with proper clearane inside an air cleaner for proper flow. More clearance is needed meaning a fatter filter housing...or one with a 'dome' and open mesh element surrounding the mouth of the pipe.

 

Great idea Tony. Just keep your hands and feet away from that TB when it is spinning (ouch) in the lathe! I may also shorten them a bit while I'm at it to give me more room for an airbox.

 

Pete

Link to comment
Share on other sites

That is very crafty Pete! I can already hear the sucking sound of the thottle blip in my head. It will be interesting to see the how it moves the power/torque curve of the motor around.

 

Thanks Dave. Not sure what it will do to the torque curve. I'm also upgrading to MSII while I'm at it (it is so easy to justify these kinds of decisions in your own mind :mrgreen:, you know, while I'm in there). I'll have it back on the dyno in the spring and will post a plot for sure.

 

Pete

Link to comment
Share on other sites

Realistically, if you have teh Bridgeport and one of those adjustable boring bars it's really a quick thing to do to open up the bore a smidge.

 

With the same Bridgeport, and a rotary table the tapered bore syndrome will get you all tied up thinking 'o.k. how much wall thickness is not enough?'

 

Packing Devcon Aluminum Putty into any low spots on the body is advisable before you start, if you're like me, anyways!

Link to comment
Share on other sites

Realistically, if you have teh Bridgeport and one of those adjustable boring bars it's really a quick thing to do to open up the bore a smidge.

 

With the same Bridgeport, and a rotary table the tapered bore syndrome will get you all tied up thinking 'o.k. how much wall thickness is not enough?'

 

Packing Devcon Aluminum Putty into any low spots on the body is advisable before you start, if you're like me, anyways!

 

Yup, I have access to a Bridgeport, so I could potentially do it that way also.

 

I need to decide if I want to make an air box that the horns are a integral part of (like the 240 air box). If I go that route, I want more than some epoxy holding the assembly to the TBs. This is why I was thinking some sort of hose/clamp arrangement.

 

I don't really have a place in the intake to mount the IAT, so I was thinking of putting it in the air box. If I go without an air box and use some filter screens, I'm not sure where I would put the IAT. Any ideas Tony?

 

ef1c_1.JPG

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...