re: Dustom's Turbocharged Harley 1250


I dont know shit yet!

know Just that lot of people in US have Turbo HD and Few Turbo Sporties around.
also Know that 883 motor is based on 1200evolution motor with just bore dia being less than 1200 and smaller dia valves. so 883 motor is way too much overengineered , as 1200cc motor itself was over engineered to accomodate all the after market modifications.

Well I have worked with a Turbo on my Diesel bike , and ones you start to like that Boost Coming in early , you would not want to trade your turbo ride for anything.

Parts required vary from Design to design of setup , but basic parts are: Turbo itself , Custom exhaust 2-1-turbo flange , dump pipe . On intake side - Intercooler ( desirable) , turbo compressor to engine intake manifold / Intercooler . Blow off valve to prevent Over boost , wide band O2 sensors for Tuning , ECM tuning device .
Oil feed for Turbo - High pressure oil to be taken of Engine Oil circulation circuit , return line to be dumped into Oil tank or CAM chest .


Now couple of tricky parts of this project are
Matching / selecting right turbo for your application :
Selection usually starts with Target HP and engine Displacement. There is a really fancy caluclator on Garette turbo website , I went and found that Smallest turbo is GT15 , and was designed for cars to provide upto 150bhp. I only want around 90bhp , so this turbo covers it well.
Also Characterstics of its Turbine side means that I will start getting some boost as low as 1700-2000rpm and will build healthy 8-9psi before 3k rpm . at 3k and beyond , BOV will come into play to keep boost down to acceptable level ( which ofcourse will be decided later in tuning stage , likely to be 8-12psi)
other Tricky part is Tuning the engine / FI for Boost and keep it from destroying itself.

NA engines suck in AIr at ATM pressure ,when a turbo shoves in AIr at higher pressure means , 883 engine behaves like a much larger engine , For EX at 14psi it behaves like a 883x2= 1766cc engine.

In an 883 application , very nicely done and tuned set up is going to be around 90-100bhp , and trust me when something makes 100bhp at low RPMs ,@5/6k rpm , its going to be Very wild ride / All Torque Muscle . one would be lucky not to find himeself in Jail if Boost is regularly used within City.

There are couple of companies making turbo for HD in USA but most of the kits they sell starts from 3.5k $ to 5l $ , too expensive for me to even think of importing.
I just hope I do not end up blowing the motor , But If I do , I have a Plan B

re: Dustom's Turbocharged Harley 1250

[MENTION=51699]dustom_99[/MENTION] seems you have planned everything. Whats the max gas pressure the engine can bear? Any changes planned for valve timing? All the best & looking forward for stepwise update (subscribed!).

re: Dustom's Turbocharged Harley 1250

For short busts it can take as much as 25 psi , drag sportsters make as much as 240bhp for short while.
But that kind of set up requires bigger injectors , water injection and whole lot of things i dont know.
120-130 bhp sporties often eat 190 bhp R1 on drag strips.
8-12 psi is doable on pump gas.

Valve timing change is not planned as stock w cam is said to be the best cam for stock head and valve size.

Bigger or more aggressive cam wont do much without head work and bigger valves.
Forced induction can pump in lot of air just cuz of pressure, smaller valve size also aids in chamber turbulence.
All this is theory and real deal will be known only with time.

Sent from my Micromax A116 using xBhp Connect mobile app

re: Dustom's Turbocharged Harley 1250

Tig welding setup started.
Initially i was burning hole in anything i touched with the torch.
After a days practice i am finally joining a few things together.
Hopefully in a couple if weeks i will be able to do a nice 2-1 exhaust for turbo.
Did practice on joining several short pieces of exhaust pipe. Just the fine tuning is lacking and consistency on round pipe joints.

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re: Dustom's Turbocharged Harley 1250

Armageddon has begun!

Guess the chit! Lol

re: Dustom's Turbocharged Harley 1250

Meanwhile.
Another Superlow converts to Superlow not Stupid low!
Capt. Ankur Agarwal from Dehradun installed my Ground Clearance Kit and is now Enjoying over 140mm of GC and loving It.
He was about to get rid of Superlow and go for some other bike. But now he says "its totally worth keeping for ever , with its only problem being addressed now"

re: Dustom's Turbocharged Harley 1250

Whole of last Week was spent in Research on how to Turbo a Harley Davidson.
And the news is not so exciting at all after all that late night study all over the world.
There are a few un answered Questions !
1. Power Vision ECU tuner tells me : the speed density system employed in Harley davidson computes Load on Engine based on Throttle position V/S Manifold Absolute pressure.
which in turn means that Timing ADvance / Retard is spread across a sheet containing MAP on one AXis and RPM on the other axis.

The Problem with Turbo would be : Once the Turbo starts providing Boost ( Anything above 100kpa) The stock ECU would not be able to process it and will fall back to 100kpa table for Spark value on various RPM.
Now only 1 unique value can be Filled on each cell in 100kpa column .
For ex: Spark advance for 3000rpm at 100kpa = 22deg
spark advance for 4000rpm at 100kpa = 19deg and so on.

but ECU will not be able to distinguish between 100 kpa , or 110 kpa or 120 kpa , whilst combustion will demand different spark values for different level of boost.
In this case NO matter if boost is 1 psi or 6 psi or 8 psi , 100 kpa table will treat it the same and provide a Spark advance value.

Not a Good place to be at.

Next problem is :
Since the ECU is not detecting level of boost , It cannot compute the level of Fuel to be added to make a GOOD / desired AFR.
I can Manually add Fuel at various RPM levels by changing Volumetric Efficiency table , However It has a Upper limit of 127%VE. It simply does not take in any value larger than 127 , out of 127 , usual fugure at certain RPM is already 110+ . at certain lower RPMs Its as low as 50% and there I have a window of Adding Fuel upto 77% more , but at those RPM there will hardly be any boost from turbo.
I have a Walk around for this problem already , will It work? Can say just yet.
Stock Injector Flow rate is 3.86 Grams/ sec , If I lower it in ECU calibration file to something around 2.8 or 3 while keeping the stock Injector,ECU will think I am using much smaller Injector and will increase Pulse width accordingly , which In turn will cause OVER fueling at Non - Boosted areas. However since VE table can be decreased , I will decrease VE for non boosted areas.

There are Loads of other Problems like OIl circulation , IAT etc which I guess can be discussed once the basic questions are resolved!

re: Dustom's Turbocharged Harley 1250

Custom exhaust build off started!

re: Dustom's Turbocharged Harley 1250

Hello dustom_99,
Congrats on a excellent thread. Before that I must congreatulate you on having the heart to modify a beast/beauty like the Superlow. I have gone throughthe entire thread and after reading the post #32 of yours here and I would like to know the following things
1. Can we Install your GC improvement kit on a new Superlow? Would it void the warranty? If Yes, then when can I install them OR how ca the GC be raised without voiding the warranty? (Apart from fitting the original accessories at the showroom)
2. Would I need any special equipments or instruments (as I have none at present) to do the GC conversion using your kit?
3. Can you post the GC Kit photos both in chrome finish and in black?
4. Will this alteration change the riding dynamics of the vehicle?
5. Can you repost the images/videos posted at the starting of the thread as they are not opening now?
6. Once your GC kit is installed, would I have to change the side stand as well? Because the bike may lean more with the older ones!
And in continuation, I have some more queries for you:
7. Have you altered the Rim and Tyre Specifications of the Superlow?
8. Will the GC be raised significantly if larger Rim/Tyres are used?
9. If not, Can I by a DIY means change the exhaust note all by myself? ( I am not sure if I can prove you wrong on your quote in post #61 of yours on this)
Thanks in advance. And I feel that me and many more owners/future owners will be immensely helped by your answers. By The way, I have these many queries because I have booked the Superlow already !

re: Dustom's Turbocharged Harley 1250

First few joints have been good. Looks like i am getting hang of this TIG pretty quick.

re: Dustom's Turbocharged Harley 1250

Those are like lmg fire of questions.
1. This kit has been installed on 5 superlow bikes , no one has had a problem with warranty or even insurance claim!
One guy broke his front rim and did go through insurance claim. Did not face any problem.
Of course if you will ask the official workshop guys , they are going to say no to the kit , just like they say no to tuners/ ape hangers / aftermarket horn n lights etc not purchased from official Harley workshop. Lot of people still customize there bikes using parts from online shops and do not face warranty hassles at all.
Other ways to improve gc include : larger front rim or longer fork tubes etc. Any of these will set you back by almost 50k.
2.No spl equipment needed. Just a few spanners and Torx key no:45. Approx cost of equipment needed - 500 bucks.
3. Till now i have given this kit in Silver powdercoat , matching with the lower fork legs. No one has demanded that in chrome or black. So no pics available for chrome or black colour. Although chrome or black powdercoat can be done .no problems.
4. Yes the dynamics will change. All for the better. Sportster has very dynamic and stable chassis , hence the name Sportster but has been bogged down by low GC in superlow. Its a lil too easy to scrape footpegs , while the bike can take much more lean angle due to its geometry.
My bike has comfortable lean angle of 35*+ ( stock is around 29*) , and i still scrape footpegs in hills without unsettling the bike.
Stock bike feels front heavy , raised bike does not.
5. I am nit sure whts wrong with images , they are opening fine on my side.
6. Yes the bike leans more on side stand , i have not changed it , neither has any one else. Not a problem i guess.
7. I changed rear tyre to mrf 150/60. Same spec as original , but much cheaper as it has conventional ply.
8. If you use 19 inch front with higher aspect ratio , it will raise the bike about 35-40 mm. But you will have to change front mudguard , front brake hose , rim + tyre. I recommend the stock tyre and rim combo , its light and amazing grip from scortcher 11 tyre. Comparable tyre alone will cost you 15k in 19 inch.
9. I have changed my exhaust note significantly by diy! I am not sure what you want to prove wrong in post 61. Its just a pic i guess!

You can shoot me more with questions, no problems! Lol
Ride hard.



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re: Dustom's Turbocharged Harley 1250

Thanks dustom_99 for that equally LMG fire kind of reply for my queries. Appreciate it a lot. Not expecting the reply so fast. Should have been fore warned by your signature!!
As for as post #61 it goes like this
Actually the sentence in the bracket was to come later but I had typed it there along with question no 9 by mistake (may be Beginner's problems - as I am new to forum).
I thought that I fit into this description very well!! Want to make sure you are for once (at least) proved wrong. ! The reason is:

I was a biker/Rider at first, now driver(!).
After moving to cars and also at the same time up the ladder in work, biking took a back seat. Now I am trying to go back and relive my riding days. But have to put a lot of effort as I have not rode regularly for the last 15-16 years. Hence I am trying to rebuild my KB100 (my first bike since 1989 which I continue to own) so that I can ride again. It will be like having an advanced training program in BASICS.

The videos in the first page are not opening. It says "the video does not exist" on both the videos.

I had been following your threads and few others' in tbhp (all on superlow and other cruisers- hyosung) for quite some time now, then stumbled upon your thread here. I was really amazed at what you have accomplished. Few bikers would have a heart to do these changes/modifications by themselves. Congrats again and many thanks.
will shoot more questions as and when they are ready.!

re: Dustom's Turbocharged Harley 1250

My first 2-1 joint is ready. Nice n smooth flow from two into one, no sudden high degree bend.
Grinding the welds n cleaning to follow
This is stock mahindra bolero exhaust pipe. Should hold good.

re: Dustom's Turbocharged Harley 1250

Watch "Harley davidson getaway to Gangotri" on YouTube - Harley davidson getaway to Gangotri: http://youtu.be/yGwJg3EOd80

re: Dustom's Turbocharged Harley 1250

Becoming Riders from Lads!