Turbocharging

The quest for improving the performance of my 2004 Heritage Softail Classic FLSTCI led me from stock pipes and breather to a V&H Pro Pipe and Ness Big Sucker. I achieved about 10% increase in HP and TQ from this intitial mod.

AND NOW WHAT NEXT?

The choices to increase performance include conventional enhancements such as increasing the displacement to 95ci or more or changing cams. Or, changing the paradigm that 'bigger is better' to 'badder is better'. A few 'badder' changes might include TURBOCHARGING or NITROUS OXIDE enhancments. Whether these latter options are 'better-badder' or 'badder-badder' will be the course of this thread.

Turbocharging seems to be a rare thing on street bikes. I have seen only one turbo-rigged Harley. An internet search uncovered a few sources for turbo kits: RB Racing, RC Components, and American Turbo Power. The costs run around $3200-$5200 to enhance HP and TQ to 50-500% over stock, depending on how wild you want to go.

Nitrous oxide at first glance seems 'dangerous', but N2O is not explosive. It merely adds oxygen to the fuel/air mix for more thorough energy conversion. I have not yet found prices for this conversion, and I have only heard of it on one bike before. I also don't know the performance increases possible.

Technically, I prefer the idea of turbocharging. A turbine compresses the air into the cylinders to achieve a 'boost' in performance. The hardware looks good on a bike, but I have many many technical questions that I hope can be resolved by my own research as well as input in this forum.

Questions about turbocharging:

What is the upper limit of boost in terms of psi (bmep) that a stock Harley TC88B can sustain? Above this limit, what modifications must be included?

What modification to the EFI are necessary with a turbo?

Can the stock drive-train handle this much extra power?

What is the best combination of modifications to prevent or minimize denotation under the increased engine pressures?

OK, you get the idea. Please jump in.

Yo, down the road,

Painter

Turbo is a an exciting concept. Power boost is directly related to the air pressure delivered to the cylinders via the turbine. This increased pressure effectively raises the compression ratio. Cam timing as well as inition timing can alleviate the potential for denotation due to the increase pressure. I need some way to relate the increased pressure to the necessary changes in cam timing and inition timing. I am working through some reference materials for the anwer.

I will check out some of the supplier you mentioned. Perhaps they have tech sheets available with the info that is important.

Yo, down the road,

Painter

On the EVO with stock pistons and 14 lbs boost you needed to be really, really spot on with timing and jetting and PRAY that the fuel pump did not fail. Turbocharging is cool, makes good power and if done right can live a long life.

However, it is much less forgiving of problems and big holes in pistons are the usual result of detonation and or pinging due to a lean condition or too aggressive timing etc. Controlling boost pressure is critical.

We installed an Aerocharger many years ago and after some initial teething problems it ran very strong for a long time. At 9 psi boost we were right at a 100 hp if memory serves and at max boost of 13-14 psi it was up in the 110-115 but heat built to fast so you could only run it for a brief test and it needed serious cool down.

Think heat here also. Compressing air builds heat, and heated air is an enemy of good combustion. That is why most turbocharged cars have intercoolers.

turbo bike-shop in Ohio

There is a Custom build bike-shop about 30 minutes from Columbus Ohio in Delaware I have watched them turbocharge a revtech engine on a soft tail custom build and a couple of HDs. He tech that works with turbos and figures out what is needed. He asked if I were interested in turbo charging my 02 Wide glide and I had to decline but hearing that bike as it goes by it distinctly cool AND SOUNDS LIKE ONE BAD-ride. He will be in Daytona with it. We have a show out here and more people were staring at it than the West Coast stuff as well as other bigger named stuff in the local area. I'll get the number to ya on here soon. There is a dyno machine onsite too.

I am glad to be kicking up some interest in turbocharging. Thanks! Keep it coming.

I have some reference to two different turbo makers: Aerocharger and Garrett. These are variable-vane turbos that seem to be durable. They run at VERY high rpm, like 100K+! Scary to have that thing whirring so fast betwixt one's legs!

CD brought up the heat problem. An intercooler starts to address this problem, so I wonder if an oil cooler could also help along with Syn oils? CD: I suppose you meant intition timing, not cam timing....

I am trying to decipher the cam designs that would relieve the potential for detonation. Intition timing seems to be a whole 'nother story to read. Also, I wonder if the fuel injectors need attention against the higher manifold pressure.

So many questions. But I'm on it.... be back with answers, too.

Yo, down the road,

Painter

air cooled

One major problem as far as long life goes is you are working with a air cooled motor as well as chain drive cams and chain drive balance shafts the B motor has alot more hardware to fiqure in the mix. How about doing something like this with a VROD? Dutch