Miatapower List Archive

This read-only message was archived from a public mail list.
Mail From: Toby Weir-Jones <(email redacted)>


Since Bill mentioned it...

My car is currently undergoing this upgrade. I've sold the turbo and
relevant intake side bits and have bought the following:

1) BB turbo
2) New K&N
3) Airbox baffle thing
4) New bypass valve
5) New intake side plumbing
6) All new stainless mounting hardware

I am keeping my manifold & downpipe, so I'll still be using the integral
wastegate and its actuator (once it arrives... ;)

I'm also pulling the air conditioning (condenser, compressor) & cruise
control.

Question: I'm planning to use the signal line that fed the cruise control
for the wastegate input signal. This has the benefit of being downstream of
the intercooler. Will this work?

Anyway the car will get its first shakedown at Thunderhill next weekend, and
dyno results hopefully soon thereafter. I'll report SOTP impressions ASAP.

Corky reckoned the stock parts (crank, rods, pins, etc.) have a bit more
margin left in them so I might try running this setup at 16-17psi and see
what happens.

I'm most curious to see what kind of results I get while using the integral
wastegate. Significant head work should be upcoming later in the spring.

twj

This read-only message was archived from a public mail list.
Mail From: "Ken Hill" <(email redacted)>



> -----Original Message-----
> From: (email redacted)
> [mailto:(email redacted)]On Behalf Of Toby Weir-Jones
> Sent: Friday, March 17, 2000 3:18 PM
> To: '(email redacted)'
> Subject: FM2 to FM3 intake upgrades (and a question!)
>
>
>
> Since Bill mentioned it...
>
> My car is currently undergoing this upgrade. I've sold the turbo and
> relevant intake side bits and have bought the following:
>
> 1) BB turbo
> 2) New K&N
> 3) Airbox baffle thing
> 4) New bypass valve
> 5) New intake side plumbing
> 6) All new stainless mounting hardware
>
> I am keeping my manifold & downpipe, so I'll still be using the integral
> wastegate and its actuator (once it arrives... ;)

I watched the UPS guy pick it up today. You will have it Monday morning.
Sorry about that. We must have been thinking FMIII that day.

> I'm also pulling the air conditioning (condenser, compressor) & cruise
> control.
>
> Question: I'm planning to use the signal line that fed the cruise control
> for the wastegate input signal. This has the benefit of being
> downstream of
> the intercooler. Will this work?

Taking the wastegate signal from the turbo outlet will give you the best
overall control of your boost set point. The down side is that your power
rise will suffer slightly because this signal source will give you the
earliest breaking point for the wastegate. Sourcing the signal from the
manifold, like the cruise control fitting, offers the best boost rise
because the wastegate is controlled by the boost in the plenum. The problem
here is that the intercooler has to deal with added boost and temperature.

I spoke to Rick about this today and suggested mounting a fitting in the
first IC pipe after the turbo. I feel this is the best point for boost
control.

> Anyway the car will get its first shakedown at Thunderhill next
> weekend, and
> dyno results hopefully soon thereafter. I'll report SOTP
> impressions ASAP.
>
> Corky reckoned the stock parts (crank, rods, pins, etc.) have a bit more
> margin left in them so I might try running this setup at 16-17psi and see
> what happens.
>
> I'm most curious to see what kind of results I get while using
> the integral
> wastegate. Significant head work should be upcoming later in the spring.
>
> twj
>

Ken Hill
"It is amazing how much money a Miata will hold." - L.Hill

This read-only message was archived from a public mail list.
Mail From: "Bill Cardell" <(email redacted)>


In answer to the question about signal source. One problem you will see with
that source is that you will be pulling vacuum through your boost solenoid
when you're off boost. You can try putting a one way check valve in that
line, not sure how if the restriction will hurt you or not. The new
compressor out pipe you're getting should have a signal source on it.

-----Original Message-----
From: (email redacted)
[mailto:(email redacted)]On Behalf Of Toby Weir-Jones
Sent: Friday, March 17, 2000 3:18 PM
To: '(email redacted)'
Subject: FM2 to FM3 intake upgrades (and a question!)



Since Bill mentioned it...

My car is currently undergoing this upgrade. I've sold the turbo and
relevant intake side bits and have bought the following:

1) BB turbo
2) New K&N
3) Airbox baffle thing
4) New bypass valve
5) New intake side plumbing
6) All new stainless mounting hardware

I am keeping my manifold & downpipe, so I'll still be using the integral
wastegate and its actuator (once it arrives... ;)

I'm also pulling the air conditioning (condenser, compressor) & cruise
control.

Question: I'm planning to use the signal line that fed the cruise control
for the wastegate input signal. This has the benefit of being downstream of
the intercooler. Will this work?

Anyway the car will get its first shakedown at Thunderhill next weekend, and
dyno results hopefully soon thereafter. I'll report SOTP impressions ASAP.

Corky reckoned the stock parts (crank, rods, pins, etc.) have a bit more
margin left in them so I might try running this setup at 16-17psi and see
what happens.

I'm most curious to see what kind of results I get while using the integral
wastegate. Significant head work should be upcoming later in the spring.

twj

This read-only message was archived from a public mail list.
Mail From: "Frank Mowry" <(email redacted)>


I did the BB turbo and the integral worked fine at 18 psi. Pegged the boost and
no spike or boost creep. I don't think you'd see a noticable difference with an
external gate. You won't see MORE power but you might see it 100 rpm sooner.
Unless you're running high boost (>20), I don't see the need for an external
gate. It's the higher boost where the integral can't bleed off boost quick
enough and you get boost spikes where you should be looking at an external.

Frank

> I'm most curious to see what kind of results I get while using the integral
> wastegate. Significant head work should be upcoming later in the spring.
>
> twj

This read-only message was archived from a public mail list.
Mail From: (email redacted)


In a message dated 3/27/2000 6:27:55 AM Central Standard Time,
(email redacted) writes:

<< I did the BB turbo and the integral worked fine at 18 psi. Pegged the
boost and
no spike or boost creep. I don't think you'd see a noticable difference
with an
external gate. You won't see MORE power but you might see it 100 rpm sooner.
Unless you're running high boost (>20), I don't see the need for an external
gate. It's the higher boost where the integral can't bleed off boost quick
enough and you get boost spikes where you should be looking at an external.
>>

The first purpose of the remote wastegate is greater power at the same boost.
This is largely a function of smoother exhaust gas flow right out of the
turbine. This is possible with some integral wg designs, but not the Garrett
styles. The key is putting the exhaust gas back into the main pipe 2 or 3
feet down the tube. Under max effort conditions the vented gases would have
their own separate pipe completely.

The second purpose is to fix the tendency of an integral to get overpowered
and loose function at very high boost pressures. "High" is hard to define,
but I expect we will find it around 20 psi. The problem of function in the
integral stems from venting to the wg after the exhaust gas starts speeding
up in the tapering section of the scroll. The higher velocity gasses are
less likely to turn corners. With the remote wg, it is possible to vent from
the slowest gas portion of the manifold and, in some cases, even give equal
access to both paths.
Corky