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Hey I have started working on the car since I got it on 05. I have JWT 260 degree cams, valve springs, a nismo intake, headers, full custom true dual 2 1/4" exhaust, NX stage 1 wet kit, and greedy e-manage tuner. I realize these aren't the best parts after reading some N/A builds on here. I have just recently figured out the massive restriction to power that is the factory intake, maf housing, and plenum. I want to focus on this problem first before going into the bottom end. The maf housing must be enlarged I know, and I plan on piping my own 3" intake from intercooler piping,
What I need to know is:
-Throttle body larger, need a spacer, what?
-Also what plenum should I use? Is the factory one with a spacer ok, I see one guy ported and polished his to get over 300. Does anyone know anything about the Kinetix V+? It is suppose to be like stock but bigger and less restrictive like a ported version. I know their SSV sucked really bad but anyway...
- also I want to port the part of the intake that the fuel injectors are mounted to, it is really easy to get to but I don't know a good shop around this area. It is small so I would consider shipping it somewhere.
I hate to keep going and going but I have a lot of questions. The blitz throttle controller, is it a good mod?
If your making your own intake remember the shorter the distance the air travels to your engine the faster it can draw air into the manifold which is one reason why i'm opposed to CAI.
What's your evidence that makes you point your finger at the stock manifold and TB for being insuficient?
throttle body - stock is more than enough at the point where you are at
mass air housing - you're nowhere near the point where you would need to consider one
porting - if you don't have a flow bench and a manometer, skip it...you can end up being worse than stock. The most restrictive aspect is the lack of balance of front to back cylinders and the spacer does a great job of alleviating the majority of this issue.
intake - the absolute least important aspect of the whole setup....stock with a decent filter will work just fine, as will any other intake on the market (some require significant tuning, some don't)
I know I don't "need" the bigger maf and throttle body yet but I wanted to get it done first since it was cheaper than doing the bottom end which I will do later. Do you think if I do these things first I will loose hp?
by don't need, I mean neither one of them will do you an ounce of good. The throttle body is not small on this car. You're at the point where you either go full bore and build a motor (assuming you want to stay NA), or be content with where the car sits power wise. Gears are also worth looking into as well
I've never used the throttle controller - others have, a few reviews were posted
Measure the pressure restriction from atmosphere to any point including plenum with an accurate peak hold/averaging manometer you will see less than 22" H2O or < 1.5" Hg at HP peak rpm it might be 15% higher at redline.
If you calculate 22" [22/27.7] = 0.794 x 6.8= 5.4% pressure loss*...................as always the valves [lift/curtain area] are the biggest restriction.
As a side note for years carbs were quoted in CFM at 1.5" Hg flow....the exact same as the pressure loss to Nissan plenum.
*If 14.7 psi in atmosphere, then plenum at WOT is 14.7 minus 0.794 psi and reads 13.9 psi WOT.
Of course the valves are big restriction but since I will be NA/nitrous I wouldn't need bigger valves correct? I just always assumed that bigger valves were not nessecary unless you are pushing massive amounts of CFM with FI.
Starting a build need intake advice+
