*Closed* 20% Off Supercharger Group Buy 2nd Gen 4.0 Engine

Yes, everything is installed and its running perfect.

Its pretty quick for a big heavy truck. The exhaust is louder than I'd like so I'll have to figure out a way to tame it some more.

UCON
2.55 pulley
7th injector
Walbro 255 pump
URD headers
URD y-pipe
URD exhaust

At WOT just before the trans shifts from 1st to 2nd gear (5700 RPM)
MAF flowing 320 g/s
Boost gauge showing a touch over 10 psi
6 main injectors @ 85% duty cycle
7th injector @ 39% duty cycle
AFR 11.5:1

With just the 2.85" pulley and everything else stock, MAF flow was 270 g/s. Now its 320 g/s. So a 50 g/s gain. Using a MAF-based calculation I've seen passed around, it added 59hp at the crank going to 2.55" pulley, URD headers, URD y-pipe, URD exhaust and 7th injector.

Eventually I'll get it on a dyno just for shits and giggles.

 

Hey mr login,

Which parameters shows the injectors on the data log ?

 

Look at the Inj tab toward the bottom. I believe it's dctxinj or something like that. I'm not at my computer at the moment.

 

Got it !

Looks like I'm at 68% / 30%. Installing 2.55 pulley tonight.

 

Did you do the fuel pressure regulator mod where you hook a boost port to it? Also do you have that maf calculation handy?
With OVTune close to releasing their hand held for these trucks I am considering getting the 2.5 or maybe 2.7 and bigger injections. Not sure if it's a good idea since I won't have A 7th injector to cool the rotors. I was considering doing a meth injection to cool it though, easier than a 7th since I wouldn't need a piggyback to run it.

 

Keep in mind when it comes time to smog your truck in CA, a 7th injector setup will probably be easier to hide than a meth setup. Both are technically not street legal here though. CA ruins all the fun stuff.

 

A little visual aid for others to see where injector duty cycle is located:

 

I'd like to see your dyno when you get one

 

No FPR mod. 43psi pretty much all times, though it does dip down close to 40 at 5700RPM/WOT.

Not sure of the original source or the accuracy but...

1GR-FE.... g/s x 1.18 = flywheel hp

 

This is true. I know a guy, how ever I think it just depends on how smart the smog guy is. With a 7th I'd also have to make sure they don't see the piggyback. CA is a pain in my ass, can't even legally have a cold air intake for crying out loud. But I can't be too salty, they allow me to bolt the supercharger up atleast.

 

That would put you around 380, not too shabby. I wouldn't be surprised if you were making even more than that, considering all the things you have done so far. At 85% duty cycle on your injectors that seems a little high do you think you should upgrade? I could be wrong but I thought I read that the injectors are pretty much topped out at 80%. Loving your setup, I would love to get ucon but for all my other mods I have planned it's a little too expensive right now. Especially since I would have to get a fresh ecu to utilize it's full potential.

 

I hear ya lol. I had the 7th installed a few months ago on my 3.4l and the piggyback ECU put up behind my glovebox so you can't see it unless the glove box is open and you look up inside and back in there. Only thing that really stands out is the shiny braided steel fuel line that runs to the back of the supercharger, but I figure I'll just wrap it in electrical tape come smog time so it looks like any of the other dozen vacuum lines around that area. But ultimately it really depends on how sharp/strict the smog tech is...knowing a guy is probably the best route to take.

 

The industry pretty much agrees that 80% is max D.C. I am considering larger injectors. Not because I'm planning to do anything more to increase power, but just for a little breathing room. Most of the time I'm not running WOT to redline so they only get that high on occasion when my right foot is feeling frisky.

 

Can the Ucon be used to drop the dc of the main injectors and make up for the lost fuel with the 7th?

 

I believe that's something Scott would need to adjust for you. I'm sure it's possible though, just not sure how that change is made.

But if you look at the numbers on mine, the 7th is already at 40%. That one injector can't do much more by itself. One injector vs six it would be at 80% in no time.

My thinking is that you want the main six to do all the work and the 7th to add just enough to do the cooling/sealing job.

 

I already talked with Scott and I don't even have a Ucon yet.

 

@loginfailed
Very nice setup, would certainly be interested in any dyno data.

What is your opinion of the 2.55 pulley and 7th by themselves, performance wise, vs. the rest of the intake/exhaust stuff you put on at the same time? I mean how much do you think is due to the pulley, how much is due to the rest of the gear?

And what size is the 7th injector vs. the other 6? I would assume the 7th is substantially larger, but you know what they say about assumptions.

Can a 7th injector be added with a factory air filter / intake? I guess the question would also apply to a std throttle body spacer on a naturally aspirated engine, but when you space the throttle body, won't the intake no longer line up with where it is supposed to mount and be supported? I would think that with an aftermarket intake, you could make up for it with the plastic piping, cut it down some, use a shorter rubber intake boot, etc.. but doesn't a spacer change everything about how the intake mounts, supports to the engine and / or engine bay?

 

Wow .. had me worried for a sec. finally got it off .

 

just one question:
HOW????