Matt H

I am going to order my injectors this afternoon, just trying to decide between the Delphi and the Siemens. Both are low impedance. The Delphi's are a cone spray pattern where the Siemens are a pencil beam pattern. Price difference is negligible. I suppose my preference is the Delphi's but I thought I would ask one last time.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

tommo951

Hi Matt,
Read this article http://www.lindseyracing.com/Merchan...e=944INJECTORS

you may need to paste this into your browser.
I have gone for the Siemens as I did not want ballasts and they seem to right for the application however if you have set your mind on Delphi's well that is the way you will go!

Cheers & Good Luck
Tom

Matt H

Tommo, thanks. I dont like Lindsey at all as an FYI. Either way Siemens or Delphi they "require" resistors. I will not be using them either way. Having spoken to some of the most knowledgable people in the business I see no need to run them. Any of the Low-Z injectors are recommended to use with the resistors. Bosch used 5.5 Ohm which is damn near unheard of. Thanks for the link. I was really asking more about the spray pattern.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

tommo951

Matt,
It was my understanding that Bosch used 2.75ohm not 5.5, the circuit impedence is 5.5ohm as they run serial circuit. Maybe my info is wrong?
Have you had a problem with Lindsey Racing? I have always found them quite good
Well spray patern is going to be down to quite a few factors including port dimension/distance relative to valve opening and induction speed. I seem to remember an article I read years ago by one of the senior engineers at BMW on this subject. I'll see if I can find it and send it over to you.

Cheers
Tom

Matt H

Thanks.

I have never been able to get anyone there to return numerous emails. The one time I got them to answer the phone they were rude and uninterested in my business. Later that day I spent 4K with another vendor and 2K with yet another. I have found their customer service to be poor and their website to be full of "Salesman" garbage.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Charlie944

Matt, with much research myself over the Siemens vs Delphi I decided on the Delphi's. This choice was made due to what I read on this site: http://www.supras.com/~riemer/sonict...rs/RCtech.html
and from what Danno had on his Guru site. I also emailed him with a few questions as well. I have not yet fired the car with the new injectors so I cannot offer any insight there. Hope that page helps. Pics of the Callaway exhaust manifold are coming soon to you.

Take Care!

Sam Lin

The cone spray pattern is the better choice, but the Delphis have indeed had a few reported issues when run with extremely high fuel pressures.

Sam

Jake951

I've measured the resistance of the stock Bosch injectors and they are 5.5 ohms, not 2.75. Put two in parallel, as they are driven from the DME, and you get 2.75 ohms.

porshhhh951

If it help's I have never had one issue with my siemens injector's. I run pretty high boost level's and fuel pressure.

Your lindsey problem is very different and to my knowledge un hered of. Did you call the right number??? lol. Dave has always given me exceptional service and advice. He infact talked me down on my head from a stage 2 to a stage 1....which takes around 800bucks outta his pocket. He said for what I needed from my car performance wise I really didn't need the stage 2 head.

OriginalSterm

i can tell you for a fact that some of the stuff from tommo's post linking the lindsey site is false. i can tell you for a fact the delphi injectors are tested at pressures as high as high if not slightly higher than what you may see on a 951.

matt, when you say pencil vs cone spray are they specified in angles? because a true pencil stream can be an issue for vaporization, spray targeting, and extreme mixture heterogeneaty (extreme rich and lean pockets in the combustion chamber). this "description" of spray is common for injector cleaning places as well. i often see spray classified as "good" or "excellent". in the lab, spray is classified (for example) as "12 degree cone with 0.5 degree offset centroid, 50 micron dv90, 35 micron smd..."

Ideally, I think finding out the true spray characteristics of the original bosch injectors would be important to determine the appropriate (upgraded) replacement. I'm sure porsche did some testing to determine proper spray characteristics for the 8v head design coupled with forced induction.

having said all of that, has anyone had issues with either injector? or dyno tested both sets for comparison?

Red1

Tony G ran 72 lb Siemens with no resistors and no problems.

My Siemens are still patiently waiting for me to install them.

Matt H

Thanks guys, I decided on the Delphi's. After consulting some people whos' opinion I highly value they both said use the Delphi's. Kevin will be in town soon, I have gathered nearly all the parts to finish this monster so wish me good luck to getting it all ready to go in the next 3 weekends.

OS - Cone Spray Angle - 22.5 degrees - single spray cone. Approximate cone angle for 90% of spray volume on the Delphi, same data not given for the Siemens. Copied from Racetronix website. I know of no real problems with either.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

porshhhh951

sweet Matt. Let us know how the install go's man. I am very interested to hear about your car finishing up. I remember when you were in dallas and still getting things together a year ago.

Glad to see you came to a decision. I think both of them are good product's.

Matt H

John - my "Lindsey problem" is not unheard of. The first time I said it I must have gotten 4-5 PM saying the same thing. I was going to buy it all from them, as like you, I was just a few hours south. I asked if I could come visit the shop while I was there on business, no response. Asked again, no response.

Emailed about buying a Bilstein coliover setup, no response.

Called about buying a head, talked to the guy for about 3 minutes, sorry dont have one 3 weeks to do yours. Can I pay for rush, nope sorry, no time.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Matt H

I started the project about 9 months ago. God I hope I can remember how the wiring goes back together.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote