Seeing as we are getting some good dynos coming out lately I put this up for general discussion . I know we have discussed this to death but I don't think anyone has tried to put actual real world charts together to get a better comparison .

 

i like this thread... I can help out - here's an overlay of a few runs. It goes past 7k, so you can get a better idea of the greddy power curve.

keep in mind this was a very mild tune, so there's people with an extra 20-30 whp over mine with the same setup.

if you can get some high res shots of the other dynos, we can overlay and get an accurate comparison.

 

I do wish we had a good dyno chart of Slavearm's 335 mazsport dyno. The couple posted are very low resolution.

 

thanks mysql101 - it was your chart I used but the one you had posted did not go past 7500 .

I'll do a better chart once I get info from Pettit installs & maybe put in SFR & Mazsport as well as they come along .
The numbers may be a bit out due to different dynos but I think they will be close enough for a good comparison.

 

Subcribes.

This could proove to be v interesting as I'm in the market for an FI solution now.

Cheers Brettus!

 

It's pretty much as I've said before. Centrifugals only make top end power. They don't do crap anywhere else and engines equipped with them make less power than stock until nearly halfway up the powerband. They are not a good match for a high revving engine. They have peak power. Take a look at the Greddy or Pettit runs. Those would be faster cars on the street as they have more average power. Peak power doesn't mean much.

 

Nice work Brettus. Finally a thread with something new. Interesting to compare the Greddy to the Pettit.

here's the SpeedForce Racing Turbo to add to the chart.

 

putting it in a new thread so that the first post has the graphs:

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/dyno-comparison-rx-8-turbo-supercharger-etc-115447/#post1857145

 

thats awesome work mysql - can you put the Pettit in there as well please

looking at that - I think I would prefer the Greddy to the SFR . Sacrifice a little up top but much better down low .

 

here it is - not the best but you can still pick the no.s off it

https://www.rx8club.com/attachment.p...chmentid=85970

 

heh. I'll wait for real dyno pics to be posted - we might get them tomorrow

 

Pettit SC looks good for the RX-8 Auto. The boost below 4,000 RPM looks nice. I wonder what their stage 3 will do?

 

that is very interesting how the power curve moves to the left for the sc... and it really is peaky

 

We need to get rid of HP ratings and start rating cars as area under the dyno curves. The largest area under the curve equates to the best average power for everyday use.

This reminds me.... why do we not have any torque curves in here...?

 

HP is a combination of torque and speed. If a kit makes more hp at a given speed (RPM), it makes proportionately more torque I should think. In this way, the torque curves would look similar. hp = tqxrpm/5252 I think.

 

that .. and becuase its embarrassing

 

Wow. You know what's kinda scary...The Greddy really looks like the right turbo for street application and seems to have the most area under the curve overall. Very interesting. I didn't think the SFR turbo was quite as peaky as it looks compared to the Greddy unit. I guess I expected more grunt down low as well...

 

Just for ***** and giggles let's say the usable powerband is from 6500-8500 rpms. The Greddy turbo in this chart would have about an average of about 265 hp over that range. The much higher peak power centrifugal would also have an average of about 265 hp over this rpm range. In spite of the higher peak power of the centrifugal, which one do you think will be faster in a race? The turbo would have a more steady rate of acceleration whereas the supercharger would be slower after a shift and then catch up on the top end before needing to shift again. It would only finally pass the turbo in top gear after the rpms climbed high enough. I'm not even going to venture at what speed that is but usably you'll never see it.

Average power is why knowing only peak power is useless. When people ask how much power something produces, they are looking for a number that impresses them. Go buy a Supra if you want mega numbers that do nothing useful except during drag races on freeways at speeds well over 100 mph. On paper seeing 326 peak hp appears much more impressive than 275 hp, More must be better right? 51 more hp is alot. However it doesn't tell you the whole story. Average power wins races. Not peak. In this case the average power is about the same over the usable powerband at full throttle but anywhere else the Greddy will walk all over it.

 

well if you look in the first post that shows the pettit as well you will notice that it is not too far away from the greddy up top but way better below 4000 which is your daily drive range .
Without that glitch in the mid range there would not be much in it at all - be interesting to see if they have resolved that.
So for a daily driver I'm going to stick my neck out & say the pettit looks to offer the best all round compromise .

 

so i am confused. again..

so in a straight line.. the cf sc is at a disadvantage in first gear to ~ 5 k.. after that all things are =.

on a road course. all things are =...

beers

 

Totally agree. Will be interesting to see how the Pettit and Greddy further develop, tune, and are compared. So far, I like what I see with Pettit... hope it gets better... and we are still waiting on the AF supercharger...

 

This shows why BMW's cars, which typically have been down on peak HP compared to others, can have such great real world numbers. They tune for AVERAGE power. The 330i before the new twin turbo engine was down on power to the G35, but yet sill managed to be faster.

This is also why I'm going to build a turbo 8 that makes about 250-260whp with a nice torque shelf and be done with it. I don't care if someone's car can dyno over 300 with a peaky power band, I'm going to walk all over them with average power in real world/track situations

 

Well it wasn't in mysql's prettier graph so I wasn't going to say that. Especially since it looks like the greddy still has more through most of the power band in your post. It's tough to tell what RPM range we're dealing with down there and if it really makes up for the rest of the power band or not.

Hopefully we'll see a dyno Chart from Shinka's install today or tomorrow to add in to the mix to get a better picture.

 

It has been a long time to get to this graph. Now we need a couple more SC's on there along with Scott's TC's.

 

Something we need to add in consideration with these graphs is $$$$$$ .
Lets just talk basic - get you running kits , not all the fancy add ons you really should have as well ......

Greddy Turbo - add say $200 to replace crap parts......$3400
Pettit Twin screw sc -$5000 + $1000? (for EMU) =........$6000
DNA Centrifugal stage 2 ...............................................$70 00(check)
Speed Force kit with powermod EMS.............................$7500
Mazsport Type1............................................. ...............$8000

Not sure on DNA (site is down at moment) or price of EMU for Pettit but I know Powermod can be had for about $1100 US . Will correct if someone can help with those .