Supercharger questions

[suzuki4life]

BTW...done.


If you want a charger.....


talk to Jason Keats at Cali superbikes.....super nice guy.

or Richard at RCCturbos....also a super nice guy.


OR Seb at NLR.....expensive...but IMHO....worth it. Very knowledgeable guy indeed.

[Gary Evans]

Backpressure on ANY engine is a good idea.

If your referring to back pressure after the turbine that is incorrect for a turbocharged engine. After the exhaust gases exit the turbine you ideally want it discharged to atmosphere as fast as practial. If you need a full exhaust the larger the better. I use a 3 inch full exhaust but the downside to size is the increase in noise even with a good canister (no free lunch).
Dump pipes causing over boost only points out that the wastegate is too small for the application.

[Uncle Bob]

hmmmmm might wanna talk to anyone who produces an entry level kit with an internal gate then about dump pipe directly causing boost spikes because the spool rate tends to cause boost creep. Doesn't tend to happen with full exhausts on the same kits.

I do build systems from scratch. Every boost spiking issue I've ever ran into I fixed by tuning the waste gate actuator.

The reason most systems get boost creep when you reduce the backpressure behind the turbo is because you have more pressure differential over the turbo, which causes a flow rate increase through the waste gate, which changes how the waste gate reacts, especially when the waste gate in question is using a relatively small flapper.

I'm getting tired of arguing over everything. If I'm so wrong on everything, then I guess I'll shut up. You've apperently researched this much more thoroughly than me.

[Gary Evans]

I didn't say he picked the wrong turbo how would I possibly know that. What he needed to achieve his goal may simply require the use of ultra high turbine inlet pressure. What I am saying is that pressures that high are not normal for most applications. Test it and find out for yourself.

All I'm saying is thats not what I've seen from my research on the subject, nor the physics involved, as I understand them.  This is going in circles.  

Time to quit research the subject on the internet and put a gauge on your bike like I did mine. Let us know what you find.

[Uncle Bob]

Since you are educating us all about turbos.....why not quit your job and contract a company to build them to your specs.........so people don't have to have the problems every other "misfunctioning" kit has?

Like I said...I've owned more than my fair share of turbo bikes.....all have had many of the same characteristics.

I don't remember insulting anyones systems....I read it the other way around actually.

And if you really are curious, I AM working towards opening my own business for building turbo systems. Unfortunately, I don't have the capitol to start it so easily.....but it is in the works.

Dont' see how that'll change anything I said though.

[Nick Kickass]

no, the reason a dump pipe is used is to reduce back pressure AFTER the turbo.  the length, shape, or baffling of the final exit doesn't matter, all that matters is the pressure in the exhaust.  The little the better.  It is quite possible to have a full exhaust system that is just as good as a short dump pipe, but it requires a large diameter pipe with a very free flowing muffler....most systems offered will have some back pressure vs a dump pipe, and you will lose a little power due to it.  It also causes (in an extreme case) for the turbo to spool slower, due to the pressure differential (there's that phrase again...)

But would you agree that the short "dump pipe" eliminates any concern for back pressure, plus eliminates any extra weight concerns as well?

But dump pipes also allow the turbo to spin almost uncontrolably fast in many instances......causing backfires, boost spikes etc. Backpressure on ANY engine is a good idea.

Just learning a little here, thanks for the info.

Not ready for the turbo, YET.

These guys get a bit vague and then carried away if disputed IMHO. Turbo or charger.....entry level...its all in your choices.


If 230hp is what you seek...and the price doesn't bother you....I wouldn't mind a supercharger for something different.


Always remember.....power/speed costs money.....so the more you make...the more you will spend if AND when it breaks.

Yes speed/power costs money and thats okay because on deployment right now I'll have plenty of money - but I'm not too crazy about reoccuring costs like replacing the head gasket regularly and the downtime that goes along with it.  If I didn't ride at 5000-7000 ft where the busa is probably making 120-130 hp I'd be happy with mild mods but forced induction looks like the only way to make even stock levels of power.

Perhaps a lowered comp, low boost (6psi), intercooled setup running in the thin air will be reliable.  I am skeptical though - I've heard you can't WOT it though all the gears without having to worry about the engine blowing up.  Not being able to use the power kinda defeats the purpose of even having it eh?

Apparently engine work has its drawbacks too like exploding clutches and con rods.  Heck maybe the 07' model is the best option.

Charger/turbo does have the cool factor though. Do you think it is feasible, if enough money is thrown at it, to have pretty much stock reliablity with 200 hp? (it'd take 6psi at 6K feet according to jason).



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[Uncle Bob]

as with anything, if you build it well and tune it well, and keep away from tempting fate, then it will last forever.

If you have such reasonable goals as 160hp at high elevation. Hell, I don't know if the waste gate would go that low! Not much danger there

[Nick Kickass]

Well, 160 is kinda low considering I figure it will cost $8000 or so... But 180 - 200 would be plenty.

[fstbusa]

Well, 160 is kinda low considering I figure it will cost $8000 or so... But 180 - 200 would be plenty.

he probably meant 260hp. Its pretty tough to get anywhere lower than 225hp on a stage 1 system. Have fun!!!