I am looking at upgrading my secondary injectors and am in need of advice as far as what I should use cc wise and also what any suggestions would be for gear to use. I currently have a pettit unlimited ecu with fulll exhaust and all the normal bolt ons except for Fmic which I will be installing shortly. I thought Jay (TurboVr6) did write up on his install but I havnt been able to find it. Oh yeh I already have a supra TT pump. Thanks!! https://www.nopistons.com/forums/pub...IR#>/bigok.gif

if you want to put larger secondaries..... i'd go for the 1600's and a powerFC. if you want drop in's you can get your 850cc bored out to 1300cc.... i like the idea of brand new fuel injectors though

Does anyone know exactly what a Pettit unlimited is tunned for/to?

I thiough the standard upgrade was 850 primary and 1600 secondaries..

pettit unlimited is tuned to every bolt on upgrade and ported engine. it basically runs the stock fuel injectors up to 100% duty cycle so it won't lean out!



most people go 550/1600's



i went 750/1600's.......

So what do you guys think of me using 850's primaries and 1600 secondaries? Also does anyone have a good write up of installing regulator and braided lines with fuel rail? Thanks Ps the reason I am persistant on using 850 primaries is because my 550's are leaking right now.

if you buy keith's rails you can buy brand new top feed injectors CHEAP

Im awaiting a reply from pettit so I know what the capabilities are of my ecu. That is unless any of you are certain and can share some info https://www.nopistons.com/forums/pub...IR#>/bigok.gif

pettit's ecus cant adjust for bigger injectors

So pettit says "unlimited" but obviously there has to be mods you cant do under ecu limits. Anyone know the extent of what i can do with this ecu?

sr motorsports sells brand new 1300cc..

they are brand new factory 850cc bored out..

so in essence..they are brand new injectors..

pending on your application.. 1300cc can provide enough fuel..

considering youve mapped out your pump and regulator to adjust..

4 850s will give you enough fuel for 375rwhp at 88% duty and stock fuel pressure. Dropping the 850s in the primary rail at stock pressure should be fine for the twins-assuming you set boost with the intention of having them last more than 6 months. This setup is supposed to be very easy to dial in and will cost you next to nothing.



If you need more fuel down the road you can add an aftermarket FPR and bump the fuel pressure up to 45. That will support enough for 400rwhp. Alternately, you could resell the 850s for around what you pay for them and spend the money on a new secondary rail, FPR and injectors. I think going with that setup initially is overkill. Keep in mind there are tradeoffs too. I have yet to speak to someone with 550/1600s that hasn't had part throttle transation problems.

I'm not saying it can't be done, but I personally have yet to hear about actual success.



Finally, you can take the money saved on injectors, sell your pettit comp and buy a PFC. You can pick up the ECU itself for $825.00. The commander is nice to have, but not necessary. Find a friend who has one and mooch off him https://www.nopistons.com/forums/pub...>/rolleyes.gif

And don't listen to Vosko, he enjoys breaking things. https://www.nopistons.com/forums/pub...IR#>/wacko.png