How to set (roughly) ATP wastegate

[Big Fluff]

I need to 'roughly' set the boost pressure at the wastegate on the Saxon.
The wastegate is ATP. Anyone know of a 'starting' point for this.

I would imagine loosen the locknut, back off the adjusting screw, run back in until it touches, then pre-load it by a 'certain' amount.
Anyone know what that certain amount should be.?
I am looking for an initial setting of about 9psi. The wastegate has had a total strip & build so the valve is seating perfectly.

Regs, Will

[debben1]

Hello Big Fluff, the 6mm screw preloads a valve spring, so back of the screw and run the bike to see if it boosts at all, you can then increase the boost gradually and safe in the knowledge that you are increasing the boost slowly (rather than having too much boost and trying to reduce it). It is imposible to give you a "so many turns in = so much boost" as each spring depending on age, use and what spring was available at the time of assembly will give a different seat pressure. These parts where always made on very small production runs so there are many different types. Ideally this should be carried out on a rolling road and under load, so that you can keep an eye on the boost guage rather than the road ahead, the boost produced simpy by reving the bike when the engine is not underload is not accurate or particulary kind to the rest of the engine. I hope this helps and hope you do not mind if I am giving you info that you already know, Regards, Steve.

[Big Fluff]

Thanks Steve, see what you mean about age of parts etc.

Can you reccomend a Dyno place nearest to me (Cheshire), one that you would trust your bike with

Also, the bike is fitted with a Mikuni HSR36 with 250 main jet, the rest is RC Z1 welded crank, 1105 RC pistons (wired bores, HD studs etc), 8.9:1cr, std cams (timed), RC flowed FF40 Rajay, RC modified ATP plenum (centre web removed), open exhaust. It tends to bog straight away whilst pulling off from say 3000rpm. Is this a 'standard' feature of a turbo bike or would you say I stick a 300 main jet in as a starting point.

Many thanks, Will.

[Steve R]

Will, I dont know if this is to far from you but Holeshot racing in Bradford are very good with Dyno work , they do a lot of turbo Hyabusa and Bandits and have the fastest street bike in the Uk, but Jack was quite happy to set my z1 up on the dyno.

[debben1]

Hello Will, as we have our own dyno I have no expeience of other dyno operaters, being an aircooled bike you will need to check how they intend to keep the bikes temperture down, most dyno places are set up to work with watercooled bikes. We use a huge 3 phase factory aircon fan with 2.5 ft fan blades and weighs so much it needs a fork lift to move it, it sounds like a helicopter taking off when we flick the switch Turbo aircooled bikes with a draw through system are never easy to set up and involve a fair amount of trial and error. They are quite sensitive to ambient air temperture, often run wooly until the full operating temperture has been reached, a result of the crude carburetor requiring a compromise between rich enough to enable the bike to start and rev with boost but lean enough to idle when warm. The fuel mixture has to navigate the relativly hot turbo compressor then the intake manifold before even entering the inlet port means that the fuel mixture has to be richer than in other applications such as with fuel injected or blow through turbos. Set it up on the rich side when cold and experiment with cold starting, the accelarator pump feature on the Mikuni is a big benifit. Regards, Steve

[fastbyme]

ur more than welcome to bring bike down to me ...the hsr42 is easy enough to set up .....the bogging down low i can sort , u dont need a dyno to jet these carbs ...sounds like the accell pump needs adjusting ..drop me a pm m8 , or have u got my number ..can talk u thru it if u want do it yourself ..regs dave

[Big Fluff]

ur more than welcome to bring bike down to me ...the hsr42 is easy enough to set up .....the bogging down low i can sort , u dont need a dyno to jet these carbs ...sounds like the accell pump needs adjusting ..drop me a pm m8 , or have u got my number ..can talk u thru it if u want do it yourself ..regs dave

Sounds a good idea...
Where abouts are you Dave ?

[fastbyme]

oakham m8 ...pm me ill drop u my mobile