LocostUSA.com

anyone have some basic dimensions for an r1 engine. also looking for the distance from the prop flange to front of the engine as it would be mounted in a bike.

thanx
andrew

What year? My 06 is different than an 03. Motor mount is different, and the clutch basket area is larger. My friend has 98 or 99 and his motor looks bigger, I cannot confirm. Best bet is to collect measures. The newer 04-06 have spring clutches vs diaphram. I can measure this weekend but it would help if you posted a photo of the motor and the measures you want.

i dont yet have a motor. im looking for some basic demensions to see if it will fit into my chassis which is being designed on cad, its not a traditional "7" build but a middy mounted longitudealy to a toyota supra diff. i also do not know which year motor i will end up with either, i intend to start construction of a rolling chassis prior to having a motor. some basic lenght, width, height measurements would be greatly appriciated of your 06 engine.

andrew

http://www.freewebs.com/bonjo2/locostphotos.htm

Mine is 19" at its widest (cover over clutch on right side, and left side cover). It is 30" tall from oil pan to top of air box, and roughly 24-25" to top of air horns (seam of air box in photo just above throttle bodies). The length from the upper rear motor mount to the leading edge of the head is about 18 3/4, without header. The sprocket output shaft is about 4" away from the upper rear motor mount, or rear most part of motor.

All measures +/- 1/4" due to it's cold out and I'm using a tape measure.

I hope this helps. The motor is tiny with a GIANT airbox.

thanks, much appriciated.

andrew

www.dpcars.net has r1 and busa motor cad files... they're not exact but close if you have a cad program.

Also note that the 04-06 motors are leaning over (forward on bike) a bit more so header angle will need to be tweaked, aout 1/4 to 1/2" less room for left steer shaft, and less height overall. Header spacing is the same, but without any air pump mess. I'm told a hood opening will still be required if running ITG foam filter, but if fabbing an airbox using alu bends to extend placement of air horns it may be possible to keep the stock taller style locost hood. I'm still split on this area as the ITG is open and easily tuned to, but a stealthy airbox could one day be pressurized.. I found alu bends that fit into the stock tbs for $8 each and can easily be welded into a universal alum ("JDM Style) CAI found at walmart or autozone- or any 3" alu pipe for that matter A rubber grommet will allow the Intake temp sensor to be mounted.

If you go 04-06, I can send you a tracing of the oil baffle with doesn't require any drilling of the stock block.

right on. lots of good info there. i dont know what year motor ill end up with, hopefully an FI model. have you made a sump baffle yet. what diff ratio are you planning on using?

andrew

I purchased a baffle set for the 04-06 R1 for just over $100. Once i get it I will see if my friend can make a stack for me on his wire edm machine and sell them for $20-30 without the tulip.

Initially, I am using the rx-7 rear end, that in the 3.9 range. A little high with wheel dia of 23.5" (same dia as the 15" setup, but doable. The U.K Guys think it will be too high and noisy for highway and track and suggested a 3.27 and not more than a 3.5 but they also assume a 21-22.5" 13x7 wheel dia. I'm using 14"s with 195/60s.

If it's too crazy, I will try and source a 3.63 dif from an old mazda 6 series or 6spd miata--though these are so rare it might be easier to convert the rear out completely. This is a high cost option here in the sates as the S-10 and a couple other small trucks are the only options, and their brake assy and center section are pretty heavy. To get them light, you're talking wilwood brakes, and drag rotors, and hollow axles ordered with a 4x100mm bolt pattern, So roughly 1100-1800 depending on source.

hmmm.

my diff is from an mk2supra/cressida with 4.1:1 ratio, and its a clutch type LSD. i did some calculations using the r1 gearbox figure with a 23.5 inch dia tire and unless i screwed up somewhere, i should be able to hit 60mph in first and top out at just over 120mph in 6th. which is right on my design parameters. initially i will run 16" wheels for road use and to get through inspection, for track use i will use 15" as there are a better choice of compounds available.

the cressida was also avail with a 3.9:1 i believe for stndrd cars, the reason i selected that diff is the stub axle bolt pattern is 4x110mm, which is a direct fit on to my 94 miata half shafts, although a .100 spacer will be required between the stub and the inner CV. or i could enlearge the bore on the stubs to accept the miata units for a flush fit. if the 3.9 unit proves too tall i could look into swapping the ring and pinion. there seems to be lots of good info on toyota differentials out there. the unit is hefty at 60lbs but is the best compromise for my situation.

keep us posted on those baffles.
andrew

FWIW - I rode in a R1 powered car once that had a 4.1 rear end ratio. The tires were 205/50-15s and we were topping out around 120. We did run out of revs before the end of the longest straight, but IMO getting five more mph would be tough. Not only because of the aero, but it the final drive were changed the effective power of the engine is reduced.

I guess I will be finding out a lot of answers regarding this come spring when I hit the track. Another option for you guys to look at would be 8-bolt and 10-bolt Toyota rear ends. All the dwarf cars use those and the center sections with different ratios are pretty cheap. LSDs are availible also.

_________________
-Jeff

Project Seven
Instagram: @RexRacer19

Thanks for the first hand info.

Based on the latest gear calc download, the 06 R1 with 3.909 gear will only produce 111 MPH in perfect conditions using the peak power RPM of 12,500 (13.7K redline for 04-06) and 195/60 14 tires. Yet a 205/55 16 will produce a solid 120, but wheels and tires will weight 8lbs more per corner. All of the R tires and extreme tires in the 13-15 range will produce between 109-114. If we go to hi perf summer (which I feel are way too pedestian for such a car) we can get to 120 as mentioned above. In all cases we are reving like a banchee in any gear over 65 and will likely get pulled over on the highway or back roads--75MPH speed limit out here in WY.

The 3.23 or 3.10 gears in the UK produce the magical 130-140 theoretical top speed, which works out to the seven's aero brick wall of about 130. One magazine tested a R1 motor'd car with 15" (195/55-can't even find them here, less all seasons) tires and 3.23 gears and said the ratios were perfectly matched, though most on the UK board feel the taller gear, light open dif, and lighter smaller tire combo the best route for track.

It appears to me a solid r compound or max perf 195-14 or 205-15 tire with a light wheel, and the tallest (US Market) rear end are in order. Even if the rear gains us 25-40 or lbs.

It seems too that the R1 motor, with every new generation has the gearing get taller and taller which keeps reducing the theoretical top speed for the same diff gearing.

I am hoping that my 3.9 gear will work out good based on the tires that I will be running, but my gut says that I will start running out of gear once the car starts to get sorted and I run softer tires. Guess I will find out soon enough.

_________________
-Jeff

Project Seven
Instagram: @RexRacer19