The Birdman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by XtraFastCRX &raquo;</TD></TR><TR><TD CLASS="quote">joe at prototype racing doesnt like to answer emails... </TD></TR></TABLE>

He is actually out of town and will be back within a couple of days. I'm sure he will get to your emails when he gets back. He is pretty good about returning emails promptly.

Blazin Si

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nuclearhappines &raquo;</TD></TR><TR><TD CLASS="quote">why not put a velocity stack on the end of a j's racing intake ?

can you even model that ?
has anyone dynoed such a frankenstein intake ?</TD></TR></TABLE>

Some one made one a while back here on H-T. I don't think they got to dyno it though.

StyleTEG

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">The AEM hump is at 4,500, notice that on Jason's graph that the hump is closer to 6,100 or so. The intake lengths were within an inch or two of each other. Notice that the peaks and valleys in the torque curve mirror each other fairly closely.
</TD></TR></TABLE>

The hump is simply a result of peak volumetric efficiency due to acustical supercharging. It's not dictated to a set RPM.

A 2" difference could make a significant difference though.

b19coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">The hump is simply a result of peak volumetric efficiency due to acoustical supercharging. It's not dictated to a set RPM. </TD></TR></TABLE>
It comes pretty close to being set to a certain RPM. A B-series motor with an AEM CAI is guaranteed a hump at 4,500 RPM-based on my firsthand dyno experience. The length of the intake dictates the RPM at which the "acoustical supercharging" takes place. A 2" change in length will make a difference, but a small one.

BryanPendleton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">
It comes pretty close to being set to a certain RPM. A B-series motor with an AEM CAI is guaranteed a hump at 4,500 RPM-based on my firsthand dyno experience. The length of the intake dictates the RPM at which the "acoustical supercharging" takes place. A 2" change in length will make a difference, but a small one. </TD></TR></TABLE>

I suppose nothing else (such as intake manifold, TB, head work, cams, etc) will influence the flow dynamics.

There are countless variables and unfortunately no "guarantees".

M@

Maybe I missed it in one of the posts, but what pressure differential are you using to model the flow?

I was thinking that some motors would pull less vacume, and it would be possible to have a different "best stack" depending on the motor.

Thanks
matt

StyleTEG

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote"> It comes pretty close to being set to a certain RPM. A B-series motor with an AEM CAI is guaranteed a hump at 4,500 RPM-based on my firsthand dyno experience. The length of the intake dictates the RPM at which the "acoustical supercharging" takes place. A 2" change in length will make a difference, but a small one. </TD></TR></TABLE>

AEM designs the intakes to have the hump at the same RPM.

Notice that depending on the application, the diameter and length change?

The easiest example is compairing a B18B (2.5" diameter), GSR (2.75" diameter), and ITR (3" diameter). They all occur at 4,500 RPM because they are designed to.

BryanPendleton

Good call there M@. That is a question I have as well. I am still investigating filter vs. no filter effects, but my next investigation is to look into different pressure differentials. Currently all my analysis's have been run with a 1bar (~30inHg) pressure differential. What I am not sure of is how that info will help me. Thinking outloud a engine is just a complex air pump, with the pump flow rates increasing with rpm. If you by any change have a vacuum gauge and run to 8k and coast down watching rpms and vacuum pressure, I think you will find 30inHg and most rpms and then as some rpm (for example, maybe 3k) the vacuum pressure will drop as rpms drop. This would lead be to think that a 30inHg pressure differential is suitable for this analysis, as the powerband at WOT is primary interest. But perhaps lower pressure differentials might aid partial throttle cruising (ie. improved fuel economy, etc).

brewer15650

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BryanPendleton &raquo;</TD></TR><TR><TD CLASS="quote"> I am still investigating filter vs. no filter effects </TD></TR></TABLE>

DDD personaly dynoed his car with and with out the K&N Filter using the prototype racing V stack and there was no lose in power anywhere. Check it out here last post https://honda-tech.com/zerothread?id=1018645&page=3

BryanPendleton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brewer15650 &raquo;</TD></TR><TR><TD CLASS="quote">

DDD personaly dynoed his car with and with out the K&N Filter using the prototype racing V stack and there was no lose in power anywhere. Check it out here last post https://honda-tech.com/zerothread?id=1018645&page=3 </TD></TR></TABLE>

I've gone through that thread. I have run 6 more analysis's using 3 different v.stack configurations. I am also using a more "complex" model which I feel better models the application. I am finding that the cone filter does influence flow rates, but the gains or losses are realistically probably negligible. The 3 configs I studied only differed by 1% at most. As I suspected though the designs better suited for a filter lost flow rate without a filter the design better suited for no filter lost when I added the filter. Reasoning for this, I discuss above somewhere, but basically it comes down to trying to "steer" the pressure gradient towards the air supply.

But again the differences are very very small.

revolt_allmotor

very interesting...

BryanPendleton

K&N RF-1048 Filter showed up yesterday. I got it modeled and plan to "reoptimize" the v.stack as well as looking at 1/2 bar pressure differetial as well to see if the design is driven by pressure differerential.

The Birdman

^^Eager to know the results!!

lohatch

some pics of an Autozone velocity stack i took today. made by a company called spectre i believe. on the dyno when the engine was ran without the stack(just 3" tube) it made the same Peak HP figure, but the curve was very jagged and lost 10+whp in spots. with the stack it was a nice smooth curve.






Modified by lohatch at 11:39 PM 2/9/2006

hayabusa160

would you happen to have the diameter of the stack i want to see if my 4.5 inch cone will fit on it hehe

lohatch

measured it today and the OD of the stack is 6.5". the ID of the inlet is 3" as well.


Modified by lohatch at 10:40 AM 12/9/2005

BryanPendleton

I was busy doing some testing at work last week and this week I am in Prudoe Bay Alaska trying to keep my butt warm. It will probaby be next week before I can get back on this project.

6SPD_EK

iTrader: (2)

on a side note Moto-C has my prototyperacing velocity stack, RBC IM & speedwerx adapter plate...they are making custom CAI piping for that set up on a k20a in ek...will keep you all posted

CRVTEC0WNZJ00

subscribing this is interesting stuff :tu

hayabusa160

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lohatch &raquo;</TD></TR><TR><TD CLASS="quote">measured it today and the OD of the stack is 6.5". the ID of the inlet is 3" as well.


Modified by lohatch at 10:40 AM 12/9/2005</TD></TR></TABLE>

yea i got the same one last week at my local pep boys. i grabed a foam filter off a carb and i put it on there. i saw it had a lip and i figure sweet i can fit a filter but no one makes a 6.5 inch filter haha

so far it works decent.

i tried to order a prototype racing one but joe didnt respond to my email

b19coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hayabusa160 &raquo;</TD></TR><TR><TD CLASS="quote">I tried to order a prototype racing one but joe didnt respond to my email </TD></TR></TABLE>
I know someone who can get them for you

hayabusa160

hook me up y0

b19coupe

IM'ed you.

DavidR

I think Bryan's product, sounds like it'll be a well engineered and designed V-Stack

MidEngine4Life

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">
I know someone who can get them for you </TD></TR></TABLE>

Could you IM me also? I've tried contacting Joe, but he hasn't responded yet.