450 bhp vs 430 bhp vs 408 bhp
06-19-2002, 12:51 PM
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450 bhp vs 430 bhp vs 408 bhp
Contemplating buying a 993 TT.
Just wondering whether there is any real difference between the basic 408 and the 430 and 450 respectively.What I have heeard there is the largest precieved performance gain between the 408 and the 430 and consequently not so much between the 430 and 450 except for the very topend i.e. above 5000 rpm.
According to P. Frere the 430 bhp 993 TT hits 60 mph in 3.8 seconds and levels out at 188 mph.
Just wondering whether there is any real difference between the basic 408 and the 430 and 450 respectively.What I have heeard there is the largest precieved performance gain between the 408 and the 430 and consequently not so much between the 430 and 450 except for the very topend i.e. above 5000 rpm.
According to P. Frere the 430 bhp 993 TT hits 60 mph in 3.8 seconds and levels out at 188 mph.
06-19-2002, 01:02 PM
#2
Hey 993 Swede...
Great choice of cars..
I'd recommend that if this is your first "high performance" car, I'd stick with the stock configuration, ie 408 HP. That's already plenty of car and acelleration in stock form.
I would rather spend the money on other things that will actually make your car handle better, ie tires, suspension, brakes, harness, etc.
I think that you'll get more enjoyment of carving through turns rather than doing 0-60 runs. Otherwise, just get a mustang or camaro. Those can make great 0-60 cars.
Btw, I've never been up to 188 mph and probably never will. The fastest that I've been is 140.
Jeff
Great choice of cars..
I'd recommend that if this is your first "high performance" car, I'd stick with the stock configuration, ie 408 HP. That's already plenty of car and acelleration in stock form.
I would rather spend the money on other things that will actually make your car handle better, ie tires, suspension, brakes, harness, etc.
I think that you'll get more enjoyment of carving through turns rather than doing 0-60 runs. Otherwise, just get a mustang or camaro. Those can make great 0-60 cars.
Btw, I've never been up to 188 mph and probably never will. The fastest that I've been is 140.
Jeff
06-19-2002, 01:15 PM
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The top speed for the 3 power levels is about the same, limited by gearing rather than power, since it is acheived after peak power at around 6600rpm. The Paul Frere test you refer to did give exceptional acceleration figures from the 430ps version, I suspect the figures were gained on a cold day. Was it 0-160kph in 8.5s (from memory). That is about as fast as a 450ps version. The 450ps version uses larger turbos so will be marginally less responsive in the lower rev ranges but much stronger after 4000rpm. If the 450ps version you are looking at is a factory Euro turbo S then it has quite lot more extras including a full sport suspension package (if you want details I would be happy to elaborate).
Personally I would buy a 408ps version then add a basic ECU/air filter/cat/exhaust mod which will give you around 440ps with stock turbos for little investment. If you want more. there is lots more
The top speed for the 3 power levels is about the same, limited by gearing rather than power, since it is acheived after peak power at around 6600rpm. The Paul Frere test you refer to did give exceptional acceleration figures from the 430ps version, I suspect the figures were gained on a cold day. Was it 0-160kph in 8.5s (from memory). That is about as fast as a 450ps version. The 450ps version uses larger turbos so will be marginally less responsive in the lower rev ranges but much stronger after 4000rpm. If the 450ps version you are looking at is a factory Euro turbo S then it has quite lot more extras including a full sport suspension package (if you want details I would be happy to elaborate).
Personally I would buy a 408ps version then add a basic ECU/air filter/cat/exhaust mod which will give you around 440ps with stock turbos for little investment. If you want more. there is lots more
06-19-2002, 01:20 PM
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TB,
Which ECU would you fit (esp. being in the UK)? I have 430 a ce moment but would be interested in just cleaning up the inefficient way the stock ECU uses the turbos. I am not really looking for a extra bhp just interested in smooting things out and getting some better use of them.
I have the extra front oil cooler, and RSR's (of course) but am also interested in your suggestion of air filter...
BTW 993 Swede in the Uk the difference in 2nd hand prices between 408 and 430 was fairly little and I would choose the 430 if you can find a good one... less oil cooler fitting to do and these lists will show that ain't a bad thing
Cheers to you both, W
Which ECU would you fit (esp. being in the UK)? I have 430 a ce moment but would be interested in just cleaning up the inefficient way the stock ECU uses the turbos. I am not really looking for a extra bhp just interested in smooting things out and getting some better use of them.
I have the extra front oil cooler, and RSR's (of course) but am also interested in your suggestion of air filter...
BTW 993 Swede in the Uk the difference in 2nd hand prices between 408 and 430 was fairly little and I would choose the 430 if you can find a good one... less oil cooler fitting to do and these lists will show that ain't a bad thing
Cheers to you both, W
06-19-2002, 01:33 PM
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I forgot about that oil cooler - good point
I'm not sure what you mean by the inefficient way the stock ECU uses the turbos and about getting better use from them.
The 430ps turbos are the same as the 408ps turbos Porsche called them KKK16.
The factory mapping, be it 408ps, 430ps, or 450ps is very conservative, particularly in the mid range (between 3000 and 5000rpm) it limits overboost to about 0.8 bar on 408ps, 0.85 bar on 430ps and 0.9 on 450ps. This limits torque severely in the mid range. If you look at the 450ps torque curve it rises steeply then is chopped off between 3-5000rpm. This is Porsche being conservative for all eventualites. A tuners ECU will allow more mid range overboost, up to 1.1 to 1.2 bar for a stock configuration engine. This overboost will "smooth out" your power delivery and give you a lot more mid range power, transforming the car. Phil Hindley can get hold of ECU mapping by RS Tuning (most tuners use their mapping and own brand it).
Whilst I've read nothing but praise from users of the RSR's I don't believe they are dyno proven. If they are not getting rid of back pressure then they will limit your torque output also.
I forgot about that oil cooler - good point
I'm not sure what you mean by the inefficient way the stock ECU uses the turbos and about getting better use from them.
The 430ps turbos are the same as the 408ps turbos Porsche called them KKK16.
The factory mapping, be it 408ps, 430ps, or 450ps is very conservative, particularly in the mid range (between 3000 and 5000rpm) it limits overboost to about 0.8 bar on 408ps, 0.85 bar on 430ps and 0.9 on 450ps. This limits torque severely in the mid range. If you look at the 450ps torque curve it rises steeply then is chopped off between 3-5000rpm. This is Porsche being conservative for all eventualites. A tuners ECU will allow more mid range overboost, up to 1.1 to 1.2 bar for a stock configuration engine. This overboost will "smooth out" your power delivery and give you a lot more mid range power, transforming the car. Phil Hindley can get hold of ECU mapping by RS Tuning (most tuners use their mapping and own brand it).
Whilst I've read nothing but praise from users of the RSR's I don't believe they are dyno proven. If they are not getting rid of back pressure then they will limit your torque output also.
06-19-2002, 10:01 PM
#6
I had the 424 HP Turbo S ECU update for about a year, followed by the 450 HP Porsche Powerkit Plus for almost three years (GT2 turbos, new ECU, and oil cooler).
With 100 octane, the Powerkit Plus is noticeably more powerful than the 424 Turbo S kit. This is especially noticeably above 5500 RPM where the car does not "die", like the 408 and a bit with the 424 kit. With 91 octane, there is a bit of hesitation from 4500 to 5500 with the 450 HP kit.
Here's some times I measured with 92 cctane. I did not measure with 100 octane:
5 - 130 mph = 16.5 sec 424 HP, 14.4 sec 450 HP
5 - 150 mph = 19.4 sec 450 HP (did not measure 424)
Because of the high RPM improvement, 5-60 times were about the same, 5-100 was about .5 sec faster. For reference, I get about 4.5 sec for 5-60 (starting from a rolling start, clutch fully engaged).
With 100 octane, the Powerkit Plus is noticeably more powerful than the 424 Turbo S kit. This is especially noticeably above 5500 RPM where the car does not "die", like the 408 and a bit with the 424 kit. With 91 octane, there is a bit of hesitation from 4500 to 5500 with the 450 HP kit.
Here's some times I measured with 92 cctane. I did not measure with 100 octane:
5 - 130 mph = 16.5 sec 424 HP, 14.4 sec 450 HP
5 - 150 mph = 19.4 sec 450 HP (did not measure 424)
Because of the high RPM improvement, 5-60 times were about the same, 5-100 was about .5 sec faster. For reference, I get about 4.5 sec for 5-60 (starting from a rolling start, clutch fully engaged).
06-20-2002, 06:00 AM
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[quote]Whilst I've read nothing but praise from users of the RSR's I don't believe they are dyno proven. If they are not getting rid of back pressure then they will limit your torque output also.<hr></blockquote>
TB - I've recently installed RSR's onto my 408bhp car and can say they don't change the power delivery at all. They do have a very nice effect on the engine sound though. Seems to improve over time also.
Will - think I'll have a word with Phil Hindley about these simple mods. The car needs an oil cooler to start with anyway. What suspension mods would you recommend?
TB - I've recently installed RSR's onto my 408bhp car and can say they don't change the power delivery at all. They do have a very nice effect on the engine sound though. Seems to improve over time also.
Will - think I'll have a word with Phil Hindley about these simple mods. The car needs an oil cooler to start with anyway. What suspension mods would you recommend?
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06-20-2002, 06:39 AM
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on a stock 408ps car, the RSR rear mufflers work fine I'm sure. Once the ECU is modified and allows more boost, this is when you need modified free'er flowing mufflers to release the increased level of back pressure which will build up at the new boost levels. The sports cats also help reduce this back pressure and improve torque and power on a 993tt running a modified (higher) boost curve. When my car was running a fairly mild state of tune a few years ago, 440ps, I had a set of Cargraphic mufflers on and decided to put back on the stock mufflers 'cos I got a bit tired (and embarrassed)of the loud noise. (sports cats contributed)The instant drop off in throttle response when using the stock mufflers was dramatic and I put back the louder, free'er flowing units the next day and instantly felt the throttle response come back. I am relating this so you realise that if your RSRs are not free'er flowing then the benefits of getting a modded ECU will not be fully realised unless you get some mufflers that work.
on a stock 408ps car, the RSR rear mufflers work fine I'm sure. Once the ECU is modified and allows more boost, this is when you need modified free'er flowing mufflers to release the increased level of back pressure which will build up at the new boost levels. The sports cats also help reduce this back pressure and improve torque and power on a 993tt running a modified (higher) boost curve. When my car was running a fairly mild state of tune a few years ago, 440ps, I had a set of Cargraphic mufflers on and decided to put back on the stock mufflers 'cos I got a bit tired (and embarrassed)of the loud noise. (sports cats contributed)The instant drop off in throttle response when using the stock mufflers was dramatic and I put back the louder, free'er flowing units the next day and instantly felt the throttle response come back. I am relating this so you realise that if your RSRs are not free'er flowing then the benefits of getting a modded ECU will not be fully realised unless you get some mufflers that work.
06-20-2002, 01:44 PM
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I just love those RSR's and their sweet ('walk fairly softly and carry a big stick') attitude that I would keep them whatever. I am not overly interested in the definitive HP figure but would love a little more torque.
For this reason I am thinking of keeping the smaller KKK16 units (as they spool up faster) but remapping the ECU because I read here and other places that the Bosch ECU that is in our TT's is not a turbo-specific unit. As such it treats the engine rather like it was naturally aspirated and lets the turbos just get on with them job themselves (i.e. when the exhaust gases finally reach them). If you change the ECU to one which will actually operate with the turbos in mind, as it were, then one can apparently achieve a better torque curve and more efficient use of boost across the rev range. Of course this may be rubbish and I hope some expert will tell us what the standard TT ECU really does for the car (and if it is indeed the same as the naturally aspirated ones).
Sports cats would be a definate upgrade to reduce back-pressure with the KKK24's but would they be absolutely necessary with the standard turbos even if they worked on higher boost across all the revs?
Jus' some thoughts. Best wishes. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
For this reason I am thinking of keeping the smaller KKK16 units (as they spool up faster) but remapping the ECU because I read here and other places that the Bosch ECU that is in our TT's is not a turbo-specific unit. As such it treats the engine rather like it was naturally aspirated and lets the turbos just get on with them job themselves (i.e. when the exhaust gases finally reach them). If you change the ECU to one which will actually operate with the turbos in mind, as it were, then one can apparently achieve a better torque curve and more efficient use of boost across the rev range. Of course this may be rubbish and I hope some expert will tell us what the standard TT ECU really does for the car (and if it is indeed the same as the naturally aspirated ones).
Sports cats would be a definate upgrade to reduce back-pressure with the KKK24's but would they be absolutely necessary with the standard turbos even if they worked on higher boost across all the revs?
Jus' some thoughts. Best wishes. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
