993GT2EVO dyno report number two
03-11-2008, 11:14 AM
#2
Addict
Rennlist Member
Rennlist Member
Graeme
Thanks for sharing
I presume this is after some ECU tuning ?
I'm afraid once again the Chassis Dyno torque inflator has done its thing !
To get 770NM you need at least 1.3bar boost and a whole lot more than a set of stock K24s
Your mid range peak torque number is seriously wrong, the accuracy of the rest of it can be determined with a GPS acceleration measuring device....
Thanks for sharing
I presume this is after some ECU tuning ?
I'm afraid once again the Chassis Dyno torque inflator has done its thing !
To get 770NM you need at least 1.3bar boost and a whole lot more than a set of stock K24s
Your mid range peak torque number is seriously wrong, the accuracy of the rest of it can be determined with a GPS acceleration measuring device....
Last edited by TB993tt; 03-11-2008 at 12:54 PM.
03-11-2008, 01:22 PM
#3
Addict
Rennlist Member
Rennlist Member
TB - Why are you always such a Doubting Thomas? 
This TT ran 500hp, 500 ft/lbs with only K24s and programming. That is not my car, but I was there and that is wheel power, not crank. Bonus points if you can guess the Dyno.
Greg H.
This TT ran 500hp, 500 ft/lbs with only K24s and programming. That is not my car, but I was there and that is wheel power, not crank. Bonus points if you can guess the Dyno.
Greg H.
03-11-2008, 01:26 PM
#4
Addict
Rennlist Member
Rennlist Member
You are fortunate that on this Tech forum we have the tools to test what the dyno "rip off" merchants (or just plain incompetant) tell us
Here is a clip from a run I did in my 993tt.
The car was in 2WD mode, weighing 1450kg and at the time had peak torque measured on engine dyno of 736NM.
Graeme, you need to get a heavy passenger on board and do the same test and see if your car pulls 0.8G peak in third gear - it won't because my car in that configuration was EVO race twin plug heads with EVO gaskets, RS cams, twin fuel pumps, K24/26 turbos, race cats and mufflers and running 1.2+ bar to hit its 736NM......
Here is a clip from a run I did in my 993tt.
The car was in 2WD mode, weighing 1450kg and at the time had peak torque measured on engine dyno of 736NM.
Graeme, you need to get a heavy passenger on board and do the same test and see if your car pulls 0.8G peak in third gear - it won't because my car in that configuration was EVO race twin plug heads with EVO gaskets, RS cams, twin fuel pumps, K24/26 turbos, race cats and mufflers and running 1.2+ bar to hit its 736NM......
Last edited by TB993tt; 03-19-2008 at 03:57 PM.
03-11-2008, 02:12 PM
#6
Racer
Join Date: Jun 2004
Location: Yorkshire, UK
Posts: 449
Likes: 0
Received 0 Likes
on
0 Posts
Looks like Rocky & Apollo are getting the gloves on once again ..... Hey Stallion, you fight great but I'm a great fighter ...... Hey Apollo, you move pretty good for an older guy. Ding, Ding!
The torque does look miles out; these Dyno Dynamics chassis dynos do seem to produce wildly inflated numbers .... I recall Weltmeister posted up a plot a while back from a 996 GT2 with only remap and exhaust showing 870 NM from memory. Another example was when Ace took his then RS ecu equipped 993tt to a chassis dyno and it made loads more torque than the stated number from the engine dyno as shown on the RS website.
As another example of extensive mods vs peak torque output ….. my single plug engine produced a meagre 729NM on the engine dyno from the following mods:
K24 RS turbos (a K24/26 hybrid built by KKK to RS's own spec)
Sport cams
Carillo rods
Ported / gas flowed heads
EVO sealing rings
RS Tuning Race exhaust with big cats
5 bar fuel pressure regulator
So you can see the 770NM is quite optimistic from a remapped stock 450 hp engine with K24's?! Do you believe the torque number Graeme?
The torque does look miles out; these Dyno Dynamics chassis dynos do seem to produce wildly inflated numbers .... I recall Weltmeister posted up a plot a while back from a 996 GT2 with only remap and exhaust showing 870 NM from memory. Another example was when Ace took his then RS ecu equipped 993tt to a chassis dyno and it made loads more torque than the stated number from the engine dyno as shown on the RS website.
As another example of extensive mods vs peak torque output ….. my single plug engine produced a meagre 729NM on the engine dyno from the following mods:
K24 RS turbos (a K24/26 hybrid built by KKK to RS's own spec)
Sport cams
Carillo rods
Ported / gas flowed heads
EVO sealing rings
RS Tuning Race exhaust with big cats
5 bar fuel pressure regulator
So you can see the 770NM is quite optimistic from a remapped stock 450 hp engine with K24's?! Do you believe the torque number Graeme?
03-11-2008, 02:35 PM
#7
Addict
Rennlist Member
Rennlist Member
I gave up on you US based guys a while ago - there is enough info on here so that anyone who really wants to test their hp knows how to do it but most prefer what chassis dynos tell them - The UK is not (quite) yet a lost cause
Trending Topics
03-11-2008, 02:45 PM
#8
Racer
Thread Starter
Join Date: Apr 2007
Posts: 296
Likes: 0
Received 0 Likes
on
0 Posts
No I have to agree I think the torque figure of 570 ft lb or 770 nm is unrealistic. I believe the factory figures where 432ft lb at 4500 rpm. So perhaps one should be expecting similar torque to hp around the 490 mark. That said if you look at the graph for boost and I am comfortable with around 1 bar it still knocks the boost back to 0.8 bar at 4500rpm. I've said all along that the car feels very quick but seems to have a hole between 4000 and 5000rpm. Not so bad now but I can still feel it when I drive it. The dyno shows that it is still present.
This is the interesting bit. Before running my car this morning another GT2 was dynoed a 95 car running new K24's and a fresh engine that has done a 2000 miles since, also been remapped by the same people as this car suffered with major over fueling through the mid range and dynoed as follows running 1.2 bar of boost against my 1 bar.
Torque almost identical, 487 bhp against 492bhp and 404 rwhp against 414. Evo heads and cams anyone ?. The most important thing to establish today was that the fueling was good prior to the oulton park RS day coming up.
This is the interesting bit. Before running my car this morning another GT2 was dynoed a 95 car running new K24's and a fresh engine that has done a 2000 miles since, also been remapped by the same people as this car suffered with major over fueling through the mid range and dynoed as follows running 1.2 bar of boost against my 1 bar.
Torque almost identical, 487 bhp against 492bhp and 404 rwhp against 414. Evo heads and cams anyone ?. The most important thing to establish today was that the fueling was good prior to the oulton park RS day coming up.
03-11-2008, 03:20 PM
#9
Addict
Rennlist Member
Rennlist Member
No I have to agree I think the torque figure of 570 ft lb or 770 nm is unrealistic. I believe the factory figures where 432ft lb at 4500 rpm. So perhaps one should be expecting similar torque to hp around the 490 mark. That said if you look at the graph for boost and I am comfortable with around 1 bar it still knocks the boost back to 0.8 bar at 4500rpm. I've said all along that the car feels very quick but seems to have a hole between 4000 and 5000rpm. Not so bad now but I can still feel it when I drive it. The dyno shows that it is still present.
This is the interesting bit. Before running my car this morning another GT2 was dynoed a 95 car running new K24's and a fresh engine that has done a 2000 miles since, also been remapped by the same people as this car suffered with major over fueling through the mid range and dynoed as follows running 1.2 bar of boost against my 1 bar.
Torque almost identical, 487 bhp against 492bhp and 404 rwhp against 414. Evo heads and cams anyone ?. The most important thing to establish today was that the fueling was good prior to the oulton park RS day coming up.
This is the interesting bit. Before running my car this morning another GT2 was dynoed a 95 car running new K24's and a fresh engine that has done a 2000 miles since, also been remapped by the same people as this car suffered with major over fueling through the mid range and dynoed as follows running 1.2 bar of boost against my 1 bar.
Torque almost identical, 487 bhp against 492bhp and 404 rwhp against 414. Evo heads and cams anyone ?. The most important thing to establish today was that the fueling was good prior to the oulton park RS day coming up.
Its great that you have kept the Motronic controlling the boost, at least if your tuning is not 110% when things get "race hot" the built in protection will limit your timing and boost to protect the engine unlike our other GT2 RLer whose fixed boost resulted in melted heads IIRC....
BTW if you have real "EVO heads" you will have twin plugs, that is what they had
If we manage to organise a mini vmax (exclusive for 911s only
)it would be great if you could make it and we could hook up the GPS and give you some real numbers
03-11-2008, 05:48 PM
#10
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Graeme
First thank you for posting the graphs in so much detail, we do not see so many graphs being posted showing boost pressure, AFRs, wheel and flywheel graphs etc.. Great info.
I would not get too hung up about these dyno numbers, but just for the sakes of a debate
and to give you something to go back to your tuner with and challenge him (Yet again! he is still saying you have an EVO engine!? ) , I would go even a bit further than TB and say that to get to 560lbs of torque, you need to be at 1.4-1.5 bar on your KKK24, which is not possible since they max out around 1.2. Funny to see that this is the same dyno that WM used
You might want to look at the graph below for reference, it shows what is directionally the maximum torque that you can achieve with these engines. The stock 450bhp 993GT2 has torque of about 430 lbs.ft at 0.9 bar if I recall correctly, if you look at the 993TT line, you will see that 1 bar corresponds to 450-460lbs of torque maximum.
As for HP with stock kkk24 turbos and 1 Bar you are looking at 460-470 bhp maximum. With slightly bigger turbos and cams you can reach 490bhp.
A GPS logged run and extrapolated Gs will very quickly get you the exact number.
First thank you for posting the graphs in so much detail, we do not see so many graphs being posted showing boost pressure, AFRs, wheel and flywheel graphs etc.. Great info.
I would not get too hung up about these dyno numbers, but just for the sakes of a debate
and to give you something to go back to your tuner with and challenge him (Yet again! he is still saying you have an EVO engine!? ) , I would go even a bit further than TB and say that to get to 560lbs of torque, you need to be at 1.4-1.5 bar on your KKK24, which is not possible since they max out around 1.2. Funny to see that this is the same dyno that WM used You might want to look at the graph below for reference, it shows what is directionally the maximum torque that you can achieve with these engines. The stock 450bhp 993GT2 has torque of about 430 lbs.ft at 0.9 bar if I recall correctly, if you look at the 993TT line, you will see that 1 bar corresponds to 450-460lbs of torque maximum.
As for HP with stock kkk24 turbos and 1 Bar you are looking at 460-470 bhp maximum. With slightly bigger turbos and cams you can reach 490bhp.
A GPS logged run and extrapolated Gs will very quickly get you the exact number.
03-11-2008, 06:43 PM
#11
Racer
Thread Starter
Join Date: Apr 2007
Posts: 296
Likes: 0
Received 0 Likes
on
0 Posts
Thank you all for your feed back. My main concern was that we had sorted the problem with the new air mass meter and a remap and that the fuel / air mixture was safe. I really cannot afford to detonate the engine and that was as many on here my main concern. The plus side was the comparison between the other GT2 and mine to see how the numbers stacked up. Although I agree that dyno's are potentially BS running two 993GT2's back to back give you an indication of truth even if you ignore the numbers produced if that makes any sense.
Andy is going to look at whether we we can dial out the drop in boost but I guess it will probably have to be at the expense of how vicious the boost comes on which is strong. I think that this would be worth while as that 1000rpm or so of thinking to yourself (come on, get on with it) is a little frustrating.
I will definately run the car at a Vmax and with any data logging you guys want to put on it. Just want to wait for better weather. I'd love to pull the double ton but with the wide body and GT2 wing I guess it ain't going to happen. I will give it my best shot though.
Andy is going to look at whether we we can dial out the drop in boost but I guess it will probably have to be at the expense of how vicious the boost comes on which is strong. I think that this would be worth while as that 1000rpm or so of thinking to yourself (come on, get on with it) is a little frustrating.
I will definately run the car at a Vmax and with any data logging you guys want to put on it. Just want to wait for better weather. I'd love to pull the double ton but with the wide body and GT2 wing I guess it ain't going to happen. I will give it my best shot though.
03-12-2008, 07:06 AM
#13
Not Forgotten
Join Date: Apr 2006
Location: South East, UK
Posts: 1,215
Likes: 0
Received 0 Likes
on
0 Posts
Graeme, these guys have forgotten more than i know, but just thought i'd mention that your mixture looks a bit lean at 4300rpm don't you think, it looks like about 0.81 Lambda which equates to over 12.5 to 1 AFR, it seams to quite quickly richen up after that, it might be fine, but just thought, regardless of the numbers, that's where your getting peak torque and maybe it could do with being a tad richer? Please educate me if I'm wrong, I'm just an apprentice
03-12-2008, 07:29 AM
#14
Addict
Rennlist Member
Rennlist Member
Jon, I probably understand less than you about what is rich/lean but I can confirm from my engine dyno data that my Motronic allows 0.92 lambda at 2500rpm which falls to 0.77 at peak torque (which is where peak fuel pressure occurs @ 6.06 bar ?) then it hovers between 0.81 and 0.87 reving up to to 7000rpm...... seems to work on mine
03-12-2008, 08:02 AM
#15
Not Forgotten
Join Date: Apr 2006
Location: South East, UK
Posts: 1,215
Likes: 0
Received 0 Likes
on
0 Posts
Toby, that's really interesting, i've read that mid 14's AFR is good for cruising, like a NA car. But when you build up boost you don't want to see anything more than 12.2 AFR which is about 0.79. Here is a quote from another thread
"in an ideal world (EFI), your AFR will be 14.7-15.0 in the cruise range (light throttle, no boost). As you begin to add load to the engine you need the AFRs to be richer. By 1 bar of boost, you are safe at 12.0-12.2:1. Richer than that and it is a waste. At about 12.5:1 and 1bar of boost you begin to risk melting the engine down. Obviously things like compression, cams, etc. may change the requirements"
I know your engine is extreme so i guess it has different parameters, as you know i melted a hole in my piston at 12. something AFR, the figure after the decimal point was flickering all over the place during the run so i've no idea what it was reading, but it had to be under 0.84 Lambda.
"in an ideal world (EFI), your AFR will be 14.7-15.0 in the cruise range (light throttle, no boost). As you begin to add load to the engine you need the AFRs to be richer. By 1 bar of boost, you are safe at 12.0-12.2:1. Richer than that and it is a waste. At about 12.5:1 and 1bar of boost you begin to risk melting the engine down. Obviously things like compression, cams, etc. may change the requirements"
I know your engine is extreme so i guess it has different parameters, as you know i melted a hole in my piston at 12. something AFR, the figure after the decimal point was flickering all over the place during the run so i've no idea what it was reading, but it had to be under 0.84 Lambda.