[ylee coyote]

Just been looking at the i/c tube to manifold tube and it is the biggest restriction in my system..
measuring up the tube it is 2.5 " at the i/c outlet
tapering to 2 " all the way up till the rubber tube at the end takes it to 3 "

Now looking at the abbott pipe it looks as if it tapers to 3 " at the last stretch.. the rubber 90 degree tube looks as if it maintains the diameter into the manifold
It looks like 2.5 " up to that point

Is this correct ?
Also why did saab restrict it so much ..
lag ?
I would have thought having a resistance there would far outweigh the bigger volume to move

 

[andycannon]

The abbott intake pipe doesnt taper off like the standard pipe, from my own experience the pipe certainly helped my car breath a little easier at higher revs.

When you look under the bonnet of a standard set up the pipe does look rather lacking in diameter compared to the abbott pipe

 

[ylee coyote]

trust me higher revs are not the problem....
its spoooooool up time..
thinking is that by removing the big restriction
(about 18" of 2" pipe ) I could get quicker spool up time ..
Have you noticed a difference ?

 

[andycannon]

Spool up time ?

Well, I had an LPT, which had upgrades in the following order

ECU + Abbott d/v + apc, JR filter, massive increase, bearing in mind I went from base boost upwards

intake pipe, no real difference noticed in spool up just less breathless at high revs

downpipe no cat & full system, big difference in spool up time

other mids since this date have not been noticeable other than the engine seems to breath better at higher revs

 

[Gordy]

Ylee,
You can have a look at mine in situ on Saturday if it will help. If it's easy to swap out would you want to take mine out and intall it in yours for a test?

 

[ylee coyote]

gordy ...don't tempt me

I have a cunning plan and I hope to have a new design by "ylee racing" fitted soon

should be nice and shiney too
might be ready for friday ( with good luck and a following wind !!)..
In my question I was just trying to find the downsides..if any.. and the answers to date do not seem to raise any...

 

[California Saab Tuner]

Also be mindfull. This pipe probably SHOULD be upgraded at your power levels, ylee ... but since the air is compressed the volume of air flowing through it isn't too much, even if the mass of air is quite high. Just pointing that out.

As a general reference a pipe like that doesn't need to be replaced unless you've done something to increase the engine's volumetric efficiency. Things like ported cyllinder heads, higher rev-limit, more aggressive camshafts. Raising the boost doesn't change the volume of air that is put into the engine. It just changes the pressure. Since only the pressure has changed the pipe diameter is of little consequence as the speed with which the air is moving through it has not changed either.

That's why Saabs can use a comparitively small throttle body on a 400hp application, while a 400 hp V8 taking in the same "mass" of air requires a much larger throttle body.

Small pipe size CAN affect spool up. As another rule, the farther away from the engine the restriction is, the more it will affect spool up. The further it is from the engine, the longer it will take for the pressure to reach it, and for the flow to stabilize out. A small-ish throttle body affects spool up very little. While I small-ish intercooler affects it quite a bit. If both flowed the same the intercooler would affect it worse than the throttle body.

Anyhow ... 400 hp ylee ... definitely time for a bigger pipe! And headers. Headers AFTER the pipe though, as they will further increase the VE and make that pipe's restriction even worse.

Both combined would REALLY help your spool up trouble though.

Dubbya~

 

[ylee coyote]

definitely time for a bigger pipe!  [/b]

... a nice polished 3 " s/s one perhaps?

And headers.  Headers AFTER the pipe though, as they will further increase the VE and make that pipe's restriction even worse.[/b]

Headers are planned but they are expensive especially with that nice ceramic coating you like so much

that will be stage 7 and 500 hp..

This will be the last engine mod for a while ..I need to tame the chassis somehow...(before july anyway !)