Just ordered mspnp
 

Ok so i just ordered MS w/ wide band and IAT Sensor Kit, and am now wondering about injectors. Right now i have the 305 injectors and was wondering if anyone has tryed to keep those injectors w/ the vortech presure raiser and ms, Insted of buying larger injectors. my goal is 250whp. I have a buget and need to know if i have to fit injectors in there or not.

If you sold your injectors and vortech you could buy some nice 550s.

I know you didn't ask this. But do you have a 9 pin serial port on the back of your laptop? If not, buy their serial to usb adapter. It will save you alot of headaches. My radioshake adapter doesn't always work right.

Just my 2 cents.

I did order the adapter. Sorry i didnt specify. Wide band, IAT. Will i need anything elce?

the whole point of ms is to get rid of band-aids. get the right size injectors

OK i think ill just get the injectors. Thanks is there anything elce i should get? Do i need 550's or are the 460's good for what im trying to do?

im running 13 psi on 460ccs, working fine with headroom.

250HP is kinda on the borderline between 460 and 550. A lot is going to depend on the turbo that you are using, the overall efficiency of the system, basically too many variables to mention.

With my 465 injectors, I get nice, smooth AFRs with 13-14 PSI on a little TD04H-15G turbo, with <85% DC, however I've never dyno'd the car and so quite honestly I have no idea what WHP this equates to.

There's a nice little injector calculator that you can play with here: http://www.rceng.com/technical.aspx#...tor_Worksheet_

For 250, you're gonna want the headroom of 550s.

How about fuel economy, I i know most of it is in the tune but will low speed in town milage be any different between 460's and 550's?

MPG will be all about the tune. you could run 1000cc injectors, and get the same MPG, as long as your car is tuned for them.

Ok that solves that. Thanks everyone for the advice.

I'm in similar shoes to yours - bought MSPNP about a month ago and installed it with the vortech and 1.6 injectors for the time being. I'll give you a bit of info I've found to reinforce the 'get bigger injectors' suggestion.
For the 6 psi that the car runs at at the moment, the vortech can supply the fuel for it but in datalogs I've noticed that even with a very smooth fuel table, no adverse enrichments kicking in, etc. The AFR still bounces around within about a 0.6:1 range. I imagine this is because the smaller injectors are having so much fuel pushed through them that an extrememly steady flow rate is nearly impossible.

I have 460's at injector rehab right now. When they get back I'm installing them. I expect that with correct fuel tuning with injectors that can correctly flow the necessary fuel, one can get the fuel curve to be very smooth. The higher boost and more aggressive timing you are running the more crucial this is. I remember reading Savington saying once that he would be pinging if his AFR was fluctuating as much as the guy's he was talking to - iirc that guy had ~0.5:1 dips and spikes in his AFR.

So, for your car, the 302's may mathematically be able to supply enough fuel for your goals when you factor in the high fuel pressure, but in my experience a band aid fuel pressure riser doesn't seem to be able supply as steady of a AFR and at 250 whp, that could mean a quick death to the motor.

my 0.02
-Ryan

your car looks pretty baller.

Ok i just ordered the 550cc injectors for $250 with tax and shipping. Does that sound like i payed a fair price?

i gave $75 for my 550 rx7 injectors.

Be sure to send them for service.

That is a horrible price. You didn't buy the ones off ebay did you?

No i got new ones from auto parts store. I figured new is better than old ones that need to be cleaned, may be not possible to clean bad injectors from ebay or some guy. They came with a 7 year 70,000 mile warrante.