Jean

I came across a thread on a known UK forum, and had such a great time reading a post by Weltmeister that I thought I should share....Most of these "in" tuners nowadays are very decent and nice guys, over and above anything else, mostly true Porschefiles, but who just 1) don't do their due diligence when they post numbers openly on the net, or 2) take people for granted or 3) simply don't know it.

Here is a dyno chart posted...by a Weltmeister representative..Dyno dynamics is a very reputable dyno, better than most probably...

" Here is what has been done to the car, a stock 996GT2.
We swapped the exhaust for an off the shelf Tubi using std tips.
Put in a free flow panel filter & billet DV's
Spent a wee while in the Dyno with Revo

Voila, just short of 540 BHP nothing spectacular there I hear you say. How about 620 lb-ft of torque at 4100 rpm tho' ?"

And here is the dyno chart...


So what's wrong? It is a lame 535HP from a GT2, no big deal??
Check out that torque number: Almost 640ft/lb of torque at 4100RPMs That is around 870NM!!

Let us see some other reknown tuners...
WM: 535HP 870NM@4100 RPM

Sportec: 540PS 705NM@3900 RPM
Gemballa: 550HP 750NM
PSI: 550HP 724NM@4500 RPM
TTP: 550HP 720NM@4300RPM
RS Tuning: 542PS 755NM@4230 RPM
EVOMS: 550HP 760NM

These guys really can extract torque huh! The best part was showing off about these torque figures, rather than questioning them themselves...

Their signature?: "We build excitment" Pure PS no BS

TB993tt

This is the same chassis dyno (Weltmiester) which measured verysideways’s torque (with RS Tuning stage 1 ECU , cats and exhaust) at 636NM and their estimate of 666NM with fully functioning clutch.
RS Tuning quote 579NM on their engine dyno.

https://rennlist.com/forums/showthre...72#post2648172
This chassis dyno is seriously overstating torque numbers.

The simple proof of this is to ask what clutch are they using in this 996GT2 ? If it is organic and not slipping at peak torque then the torque is somewhere south of 790NM (581lb/ft).

870NM(640lb/ft) would fry an organic disc as peak torque is hit in 3rd gear upwards PERIOD.

Jean

Yes I would say > 75 ft/lbs!
If I was the customer, wouldn't I question these numbers? Now where is that AX22 thread?

viperbob

They are using REVO software it look like. Pretty funny though.

Bob Rouleau

The GT2 engine is seriously underrated to start with. Mine showed 517HP and the only change was a Fabspeed exhaust with race cats.

I wonder what gear they ran the car in .. torque multiplication ini the gear box perhaps? I was taught to run in a gear nearest to 1:1 drive ratio for that reason. I am not a dyno expert though.

Jean

Bob,

The tuners compared above are all on GT2 based engines. This specific car apparently dyno'ed 461BHP and 450lb/ft of torque when it went to the shop.

The gear they used is 4th gear. which has a ratio of 1.12, but my understanding (I am no expert either) is that they correct it.. The fishy thing here was the unrealistic torque curve number rather, which showed an increase of almost 190 lb/ft with an ECU remap and little more .

Bob Rouleau

Jean - understood and agree. The TQ number is fishy. I also think the 461 before number is suspiciously low. Porsche claims 456 and usualy understate their engines by 5-10 percent. GT3s claim 380 BPH and dyno around 405 BPH. I would expect no less from a GT2.

Rgds,

Woodster

I think it was the free flow air filter and billet diverter valves that allow such amazing
torque!
and to think I bought billet diverter valves...what was I thinking?

Marty K.

Bob Rouleau

Marty- the diverters were not a waste of money. The OEM ones are notiously weak and fail prematurely. No extra power mind you, but they do prevent a loss of power

uk trucks

So the Rennlist collective "Keyboard Heroes" strike again ? My reply is probably not going to win me many friends but most of the doubters [tb993tt apart] are geographically far removed from Silverstone, so it is quite irrelevant if I upset a few people in USA or Middle East. They were not going to shop with us anyway as they dont believe our numbers.

Once upon a time people believed the world was flat and we could never go to the moon, both of these myths have been sucessfully dispelled, in the educated parts of the world. Therefore just because no one else has done what we have, it's not possible ?? Because messers RUF or RS Tuning have not done it, it cannot be done. What utter drivel !

We recently had a 996TT X50 tuned by one of the UK's leading reflash suppliers on our dyno for a powertest post them doing it and it had boost in our opinion, in all the wrong places and had low torque, so if our dyno is wrong then this particular car was even worse than we thought ?

Sadly it is not possible for me to dispel this fishwives gossip from here except to say that we will gladly run one of our prepared cars against anyones [like for like i.e 993 Turbo or 993GT2 etc quoted mods/bhp etc] at a UK venue. No dyno just pure in gear acceleration to see who accelerates fastest and therefore has best torque ??

Any takers ??

Allan

red993tt

Allan

If possible I'd like to see your car doing some runs form 60-130mph with a GPS device such as AX22 and share with us your results.

uk trucks

As soon as we get the opportunity we will carry out a data logged run on some cars.

BTW the 996GT2 still had the "transit code" embedded in the ECU, so the dealer that sold it or 1st serviced it had never flashed it up to full strength, hence why the torque was down by so far when it first came in.

Cheers

Allan

TB993tt

Allan

A run of my car on your chassis dyno will NOT lay this accuracy issue to rest - I have tried to explain it to you many times before, but you just don't believe it.

You talk of inlet temps of 23DegC - I guess you are talking about ambient temps here ? inlet temps on a dyno pull should replicate those found on the road under load in order to be able to tune the car correctly and give accurate numbers. Inlet temps at maximum revs under 6th gear load are typically 55 DegC (with a 20degC ambient), do you even monitor these when you are tuning on your chassis dyno ? Please tell me you do ?

As you have pointed out the "fishwives" have spoken long and hard about why some of the mega chassis dyno tuners are delivering inflated numbers, but I have to say the one quoted above takes the biscuit

You are a full 120NM higher than the six other tuners Jean details. Surely even with your optimism that might seem a little odd ?

This topic has to be debated and exposed as there are people who are paying for something which they are not getting IMO and your dyno suppliers need to be aware that at least on these Porsche tt engines the torque figures being measured are not comparable with strapping the tuned engine on the Porsche engine dyno.

I have data from my car running in 2WD mode at ~1450kg 60-157mph on an AX22.
You need to get one of your 993GT2s to do a run with an AX22 (Guy R has one which he may lend ) of at least 60-130mph.

We can look at the data and decide whether the fishwives need to take up knitting

Konstantin

sometimes it is not the car or the tool (the dyno in this case) who reads worng. It is teh user who do not know how to use the tool.

For everything else a visit at Tuner grand prix 03. June 2006 in Hockenheim can show what the car is realy capable.
no BS and no PS. Just pure drivable perfomance counts.

sometimes less is more.

Konstantin

Jean

Hello Allan,
Thank you for chiming in, it is a pleasure for us to have you here. Regarding your description of heroes, I will consider it just silly. Afterall some of us have held a spanner in our hands once or twice during our lives, and even seen some slick tires in pictures and all.

It would be great if you could think other than from a sales pitch angle for a second, we are trying to have a rather technical discussion. We are irrelevant for your sales maybe, but irrelevant about the image you portray in the largest Porsche forum in the world, maybe not, think again.
The world is a very small place nowadays and many of us don't have geographical boundaries when it comes to our engines and where we spend our money building them.

Yes to your question, because they have not done it, you can't either. All, including the famous German tuner that you represent TTP, and the other Porsche newbies like RS Tuning and RUF, need to upgrade turbos from the stock GT2 K24s that come with the 996GT2 because of how much CFMs those turbos can flow, based on their physical dimensions.. That is why these newbie tuners that you mention and a couple of dozen others that I can show you, cannot go beyond 750NM or so with the stock GT2 turbos, and they need to upgrade turbos once they reach those levels. NOthing to do with Revo wizzardry and fuel and timing maps.
I take it that you are also one of the tuners getting 550BHP from the 993TTs on stock K24 turbos?
What are your conditions, Would you bet your car against the other, who looses gives up his car?

I suggest you go back to your (I hope) more technical partners and inquire about the technical questions being raised to you above, and maybe come back to us with a more valuable answer than the ones you just posted.