186 mph (300 km/h) two-way average top speed

[greenberet]

…with a naturally-aspirated 3.0 liter 5-speed measured by GPS, filmed in high definition.

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Engine modifications:

• Comptech airbox
• Unifilter foam air filter
• Extrudehoned intake manifold
• Comptech ported and polished cylinder heads
• Comptech high-lift camshafts
• Cantrell headers with ceramic coating
• HKS muffler
• Autothority engine management chip custom programmed with car on dyno

Aerodynamic modifications:

• Homemade complete front and rear undertrays
• Homemade air dams in front of all four wheels
• Dali 2002-2005 OEM trunk lid spoiler replica
• Bilstein dampers that lower the car about 2 cm
• Procar Specials front blinker covers (mounted temporarily with duct tape)
• Homemade styrofoam plugs for air conditioner openings in nose of car (temporary)

 

[greenberet]

Some notes:

I filmed this with a Canon HF10 CMOS-based rolling shutter video camera and the picture quality is much worse than with a CCD-based camera. I think that even my little CCD-based still picture camera set to video mode shoots better in-car videos. The sound quality is better with the real video camera, though.

The car felt a little squirrelly during this run so I didn’t keep it floored as long as during my last top speed run (see video on YouTube here). That, plus there was more traffic this time. At 0:21, 0:34, and 2:15 into the video, you can see the car pulled to the right as I got off the gas. Not very confidence inspiring. After my last top speed run, one of the CV joint boots on the right side of the car split. The suspension wasn’t realigned after removing and reinstalling the axle, so maybe the alignment is a bit off. During the last top speed run, for comparison, the car was totally stable.

While turning around between the two runs, I noticed a strange vibration from 1400-1800 rpm and there was a kind of chatter at idle. The vibration reminded me of how my brother’s car vibrated years ago when the engine mounts failed, so I figured that might have happened to my NSX as well. I thought the chattering was from the transmission. For a while now, my transmission has been chattering a bit when it’s fully warmed through, the car is stopped at a traffic light, the transmission is in neutral, and the clutch isn’t depressed. When I press the clutch, the chattering goes away. Between the two runs, the chattering stayed pretty much the same regardless whether the clutch was depressed or not. I figured maybe the transmission oil was really hot, so I short-shifted on the second run heading west.

After that second run, while turning around to head east again, the car still had the same symptoms. If anything they had gotten worse, so I didn’t do any more top speed runs. During the 400 km (250 mile) drive home, I didn’t exceed 270 km/h (168 mph). When I got home, there was still a vibration between 1400-1800 rpm and the unusual chattering was still there. Looking under the car, the cause for both symptoms seems to be a failed crankshaft balancer pulley. Maybe the knock at 2:27 into the video is the crankshaft balancer pulley failing. Thank God my engine isn’t toast!

If you want to find out your car’s top speed, you really have to do a two-way run to make sure the wind and hills are not affecting your measurements. If you just want to go really fast, drive down a hill. Attached is a quick-and-dirty spreadsheet calculating how much you can increase your top speed depending on the hill’s slope. Remove the .pdf ending from the file, open it with excel, and have fun seeing how much of a slope you need to break 200 mph with a stock NSX (if gearing allows). To know what speed you’re actually traveling, you really should use a GPS device or a stopwatch. How much your tires are worn down, whether they were even produced to the exact specification on the sidewall, how much they’re slipping, etc. all make the speedometer and tachometer readings slightly inaccurate.

 

[Cozmo]

Wow!
I hit 114mph (in a dream) recently and I thought my hands were going to fall off and my heart beat right out of my chest.

 

[goldNSX]

greenberet: your car is very stable at those speeds! Luckily your harm. balancer didn't fail there.
I was in the 155+ mph region last weekend and my car still needs work to feel stable. Problems (old driveshaft boots) appeared.

Great video!

 

[greenberet]

Luckily your harm. balancer didn't fail there.

Actually, the harmonic balancer did fail while the first half of that video was being shot. Maybe I was driving fast enough that the plastic timing belt cover melted from the friction and splattered onto the oil filter instead of cracking and throwing pieces at the timing belt. In any case, I'm glad the belt doesn't seem to have skipped a tooth. Or several.

 

[NetViper]

Wow. That was cool! Glad you didn't damage your motor! I can't imagine driving home at 168MPH

 

[NSX 3.0]

That is awesome !!!

 

[davidf]

Damn that was badass.

 

[YellowHaze]

You've displayed way more cojones that I ever would by doing that. Passing cars on a 2-lane highway at those speeds?! Yikes!

Hey, I like driving at speed and taking turns aggressive as much as anyone. It's also interesting to see someone do it in an essentially stock car and especially an NSX. I simply would never do what you did unless I was on a track.

Be glad no one or nothing got in your way. At those speeds, you and your car would disappear- poof!

 

[greenberet]

Yeah, I am glad no one got in my way. My NA1 brakes are not ideal for scrubbing off a lot of speed very quickly.

Be that as it may, driving at high speeds is common here and maybe it’s something you get used to. I think the BMW I passed at 1:47 and the Audi I passed at 1:50 were leaning on their 155 mph speed limiters.

Despite the high speeds, the death rate on German highways is half that on US highways per 1000 miles driven. At US speeds, you may be able to walk away from an accident. At German speeds, um, you often won’t. Despite that, you’re twice as likely to die driving 1000 miles on US highways as you are driving 1000 miles on German Autobahns. And it’s not just safer over here, it’s a lot more fun!

 

[nsxotic911]

Yeah, I am glad no one got in my way. My NA1 brakes are not ideal for scrubbing off a lot of speed very quickly.

Be that as it may, driving at high speeds is common here and maybe it’s something you get used to. I think the BMW I passed at 1:47 and the Audi I passed at 1:50 were leaning on their 155 mph speed limiters.

Despite the high speeds, the death rate on German highways is half that on US highways per 1000 miles driven. At US speeds, you may be able to walk away from an accident. At German speeds, um, you often won’t. Despite that, you’re twice as likely to die driving 1000 miles on US highways as you are driving 1000 miles on German Autobahns. And it’s not just safer over here, it’s a lot more fun!

Very nice. The one thing Germany has right is it's speed laws.

 

[blodi]

I think the BMW I passed at 1:47 and the Audi I passed at 1:50 were leaning on their 155 mph speed limiters.

I can only imagine what they must have thought when they are doing 155 and get passed like they are standing still! Amazing video...thanks for posting!

 

[SaleenS7Rs]

the fastest I ever went in a car was 145mph and that was pretty cool I bet that extra 40 is so much better:biggrin:

 

[Bram]

Wow, that is just great on a stock NSX, I wish we can do this in NA. In Europe the drivers are much better aware of high speed cars, and move over when you approach

I was in Italy last week on Vacation......on the Autostrada Flat Out in my Fiat Panda...........140KPH


Bram

 

[SoCalDude]

Amazing! So much for the drag limit of 168 mph. Looks like your aerodynamic mods worked really well. Congrats!:biggrin:

 

[UnhuZ]

Amazing! So much for the drag limit of 168 mph. Looks like your aerodynamic mods worked really well. Congrats!:biggrin:

that and turning TCS off to be able to get over 280km/h :tongue::tongue::tongue: right greenberet?

now i have a suctioncup to support a camera....i must do some runs also... with my almost stock NSX :biggrin::biggrin::biggrin:

Thanks,
Nuno

 

[davidf]

I can only imagine what they must have thought when they are doing 155 and get passed like they are standing still! Amazing video...thanks for posting!

Actually they probably see that on a daily basis. After all, it is the autobahn. :wink:

 

[davidf]

You've displayed way more cojones that I ever would by doing that. Passing cars on a 2-lane highway at those speeds?! Yikes!

Hey, I like driving at speed and taking turns aggressive as much as anyone. It's also interesting to see someone do it in an essentially stock car and especially an NSX. I simply would never do what you did unless I was on a track.

Be glad noone or nothing got in your way. At those speeds, you and your car would disappear- poof!

If I'm not mistaken the slower traffic is not allowed in the laft lane. Someone please correct me if I'm wrong {it won't be the 1st time} but I swear I heard it on the discovery channel.

 

[fourringpilot]

I nominate the above clip for NSXPRIME Video of the Year.

 

[Jetpilot3]

Definately movie of the year!

 

[RON98]

awesome :smile:

 

[goldNSX]

My NA1 brakes are not ideal for scrubbing off a lot of speed very quickly.

I'd say NA1 brakes are crap for the Autobahn. I was impressed by the NA2 brakes with HAWK HP+ pads. Night and day.

 

[greenberet]

Thanks for the congratulations!

Looks like your aerodynamic mods worked really well.

I don’t know. When my avatar picture was taken in 1999, the car had the same engine mods as now but no aerodynamic mods whatsoever other than closing off the a/c openings in the nose of the car and lowering it with Eibach springs. With 245/40 17 rear tires, the car pulled to an indicated 8000 rpm in one direction and 8050 in the other. If that was below 300 km/h, then probably not much. All the aerodynamic modifications since then don’t seem to have increased the top speed a whole lot.

Last autumn, before I built the rear undertray, the car got up to 299 km/h in one direction and 301 km/h in the other according to GPS. I was hoping the rear undertray would increase that but I haven’t been able to measure a gain. Maybe the engine is losing horsepower as it gets older and the aerodynamic mods are keeping the top speed the same despite that. Or the engine is still in good health (like my dealer says) and the aerodynamic mods didn’t make that much of a difference after all. They took a lot of time to design, build, and install, though.

that and turning TCS off to be able to get over 280km/h :tongue::tongue::tongue: right greenberet?

Yep. With my 255/40 17 rear tires, the car runs into a speed limiter at 282 km/h (175 mph) if the traction control is on. Turn it off and you can go faster and the TCS failure light comes on instead, like in the avatar pic.

I forgot to turn off the traction control during this run and you can see the car hitting the limiter at 282 km/h (1:50 into the video). I turned it off and got on the gas again at 1:53 and was able to accelerate further.

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Note: according to the weather report there was a 14 km/h breeze from the west lowering my top speed in the first half of that video, when I was driving into the wind. That turned into a tailwind when I turned around and headed east, but my rev limiter kicks in at a bit over 300 km/h depending on how worn down the tires are.

 

[troca]

Wow-Fahrfergnugen! Really nice video, glad your aero mods came out well. Traffic wasn't too bad really, much better than I have seen many times on the Autobahn, don't try that in August! With my short gears and 4.22 gears I couldn't do that, not to mention that it is much harder to find a place here in the Midwest that is free from cops (all the more active these days of short budgets since we all know traffic enforcement is about revenue more than safety anyway) and safe but got up to about 140 with ease on the track so I think I could redline with the short gears. I'll be replacing my balancer with other mods scheduled for this coming winter, as I was reading your post I kept thinking- balancer?-balancer? and sure enough you got to it. Glad you survived that and made a point of telling us, confirms my decision to replace mine. Best regards, Tony

 

[s14_tat]

that is crazy, its very hard to get that sensation of speed on film but on your video, everything looks like a damn blurr.