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Results.....experiences....

 
Old 07-28-2004, 07:48 AM
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Christer
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Talking Results.....experiences....

OK, now that I have managed to clear some work away, without further ado I will not bore you with the whole story at 9M over the last few days (which included almost setting my car on fire...not 9M's fault though!) but post the results of a 3 hour dyno session:

HP 339.9 @ 6710rpm (corrected)

Torque 288.7 @ 5360rpm

Ambient temperature 106degF
Barometric pressure around 1010

Unfortunately the dyno's printer was still not working and although I tried to take some photos of the screen, these are not very clear.

As you can see from the above, the dyno room was extremely hot (there was a tuned M3 coupe in there before us). We only managed about 6 runs in a 3 hour period due to the temperature, and most of these were in 5th gear. The dyno was showing quite significant losses, and subsequently the best we could do in 5th gear was around 278rwhp, and we did one 4th gear run only towards the end which yielded around 10rwhp more. So on the day in that heat the result was somewhere around 285-290rwhp. Before the session I also had some problem with brakes dragging (RS brakes fitted earlier that day), but it is impossible to say whether this affected the rear or the front, so no excuses.

In order to post curves, I will get another power run done locally to me, perhaps at GForce or JZM.

Overall impression:

I think both Colin and myself were a little disappointed with the figures, especially the torque - but I guess the temparature didn't help? (If anyone knows what kind of difference it makes, please post here...) I was hoping for 310+rwhp and over 300lb/ft of torque, but again the circumstances may have been wrong to expect that...especially as we had very little time to map things correctly - the other Motec and Motec+1 maps (that 9M use) took a lot longer than 3 hours to develop. At the end of the day, we tried something new which I believe can become a lot better with some further work.

If Colin reads this, he may want to add his own comments?

On the subject of driveability, the car is improved 100%. You may remember that before I mentioned this being a bit of a pain, the partial throttle settings were incorrect which made the car difficult to get off the line sometimes (wihtout clutch abuse) and also when on trailing throttle at low revs when applying throttle the car would 'buck'. This has been all but eliminated now, so the car is a lot easier to drive. Performance wise, I can tell you that the figures we got as a base run was around 280-290hp and around 260lb/ft of torque (this is the figure whilst running in with the wrong mapping) so the difference now is quite evident. Anyone wanting a ride or drive can meet up with our usual crew anytime to see for yourself.

The GHL exhaust was blowing slightly which 9M also managed to fix so in my mind it sounds nicer than ever.

The future:

Well, I am satisifed for now - although I am not ecstatic at this stage. 9M have done an excellent job and in the circumstances (custom build, very limited time, engine fire ) have produced something which is a lot closer to what I want the car to be. I would like to do further work with 9M in order to find out where we can take things further, and figure out where the custom parts/setup that I have used can yield some further benefits. I am convinced there is more there to be had, but on the day we just couldn't find it....

In the meantime, I am just going to have fun!
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Old 07-29-2004, 04:49 PM
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Since you seem a little disappointed with the HP and torque here's a little snippet from 9M
The rolling road test on the 996 revealed a figure of 299bhp (flywheel calculated) which suprised me a little considering Porsche quote 320bhp!. Either our rolling road is reading low (and our 964 remaps returning 290bhp are really giving 310bhp!!) or Porsches published figures are wildly out - who knows?
A dyno run elsewhere would be interesting.

I don't think your project is finished yet. As you know there are quite a few unknowns in what you are trying to do and how the different components you have used work togetheris not entirely predictable.

What strikes me is that 9M Motec +1 conversions produce similar results. Perhaps there is a bottleneck preventing futher power gains; induction or exhaust???

339bhp and 289Nm are big numbers. Losses to the wheels appear high.
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Old 07-29-2004, 10:08 PM
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Hi Christer,
Doesn't look too bad given such high ambient temperature. Engine heat soak and oil temp also affect HP. At such temps, humidity starts to have a much greater effect as well. Do you still have knock sensor?

Try this link for a simple calculator to adjust for various parameters: http://wahiduddin.net/calc/calc_hp_dp.htm

The bucking at low rpm part throttle can be tuned out by using less aggressive increase in ignition advance vs rpm

When you do the next run could you see if you can plot A/F ratio graph next to torque and hp curve?

Many I know get very good results when they do main tuning on dyno and then do a fine-tuning on the road (butt tune) as this simulates the real world. They do it with computer on board and A/F sensor in the exhaust and fine tune for various scenarios like full/part throttle acceleration, deceleration, cruise, different loads (hills), etc
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Old 07-29-2004, 11:38 PM
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joey bagadonuts
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Originally Posted by tonytaylor
Losses to the wheels appear high.
Perhaps some lightweight tyres are in order?

So how did this compare to your before dyno results? Did I overlook them? The 280-290 hp base run figures were for the current motor, correct? Even if you were running some 260-270 hp prior to the overhaul, I think your results look very impressive. How did you come up with the 310+ hp and 300 lb ft goals? Was this the pre-work estimate? Finally, why weren't all the runs carried out in 4th gear? I thought that was the correct ratio for such tests. Is that not the case?

Sorry for all the questions. When I finally blow up my engine at the track, I'll probably carry out a similar upgrade. Just looking for a little more info.
Congrats and enjoy!
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Old 07-30-2004, 05:05 AM
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Christer
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Tony

Considering the improvement (in both power and driveability), I am of course happy - the only thing is that not realising the potential we thought the motor had is a bit annoying. By that I mean that the power was pretty close to a Motec +1, and we thought it would make more than one of those. But in any case, it isn't over - I am going to have some fun and come back to it when 9M have their own dyno up and running perhaps towards the end of the year...

Pzull, I will probably get another dyno done to compare and if they supply A/F ratios then I will get those as well. We had limited time on the road and dyno, but the driveability is not an issue now. We didn't have time to do any part throttle setting on the dyno either. Again, I want to get back to this later.

Joey, according to the JZMachtech dyno I had around 220rwhp before any work was done - that was with the GHL exhaust - before that I had 207rwhp. So it is a big difference of course. As I say, the only gripe I have is the not reaching the potential - the car does go well now and is a joy to drive. 9M have a Motec +1 package which consists of a 3.6 with slightly longer duration cams than standard and the titanium valve gear etc and the gas flowing of heads and case - and when 9M tested that - the best they got over a period of time was I think 339hp (corrected) but this worked out at around 305 rwhp. That was winter time though, so the temp was a lot lower. However, that package also made over 300lb ft (just), but again maybe the temp makes a difference. So I would say that I am around the same figure but as Tony says, I use a different intake, different exhaust, larger capacity (3.8), 310 degree cams and all that so it is not so easy I guess to find the optimum...

Thanks for replying, hopefully this exercise will maybe benefit someone else in the long term - but it ain't over yet. We will see what happens at a later stage...
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Old 07-30-2004, 05:13 AM
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Christer
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p.s. I don't know why the runs were not all done in 4th gear - I think Colin said it didn't matter. It was only after we remembered that an RS has a shorter 5th gear than my car that we did a run in 4th...I guess the ratio is programmed in to the dyno...?
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Old 07-30-2004, 10:08 AM
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Christer, if you don't mind me asking how much did the project cost you (just the bits that were for power/torque)?

I have been quoted $3.5k for change of engine management to Autronic using Alpha-N (secondary manifold absolute pressure) which is similar to motec but slightly less mapping points. This is for management unit and labour for installation and tuning only. Does not include larger throttle body and larger injectors. How does that compare with the cost of motec+tuning (if you have cost breakdown)? Target peak bhp stated was circa 300bhp

A lesser but funky mod that a Japanese tuner did for a 964 in Taiwan using a japanese piggy back unit (with closed loop for low revs and open loop for high revs), removal of cats (apparently used resistors to avoid warning lights) and get this.....BMW 735i MAF sensor. Cost of mod was about $1,450. Owner didn't ask for dyno numbers but said that on his favorite test road he now hits max speed 290kph when previously he hit 270kph (didn't say if flat or slope surface), but based on fact that drag increases at the square of speed, it equates to about 15% increase in peak bhp to overcome increased drag to reach that terminal speed. ie. about 284bhp

But yours is by far the most exotic/elaborate NA mod so I've come across so far and of course the highest increase in performance, although can't understand why you're not ecstatic??

Anyway a very long-winded way of just wondering if the theory of diminishing returns apply if project is well planned like yours.

PS. Labor charges where I live is probably 1/2 - 1/3 the cost in UK/US

Last edited by pzull; 07-30-2004 at 10:02 PM.
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Old 08-02-2004, 04:43 AM
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Christer
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Pzull

The cost of the power stuff alone is difficult to pick out. Let's see, the cost of the rebuild probably would have cost around £5500-£6000 in the UK on its own (not just top-end, all of it). I needed new pistons and cylinders anyway to update to the new design, but I purchased 3.8 Cups instead of 3.6 at a greater cost - perhaps another £800 on top. The Motec is slightly tricky to remember, because normally 9M charge around £4500 for the Motec conversion and mapping - in this case though because I was using so many non-standard parts they charged me for the Motec parts whilst runnign in and then for the (limited) mapping we did last week. I cant remember the cost of the cams probably around £900, plus the Carillo's at around £950 and then some labour for the gas flowing...oy yeah and titanium valve stuff.

So.....I guess I don't know really - it must be around £6000-8000 at a guesstimate....

Don't get me wrong, I am happy - but not ecstatic as I don't think the full potential was realised. Having said that, all the cars dynoed on the day were having a tough day getting any good figures - so I'll come back to it later in the year. I might do a dyno run locally to me at some stage to get another viewpoint, but the car is clearly performing well so...we'll see....

In the meantime, I really have to try to make these new wheels fit - the fronts are not a problem but I am thinking rolled arches in the back......some rub inboard.....yesterday I did go round a roundabout at 60 on the outside of a 5 series with screaming tyres and i actually smelt burnt rubber afterwards....i hope it wasn't rubbing but I have got a feeling.....
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Old 08-02-2004, 12:01 PM
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Christer, Can I ask why didnt you just supercharge your car,the figures for supercharging a 964 are impressive and It would have worked out around the same as you spent even with the rebuild.

Paul
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Old 08-02-2004, 12:12 PM
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Christer
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Originally Posted by dove
Christer, Can I ask why didnt you just supercharge your car,the figures for supercharging a 964 are impressive and It would have worked out around the same as you spent even with the rebuild.

Paul
Hi Paul

I wanted a naturally aspirated solution as it is my preference. A supercharger in terms of power would have done a similar job, although not in delivery.
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Old 08-02-2004, 12:24 PM
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Pzull,

actually, required power is proportional to cube of speed.

Drag (force) is proportional to square of speed, and force * distance = energy, so energy per unit distance goes up with square of speed. However you are also traveling that distance faster: hence required power (energy/unit time) is proportional to cube of speed.

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Old 08-02-2004, 12:35 PM
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Hi Christer

I get confused with all the different BHP's! For comparisons sake my 993RS has 300BHP and my 964 had 250BHP - what is your equivalent figure now?!
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Old 08-02-2004, 04:52 PM
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Piers,

No doubt Christer will answer for himself but from his post he has [email protected], [email protected] and 289ft/lbs torque.

A "healthy" 993RS on the same dyno would/has yield [email protected], [email protected] and 265ft/lb torque.

Its worth looking at the dyno graphs overlaid each other. I have [email protected], [email protected] and 265ft/lb torque but overlaying the dyno graphs shows the 993RS to have significantly more torque/bhp over the mid-range rev range. This showed following one on track when he was able to just edge a little distance in front in each gear under full acceleration

In my experience on track the Motec+1 are a fair bit quicker than 993RS's using only the 5spd gearbox (ie are M0tec+1 have been 964s)
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Old 08-03-2004, 04:56 AM
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Thanks Tony. I've discovered how close all these cars are to each other on the track. At Castle Coombe with PCGB last month I had trouble keeping up with stock 964's but was staying ahead of some 996's but not others. It reinforces the old adage re. best mod is a better driver!
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Old 08-03-2004, 09:35 AM
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Originally Posted by Dave R.
Pzull,

actually, required power is proportional to cube of speed.

Drag (force) is proportional to square of speed, and force * distance = energy, so energy per unit distance goes up with square of speed. However you are also traveling that distance faster: hence required power (energy/unit time) is proportional to cube of speed.

Oh yes, that makes sense, you're right. So that Japanese mod equates to about 306bhp on flywheel....a bit optimistic...but i gues it's a very rough gauge of increase since its hard to determine exact top speed by staring at speedo at those speeds

Christer,

I see what you mean about ascertaining attributable cost of such a complex project. I think you will continue to see improvements with tuning refinement going forward, your engine will continue to loosen up (in a good way) and will require fine tuning down the road as it stabilises - I believe you are using Alpha-N instead of Absolute Manifold Pressure for mapping. I read that former is better when tuning is spot on but does not adjust for changes to state of engine
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