Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Injectors - choosing the right Design III (and some II info)

Thread Tools
 
Search this Thread
 
Old 03-28-2011, 11:48 AM
  #31  
Landseer
Rennlist Member
 
Landseer's Avatar
 
Join Date: Sep 2007
Location: Johnson City, TN
Posts: 12,143
Received 356 Likes on 205 Posts
Default

OK.

These are the 24 lb injectors I'm going to try in the 85 Platinum car that's got weird power problems. Just arrived.

New, $167 delivered from Blue Oval Industries (near Harrisonburg, VA) (in-state / tax)

Will take good pictures of fit-up. Need to figure out where to cut the necessary upper groove for the retaining clips.

Looks like the O-rings will work in my rail. More to follow on that.

Gotta prepare for an interview, so can't deal with this install till later in the week.
Attached Images       
Old 03-29-2011, 10:58 PM
  #32  
928mac
Drifting
 
928mac's Avatar
 
Join Date: Oct 2009
Location: Alberta, Canada
Posts: 2,638
Likes: 0
Received 2 Likes on 1 Post
Default

Originally Posted by Landseer
OK.

These are the 24 lb injectors I'm going to try in the 85 Platinum car that's got weird power problems. Just arrived.

New, $167 delivered from Blue Oval Industries (near Harrisonburg, VA) (in-state / tax)

Will take good pictures of fit-up. Need to figure out where to cut the necessary upper groove for the retaining clips.

Looks like the O-rings will work in my rail. More to follow on that.

Gotta prepare for an interview, so can't deal with this install till later in the week.
Holy Chris, those look really nice. Under $200 for all of them?
Old 03-29-2011, 11:05 PM
  #33  
Landseer
Rennlist Member
 
Landseer's Avatar
 
Join Date: Sep 2007
Location: Johnson City, TN
Posts: 12,143
Received 356 Likes on 205 Posts
Default

Yes.

Just got done dremel-cutting some additional slots.
Got it close enough, I think.
Lathe approach noted above would have been more precise.
Should have at least made a little guide jig.

Am tired, and its cold outside, but I'm wanting to install them tonight.

Looks to me like the O-rings on them will fit both the rail and the manifold.
More to follow.

BTW, Roger pointed me down this general path, knowing I would be ok if they weren't exactly plug/play. Class act. But lets see where this ends-up.

Here's the 944 injector I'm gauging against ( its 9mm from top to center of slot ). This is consistent with notes above of 8.5 to 9.5mm.

Also, you can see my adequate slots. Not my best work.
Attached Images   

Last edited by Landseer; 03-29-2011 at 11:58 PM.
Old 03-30-2011, 10:22 AM
  #34  
Frank Castle
Instructor
 
Frank Castle's Avatar
 
Join Date: Jun 2001
Location: Shenandoah, TX
Posts: 124
Likes: 0
Received 1 Like on 1 Post
Default

Has anyone considered making some simple sleeves from Delrin or Aluminum that would shoulder on the lower body of the injectors? Would allow you to use any injector without the worry/need to machine the keeper grooves. Just a thought.
Old 03-30-2011, 11:21 AM
  #35  
killav
Rennlist Member
 
killav's Avatar
 
Join Date: Apr 2006
Location: North Richland Hills, TX
Posts: 1,534
Received 7 Likes on 5 Posts
Default

Chris,

I purchased these exact same injectors for my turbo project last October. I cut the grooves into the injectors just as you are doing. I wanted to let you know that I did change out the O-rings. The o-rings that ship with the injectors, especially the top ones that plug into the metal fuel rail, were slightly smaller than the stock ones. The o-rings that Roger sells are bigger, and are a much more snug fit. Just FYI.

Also as a benchmark, at 7lbs of boost on my car, the duty cycle of these 24 lb injectors is maxed out. This is at around 50-55 lbs of fuel pressure under boost.

I am looking to upgrade to 30lb or 36lbs injectors very soon.
Old 03-30-2011, 11:26 AM
  #36  
dprantl
Race Car
 
dprantl's Avatar
 
Join Date: Dec 2003
Location: Atlanta, GA
Posts: 4,477
Likes: 0
Received 3 Likes on 3 Posts
Default

Originally Posted by killav
Chris,

I purchased these exact same injectors for my turbo project last October. I cut the grooves into the injectors just as you are doing. I wanted to let you know that I did change out the O-rings. The o-rings that ship with the injectors, especially the top ones that plug into the metal fuel rail, were slightly smaller than the stock ones. The o-rings that Roger sells are bigger, and are a much more snug fit. Just FYI.

Also as a benchmark, at 7lbs of boost on my car, the duty cycle of these 24 lb injectors is maxed out. This is at around 50-55 lbs of fuel pressure under boost.

I am looking to upgrade to 30lb or 36lbs injectors very soon.
Don't do 30lb or you will be upgrading again soon. I was maxing out 30lb injectors, so I went to 42lb and was done with it. Since you have access to a Sharktuner, you shouldn't have any issues running 42lb'ers.

Dan
'91 928GT S/C 475hp/460lb.ft
Old 03-30-2011, 12:20 PM
  #37  
killav
Rennlist Member
 
killav's Avatar
 
Join Date: Apr 2006
Location: North Richland Hills, TX
Posts: 1,534
Received 7 Likes on 5 Posts
Default

Dan,

Cool-thanks for that info. The car does not lean out with the 24 pounders. I currently have the air/fuel ratio around 11.5 or so to 1 at WOT. If I were at 12 or 13 to one, the 24 pounders would more than likely not be maxing out.

Not to hijack, but I do have a lot of cells in the meat of the power band that are in the high one hundreds out of a max of +127 on the cruise maps. I am using a custom injector size of 22lbs as well which fools the LH and keeps the all of the cells from reading +127 over a large swath. I'm sure 42 pounders would bring these numbers way way down.

The five-O injectors work great and have performed flawlessly.
Old 03-30-2011, 05:48 PM
  #38  
Hilton
Nordschleife Master
Thread Starter
 
Hilton's Avatar
 
Join Date: Jun 2006
Location: ɹəpun uʍop 'ʎəupʎs
Posts: 6,279
Received 54 Likes on 44 Posts
Default

Originally Posted by killav
The o-rings that ship with the injectors, especially the top ones that plug into the metal fuel rail, were slightly smaller than the stock ones. The o-rings that Roger sells are bigger, and are a much more snug fit. Just FYI.
Mike, the S4's and later need a larger lower o-ring, to seal the larger hole in the intake.

My understanding from other posts here on Rennlist is that the early 32V motors use the stock Bosch o-rings that new injectors come with for both top and bottom.

Chris, I'm watching with interest - my tracking info for my 19lb injectors hasn't been updated since they got to Oakland in CA.. USPS seems to be borked lately for international shipping.
Old 03-30-2011, 06:02 PM
  #39  
Landseer
Rennlist Member
 
Landseer's Avatar
 
Join Date: Sep 2007
Location: Johnson City, TN
Posts: 12,143
Received 356 Likes on 205 Posts
Default

I thought about the fact you were still waiting.

Its 41F and raining here --- garage is already full of other 928's on jackstands --- am on the fence about installing tonight. Fingers crossed they'll wake up this car though.

I've got a bunch of those O-rings from Bosch kit 1-287-010-704 that roger supplied for my 86 car, and that fit the 944 too, but they look to be same diam. More to follow.
Old 03-30-2011, 06:45 PM
  #40  
killav
Rennlist Member
 
killav's Avatar
 
Join Date: Apr 2006
Location: North Richland Hills, TX
Posts: 1,534
Received 7 Likes on 5 Posts
Default

Totally missed that this was for an 86 not an S4. Sorry.
Old 03-30-2011, 07:23 PM
  #41  
Landseer
Rennlist Member
 
Landseer's Avatar
 
Join Date: Sep 2007
Location: Johnson City, TN
Posts: 12,143
Received 356 Likes on 205 Posts
Default

Hilton's is S4, he awaits injectors.
Meanwhile, while we wait, I'm working on the 85/6 using design III.

Good post anyways, highlights the issue.!
Old 04-02-2011, 02:23 AM
  #42  
Landseer
Rennlist Member
 
Landseer's Avatar
 
Join Date: Sep 2007
Location: Johnson City, TN
Posts: 12,143
Received 356 Likes on 205 Posts
Default

OK.
Injectors are installed.
This has finally solved the weird sluggishness of my 85 platinum car!
Unbelievable difference.

Some pictures
Attached Images      
Old 04-02-2011, 04:52 AM
  #43  
Lizard928
Nordschleife Master
 
Lizard928's Avatar
 
Join Date: Apr 2003
Location: Abbotsford B.C.
Posts: 9,600
Received 34 Likes on 25 Posts
Default

I just installed design III siemens 60# injectors today and got a little sharktuning done.

Need more tuning for sure though.
Old 04-02-2011, 05:23 AM
  #44  
Hilton
Nordschleife Master
Thread Starter
 
Hilton's Avatar
 
Join Date: Jun 2006
Location: ɹəpun uʍop 'ʎəupʎs
Posts: 6,279
Received 54 Likes on 44 Posts
Default

Originally Posted by Landseer
OK.
Injectors are installed.
This has finally solved the weird sluggishness of my 85 platinum car!
Unbelievable difference.

Some pictures
Nice pics Chris, thanks. My yellow 19lb Design III's turned up this morning - they're used, but I've ordered new plastic caps and already have new o-rings for them (top are correct Bosch size, and bottom ones are from Roger to fit the S4 intake). I'll also test them on the bench using a 12V supply, a momentary push button to pulse them, some fuel hose, and compressed air to push the injector cleaning fluid through at 45psi or so.

I'll post some pics of the injectors in the rails once I get the rails off the car (tonight), comparing the fit of the grooved design III's versus the Design III's shown in post 1 with no grooves or thick collar to cut them in, versus stock.
Old 04-02-2011, 08:34 AM
  #45  
Hayk928
Instructor
 
Hayk928's Avatar
 
Join Date: Oct 2009
Location: Close to my sharks - Hamburg
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Default

Hi Hilton & all,

Today I got my 24lbs injectors from Five-O - Bruce told me that they will fit without any changes except the 16mm o-rings. Bosch p/n 0280156013.

Name:  injectors.jpg
Views: 3606
Size:  114.7 KB

I'm going to update after fitting them.


Quick Reply: Injectors - choosing the right Design III (and some II info)



All times are GMT -3. The time now is 01:36 PM.