Saabscene Saab Forum - Saab Technical Information Resource banner

1 - 10 of 10 Posts

·
Registered
Joined
·
8,948 Posts
Discussion Starter #1
Does anyone know off the top of their head what the base boost is on a 9000 CS Aero? all othes are 0.4bar, is the Aero 0.45?

After yesterday's poor showing at Wimpole (below 3000 rpm), and a new aqasition which is just begging to be placed between APC valve and wastegate

Hopefully that should spice the low end up a bit.

Probably should have tried fitting it yesterday and giving it a quick test on the RR.

Andrew
 

·
Registered
Joined
·
8,948 Posts
Discussion Starter #2
Then again, I could have just gone to BillJ's site here to have got the figures.

Doh!

Andrew
ps, 0.48 bra it is (7psi)
 

·
Registered
Joined
·
8,948 Posts
Discussion Starter #6
Well I've just been out and checked my base boost, party due to the poor showing on Friday, and partly as prep for fitting the MBC, and it only set at 5.5 psi (0.375 bar), way too low!

The wastegate rod did fall off 2-3 years ago, and was refitted by Saab, but I wonder it it had also come loose too and they just bunged it back on.

Does anyone know what the impact of running a base boost too low is? (apart from being able to run the most useless fuel in the world with no problems).

Will this poor base boost have been the cause of the low power below 3000 rpm?

Andrew
Waiting for the car to get cold now so I can add some turns (lots??)
 

·
Registered
Joined
·
8,216 Posts
Originally posted by Scaero (ecopower stg0):
[qb]Does anyone know what the impact of running a base boost too low is?[/qb][/b]
When my Aero base boost was low (after a turbo replacement), the car felt really gutless unless I thrashed it. Sounds like the same problem you have with yours.
 

·
Registered
Joined
·
8,948 Posts
Discussion Starter #9
Well I went at it this evening.

The R pin was missing, but I managed to get the rod off with some effort (bad move..., also there was no load on the rod!)

The locking nut was rusted to nothing and I couldn't loosen it. Further inspection showed that the threads were rusted away up the ros so there was no chance I was going to be able to adjust it.

Next I decided to take the entire wastegate rod and diaphram off (2 bolts, 1 pipe).

This showed that there really was no way to adjust the rod.

Next I decided to place a pair of packing washers between the diaphram and the turbo (equivalent of shortening the rod) and refit.

Next reattach the rod and I find the hole in the turbo wategate shaft is blocked so I can't get a new pin in.

I've jsut hooked it on for now and I off to Maplin tomorrow to get some 6mm press studs.

Result? 6psi..

So tomorrow evening I'll add some more washers (i've 3 thicknesses)

I also checked the Carly's base boost, 5 psi. Hmmm I wonder how rusted up that one is.

Andrew
 

·
Registered
Joined
·
8,948 Posts
Discussion Starter #10
Yippee,

I've got my bas boost up to 7psi (7.25ish was the highest I saw, and 6.5 the lowest).

It took 3 thick washers (3.75mm) of packing under each of the wastegate actuator bolts to get it there though.

And the result? very little I think. I am seeing a slightly higher spike at max boost (18.5psi) but it drops to 15psi again, and occasionally blips up to 17 then back down again.

Low boost seems unchanged.

5th gear, from tick over, foot to floor

1000rpm 0psi
1500rpm 5psi
2000rpm 14psi (begins to pull)
2250rpm full boost (now pulling well).

What's wrong? Are these figure representative? torque is supposed to be 258lbft at 1950rpm, I don't think it is there yet?

Now confused.

Andrew
 
1 - 10 of 10 Posts
Top