So I finally put on the 3.12 pulley on my 5AT G35c with stock H/E and here are the results.

Current mods:
3.12 pulley
550cc injectors
Greddy EU
Walbro Fuel Pump

The tune is great. The throttle response is 10x better than it was with the SS box. I remember with the SS box the car would stumble slightly sometimes and it wasn't as smooth, but the EU is great!

o, and I haven't blown any coils yet, lol...(knock on wood)

The dotted lines are from the 3.33 pulley and SS box...





We had to scale down the power up top because it was detonating so my peak hp isn't amazing, but the meat of the "curve" is nice. I'm fairly pleased with the results, but boost is a drug for which there is no rehab

 

Nice soild increase in boost about 1 psi which would be expected with the 3.12 pulley.. The A/F is a lot smoother above 4800rpm which would explain the difference you noted. With the 550inj and walbro what is your fuel pressure at idle and under non boost? Did you modify the wabro so as not to have the fuel press go above 80psi..

 

Exactly. I really didn't like that the SS Box could only be tuned every 500 rpm and not by boost. The walbro had the TN modification done, and I am not experiencing the "1/4 tank is actually empty" scenario. The 550cc injectors are also at about 80% duty cycle.

I see you have 440cc injectors and I'm assuming you have the 3.12 pulley. How much boost are you seeing at redline and what duty cycle are your injectors at? According to my tuner's calculations 440's would be pretty much maxed out with a walbro, which is why we went 550.

 

I see 9psi. I don't know what the inj duty cycle is but it was tuned with them and the walbro and no indication of leaness up top...What is your fuel pressure...Do you have a gauge? When I was with the stock fuel and 3.33 pulley, fuel seemed to be ok with a little leaning up top. In adding the 3.12 pulley which raised the boost 1 psi I rationalized it should also be ok..Next time I tune I will try to get the duty cycle..

 

I currently don't have a fuel pressure gauge, but my installer indicated all is well after the mod to the walbro. I've noticed that Z's seem to get more boost out of the 3.12 than G's. I wonder why that is. You would also think that H/E would lower boost so why I'm only getting 7.5 is a bit puzzling.

 

Rare that someone actually praises the EU these days

Nice setup

 

Thanks. Well, it's def. a big step up from the SS Box and it seems to suite my setup well as of right now. I was told by my installer that he did a mod with the EU to prevent the coils from blowing, so we'll see what happens

 

How big of a deal is it if one or two coils blow? You can still drive your car somewhere to get new coils right? just, with less power... ?

And they can be installed in about 1 hour I'm thinking?

 

True, but other members seem to make a big deal out of it. I stocked a few just in case, lol.

 

so does this graph indicate 370whp/330wtq? good job

 

Indeed I thought people could figure it out for themselves, lol. I gained 30wtq and 30hp from the 3.33 pulley except up top because of pulled timing due to detonation . Not bad for an additional ~1.5 psi.

 

Congrats Andy, looks good & solid.

 

I was sorta asking a real question, I wasn't trying to make it rhetorical

can you drive the car with a blown coil or two, at least far enough to get it fixed? and it's a quick fix right? ~1 hr?

 

U have to remember dynopak read about 10% higher than youre regular dynojet but it's pretty good especially when u dont have headers/exhaust.

Also, I'm very surprise with 550cc u are already at 80% duty cycle. Something doesnt add up there. I would get a fuel pressure gauge hooked in the cabin and see where u stand when u are at WOT. I'm beatting its in the lo 30s due to having no return line and regulator.

 

Nice tune , Im surprised you didnt get more boost out of the smaller pulley .

You are mistaken when you said you cant tune via boost with the SS box . Yes..when tuning by rpm , its every 500rpm . But you can tune via boost and that is every .5psi of boost . I have mine tuned to 15psi using boost only for timing and fuel . My A/F curve is pretty dam smooth . Just as if not more so than your's with the EU . The trick to getting a good transition between the stock ECU and the SS box is best done at 1 to 3 psi instead of the onset of boost

 

so they say

i'm going to check out my fuel pressure soon...i have a couple other loose ends i need to tie up regarding the car.

what matters most is how it runs, and it runs great

 

I was very surprised myself, but from what I've seen, the 350z is getting more boost from the vortech as well as different year. I'm not sure why, but it does. Every car is different as well, so I'm not too bummed. What I was more dissapointed by was that I was detonating up top and had to pull a lot of timing

I stand corrected regarding the SS box...

 

So the TN mod to the Walboro gets rid of the high idle problem? I would think 550's are a little overkill for just the 3.12 pulley. Are you thinking of upgrading to the 2.87 later on? Btw, did you get to test out that non-slip machined pulley yet? Thanks.

 

Yes, the TN mod is supposed to keep the fuel pressure in check. I will have a fuel pressure gauge installed soon to take a look if it really does work

It is a little much, but yes I will be upgrading soon. I will be trying a 2.8 pulley from reichard racing along with a larger crank pulley, re-routing the belt setup and using an external wastegate with ebc to bleed boost off at 8-9 psi. I was talking to a couple of mustang guys and have a few ideas of how to improve on the Vortech setup. I know a couple people have tried it with limited success, but my shop and would like to try it as well . Will def. keep everyone posted of the progress.

 

I dont mean to sound dumb here but whats the DISadvantages of having a smaller pulley? I know that increases boost. Is there a down side for having a smaller one?