485whp RB20DET on racetrack

[Skym]

485whp RB20DET on racetrack (around 550hp at engine or more hp than a Group-A RB20DET) -

http://www.youtube.com/watch?v=gGnS9BhjoJY

Running on E85 gas (72hp more than on 98 pump gas with I think the same boost level). I think still has stock cams.

98 pump gas -

http://www.youtube.com/watch?v=-Lk1PZcHaUs

I think he's aiming for around 515whp (around 580hp at engine).

[burton160]

This is crazy! I agree it doesn't sound like upgraded cams.

[Skym]

I can't believe it's a RB20DET.

It supposedly has stock conrod bolts, stock conrods, forged pistons, metal headgasket, ARP 2000 headbolts, etc. Also has a Accusump setup and when engine was pulled down he said it looked ok, no problems so the Accusump is working.

Also the ignition system is said to be letting it down, so once that's upgraded he's aiming for 515whp.

[Rush_in]

That just goes to show that you never underestimate a Really Ballsy series engine

[Skym]

I agree. Also has upgraded valve springs, etc.

I think it's a misunderstood engine (how to modfiy it) and once get the combination correct it can be quick. At Bathurst the RB20DET-R engine in R31 GTS-R just lacked the hp vs Ford Sierra and that can be seen in this videoclip -

http://www.youtube.com/watch?v=PKxgQoDkZhY

That's why the RB26 was used and 4wd to help get hp to ground in dry or wet conditions and don't have to pit for new rear tyres (Audi proved this with 4wd).

[Rush_in]

interesting vid, the Cossy has 2 less cyl thus i think it can get through the power band faster. Its a track with a lot of straight lines so cars with fast revs and high HP can stay dominant but if the track had more bends i think think the R31 would've taken it cuz it creates more torque. you can see it that R31 comes out of the corners faster then the Cossy

i dont think is misunderstood, its probably because people know that there is a 26 out there that can do more so why spend money on a 20. It just got forgotten in the modefing world because its not the biggest and best. every motor can be fast with enough money sunk in to it, however i do believe its a better built motor then the 26 its not as high strung

[Skym]

Ford Sierra is quite laggy. Watching this videoclip of Rouse's ex BTCC Ford Sierra racecar shows how laggy it can be -

http://www.youtube.com/watch?v=0JAD0Z7Ilfo

But once on boost the engine really moves car.

This is Percy in R31 GTS-R (only 400hp at engine and GTS-R in Australia, Japan had around 440-480hp when they raced and the Ford is said to have 500hp) vs the car in videoclip above with Rouse driving -

http://www.youtube.com/watch?v=9mcpfLMQsp8

That Skyline is in Nissan's racecar collection in Japan (Percy, etc names on front? fender? gives it away).

With RB20DET they drop down gear to keep rpm into the small powerband which was around 4800rpm-7500rpm. The neat part is the throttle jab technique which makes it easier for RB20DET powered Skyline to catchup in the corners and when exiting short low speed corners. That can be seen at around 2:40 in the Bathurst videoclip.

Another example is in this videoclip where he uses the same drop down gear, jab throttle technique at 1:40+ (around 500hp at engine with the modern tweeks they have done) -

http://www.youtube.com/watch?v=BIasNcIrZcM

That's the bonus of the RB20DET, as it has good transient response due to the shorter stroke. I think Honda engines are better with transient response.

If you compare the Group-A RB20DET to the R32 RB20DET in first post, you can see that on E85 with good tune, modern turbo, etc, the R32 RB20DET is not that laggy with stock cams and can produce around 550hp at around 22-23psi (around 1.7bar x 14.5psi = 25psi for Group-A engines with custom aftermarket cams, T3/TO4E turbo, equal length extractors, etc).