leonsamonas

funny how there was no mention of a problem before, you must know your engine really well but suddenly (after being clearly wasted) you have developed an alleged problem, hmmm...figures

if you look at the video on the first straight where we started side by side, from 3rd gear onwards you are being trashed, if we didn't need to slow and turn at that stage you would have been nowhere, as we can see on the other side.
p.s i suppose your nerves got the better of you because we had clearly stated a 2nd gear start on the 2nd straight and i can also see you count to three on the video...surely that's what we had discussed....one, two, three, GO...
better luck next time (if you show up for some more humble pie )

here's a refresher (rs tuning vs ruf)
http://www.youtube.com/watch?v=6cXvxf0KVMc

I don't think it's faster, I have undeniably proved it at vmax, if you want to waste time with your ax22 go ahead, but when it comes to me vs you in the world where variables are equal (i.e vmax event) there was only one winner

don't worry, i'm sure you'll think of a few more excuses, my advice is

Sport auto "THE most respected car magazine in the world in terms of the tests it does on cars" pull the other one

p.s if your car was 'geared' to do 193 and mine to do 'more' shouldn't it accellerate quicker than mine?? where's the evidence of that

Stummel

sport auto is a reputable source for performance measurements.
they also race the Ring with any car, but that is not so comparable as the straight line measurements.

Jean

Leon,

Just one question, are you sure you can beat Toby's car in a similar run to 190mph for instance (no gearing issues) or any other acceleration run again, and are you willing to put your money where your mouth is?

Cheers

NineMeister

Sorry Toby, never intended to start a witch hunt, all I am really interested in is the shape of the power and torque curves, because faster cars with the same bhp usually just have a lot more area under the power curve than a slower one. Irrespective of the relative accuracy of whatever dyno they use (and personally I think a torque/rpm measurement is pretty much the same the world over), it's really the curve shape which will allow me to interpret how other engines might stack up against it, not just the absolute numbers.

On a lighter note, how come "very expensive" does not cover the cost of a printer or produce a jpeg?

TB993tt

Are you calling me a liar ?
If you want to phone the owner of Tech 9 Motorsport (who you know) he can give you a detailed explanation of what was wrong with my car and why he gave me a sizable credit for my trip to Germany to establish what was wrong.

So you think I am lying about being in 3rd gear compared to you being in second ? watch the video again and look at my rev counter, or count the changes
If your car was so much quicker why was it only 5mph faster - that is not a "thrashing" in my book.
So that is a no then for the AX22 ?
I am sorry you have never heard of Sport Auto Magazine - ask Herr Ruf
Do you understand what "geared" means ? look at the chart above, it runs out of revs, 193mph is at the rev limiter.
It did not accelerate as quickly as yours because it had less power and was heavier - the gearing was actually in your favour since these turbo engines accelerate fastest with longer gears - I won't even get into that as I suspect it would be a waste of time.
Thankyou for being so gracious

TB993tt

Colin
I have seen the curves which your chassis dyno can produce for these engines running with fixed boost and they are very simialr in shape to my curve -so there is your answer, it won't tell you anything
I completely disagree that a torque measurement is the same the world over - I have seen your machine tell people they haqve 800NM when they are running componentry not capable of producing those numbers (Porsche comparable).
BTW I am not picking on you, the classic was the Weltmiester torque monster 996GT2.

NineMeister

No, I agree with you, the way that an inertia chassis dyno works is definitely different to a constant rpm engine dyno and certainly the old Bosch software that I was running possibly favoured the way those 993 turbo motors spooled up. After upgrading the control hardware & software I am now able to add eddy current brake load during a run, hence loading up the engine a lot more through a test and making it work harder. I fully understand that and whilst my results may or may not be as accurate as others, what I have now found is that the tests I have made on turbo cars since are very consistent, even between runs that may be weeks apart. I do find it ironic though that my dyno will measure a 996GT3RS at 408hp, std GT3 at 385bhp, 997S at 355hp & 987S at 280hp which are all Porsche comparable figures, but there are always doubts levelled when the same dyno to the same standards measures the 9m 4.0 litre engine at 440hp, and unfortunately not always in public.

Using the "black dyno" is definitely the best measure of a cars performance but we should keep in mind that since no-one accepts uncorrected dyno numbers, unless cars are raced (read measured) side by side (or one after another on the same day) we should look to factor in air pressure, temperature and humidity corrections to the 60-130 (100-200 or 100-300) times. If not poor Jean will always be slower because he tests in a desert and us Manchester folk will be faster 'cause it really is bloody cold "oop North".

One day last week my dyno predicted a correction factor of 4% which would "add" over 20hp to your car, for instance, which would definitely make a difference to your 60-130 time. Food for thought I suppose. Incidentally, if ever you are testing in the area you can always call me and I will let you know the Cf from dyno's onboard weather station, may be useful for Jean's calculations.

935racer

What a terrific thread! I am not quite sure if its a "mines bigger than yours" scenario or if it is trying to be scientific. If its the former, well, I will leave it up to you big boys, if its trying to be scientific I would like to add my two pennyworth.
Firstly someone states that a turbo will accelerate faster in a taller gear. Wrong. Its a simple law of physics. Torque accelerates a car and the lower the gear the higher the torque multiplier is and thus there is more torque available at the wheels to accelerate the car. Of course, there will be more gearchanges required and the subsequent loss of time due to each change but I think that an extra gearchange will still give higher average acceleration.
If you want to measure engine power then use an engine dyno. There is no substitute. Changes can be made under controlled and repeatable conditions and thus any gains (or losses) in power can be verified. This is the most important factor in engine developemnt. You must be able to verify the results and without repeatable readings you are simply kidding yourself. If you want to see whose car is faster then the 60 to 130 (or 150) m.p.h. runs are fine. Just dont forget aerodynamics. The aero drag is by far the largest force to overcome and 911 of all derivatives are notoriously draggy.
I am also amused that people believe it is only the RS Tuning and Ruf type establishments that can produce good reliable power. This is simply not true either. Producing good reliable power from a turbo Porsche is not rocket science. Its a case of everything in moderation, heat, boost, compression ratio etc. It is expensive and you do need good components (although you dont neccessarily need intercoolers costing the earth!) but the secret is knowing what works and what doesn't.
Anyway, thats my tuppence worth and I cant wait to read the next installements!
Richard.

Rassel

If this turns into a pie throwing contest, then such a low quality of discussion belongs in the Off Topic area. Actually, the 993TT board is one of the best ever on Rennlist since it has such a high standard and none here would probably be impressed anyways.

*flame suit on*
Are we going HP vs. Torque?

TB993tt

Colin
It is this old chestnut which I obviously don't understand which is that when people attempt to tune using the 10sec power run method the numbers just don't perform on the road - if you have found a method of loading and tuning whilst under load then I would guess your numbers are going to be more Porsche like. Certainly Sportec and Manthey and Mr PhD on here seem to be able to tune pretty well using chassis dynos and this "loading" method.
Regarding the 60-130 runs, of course you are right - for my 6.9s run I waited 'til the conditions were perfect I guessed it was worth 20hp- in warmer weather I am a solid 7.2s
I have a my very own hammer now so I can see exactly what the engine ECU is reading, and the obvious thing is how the air mass changes with the weather

935Racer
Glad you're enjoying it
Leon's is definately bigger than mine, I have no desire to go over 190mph again whereas he seemed to relish it.
Of course you are technically right with the gear issue however the gearchange time IS important and makes quite a big difference to an acceleration run. Check out this thread: https://rennlist.com/forums/showthre...ghlight=torque
If one has a very broad power curve with for example 95% of peak power from 5000 to a peak of 6700rpm then longer gears which utilise the full 1700rpm will accelerate you the fastest - building an engine with this type of real power curve is difficult and most cannot do it.
I don't agree with your statement about 911 being draggy, relative to which othe rcars ? RS and Ruf proved in '88 that a 911 ccould do 213mph with just 469hp, I'm not aware of any other car which can get close ?
Porsche tuning may not be rocket science, but it is surprising how few tuners can do it right.
Oh and I don't agree about intercoolers, the ones that work cost plenty

schnele

Toby, I just watched the video I think there was about 5-7 car lenghts. I am not going to fan the fire and encourage puerile behavior on this board but I think the tape says it all.

leonsamonas

wow I must have really struck a nerve, didn't wish to upset you quite so much toby , i know you take this data stuff really seriously and of course i'll run the ax22 at next vmax in march, all I'm saying is that i spend more time driving my car (and by driving i mean driving on race circuits around the country and around europe to its and my limits, let's just say to each their own my friend..

p.s i wasn't suggesting you were lying about 3rd, just saying you obviously didn't pay enough attention when we were discussing the rules of engagement

BTW 193 mph to 198mph equates to how much distance at that speed, please enlighten us less technically minded (just tell us in car lengths)

MOD500

Whilst I don't subscribe to embracing men in vests and long socks in the surf, threads like this remind me of:

http://www.youtube.com/watch?v=mYOTK_6fIh8

I attended the last v-max, and think some further explanation is very pertinent. Am trying to be unbiased of course, since my own car has a little RS Tuning mojo.

TB's car did have some issues; he posted upon realising this here (page 4):

https://rennlist.com/forums/showthre...8&page=1&pp=15

I recall when myself and Leon did a run together this time he had the lead from the start, and upon hitting 3rd really pulled away like I had shifted into neutral, and left me eating his dust. Now nothing too perplexing in this you may say. But, I recall from the previous v-max to last in July, we ran together and there was nothing in it. I posted my thoughts at the time here:

https://rennlist.com/forums/993-turbo-forum/283629-vmax-today-any-news.html

So, given this last v-max in October I had changed my front splitter and rear wing to reduce drag, plus installed a MAF type Secan EVO intercooler I was bemused to how Leon could have dealt such a Drago-esque blow.

The only reason I can think of is the 102 race fuel Leon had in his car? I was running super unleaded plus 2 bottles of octane booster BTW, the same as the run in July. I am interested to what difference would be seen in the performance of mine and TB's motor's if we were to run such uber juice. It certainly seemed to be analogous to Leon popping a few little blue tablets in his tank. I mailed RS to ask of the safety of using such gas in my car, and in true style they have not bothered to reply!!

So, not as simple as it seems in my honest opinion, and certainly not clear cut enough for to be banded around.

Hopefully RS will advise regards the 102 juice, and we should be able to see the relative effects at the next v-max.

Also, I feel it prudent that discussions on here should remain civil, and not degenerate into saying people are telling falsehoods and the like. This whole tuning thing is so fascinating, and it is great we are able to see how cars fettled by the different tuning houses compare.

Kind Regards



Martyn.

leonsamonas

with all due respect martyn, i missed a gear on that run, nevertheless relish the challenge at next vmax....

MOD500

Which run Leon, v-max in July or Sept?

Thanks


MOD.