Hello. I'm not entirely familiar with 350z tuning. I bought a used 350z with a vortech supercharger with 3.12 pulley. I was trying get it tuned (since everyone recommends it). I found out the the I have a bad split sec box (from GTM and Stillen) and it has 12:1 AFR. What are my options?

1. Replace Split Sec Box use existing fuel upgrade from Stillen (approximately $600 +$300 installation and $350 dyno tuning).

2. Buy Utec and upgrade to 440 injectors, fuel pressure regulator and walbro 255 pump (approximately $3,000 including installation and tuning).

3. Remove Split Sec, install 440 injectors, fuel pressure regulator and walbro 255 pump, and tune with factory ECU using UpRev Osiris programmer (approximately $600 for tuning and $1,300 for installing fuel stuff above).

I'm not sure what the best option is, and if UpRev can even tune it. Can anyone shed some light. Sam from GTM recommends options #2, but obviously it's the most expensive one. I like to do Option #3, but is it possible to scale new injectors and pump using the UpRev Osiris?

 

The answer to that question is a tentative 'yes'. The only drawback is that the Osiris uses the MAF for it's reference data instead of relying on speed density with a MAP sensor. Several members on these boards have gone this route with good results.

As you can tell by my sig., we went with your option 2, as Sam recommended to you. We were advised by Jeremy at Performance Factory and Mark at SGP to go with the UTEC and the upgraded fuel system as the most reliable and flexible method. As our setup is used as a daily driver, this was the most important thing for us and the overall cost was a secondary consideration. There is no absolute 'right or wrong', just different options and you will need to pick the one that best meets your needs.

 

Talk to Shawn Church about UpRev if you go that route.

 

+ 1 ^^^^^

But I think $3000 for #2 is pretty dam pricey....yeh...yeh....I know you get what you pay for , but a Utech and tune should be around $1200...$1800 more for injectors , preasure regulator , and pump .....installed...is deep.

 

How did they determine the Split Second box was bad?

 

I've went to GTM and Stillen, and they both concluded that the Split Second is bad. It doesn't seem to cooperate with the laptop computer when they hook it up. I think Sam at GTM spent the whole night trying figure it out (sincerely appreciate the effort).

 

I agree that it's a little bit pricey, but it includes taking out the "hard-wired" Split Second box (which I'm a little nervous to take it to any shop) and auxillary fuel pump that comes with original Vortech kit. I think the fair price is around $2,500, but I'm willing to pay him the extra $500 because he'll guarantee me that everything will work perfectly or I get my money back.