Stikya

iTrader: (1)

Could someone w/ a SARD FPR and nitrous tell me what size fuel jet you use (for around a 100 shot).

I've purchased 10 jets now and can't seem to get my psi under 100. I know a 100 shot only needs about a 87-90psi. What jet will yield this?

Stikya

iTrader: (1)

Comon', I know some of you out there have a SARD and nitrous. Speak up!

Sprint

iTrader: (10)

i don't think it matters what fuel jet you have.. because you are tunning the Sard to the optimum pressure you want.. so you could run a .042 jet.. be real rich.. and then tune it to 85 PSI for spray

Stikya

iTrader: (1)

You only tune the actual SARD at idle (using it's adjustment nuts). Once this is set, all fuel tuning is done with the nitrous jets and changing vacuum pressure (w/ the nitrous kit jets) while spraying.

And my thought is...

Everyone tunes their idle the same (38psi-ish).

And, the same SARD FPR, with the same fuel pump (everyone gets the Walbro), with the same fuel jet choice, will produce the same psi (on juice).

So, someone using SARD should be able to tell me what jet they use and what psi that yields, and I can assume I will get the same resutls.

See?

(I'm tired of buying jets, and making endless, expensive trips to the dyno w/ no results.)

Sprint

iTrader: (10)

ok.. well my SARD is sitting in my room.. and i havn't sprayed since March..

CalsonicSE

iTrader: (3)

It is NOT true that if everyone uses the same FPR, same fuel pump, & same pressure jet, everyone will get the same fuel pressure. ALL CARS ARE DIFFERENT. For example, some people use the biggest jet possible and they still can't get their FP low enough.

IMO, people with a high flow fuel pump and a FPR first compare what fuel pressure they are actually getting at N/A WOT to their desired fuel pressure, and then adjust their FPR correspondingly. The psi you'll get at idle will just be a result.

For example, I had adjusted my FPR until I got 43psi (stock #) at N/A WOT and idle ended up to be around 30psi. When I first adjusted the FPR to get 34psi (stock #) at idle, my N/A WOT fuel pressure was 48psi.

Also, the fuel pressure you'll get while spraying also depends on your bottle pressure.

Anyway, to answer your original question, with a Walbro, SARD, .042 nitrous jet, & .040 fuel pressure jet, I am getting 83psi when spraying at ~1200psi bottle pressure. N/A, I am getting 45psi WOT and 32psi idle.

Jime

iTrader: (10)

I have seen many, many bypass sizes to get the same fuel pressure in different cars, not exactly sure why but thats the way it is. My car used a .038 bypass to get 85 psi for a 100 shot but I have seen a lot of people have to move up to a very high jet to get the same psi.

The only way to eliminate all that and use the same jets is to switch to NX. Then you use stock fuel pressure and everyone uses the same nitrous and fuel jets for a given shot. Eliminates tuning because the nitrous and fuel jets are bench tested with a given fuel psi so that it always gives the same air/fuel ratio.

Stikya

iTrader: (1)

Well, thanks to all for the info. Based on this, I've adopted a new strategy....

I'm going to the dyno w/ a drill. I'm going to start w/ with my current fuel jet, and keep boring it out (little by little) until it produces a run where my FP is somewhere in the 90's.

Then I'll up my Nitrous jet, until my A/F is in the mid 12's, and call it done.

BTW, anyone know where you can get really little drill bits, increasing in size by small increments?

sx7r

iTrader: (15)

hardware stores or hobby shops have small drill bits. i ran no jet in the bypass tee at 1200psi and got 85psi fuel pressure.

Stikya

iTrader: (1)

No jet? Are you kidding me?

If you got 85 w/ no jet, and I want 90's (which would mean a jet just smaller than the width of the vacuum line) I may have a lot of drilling to do on that jet.

jdmmax

iTrader: (6)

i tried drilling out a fuel jet to get the fuel pressure down. heheheheh for me i was unable to get the fuel pressure down below 89. with one of my fuel jet drilled out till there was barley anything else to drill. hehehehe good luck dude!!!!!1