Saabscene Saab Forum - Saab Technical Information Resource banner
1 - 20 of 26 Posts

·
Registered
Joined
·
14,305 Posts
Discussion Starter · #1 ·
Well,
I finally got round to getting Bubbles on a reputable rolling road today... and it was quite interesting... a bit of tweaking with boost and we were able to get 290hp (corrected) at the flywheel... however it's difficult to drive like that as below 3500rpm it was too easy to run in to oversboost cut off. There's more I can do to sort this; reducing the preload on the actuator will help, although it's near it's minimum at the mo (it's a 12 psi spring),but it's all hassle...

So we settled for a "driveable" power of circa 270hp with a stomping great 330lbft of torque just above 3500rpm!! That equates to a peak boost of about 1.45bar, holding circa 1.25. Although the hybrid turbo really only spins up later, as you'll see from the graph below, there's over 260lbft available from about 2500rpm all the way to over 5000rpm. Why do I say 260? Well from memory that's the peak torque figure for a "standard" Aero to give a comparison. Torque is the upper curve, power the lower.

At the wheels today was a lower 215hp... but a standard scooby apparently only manages to get 150hp to the wheels!!

What more can I say other than

 

·
Registered
Joined
·
31 Posts
Impressed by the results. Really nice curve. I have a Speedparts stage 3 kit on order which is supposed to give 275bhp. I would be interested to see what that *really* equals...

To be honest with you and, as you probably know, Scoobies are not that fast. Drivetrain losses = about 20% (hence 150bhp at wheels and poor fuel consumption) + they are barely lighter than a 9000. Evo mag found them to be slower to 100mph than a 172 Clio! I have beaten stock Scoobs with my old modded T16s and have kept up with older Scoobs so I don’t even think they would be worth your time bothering with despite the incitement that Scooby drivers air with their tragic and misplaced arrogance. A new M3, however, is another story...

Alanb
 

·
Registered
Joined
·
8,216 Posts
drabux? Isn't that a name from the 900 era???

Anyway, Mark, I think we need to do two things:

1) Get my car on the same rolling road. Was it Power Engineering?

2) You drive my cr4ppy Aero at the Abbott track day to show me how to get some decent lap times out of it and I'll let Bubbles show me how a really fast car drives.

Interesting - Maptun claim my car will achieve 450Nm (330lbft) at 3000RPM and 275hp at around 5500RPM. It'll be October, so I'm hoping cool weather will close the gap a bit between mine without water injection and yours with it. For reference, my peak boost is around 1.6 bar.

And I seem to be doing quite well on the traction front (as well as can be expected without an LSD anyway) so it'll be interesting to see how I get on if it doesn't rain. I'm hoping all this dismantling and re-assembly of the suspension will be worth something...

Anyway, nice result.
 

·
Registered
Joined
·
8,216 Posts
Oops...


Know what you mean, though. Embarrassing or what?

Grip problem is now much reduced due to new S-03s that are above the legal tread depth limit, front wheel alignment set to something like it should be (nothing like it left Abbott with) and a decent level of damping.

Some more tweaking of the shocks might make a difference and then it's onto experimenting with tyre pressures.

I'd hate Mark's LSD to give me an excuse for not keeping up with him...

Oh, and Mark, a standard Aero gets almost 260lbft from 1900RPM...
And does Bubbles sport the higher ratio gearbox, i.e. can she hit 70mph in 2nd gear with standard wheels/tyres?
 

·
Registered
Joined
·
14,305 Posts
Discussion Starter · #7 ·
OK, Bill, you're on for the track day.

Yup, it was Power Engineering in Uxbridge. They regularly calibrate their roads. For ref, if you go down there, ask to make sure it's booked on the 2wd road not the 4wd, cos that's what I used.

Interestingly enough, they reckon that water injection decreases power slightly whilst within acceptable limits... and mainly use it for detonation protection. I'm confused now especially as the guy reckoned he did a run without it and it showed slightly less power, when the last one I did had more Mind you that might have been because the other one was running hotter... so I'm going to reduce my injector size. Of course to increase power I could always run a 50% methanol mix in the washer bottle

I'm very pleased with the results (and they were impressed too- esp with the torque) considering that it's 70hp over the stock 200hp. Of the individual items fitted, the claims are roughly:

ECU +40hp
Exhaust +10hp
Itercooler +10hp

So that's at least another 10hp on top- because the stock figures are quoted in "ideal" conditions. Also the cooling isn't quite as good on a rolling road so there's a bit of loss there too.

Yup, 70mph in 2nd is no prob (I thought all 2.3FPTs had that box), although it's a very uneconomical way to drive at the national speed limit

Has anyone got a curve for a standard Aero or 2.3FPT btw for comparison?

Off now to fit the go faster seats...
 

·
Registered
Joined
·
8,216 Posts
Nope, I think Bubbles would have been one of the first to get the higher ratios. They started in '93, I believe, for the introduction of the Aero. Then the engine and gearbox changed in '94 (shorter engine block to fit the NG900, and the gearbox changed too), so they only did that particular box for one year.

My '90 CD 2.3T (one of the earliest 2.3FPTs) had the lower final drive - it redlined at 60 in 2nd, the same as my '87 9000T did. That gearbox with some decent tyres and suspension (and maybe your LSD?) would be great for street racing, if I were into that sort of thing

When the gearbox in the Aero finally dies (168K miles at the moment, and all that boost in 2nd gear that brought such a smile to Leon's face must eventually take its toll), I might consider replacing it with a lower-geared unit. 2nd gear in my CSE 2.0LPT revs out at well under 60. Perhaps that ratio might have advantages.

I understood that water injection gave no gain and was slightly detrimental to power, all else being equal, but that its advantage was that it raised the threshold of detonation to allow you to increase boost, advance ignition timing, etc. for more power.

I'll give Power Engineering a ring. What was their rate?
 

·
Registered
Joined
·
8,948 Posts
Bubbles...

Mines a stock Aero running 1.1 bar boost (it was as close to the 1.08 spec the garage could get to when the turbo was repaired 5 years ago).

312 lbft @ 2500 and over 280 from 2400-4600
248.5 bhp @ 4750 with over 230 from 4200-5700+

Edit... at wheels power was around 203bhp, trans loss of 45bhp figure

Things of note - Car ran out of air too early, but was due a full service, air filter, plugs etc, and could have done with running 97/98 octaine fuel not the sainsbury cheapo unleaded.

One day I'll sort that out and retest.

Mods done so far (since test) are just limited to very recent poly bushes.

What other mods have you done? Anything I could do to mine cheaply??




Andrew
 

·
Registered
Joined
·
14,305 Posts
Discussion Starter · #12 ·
OK, rough comparison overlay between graphs for Andrew and myself below- alhough I don't understand how 240 odd horses and 310lbft is coming from a "standard" Aero...

Interesting that the graphs bear out my feelings about the difference the hybrid turbo made- slower lower down, but more potent higher up the rev range

Andrew's torque highlighted in green, power in blue

My torque red, power magenta
 

·
Registered
Joined
·
8,948 Posts
hey, now that's one smart looking graph.
alhough I don't understand how 240 odd horses and 310lbft is coming from a "standard" Aero...[/b]
Could be traditional Saab understatement or just driven like a devil for 128,000 miles??

It definately pulls much harder than my 2.3 carlsson.

The Americans always said the 91 9000 2.3T's were always much more powerful than their 200bhp specs indicated.
 

·
Registered
Joined
·
8,216 Posts
Originally posted by Bubbles (fka Mark E):
[qb]PS Bill, it's £45 plus VAT[/qb][/b]
Plus VAT???

I'm sure they didn't tell me that. Better ring to cancel, then. I can't afford it

So did you get that messing around with the boost thrown in for £45 + "Victimisation And Theft", or did you have to pay extra?
 

·
Registered
Joined
·
8,216 Posts
Originally posted by Bubbles (fka Mark E):
[qb]I don't understand how 240 odd horses and 310lbft is coming from a "standard" Aero...
[/qb][/b]
Nor me. Perhaps we're back to the subject of what exactly the transmission loss is for the 9000, and whether it is constant through the RPM range (probably not).

Andrew, what year is your Aero? If you're looking for a cheap upgrade, you might be lucky to find it's fitted with a heatplate between the inlet manifold and cylinder head (only some '96 and '97 Aeros, apparently). If so, the ECU is programmed to give higher boost at the top end of the RPM range to compensate for the restriction. If you remove it, the ECU doesn't know any better and will still boost higher than standard. Believe me, it is very noticeable - I did it on mine before I got the Maptun upgrade. You'd probably get about 240hp.

Hmm... that figure sound familiar? Doesn't explain the massive torque, though.

I'd heard Americans say that about '91 and '92 9000s too. However, I've also heard that it's a myth. I imagine it's due to the fact that the '92 and earlier 2.3Ts had a lower final drive that made them quicker off the line. My '90 CD would have been great in that respect if I'd known then how to get the front wheels to stick to the road. As it was, with cr4ppy tyres and probably worn suspension, the TCS got exercised almost every time I pressed the accelerator
 

·
Registered
Joined
·
8,948 Posts
My Aero is a '93, 1st year of the 3.6 final drive.

The Carlsson is a '91 with the 4.05 final drive.

The gearboxes for the 91-93 2.3 T's are identical for TCS cars and identical for Non TCS cars (TCS cars got stronger diffs).

The difference between <=92 and 93 was only the output shaft and final drive gears.

'94 went to the new short gearbox
Pre 94 2.3T gearboxes are getting like hens teeth to find in good order and are £1350 from saab. 93's are almost impossible to get as they were for 1 year only.

On my carlsson I seem to be forever changing gear when overtaking, in the aero peak torque is around 72mph and seems to give massive 5th gear overtaking pull from 50-55mph+.

Also, the Aero's TCS works really well and gives powerful acceleration in 1st and 2nd with only very mild black lines and tyre screaching.

Andrew
 

·
Registered
Joined
·
2,277 Posts
The question of how much power is lost through the transmission is a good one...
I've seen an unqualified 16% quoted, but with no reference to the source. As stated earlier, the power graphs produced from rolling roads are 'corrected', but why exactly? Supposedly to give a figure that is comparable to the flywheel horse-power quoted by all manufacturers. This in itself an inflated figure that bears little relation to the amount of power availible to propel the vehicle up the road, but we put up with it as this is all they are likely to give us. Consider the "at wheels" figures for the Aero (215 bhp) and Scooby (150 bhp) earlier in the thread. All the time rolling roads produce "flywheel horsepower" graphs without showing what has been corrected for and by how much, the results can be seen (in isolation) as worthless. If on the other hand mods are being performed and comparitive figures taken on the same 'road then they are of use...
Nick.
 

·
Registered
Joined
·
8,948 Posts
The rolling roads measure bhp at the wheels on an acceleration run, and losses on a decceleration run (clutch dipped).

My max figures were +203 up, -45 down (about 18%)

The correction is to (for me) DIN 70020 standard. Possibly to account for 2 wheels contact points of the rollers rather than the single point of a road.
 

·
Registered
Joined
·
8,948 Posts
DIN 70020

Power and torque readings (e.g. from a dynamometer) are affected by air temperature, pressure and humidity. To facilitate comparison, the data are adjusted - or normalised - to standard pressure, temperature and (sometimes) humidity values. There are three main normalisation standards in use by the media:

· Economic Commission for Europe (ECE) - Swiss-based arm of the United Nations - standard EC 95/1

· Deutsche Industrie Norm (DIN) - German standard DIN 70020 (TBC)

· Society of Automotive Engineers (SAE) - US body; the standard most often used by Dynojet.

The values of one standard cannot be directly compared with those of another, they must be adjusted.

The following relationship exists between EC and DIN HP ratings:

1 HP (EC 95/1) » 1.015 HP (DIN)

A suitable conversion for SAE HP is not known, though the following relationship is believed to exist:

1 HP (EC) > 1 HP (DIN) > 1 HP (SAE)

i.e. SAE power and torque numbers are larger than DIN, which are larger than EC.

The characteristics of the DIN and EC standards are:

· DIN 70020 (TBC) = 1013 hPa pressure and 20°C temperature.

· EC 95/1 = 990 hPa dry pressure and 25°C temperature.

(dry pressure is calculated as normal pressure less humidity)
 
1 - 20 of 26 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top