Jump to content

Draw through: distance carb to turbo?


Recommended Posts

Thanks guys, usefull info here!

 

Will check in to adapting the HSR 45 Zepp, my mate can CNC whatever I need so a new floatbowl with different fittings is no bother.

 

Yes the yellow was fucking terrible...!!!

 

I really should take some recent pictures and post them, will do so when the last bits are back from the painters!

 

Meanwhile I've changed the complete exhaust!!!

 

I kept to the design of GJG as far as the headers go only now I went from 28 mm internals to 30mm internals into a 60mm collector instead of 35 mm.

 

Also I've complete changed the linkpipe to the turbo: from a weedy 30mm to 60mm and with an exact fit to the turbo rather than a 30mm round hole blowing into a suare hole that's about twice the size...

 

First impressions without riding it: runs smoother at idle and revs quicker so off to the dyno next!

Link to comment

Don't want to piss on your parade but as far as i know the bigger the pipes the lower the gasspeed wich can result in even slower spool up.

Probably smaller turbine wheel and housing wil have bigger effect in faster spool up.

increasing pipe sizes can result in higher bhp output but i think that wil only work if you do really big numbers .

correct me if am wrong

 

Link to comment

Yes, the smaller the diameter the higher the gasspeed, this much is true.

 

However, gasspeed doesn't really tell the whole story:

 

Due to the small diameter the engine can't breathe properly, it can't push out the exhaustgas fast enough which is affecting several things such as the burn inside the chamber, the heat of the engine and also spool up because now there's no restriction and more gasvolume to help spool up.

 

Mind you, spool up isn't bad anyway.

With this exhaust it idles easier, runs leaner at idle and it revs quicker so I don't think it'll be all that bad...a 1216 cc engine putting out 285 BHP on such a small exhaust is pretty good but imagine what a restirction the exhaust must be on this engine!

Link to comment
  • 4 years later...

I am having the same problem with ss super e draw through, rajay turbo. Small tire gs 1168 dragbike running on street . If I takes off the air filter it runs fairly smooth till cruising at highway speed then it stumbles , big bog if you do not roll on throttle just right. Put the air filter on then the bog issue is  much better but at lower speed cruising it runs rough. I am wondering is hs 42 would improve things or if  I built an air box ?

Only running 7 pounds boost for now, and back when it raced we ran pump gas and 12 pounds boost about 190 hp.

Link to comment
  • 3 weeks later...
  • 2 years later...
  • 1 month later...
  • 4 weeks later...
On 12/18/2015 at 9:19 AM, Leblowski said:

I know but the bike didnt do 270 when it was owned by gjg as far as i know

so if you have all the bits just put it back but install a thunderjet to get midrange good 

changing the place of the carb wont change anything in how the bike runs on low rpm it al comes down to tuning 

there nothing wrong in how it was designed and installed by gjg

as they say Never change a winning team

Hi, i know it´s an old thread but i am building a draw through 1216 Bandt at the moment, and thinking about fuel delivery.

I will go with HSR carb, and was checking the Thunderjet page, i think this is the way to go.

What caught my attention was the thought to have a second float bowl just for the Thunderjet fuel delivery - does anyone have experience or records of using that ?

Looks really promising to me !

Link to comment

Never heard or seen that mod before - care to give any known details? I guess the issue is providing fuel to it, in an 'orderly' way and consequently not over-fuelling it ?

Thinking sideways for a moment - I wonder if the fuel stage from a wet nitrous system could be used to similar effect as a thunderjet? ie. switched on big boost but independent of the carb mixture workings but still easily jettable - just a thought?

Link to comment

Well, it's been a while, but I'm back and so is the EFE!!!

I always regretted selling it, and by chance I was offered to buy it back from the person that bought it off me years ago!

Fortunatly he hasn't made any significant changes to the bike, so I can pick up where I left off!

I still have a HSR48 sitting pretty that came of my Harley, but I'm also still thinking of injecting is with an electronic TB in front of the turbo.

 

Oh joy, here we go again....

  • Like 3
Link to comment

Took delivery of the buke today, hadn't run dor four years but started up no bother.

Fiktthy though, so needs A LOT of cleaning, but think I'll just take it apart next year as I intend to change a couple of things anyway.  

 

The seat will benre upholstered next week, am going to have the seat scooped out so I sit more 'in' the bike than on top of it, and the foam will be replaced with new much harder foam.

Decided to get rid of the thunderjet equiped S&S Super B as well, will start collecting parts for fuelinjection instead.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...