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Old 07-12-2012, 02:43 PM   #41 (permalink)
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The rotrex doesn't make any low down power over stock, and adds little to the mid range compared to a turbo or supercharger. However, if you keep the rpm high, they work ok.

I did back to back comparisons with two similar Civics a couple of years ago, both with K20 engines - one with a M62, the other with the rotrex. The M62 made 285 hp, the rotrex 335 hp. Doing time to rpm tests the M62 was faster below 4000 rpm, and then equal to about 6500 rpm or so. Above 7000 rpm the rotrex was faster. Distance to speed from a rolling start gave about the same terminal speed (I think it was 78 mph for the rotrex and 77 mph for the M62). Again, on a race track the rotrex would be much faster because you're able to keep the rpm up.

Bang for buck I'm not sure my $1800 (brand new) K24 + $1000 M62 can be beat...
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Old 07-12-2012, 03:02 PM   #42 (permalink)
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The rotrex doesn't make any low down power over stock, and adds little to the mid range compared to a turbo or supercharger. However, if you keep the rpm high, they work ok.

I did back to back comparisons with two similar Civics a couple of years ago, both with K20 engines - one with a M62, the other with the rotrex. The M62 made 285 hp, the rotrex 335 hp. Doing time to rpm tests the M62 was faster below 4000 rpm, and then equal to about 6500 rpm or so. Above 7000 rpm the rotrex was faster. Distance to speed from a rolling start gave about the same terminal speed (I think it was 78 mph for the rotrex and 77 mph for the M62). Again, on a race track the rotrex would be much faster because you're able to keep the rpm up.
Yea we have gone round and round on the Rotrex things. But Derek does bring up a great point. Horsepower under the curve is ultimately what accelerates the car. Most people tend to look at the peak numbers generated on a dyno and not the average power under the curve. To that end the Rotrex (or any other centrifugal blower) typically has large peak power, but less area under the curve than the peak number suggests. This is because boost (and torque) continues to build until the RPM cutoff.

So just as Derek pointed out a 335whp Rotrex car will nearly identical in time to distance on something like an auto-x when compared to something like a 300whp M62, or even a 290whp NA car. On the street where much of your acceleration is done from low or mid powerband the 335whp Rotrex car (or even a 350whp Rotrex car) will feel considerably slower than the previously mentioned NA or M62 supercharged cars.

The beauty of the Rotrex lies in its efficiency... and packaging (to some degree). The Rotrex is inherently a more efficient compressor and therefore boost-to-boost will heat the air a little less than a turbo, and considerably less than an M62. Additionally the packaging allows for a correctly sized external air-to-water cooler to be fitted. Finally, while the Rotrex kits may be a little down on average power under the curve in comparison to other forms of induction it is pretty easy to make big power out of them. Sure a 450whp Rotrex setup may not be as potent as a 450whp NA setup... but good luck getting that kind of power NA or some other way. 450whp Rotrex is still a **** ton faster on a racetrack in comparison to a 350whp positive displacement blower or even 400whp positive displacement blower.

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Bang for buck I'm not sure my $1800 (brand new) K24 + $1000 M62 can be beat...
Derek.. what kind of connections do you have being able to buy a new K24A2 for $1800?? That's stupid cheap!
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Old 07-12-2012, 03:11 PM   #43 (permalink)
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P.P.S

Anyone looking for Rotrex + Honda + Lotus inspiration go check out this guy's videos. Looks like he just got his built K24 + Rotrex setup going... and it looks surprisingly dialed in. The thing is downright stupid fast; The speed at which he catches exotics in his videos is silly. Not too bad of a driver either:

evo11 - YouTube
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Old 07-12-2012, 03:36 PM   #44 (permalink)
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The rotrex doesn't make any low down power over stock, and adds little to the mid range compared to a turbo or supercharger. However, if you keep the rpm high, they work ok.

I did back to back comparisons with two similar Civics a couple of years ago, both with K20 engines - one with a M62, the other with the rotrex. The M62 made 285 hp, the rotrex 335 hp. Doing time to rpm tests the M62 was faster below 4000 rpm, and then equal to about 6500 rpm or so. Above 7000 rpm the rotrex was faster. Distance to speed from a rolling start gave about the same terminal speed (I think it was 78 mph for the rotrex and 77 mph for the M62). Again, on a race track the rotrex would be much faster because you're able to keep the rpm up.

Bang for buck I'm not sure my $1800 (brand new) K24 + $1000 M62 can be beat...
Nice comparison. One thing that needs to be taken into consideration is the size of the rotrex charger. At those numbers I'm guessing it was a c30. I am running a c38-71 and could have still gone with a c38-81 and even the new c38-91 and seen even more power. I would have gotten the c38-91 but I got my charger new for almost half price. I got my car semi tuned at 15psi and called it a day. WhatsADSM is going to help me with some final tuning and I also need to relocate my boost sensing line. So there is still some room to be had with my setup which is floating around 385-393whp now. Yes
Article says 400whp and it will probably be more then that once I'm done playing with the existing step.


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Old 07-13-2012, 10:55 AM   #45 (permalink)
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Derek.. what kind of connections do you have being able to buy a new K24A2 for $1800?? That's stupid cheap!
Brand new TSXs on a train which derailed. For liability Honda sells the cars off as parts (now they may shred them like Nissan). There were a bunch on k20a.org for sale. Mine had never turned - there was assembly grease in the engine but no oil.
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Old 07-19-2012, 03:37 PM   #46 (permalink)
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Here is update number #3.. yes more teaser pictures.

One Hot Lap: A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part III
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Old 07-19-2012, 06:54 PM   #47 (permalink)
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Great update! Getting closer to a final post?
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Old 07-19-2012, 07:16 PM   #48 (permalink)
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Getting closer im going to break down the build a bit then do the "final".


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Old 08-27-2012, 09:17 AM   #49 (permalink)
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So what happened to this?
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Old 08-27-2012, 11:26 AM   #50 (permalink)
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More up dates coming. I have been really busy lately


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Old 01-17-2013, 11:50 AM   #51 (permalink)
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Here is part 4!

Sorry I have been busy.. The next update won't be too far along and you will have some real pictures soon. Scouts honor!

Haters gonna hate but I love the car and its going under some changes now which will continue onto my One Hot Lap series.

One Hot Lap: A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part IV
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Old 02-26-2013, 11:33 AM   #52 (permalink)
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400whp Lotus Exige S Onhotlap.com release

Part V is up!

http://www.onehotlap.com/2013/02/a-l...urned.html?m=1


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Old 02-26-2013, 03:52 PM   #53 (permalink)
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Jesus your entire swap started off badly!

These bumps in the road tend to happen on big projects like these... I would know!!

Nice write up though keep going!
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Old 02-26-2013, 07:08 PM   #54 (permalink)
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400whp Lotus Exige S Onhotlap.com release

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Jesus your entire swap started off badly!

These bumps in the road tend to happen on big projects like these... I would know!!

Nice write up though keep going!
Yah and the series isn't over yet!
Thanks for the input!


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