Visual differences between 550s and 650s?

[Rice Over Wheat]

My injectors are Delphi 650s from Forced Performance. When I bought them, they were sold out of 550s so I got these instead. They came in a ziplock with a simple label saying DSM Delphi 650 injectors. Now anyone who's read my tuning threads can see that I've tuned most of my knock out with -20% HI settings, +/- a few adjustments here and there. Other people with 650s usually find themselves well tuned around -29% to -32% HI. When I try to lean out beyond -20% I get lots of knock when I should be pig rich.

What if they put the wrong injectors in the bag and I have 550s instead? That would put me much closer to the optimal tune of -18% for that size injector. So, is there any way to tell visually between 650 and 550 Delphis?

They are the typical grey/black ones. They look like these:

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...but oem lower injector seals sit right in the groove in the nozzle and not so high as whatever is in those pictures.

 

[CanadianTSi]

Do they have 650 scribed in them by hand as the Injectors in the Pic do?

 

[Rice Over Wheat]

Yes, but if it's hard to see any visual difference, it may be possible they mixed them up. Heck, even if one or two of them were 550s my fuel delivery could be all out of wack. I just can't think of any other reason why I can't lean further than -20% without pulled timing when my afpr is set correctly, no fuel leaks, and pushing a lousy 28 lb/min airflow. 58* outside and I've never heatsoaked my fmic yet.

 

[CanadianTSi]

Well then the only real way to tell would be to send them out to be flow tested.

 

[Rice Over Wheat]

Might have to do that or swap with someone else with 650s and see if there is any difference. Because I was going to get an eprom and if it's set for larger injectors than I have I may be in worse shape.

Might be a dumb question but who does injector flowtesting?

 

[andymoraitis]

You can either send them to RC Engineering or FIC:

http://www.rceng.com
http://www.fuelinjectorclinic.com

Both of them provide flow testing and cleaning services

Cheers,

Andy

 

[kraka]

Agreed...If you cant tell by identifying it, then a flow test should show the results...

A good cleaning wouldn't hurt either

 

[Rice Over Wheat]

Well they are brand spanking new so I don't think they need cleaning. But the flow testing sounds good. I'll probably buy an extra 650 and swap one to have it tested. Thanks for the advice guys.

 

[selmerguy]

What are the numbers on the rail side of the injector? There should be about a 12 diget nu,ber with a space about 4 digets into the number.