Saabscene Saab Forum - Saab Technical Information Resource banner
1 - 17 of 17 Posts

·
Registered
Joined
·
323 Posts
Discussion Starter · #1 ·
ive got a totally unmodded 97 Aero, just put a JR air filter in and having a full 3" JR exhaust plus cat done next week. So has anyone any idea what increase in bhp this will give me on the basic 225?

Also i am considering upgrading the ECU, is this wise considering i am still on orig spec discs, pads, springs etc( tho pads and discs are new all round)will the increase be unsafe ?

Cant do the lot due to finances at the mo, but would really like the ECU upgrade if its safe, so any advice please?

Ta.
 

·
Registered
Joined
·
8,216 Posts
The JR filter might net you a couple of horsepower. Removing the "snorkel" from the airbox should help too. On a '97, you might find you have a "heat plate" fitted to the manifold. If so, there is free horsepower waiting to be unleashed. I'm not really sure of the purpose of the heatplate - either to reduce cold start emissions or to improve cold starting in deep sub-zero temperatures. Either way, only certain '96 and '97 European/UK models got them.

The heat plate intrudes into the inlet ports and is quite restrictive, so Saab increased the boost at higher RPM to maintain the 225hp of previous models. If you remove the restriction, you still have the boost. This, along with your filter to help the engine gulp all this extra air, should raise peak power to around 240hp with the standard ECU.

To be honest, the braking system on the 9000 isn't that bad. It's not brilliant either. However, by fitting an ECU upgrade, you're probably not going to find the car going much faster than it currently does. It'll just get there faster. So I wouldn't say it would be dangerous without upgraded brakes.

You might find yourself wishing that you didn't have to slow down so much for corners, though, once you can get to them more quickly. Just drive sensibly and don't take corners any faster than is safe. Presumably, this is what you do currently.

It's not the car that would be dangerous with more power on the standard chassis, but the "loose nut behind the wheel"
 

·
Registered
Joined
·
14,305 Posts
On a limited budget, if you're after enjoying the car
, the first thing I would do is fit lower/stiffer springs. These can easily be had for under £200. This comes with the following caveats:

1. Your shock absorbers are OK. If they're not, then stiffening the springs will give you problems. I know the Aero was slightly lower (10mm IIRC) than standard, but to get the most out of the engine, you need a still lower and stiffer springing.

2. Your brakes are OK, although I would at least upgrade the pads.

Also worth considering is the state of the various bushes on the suspension. There's been much discussion about the relative merits of poly vs standard bushes. I suspect much of the improvement in handling folk report from fitting poly ones is down to the fact that their old rubber ones were worn. Cheap to do but very worthwhile are the rear ARB bushes. Abbott list most of all other the likely candidates, although you'll probably find them cheaper from the likes of Powerflex/Superflex. Elkparts stock these. You ought to be aware though that the Abbott ones are custom spec tend to be more of a compromise between comfort and performance.

Other stuff- as Bill says, removing the plate is "free" hp. The bigger exhaust will give also an improvement in response.

If you do go for the increase in power via the ECU then, IMHO, you will end up using it. In practical terms this may not make you drive any faster top speed, but you will get there significantly quicker. It will alter the way you drive, and so I would strongly recommend a commensurate improvement in the chassis and braking.
 

·
Registered
Joined
·
14,305 Posts
Yes, Elk do stock the different sizes. Your Aero will have a 19mm ARB.

I haven't removed the heater plate myself, but I don't think it's too involved- at garage rates I would guess somewhere between 30 mins and an hour tops.
 

·
Registered
Joined
·
3,892 Posts
Ed Abbott recently quoted me 2 hours labour for removal of the heat plates....
But me thinks this was a diversionary tactic in trying to get me to buy an ECU upgrade instead..


Andy, the route you're taking is the one I was heading down, and my estimate was something between 240 and 250hp after fitting the full JT, sport cat, JR filter and removal of the heat plates.

I'd suggest go this route, then later look at some brake/suspension upgrades, and later after this go for the ECU....perhaps finally a LSD...
 

·
Registered
Joined
·
360 Posts
How can you tell if your car is fitted with a heat-plate - can you see anything from the outside?

Mine's a '97 2.0 lpt (auto) and I need all the power I can get!

Had a quick look on BillJ's website but could not find an obvious link to heatplates.

Thanks
Mike
 

·
Registered
Joined
·
3,892 Posts
I think Bill will be doing something about heatplates on his site, because he took a photo of the heat plates, in-situ on my Aero for this very reason......
Obviously, he's been a little preoccupied of late destroying Aero transmissions......
 

·
Registered
Joined
·
103 Posts
Heatplate:

I took mine out last week, took between 3 and 4 hours (with learning as I went...what to undo,in which order etc). You will need to buy a new inlet manifold gasket £2, some gasket paste £2.68, and I needed 6 M8 washers on each of the 9 studs, ie 54 in total £1.25, to pack out the space left from the heatplate.

End Result:

Difficult to quantify as I don't have any proper measuring equipment but cold starting is better, turbo boost is about the same - 3/4 into the red past the stripy bits, the car generally 'seems' more responsive. I am on my second tank of Optimax, so this may be taking more effect now.

Car: 2.3 FPT

Many thanks to BillJ for help on this.
 

·
Registered
Joined
·
8,216 Posts
Originally posted by Mike Hunter:
[qb]How can you tell if your car is fitted with a heat-plate - can you see anything from the outside?[/qb][/b]
Yes, it is visible. Where the inlet manifold bolts to the cylinder head, you are looking for an aluminium plate sandwiched between the two, about 4-5mm in thickness. You will also see two manifold gaskets - one on either side of the heat plate - where engines without the heat plate will have only one gasket between the manifold and head.

Here's one of the photos I took of aeropilot's heat plate. The camera is on top of the manifold, looking towards the front of the car.



And here's what it looks like once it's out. Those huge heated "fingers" reduce the available port area by around 20-25%.



The greatest benefit will be seen at higher RPM (say 4000 or higher) where the restriction due to the heat plate has the greatest effect. When I did it (and removed the snorkel from the airbox, although I don't know how much difference this made), the car pulled noticeably harder at higher RPM.
 

·
Registered
Joined
·
360 Posts
Good news - Bad news.

Finally got round to looking for the heat plate.

Good news - there isn't one so I don't have to mess around trying to take it out.
Bad news - no cheap performance enhancement!

2.0lpt, B204S engine, auto gearbox, MY '97
 

·
Registered
Joined
·
78 Posts
My aero has only an open filter (no more airbox) in the fender and a full JT 3" exhaust from the turbo on back. I don't think there's much more power but the throttle response and turbo lag are improved and boost comes on sooner in the RPM range.

A good start, the stage 4 ECU from SQR or Maptun or Speedparts or whoever is coming (sometime hopefully sooner rather than later).
 
1 - 17 of 17 Posts
Top