I've been searching quite a bit lately and haven't come up with any answers so I have a few questions for you more experienced FI guys so bare with me.
I see not many people have aftermarket cams on their car, is there a reason why not many people buy them? If anyone does have cams, do you have any suggestions as to what brand to get and how much rwhp gains can I expect?
I have a vortech supercharger running 8psi with a 3.12 pulley, exhuast, headers, new injectors, e-manage ultimate, valve body, tranny cooler, and torque converter with 350rwhp. Now would it be a good idea to get new rods and up the psi or would yall suggest other parts to go along with the rods. I want to get around 450-475rwhp so any help will be considered and appreciated.
Thanks in advance

 

With the AT5 its hard to get that WHP your looking for . I have built motor 8.5 to 1 pistons , rods , at 13 to 14psi with a T-trim blower , bigger IC , bigger IC pipe , Nismo cams , headers ,no cats , 2 1/4 inch dual exhaust , return fuel system , 550 inj. , and w/m injection . With a conservitive tune on a Mustang dyno I'm at 425 whp . Could get 10 to 15 more whp , but I dont want to take a chance with out a better EMU . On a DynoJet dyno I woud think it would dyno around 460 to 480whp . Remember ...you need 14.7psi to double your whp when N/A with a supercharger .

 

why did u go with such a low compression? I bet with 11:1 ratio psitons u can gain around 20+ hp. I understand turbos going low compression so they can boost more psi but for sc it's similar to NA setup.

 

stock compression and 8 or 9 psi , would have been fine . 14 psi is getting up there and I am looking to boost safely . I was expecting more boost also . But belt slippage stopped that for now .

What makes you think a SC is more like a N/A set up ? Boost is boost . 14psi with a SC is the same as 14psi with a turbo . Except you will lose less power to the wheels with a turbo

 

I have 10.5:1 pistons with my build. I don't believe the difference between 8.5:1 and 11:1 would be that great (20 whp). The issue with higher compression pistons is the increased risk of detonation with higher boost. I have the 3.12 pulley on now and am real hesitant about upping boost to the 2.87 pulley. If I did so I would need to add a lot of other precautions to lower coolant and oil temps, etc. When my engine was built, we put in a stock head gasket. I would definitely want to put in a better h/g and upgrade the studs, etc., if I increase boost at all. I am wishing that I went with about 9:1 or so to lower the risk of detonation.

 

Ya, I hear u about the risk of detonation but with 10.5:1 I think that is just right and I doubt the risk of detonation would be that great since your rods/pistons are already upgraded to handle the pw.
I'm not sure why u havent upgraded to the 2.87 pulley when u have pistons/rods? Why would u need to worry too much about oil temps unless u plan on tracking the car every wknd or always have a lead foot when u drive. how much hp are u making now with the 3.12 bc I dont even think u really need pistons/rods unless u pushing over 400hp?

 

I was having overheating issues with my built block and it was never concluded if it was due to air in the lines or head lift. However, there was some audible detonation happening. Before I tore the block down to replace the head gasket and upgrade the studs, I had my mechanic install the head strengthening mod (purchased from overzealous1 on my350z.com) which seems to have worked. (I also had the tune tweaked). But i can never be sure if it was the mod or if we finally just bled the coolant system completely.

Heat is the enemy. I want to get things as cool as possible before I crank up the boost any higher. Also, i am a little short on $$ and I can't afford to tear down the engine to replace a head gasket at this time if the need should arise. I am in the process of adding J&S Safeguard and will feel a little better once it is in. A built engine is not bullet-proof, you still need to take precautions.

My last dyno run a few weeks ago was 410 rwhp/340rwtq.

 

wow 410rwhp on the 3.12 is good. I'm only at 350whp with the 3.12 pulley so at most I can gain with 2.87 pulley is 380whp.

 

I think the big difference on my setup is all of the other items I have. there is increased flow from Crawford plenum, the headers, hi-flow cats, and exhaust. That coupled with a great tune on the emanage ulimate, larger injectors, etc.

 

I have basically the same mods. MREV 2+ with 5/16spacers, borla exhaust, alphawerks hearders, kinetix hi flow cat, EU, 380cc, and fmu/inline pump. I'm still puzzle why my numbers are soo low. The only reason I see from the dyno is my A/F ratio up top is around 10.5 which I think I could have been in the low 11s instead and it was around 96 degrees.

Anyone know if going from 10.5 to 11.2 will net much hp difference? It seems like most ppl with my mods and 3.12 pulley are at least getting +380hp. I'm really tempted to go out and try a different dyno to see if the numbers are constant.

 

Dyno could definitely make the difference. FYI, my numbers are from a Dynapack dynamometer. Like you say, ou mods are similar. Only differences seem to be I have full return fuel system, 440 inj., and tuned A/F ratio is quite a bit leaner (mid 12's).

 

Mine are set pretty much at a flat 11.8 -

Rick

 

After looking at my wideband more closely, I noticed it staying in the 10.0 all the way to redline. Is that just too rich and maybe the reason for my low hp?

11.8 would be nice if i actually had pistons/rods but with stock setup I think 11.5 is the most I would like to be at.

Anyone know how much hp difference between 10.0-11.0 a/f ratio?

 

I have the stock vortech set up along with - Fluidampener crank pulley, 5/16" spacer, Strup headers, Crawford HFC, and HKS exhaust (no other mods) and i'm 355 rwhp. With the 3.12 pulley, you should deff. be up near 380 rwhp depending on your tune

 

350whp is alot of power.!!