Just wondering what everyone's max kPA intake pressure readings are. Post your mods list and whatever else might affect this reading, and max dyno'd hp with your readings. Also, how does everyone think this reading relates to potential power output?

 

who has a boost (vacuum) gauge on their N/A car?

 

 

Maximum IM pressure on an N/A car? The highest pressure you can record in the IM of a N/A car is probably with the motor turned off, with the car located at a low elevation inside an anticyclone... At that point you'd probably get something close to 105 kPa absolute (or 3.7kPa gauge)...

 

I wonder what it is here at 7400' altitude.

 

I was just wondering because in modding my butt dyno showed an increase of hp and also increased my kpa substantially. I was just curious as to the correlation between the two. My VAFCII shows manifold pressure I didn't know it was deemed such an insignificant value my bad.

How would manifold pressure not be directly related to hp/tq? I just don't understand

 

mine reads just under 1,013 hPa at full throttle under ideal conditions, but that depends on whether or not the sky is clearing up or beginning to cloud, and how much water is in the nearest stream

 

Im more of a in Hg kinda guy........PSI is good to see too.

 

Very amusing...

sea level atmospheric pressure = 101,325 PA or 101.325 kPa

So let me rephrase the question. Has anyone else achieved greater than atmospheric pressure N/A? My goal is to break 130 kPa and chirp 4th. But keep going if you think it's still funny. I'm really scared of a "400 hp" turbo haha not



Beware the beast

 

i think it's funny still, but now that you've explained how you were measuring it I understand. I thought you had installed some autometer vacuum gauge or something on your N/A car.

i don't understand your comment about being scared of a 400hp turbo max though. I'm assuming it was directed at me since I think I'm the only one in this thread with a turbo max, but I don't understand where you were going with it (I can't imagine you're suggesting that your car is going to be faster N/A than I was with a turbo lol).

 

You are saying that your car is boosting N/A?
Don't know if supposed to be a joke, but I'll post anyway. :P

manifold vacuum has nothing to do with how much power you're making.
Just intake restriction. Other then ram air you can't go over ambient pressure..

 

It's the voltage interpretation of the AFC since the VAFC is designed for Hondas, which do not use a hot wire, and use a MAP sensor instead.


Get a SAFC, they read in MAF %, little better correlation.


And, even if "ram air", it doesn't have an effect until speeds close to mach 1, this has been discussed here before.

 

so it's not even a pressure reading (I didn't think AFCs had a pressure gauge but wasn't sure).

i'm back to thinking it's really funny.

 

Guys, isn't that what dynamic supercharging is all about? The helmholtz resonator. The length of the intake runners, varied in 2 stages with mods like the 00VI, etc, all working to take advantage of resonance to force (as in kpa) more air into the combustion chamber?

SicX6spd, what type of intake do you have.....did u get rid of the OEM stuff, like the resonator? I would suggest that you put it back and maybe free up air restrictions in front of the airbox. in other words, the OEM air filter box, all that plumbing in front of it like that snorkel that sneeks in air on top of the radiator, the U shaped tube the seems to route intake air into the side fender etc.

 

yes that is exactly what dynamic supercharging is. what is funny is that he's apparently getting phantom readings from the VAFC, not actual pressure readings.

 

The kPa reading is from the manifold pressure reading on the stock ecu. I am using dynamic supercharging to increase the amount of air in the intake and have tried many different setups.

I'm guessing Nealoc187 was one of the chicago "g"s that murdered a few people July 4th weekend. He got all butt hurt cause I said he can't drive his car right and I chirp 4th daily in my N/A and he's on his 3rd engine I'm on original stock clutch with 135k that does have to hurt

 

There is no MAP sensor on these cars. As stated prior. Please stop.

Not sure if trolling or serious but 95-99 MEVI's and 00-01 VI's have dynamic supercharging, 02-03's do not have such features. Even then, ... I'm not even going to try.

 

How old are you, like 12?

 

i chirped 4th daily as well, when i put on 12"s.

My BBmaf read 4.58V at 7150rpm, real map sensor (greddy) read -0.1 PSI, which i guess is -.689kPa. I haven't checked the VAFC pressure reading since i went SC, I will when i get back to the states.

If Nealoc is one of them "G"s, I have mad respect for him. He somehow managed to get pissed at your statement that you made in August, according to you get butthurt, and then travel back in time to the 4th of July and murder a couple dudes. That's pimp as hell.

 

95-01 cars do have a BARO sensor, however any VAFC installation that I see splices the harness directly to the MAF wiring.

Do you own a Honda? Because only Honda owners measure their car's horsepower and their driving abilities by the amount of traction loss that takes place.

GReddy boost sensor will read more accurately than your VAFC would.

In all seriousness, you should see positive atmospheric pressure if you incorporate some type of ram-air intake in a high pressure area (foglight/bumper area) at higher speed.

Read more here. http://www.8thcivic.com/forums/intak...-analysis.html

Anyways, nobody with a legitimately fast Maxima has this installed on their car, including Mr. Neal whos stock 4th gen's 1/4 mile acceleration is on par with that of the gravitational pull to earth.

 

We talked about this years ago on here, and it was calculated that the speed necessary for above ambient was too fast for most craft with tires. Needed wings for that.

 

 

lol i could unplug two coilpacks and still outrun you with my car NA, let alone when it was turbocharged.

let me know when you run 13s. meanwhile i'll be down here in the 12s and i won't be so confused as to which way is up when it comes to working on cars that i'm thinking I'm getting kPa readings from a device which has no pressure sensor hooked up to it. Noob.

in fact let me know when you have set any maxima 1/4 mile records at all. I'll be over here with the 20 or so that I've set at different stages of modification. or let me know when you've innovated a single mod on these cars, i'll be over here with the dozen or so that I have.

you're trying to follow in the footsteps that i left 10 years ago and it's abundantly clear you haven't a clue what you're doing.

 

Ok I get it... That thing is interpreting some sort of signal from the maf into kpa
It looked pretty bunk, and it is.
Making boost n/a

sicxspd: What is that thing reading at with the engine off or at idle?

I've read about a salt flat 70's Z making like 1-2psi with a super long trumpet sticking
out the front going 170mph. But it's just from the internet and if it was legit then all the salt flat n/a guys
would be doing it.

 

Hey just thought i'd let everybody know i chirped 4th last night and walked on a new wrx that runs low 13s stock and he was not stock sorry.. and idk how i matched him off a dig with all my traction control issues launching at 3k... haha 12's you say nealoc? Some power shiftin n poppin' and 12s are a cakewalk and I'm not even stripped whatsoever.

Ram air works and I recommend people to build your own setup the ONLY downside is significant drag increased it really needs to be a streamlined setup to reduced the drag induced as much as possible. Buy some ducting from home depot and make a nice trial setup for a few bucks just to see if I really am full of it or not. I built mine with 4" ducting and a gutter spout with zip ties and tape its ghetto but it works.

 

Take a look at the 98-02 camaro SS, that ram air setup boosts about 50-60 hp and is extremely efficient and direct why isn't it possible with any other car?

 

Snake oil.
Huge BS claim there.

 

uh huh. you let us know when you have a 12 second NA timeslip from your maxima with no weight reduction.

beating a some joker on the street means nothing.

 

The 2001 Camaro SS had 325hp, and the hood scoop alone did for 50-60 of that? I'm gonna take my grinder to my hood tonight....

Dude in the WRX probably didn't know u we're racing. He was like wtf is this guy in this 15 year old family car doing.

 

Correction:

What is this guy in a 15 year old post-crash and zip tied family car doing.

 

That guy sounds like planecrash.
Were you around for him?

Iirc his real name was aviation005.
Great reads.

 

Troll.

 

cool. we'll agree to disagree. a few more minor details and i'll throw up my 12 second timeslip and 2 birds

here's the post-crash troll grocery getter chirping 4th zip tied


untuned.... original clutch grabbing like a champ no wonder you guys are mad

filmed off-road

 

we'll be waiting with bated breath.

you sure are proud of this chirping 4th gear thing lol

 

This is done by keeping the RPMs at idle and popping the clutch.


And the video proves no chirp.

Why even post?

 

Dont hear no chirp... Btw i have a vafc2 and the IM pressure reads from -15psi to +15psi. On wot wit 00vi on 3.0 I get 0 or kaybe just over 0psi.

LOL aviation005 classic

 

Worst video ive ever seen.

What size tires do u run? Nmexmax has a huge thread about intakes. Huge short ram intake that's length tuned and properly sized with velocity stack has been actually dyno proven to show biggest gains.

 

Trolling or not -- I just don't get how some people can claim they're running 12-13's 1/4 mile without having the slightest idea how fast that actually is and what kind of cars are actually running those times.

My old M3 (euro spec) ran 13's stock, people don't realize how fast that is, and that was with perfect driving on a good day with perfect shifts. There is NO WAY, and I mean no way in blue hell that any stock Maxima is running into the 13's. It's IMPOSSIBLE. N/A built up and fully bolted on with proper tune, with the VQ35 (can't do it with the VQ30) and 5th/4th gen body can get you there, but that's about the only way you can do it outside of going F/I. My car is 95% fully bolted-on and tuned with e-manage, just installed a transgo kit as well, and I would never try to claim those 1/4 mile times because it's laughable. Myself, along with many others here, I'm sure would love to see a time slip of your 1/4 mile ET, and I'd be willing to bet you're gonna be much closer to 15 sec 1/4 mile than 12's or 13's, maybe a 14.5 IF you're lucky and you slip the clutch. But I'm not hating or trying to argue, produce an official time slip w/ 12-13 sec 1/4 mile ET and nobody will be denying it anymore, I'd be very surprised if you got anywhere close to mid 14's and I'd be shocked if you ran anywhere close to low 14's.

My numbers were very close, but never a positive reading. I usually get an average reading of -11.5psi during normal driving, -13.5psi at idle. The numbers get lower during WOT but never get to zero, I've never seen them go lower than about -4 to -5 at any given time. As for manifold absolute pressure, it should always be strongly negative/below atmospheric at idle, and around zero at WOT. The number itself will depend on the area you live in, but it should never go much above zero (actual atmospheric pressure) at WOT because if it does that simply means you have BACK-PRESSURE in your engine (or you have forced induction and are driving incredibly fast).

At idle, you should always have negative vacuum, at least 20 inHg is the known "normal" number, and higher idle vacuum means healthy engine. At WOT is the only time your vacuum should turn into boost, if it fluctuates too much during idle you probably have a vacuum leak. During acceleration the vacuum #'s will move towards positive (boost), but should never become a positive # or go over zero, if your vacuum readings at WOT are going above zero into a positive reading, and you DO NOT have forced induction, then you have BACK-PRESSURE or the intake is restricting air flow. Only a boosted car with F/I should ever see positive vacuum (aka boost), otherwise if you get +15psi at anytime it means your engine is building back-pressure or not getting enough air in the intake and if it's fluctuating between -15 and +15 during idle then you probably have some much bigger problems.

 

lmao wtf is this? somebody with a stock 5th gen is actually challenging a boosted 4th, and not just any old 4th gen, the most powerful one we have ever seen on a stock motor?

 

There a few freakish VQ30s out there that have cracked 13s NA, infact ceffy's VQ30 was making enough power to crack 13s.