Ariel.Club Forum

The TTS air to air heat exchanger is built to fit under the airbox cover, yes. In this application we just tilted it forward to fit, but with a smaller deck K20 and smaller C30 Rotrex it will fit vertical without any angle.

We have a tune! The shop finished tuning it, I was a bit surprised how conservative they went but that's fine by me. We still got a 400hp crank motor on boil. The dyno came out 258wtq/338whp which is roughly equivalent to 300tq/400hp at the crank. For reference, stock my 230hp SRA (which is a base 205hp K24Z7 with intake, header, exhaust, and tune) made 190whp and a stock Civic Type R which is rated for 306hp crank made 271whp on this dyno. At the 7,200 rpm redline that was set, the Rotrex only pushes 10 psi. AFR is very conservative. The shop said the car cools down very well, and the air to air charge cooler is solid. Will test the car soon on track.

https://drive.google.com/file/d/1krsbFs ... sp=sharing

Nice figures!

Well done you must be pleased! 400Hp in an Atom will be rapid!!!

Peter255 wrote: ↑Mon Jun 01, 2020 7:01 pm Nice figures!

Well done you must be pleased! 400Hp in an Atom will be rapid!!!

I don't know what I am more excited about, the straigtline speed increase to make more passes and hit more top speed records, the noise of that blow off valve, the sexy look of the sidepods, or hanging with the well driven Normas or Radicals that will be shocked and awed to see an Atom flying by.

cvjoint wrote: ↑Mon Jun 01, 2020 7:28 pm

Peter255 wrote: ↑Mon Jun 01, 2020 7:01 pm Nice figures!

Well done you must be pleased! 400Hp in an Atom will be rapid!!!

I don't know what I am more excited about, the straigtline speed increase to make more passes and hit more top speed records, the noise of that blow off valve, the sexy look of the sidepods, or hanging with the well driven Normas or Radicals that will be shocked and awed to see an Atom flying by.

Wouldn't a standard Atom (~300bhp supercharged or turbo) on slicks be quicker than a Radical, SR3 at least. The SR3 lacks the power on exit and straight line speed but has the cornering speed. SR8 is a whole other beast and I don't think any Atom could keep up with a well driven one.

Well, my Atom was making 300hp/230tq all motor a the crank. A well driven SR3 is about 3 seconds faster, even though I have dual element wings front and back. They are on slicks too and have roughly the same power to weight. However, that SR3 body is much more slick and low drag. Even if I powered out of a slow turn faster they'd catch up and carry more speed towards the end of the straight. They still had me in high speed cornering. I have passed Radicals before but not the fast guys in the front row at the Radical cup.

With 400hp I think I should be able to take the fight to any of the SR3s. SR8s are beatable I believe, but it will take a very high strung engine and some good body work to do it. We have to reduce drag substantially or increase power substantially.

It turns out the combination of silicon hoses to clear the tray and the apparently restrictive Jim Wolf Filter was collapsing the hoses on the intake. Shop revised the intake system by reducing the use of hoses and adding an even larger filter element and raised the rev limiter back to 8,000 rpm. The car is now at 274 wtq 395 whp, 310 tq and 450 hp at crank assuming 11.5% drivetrain loss. Max boost is 14 PSI at redline and Rotrex is spinning at 74,500rpm, far from the 90,000 rpm limit. The only dyno I've seen on the V8 was at 400whp so it's now up there with the big boys!

Nice! I bet it will feel crazy to drive, but a lot of fun I am sure. You can see just how linear those engines are in terms of power delivery. Can you explain the silicone hoses, what was the problem here?

simonrhart wrote: ↑Thu Jun 11, 2020 10:30 am Nice! I bet it will feel crazy to drive, but a lot of fun I am sure. You can see just how linear those engines are in terms of power delivery. Can you explain the silicone hoses, what was the problem here?

I bet it's loads of fun! The power to weight is somewhere between a Veryon and a Chiron. Will take it to Laguna Seca this weekend. Will I lift of over the crest, fly, or keep the throttle pinned and trust the aero? Exciting times!

The heads on these true VTEC 4 port Honda engines flow like no other. I have to add that torque would have climbed much much more aggressively and therefore power too if I didn't use a tripple pass muffler. I'm robbing the engine of at least 30hp up top by using this in order to pass 90db @60ft regulations. Honda engines love a straight through muffler but I couldn't get it anywhere near 96db let alone 90db with a straight through design. I even tried a massive truck long straight through muffler.

The intake had to make a 90 degree bend to clear the engine cover and the only way to do that was to use a silicone coupler for the intake pipe. That's to make it all accessible at track days for inspection and all. Although I chose a custom massive Jim Wolf pop charger matched to the Rotrex inlet size, it was apparently still very restrictive for the amount of air the engine was inhaling. When I would go full throttle the air demands would overwhelm the filter and collapse the intake couplers. With the intake pipe shut by the couplers the engine would try to get its air from the blow off valve port. Sometimes even the blow off valve was shut due to vacuum. Hence, all the engine could do is keep the RPM steady. The lesson here is to try to use as few of those couplers as possible, they are weak unlike the aluminum pipe and can shut off the airflow.

So what we did now is to cut the engine tray to have a simpler intake that is 99% aluminum tubing. We also replaced the filter with an enormous one.

Finally, got some much needed R&R, i.e. Ran the Rotrex! 7 months of not driving made for some questionable driving moves, but the boost made up for it in shoves. Pinched a 1:32.2

Lovely stuff! What a machine!

Great pic of the rear parked up like that too!

Peter255 wrote: ↑Tue Jun 16, 2020 8:21 am Lovely stuff! What a machine!

Great pic of the rear parked up like that too!

TY!

Got one more to show the pods I got from the UK! Ahh, looks like I already spun in turn 2 before I took this pic. Sorry about the dust

Added some comments to the fastest lap session from time trials last weekend. Skip ahead to 5:45 for the fastest lap.

The Atom killed it with the quickest time of the day. It even slotted favorably in the top third of the qualifying times set by Trans Am series that shared the track that day. Trans Am now includes the likes of 600hp AMG GTR GT3s.


https://youtu.be/b7i-vE-hqBU

Love the subtitles [mention]cvjoint[/mention]! But where was the corkscrew?

I played that track forever as a teenager on the PlayStation. So happy to see it come to life in an Atom.

Top work! Stuff of dreams...

The post below was at Laguna Seca, which is known for the corkscrew:

cvjoint wrote: ↑Tue Jun 16, 2020 3:06 am Finally, got some much needed R&R, i.e. Ran the Rotrex! 7 months of not driving made for some questionable driving moves, but the boost made up for it in shoves. Pinched a 1:32.2



20200613_201106.jpg

The last post was at Thunderhill Raceway. This one has a little over the top drop, but it was bypassed in this configuration.

Laguna is definitely the more famous of the two and appears in simulation games. Going back there this weekend. Many fast cars joining this time around for some eye candy footage.

I enjoyed that! nice driving. Looks like you are having a blast. Regarding data acquisitions, dump the Race Technology and get some nice AIM kit with lap counting. You can then overlay laps and compare the entire lap along with many sectors you define. It's leaps and bounds ahead and you don't need any engineers to look at this data either.

I noticed you don't have the bug splatters installed, any reason for it?