Vl Dose - afm  

iamhappy46

You have your information wrong The Nissan/VL AFM are perfect for running in a blow through setup. The AFM signal is derived by heating the coil and the amount of air passing through 'cools' the coil and the AFM creates a voltage signal to send to the ECU based on how much the coil cools etc. It will NOT give a false reading, it will only mildly alter the throttle enrichment map(which if you have a FMIC, will actually make it more accurate!!)

I suggest you search the vlturbo forums on how they do it

Flap style will NOT work on a Nissan ECU... ever.

pulsarator

awesome, cheers for clearing that up

topgun00

mate this may help for what you want to do

DOSE PIPE TECHNOLOGY 101

Step One - HOW TO MAKE YOUR CAR DOSE

Firstly, you need a turbo. (Yes, I've actually had people with N/A's asking me how to make their car make the zutututu noise lol.)

Second, you need an intercooler. Any will do, but I recommend one of those cheap hybrid copies, unless you are intending to run low 10 second passes - in which case you wouldnt be asking me how to dose.

Third, once you have an intercooler fitted to your VL - Remove all your intake stuff off the mouth of the turbo, and cut a section of your cooler piping out and fit your AFM (Air Flow Meter) there.



Its not that complicated to measure up how much of the pipe you need to cut.. I just placed the AFM next to the pipe and roughly marked how much to cut out with a marker.

Fourth, once the AFM is in the piping, you have the freedom to put whatever you want infront of the turbo intake.

All a dose pipe does is amplify the sound of the compressor surge

So all you do then, is attach any kind of pipe to the mouth of the turbo with some silicon hose and hose clamps, and dose away.

Step Two - DOSE PIPES

There are a number of different pipes you can use, I usually get some offcuts from midas and experiment with them, they are outlined below.
When dealing with dose pipes, you must forget about the intake practicality/temperature/whatever... we're not after optimal performance here, were muzzas, so we want a loud ass dose.. having said that, you have a few options...

90 Degree Bend Pipes
Decent dose, medium pitch, medium length, definition, delay...
This is what most people use, and it gives a decent dose, with a pod filter on the end, the negatives of this are that its vulnerable to bumps (and Australian roads are horrific at best) and it will also fill up with water, which may or may not get sucked through into your turbski. And water cannot be compressed.. i dunno what problems it may or may not cause, but i'd rather not find out.

You can hear this dose here

Straight Pipe with mesh
This is what i use, and you have two options here...
#1 - 17cm long 2.5" pipe with mesh on the end.
This gives the classic loud as all f**k high pitched, screaming, perfectly defined dose... It's the muztek classic, as i like to call it.
Frequently heard down chapel st. Awesome.

You can hear this dose here.

#2 - 15cm long 3" pipe welded onto a 4cm long 2.5" pipe rolled and welded to the 3"...
This gives a dose an octave lower than the 2." straight pipe, and the advantage of this one is that the 2.5" section does not need to be clamped onto the mouth of the turbo with silicon hose and hose clamps, it just slides right on over it, and wont move. Magical.
I like this setup because i can quickly swap dose pipes over for different occasions...
The 3" one is not as dramatic and attention seeking as the 2.5" one, and I use it for day to day use. The 2.5" one i keep for cruises and special occasions.

Aluminium Gutter Piping
I have also experimented with using a piece of 3" aluminium 90 degree bend gutter piping, and with either a pod or mesh on the end, it works really well.
It gives a dose an octave lower than the 3" straight pipe, and doesnt sound like a screaming sound at all, but rather a deep, bassy, doberman-barking kind of sound... woof woof woof woof. Very intimidating, very ballsy.

Small piece of straight pipe
To further raise the pitch of the dose, you can experiment with smaller pieces of 2.5" straight pipe.
In the past, ive used 10cm, 5cm, and 3cm pieces individually, and each gives a different sound. Lovely.

Different options in air filters/mesh
If you have no power steering in your vl, then you will have no problem fitting a pod to a straight dose pipe, and will have plenty of room to run a 90 degree pipe to wherever you please.

Step Three - CLEARANCE & FILTRATION
But one problem alot of people have when trying to make a dose pipe fit is that the powersteering gear only gives them a MAX of 20 cm in which to have a dose pipe and air filter setup, which is nowhere near enough to have a nice dose pipe, and a pod filter.
I spent some time screwing around with pod filters and stuff to find a smaller alternative, and came up with the mini pod, or c**k pipe as it has been named...
Heres a pic of it, its basically a cut down, modified pod filter, secured to the dose pipe with some silicon, hose, and 2 hose clamps.

http://illusionunderage.com/vlthistory/vlthist17.jpg

It protects the turbo and motor from dust, dirt, rocks, birds, small children and animals that may find their way in through the mesh.
Alot of people find that having a pod or some kind of filter on the end of the dose pipe sacrifices the clarity and quality of the dose itself, but ive found that using this kind of filter keeps the volume and pitch intact and keeps the dose hecktick uleh.

Other things you can use are....
metal mesh from a kitchen sieve - works well, i use it sometimes
if you have an old cheap pod ready for the bin - the mesh of that is superb
any other mesh made of a material that will not melt under extreme temperatures!

Remember the heat, kids! ive heard of people using stockings.. well theyre made of nylon, and they melt! even if you can find pure cotton ones, the henia of them is too high, and because there isnt much surface area covering the pipe, your car will run like crap, and struggle to make boost efficiently because not enough air is being sucked through.
Also, you cant stretch a piece of pod filter paper across the mouth of the pipe, because again, the surface area is not enough to suck enough air - I tried this and it wouldnt make boost because it couldnt breathe.
The mini pod like the one shown above is perfect.

Let it be known that all these different dose pipes and their corresponding sounds apply to stock T03 turbo's!!!

Step Four - TURBO'S OTHER THAN T03'S
Ive been getting an increasing number of PM's from people wanting that muzza high pitched dose, and are running T4's and GT series turbo's on their VLs, so I will try to outline what you need to do to get that sound for each respective turbo.

T03 Highflow
Because of the increased size of the compressor wheel, this turbo naturally has a deeper sound when compared to a T3, usually an octave lower. As a result of this, the closest you can get, is by using a 2.5" straight pipe, between 15 - 20 cm in length.

T04 & GT Series turbo's
These turbo's are huge. Because of the even bigger compressor wheels, and intakes, they have an even deeper dose note when compared to the T03HF and T03 turbo's.

Because so many people with these turbo's have been asking me how to get a T03 muzza dose out of it, i'll explain now, but let it be known that in order to get that dose, you will be sacrificing performance.

I dont know how big the intake mouths are on these turbo's, but Im pretty sure that they are 3" to 4", as a result of that, sticking a 2.5" diameter dose pipe on it MAY raise the pitch of the dose by an octave or two (I'd imagine that it would), which is all well and good, however, it is severely impeding the intake of the turbo and the motor, and may or may not result in the car running rich and bogging down.
However, If you want to just dose like a muzza for a while, I would recommend having two dose pipes - one for every day use, and one for attracting a sh*tload of attention.

I'd personally be a bit weary of doing this, because something which is designed to breathe through a 4" space being forced to do so through a 2.5" hole is not going to operate at its intended efficiency (and would be like a person trying to breathe through a straw).
Having said that though, if you want to do it - do it.

Step Five - REMAINING (SEMI)LEGAL
You can get canaried for not having an air filter - and/or having more than one intake modification.
Your cooler counts for one - and your dose pipe counts as number two.
A way around this is to run your airbox and your dose pipe concurrently.

Like so:
http://u-djs.com/stealth1.jpg

Basically - what I have done here is fit my dose pipe and run some heatproof plastic memory hose to the filter on the end with a loose connection so the sound doesnt get muffled, and run that to my airbox - which then runs to a CAI pipe.

Very simple and very effective, because you cant see the dose pipe or filter from any angle at all.
So technically speaking, you are still retaining the standard airbox - so you are remaining legal - and you get a muzza dose! Yay!
I think that should cover just about everything (at least everything I can think of right now

I'll probably add any new information into this post as it comes to me - So that this can hopefully be a comprehensive dose guide.

pulsarator

cheers, already knew how to do it but just wasnt sure bout my afm, anyway its done now and im pretty over it already. thru the week im gunna remove the dose pipe n just put a "cock" pipe on instead.