Exhaust studs.

[Pete.]

Hijack away because a discussion about exhaust studs vs a discussion about a 200 mph + turbo'd bike doesn't take too much thinking about.

OK well to keep it on topic I'll start with this photo. The original bolts were M10 x 1.25 and I drilled them out to 10.8 then hand-tapped them 12mm x 1.25 for the high tensile socket cap head bolts. The shorter main bearing/bottom crank case bolts were M9 which I also drilled and tapped to 12mm x 1.25.

The entire system was built by me except back then I had no suitable welding plant (or skill) so I didn't do the welding. I started out with this pile of expensive parts. Best part of 5 grand here. JE pistons, Carillo rods, HD bolts and gaskets, HD valve springs Bosch 600hp fuel pump and a fuel pressure regulator I can't recall the maker. Garret 500hp GT30R turbo was destined to go on a Skyline but the project was sold off so I bought it. MTC lockup clutch and MRE cover. Adjustable cam sprockets. I didn't use the big wastegate but went for a Tial one and 50mm blowoff.

I bought a £400 CNC plenum cut the front off with a mini grinder and welded on my own design of watercooled charge cooler. The late Pete Bolas (hotrodder) welded the cores, a job that even the manufacturer declared would be "very difficult indeed" but he made it look easy. Also cut holes in the top for four extra Siemens Deka 60cc injectors which were (are) controlled by a Microtech fuel injection computer. The fuel rail was the fist thing I ever made on a milling machine.

Hotrodder welded 12 of these ends without a single leak. The edge he welded was just 1mm wide pure ally onto 6mm thick 600 series side plates. Awesome skills. This was his practice piece.

Headers were inch and a half dairy pipe I cut and fitted it all up in a jig and someone welded them for me.

When it all came together it looked like this.

 

[bricol]

I always take the studs out and use bolts or cap heads after running a sharp tap down the holes..better for in-out maintenance and never fall foul of studs failing in future.

Problem tends to come several years down the line of trouble free, no-fettling required, running. Caps heads corroded, and not too chuffed about the heat cycles. Even with nickel anti-seize (banned in the State of California, is says on my tin), some of the well-hidden internal animal has to come out to get them out without too much damage to the important bits.

I swapped to mild steel studs, threaded as required each end, and brass nuts. No issues since, even on turbo-ed engines.

 

[Pete.]

I also made the 3" exhaust and silencer.

The silencer actually worked quite well it was loud but not obnoxious. Of course the turbo gave a bit of noise damping.

I cut up a standard radiator and bent it a little so it fitted snug inside the bike's main rad. This was for the charge cooler. Used an electric pump to circulate the coolant and added a second fan to aid cooling.

Performance-wise torque was increased from 105 to 228 foot poundsand power from about 175hp to 405. Accelleration in 4th gear was the same as the stock bike in 1st and it would easily wheelstand at 180mph.

 

[Pete.]

Oh yeah, and I used stainless exhaust bolts

EDIT: This guy is now the owner. He's painted the fairings but it is my old bike the guy I sold it to sold it to this fellow. At 340HP he must have been running at about 10psi of boost but the bike is good for 2 bar.

Jay joins the 200mph club

On Tuesday 8th September 2020, 3 DDR vans rolled onto Elvington runway 26.Jay, Stew & Rik took the "Quarterback Punk" to the Straightliners -Top Speed Tuesday event for some shakedown runs. With Race fuel added to the 340bhp Turbo Hayabusa, and in near perfect weather conditions, Jay set off for...

www.demondesignsracing.com

 

[roofman]

@Pete. simply awesome ..thanks for that. Did that GT30R have much lag as the compressor wheel and housing looks huge.

 

[Pete.]

@Pete. simply awesome ..thanks for that. Did that GT30R have much lag as the compressor wheel and housing looks huge.

For running around on the road it did but it was a blessing because the first system I built with a GT28R was an absolute wheelie animal.

Here is a *really* poor quality vid of the first time I ever rode it.

Dropbox

www.dropbox.com

 

[roofman]

For running around on the road it did but it was a blessing because the first system I built with a GT28R was an absolute wheelie animal.

Here is a *really* poor quality vid of the first time I ever rode it.

Dropbox

www.dropbox.com

Yea those GT28,s have a really fast spool up. Getting it vertical there i see. Been waiting 20 years to build a tubbed bike but work and life gets in the way. Will get it done real soon though before i run out of bottle to ride it being post 60 old

 

[Pete.]

I heard that it's for sale. I don't know how much but you might try asking. Could well be cheaper than building one, cetainly a lot easier

 

[roofman]

I heard that it's for sale. I don't know how much but you might try asking. Could well be cheaper than building one, cetainly a lot easier

Just cant do other peoples specials mate..you know how it is, everywhere you go and start talking it always starts with "I actually never built it but i put a new sticker on the tank"

 

[daf45]

Thanks for sharing P

 

[Kram]

Cant remember what studs I used last time but dont use any from honda, particually not their m8>m7 reducing studs as they go brittle. Nuts, I couldnt find any for sale so got some 12mm hex brass and turned them 18mm long and blind to keep water out.

 

[Mr Fro]

I've got to be honest @Pete., your turbo bike build makes mine look a bit... budget.

Mine was a mutch more "cobbled" affair - my budget was a grand and I only went slightly over. Got a hike of around 75% in power at quite modest boost so it worked out reasonably well.