I was going to order 42# Racetronics when I ordered my Racetronics plug and play fuel pump this last Friday. I'm putting out about 440 RWHP and my stock 26.4's from 6,000 rpm up are going to almost 15/1 afr and my fuel pressure is dropping to about 40 psi. From reading multiple posts there seems to be a potential tuning issue with the Racetronics. The sponsor I ordered from convinced me I would be better off with the 30# SVO's. I told him I was going to a 402 next year and that is why I was considering the Lucas 42's and he said I still would be better off with the 30# SVO's. In fact he said they just tuned a 427 that was running the 30# SVO's and it ran great. Are the SVO's the right decision?? I need to know ASAP before the order is sent out!!!!!!

 

You can get FMS 42lb injectors on ebay for 240 plus 10 shipping, used these on about 330rwhp plus a 150 shot and they work great.

 

Are those Bosch or Delpi/ Lucas. Also Nothing comes up about fuel on Futral's site. My main concern still is what size is optimal?

 

30 lb injectors will work out to 34-36 lb depending on fuel pressure...I think you'll be fine with those

 

Link please.

 

I ordered the 30# SVO's after talking to Paul at Thunder, he says they are using the 30# on 402, 408 and 427 as long as they are not blown. Appearantly you get fuller use of the duty cycle and better atomization using the smaller injector. The was I understand it is an injector at 50% duty cycle is not as efficient or doesn't produce the power as one at 90%. My friend who will be putting out almost 500 rwhp just ordered the same injectors.

 

you dont wanna run the injectors over 80% duty cycle. personally i would have went with the larger ford ones, 42's. you could have also used the GM 36#ers as well. for 480 rwhp at 80% duty cycle 37# injectors were the limit. i went with 38# injectors myself. they are racetronix and arent too bad since the cam install. 30# fords are rated at a lower pressure so they are actually mid 30's right? i have about a 65% duty cycle with f13 cam and out of the box afr heads, bigger intake and maybe getting the heads shaved made me want to go bigger on the injectors. i havent seen anything to show that a lower duty cycle produces less power than higher duty cycle though. once you get a high pulse width it wont really matter IMO, also depends on the injector style

 

Link to buy FMS 42lb injectors for $250
http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

 

I understand what you are saying, I definitely had planned on the 42# because next year I want a LS2 402, but Paul was adamant that the 30#'s were the way to go. When you think about it Thunder Racing has put together some of the fastest LS1's in the country. Also at 58 psi the rating is 35#. If I screwed up it won't be the first time.

 

I"m running the FMS 30# units and they work great. Nearly 440rwhp.

$230 I think from Summitracing.com

 

New Era Performance (sponsor) has them even cheaper, $219.95 for eight!