Topic: Building my own turbo kit

[hotdog]

Hi forum, I am considering builing my own turbo kit for one of my project cb750's, this would be a project and may take some time as I have 2 other motors to finish first, possibly then move house and as finances allow.

Current specs -
1. Pull through system
2. HSR42 Mikuni
3. Oil feed from oil pressure switch (with a t-peice fitted),return to the clutch cover and cooler
4. Rajay B25, depending on cost, but a rebuild and age may rule it out.
5. Manifolds I can make as I have a Tig. I would like to make them close to what has been proven before such as the ATP intake and its split plenum. And some ideas on the exhaust dimensions used on other kits from the day
6. Majority of parts will be sourced second hand through places like ebay
7. Capacity will be 970cc with  K model Arias pistons - aiming for @ 8:1CR and 10psi - this will be a street bike
8. F2 head
9. Ignition will be an ARD magneto

I do need some help and forum members ideas and thoughts on fueling requirements under boost and will probably PM some of the below owners of these bikes for their thoughts if they dont post here.

There are some really great turbo bikes already featured on the forum such as -

Jim F's - http://forums.sohc4.net/index.php/topic,101267.msg1131201.html#msg1131201
Bamboozler's - http://forums.sohc4.net/index.php/topic,59262.0.html
Voxondas - http://forums.sohc4.net/index.php/topic,41157.msg424250.html#msg424250
Blue71turbo's - http://forums.sohc4.net/index.php?topic=56783.msg612975#msg612975
76kcafe's - http://forums.sohc4.net/index.php/topic,140453.msg1591644.html#msg1591644
Boosted applications thread - http://forums.sohc4.net/index.php/topic,58771.25.html
More good info here - http://forums.sohc4.net/index.php/topic,134478.msg1513446.html#msg1513446
And more - http://forums.sohc4.net/index.php/topic,131098.msg1461795.html#msg1461795

Looking forward to any and all input on this.

[ivanhoew]

hi hotdog , in cae it helps ,

 i have a 400/4 turbo ,and a cb500 twin turbo .build about 20 years apart . i went with the blow through cv carbs on the 500 , and its a lot better than the suck through ,and was easy to tune . if you can get a rack of cv carbs on the 750 , it will be nicer to ride .

 i use a t25 on the 500 , boost is in at 3800 ,and pulls hard from 6k to 11k. the gt12 is a bit tiny .

look at the pk bhp you want , say 150 bhp ,for example , then pick a turbo off a car with that sort of power. the turbo i am using is off a 2.5 litre diesel citroen . my max power when built was 135 bhp on 15 psi .

regards
robert

[hotdog]

Thanks for your comment Robert, since the original post I have been doing a lot of research and reading/understanding turbo maps. You are correct the gt12 is too small for an 836cc engine.
Also carbon seals are only available for a few select turbo sizes, none of which are suitable.
Push through CV carbs and a Mitsubishi TD04-13G are my choices so far.
Just need to do some research on a suitably spaced rack of CV's.

Edit - Turbo is Mitsubishi TD04-09B

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[ivanhoew]

that sounds a good selection , although you might find the tdo4 a little big , depends on the a/r of the turbine housing  ,see if you can get one in the .3x range .rather than .4 .or .5 .


re throttle bodies , they are easy to respace if you get some gsxr600 early ones , i respaced these ..






and lengthened the connectors like so .





for this project ..






regards
robert.

[strynboen]

Stalin orgel....

[SOHC4 Cafe Racer Fan]

Stalin orgel....

Are your referring to:  http://www.ebay.ca/itm/Italeri-1-35-Katiusza-Stalin-Orgel-missile-launcher-/271866028446

I think we may have lost something in translation . . . .

[hotdog]

Any input appreciated......


                           Compressor                                                                Turbine
      Turbo     Wheel    Inducer dia       Exducer dia     Trim       Housing        Wheel      Exducer dia   Inducer dia       Housing
TD04-09B    9B        1.365                   1.930            50         TD04-09B        TD04           1.57            1.86            TD04-6cm2 (6 cm2 = 0.41 A/R)


My calcs are -
PR - 1.68
Cu.I. - (836cc)51.01
DR - 1.4
V.E. - 80%
4ST
10K max RPM
10PSI BST
1lb/min = 15cfm

CFM=DxCIDxMax RPM   xVExDR
                  1728
So.....

0.5x51x10000     x0.80x1.40
          1728

= 165.27CFM/15
= 11.01lbs/min

P.R. of 1.68
CFM of 11.01
10 PSI
10K rpm's

Map for a TD04-09B http://www.stealth316.com/images/td04-09b-cfm.gif

Another - http://www.stealth316.com/images/td04-09b-jlspecstock.gif

Also considering the option of mounting an under-seat turbo to force feed the Mikuni HSR42  into a custom log style manifold as I already have that carb...I know 4 CV's would be better for fueling but it couldn't be worse than a draw through system..right..?
Wondering if the log manifold mounted in a force feed situation would still require a splitter "a la ATP"

[ivanhoew]

i would step up your ve to 95% . and then add a bit for contingency , i would try for a 14-16 lbs/hr ,at 2/3rds of max flow, turbo sort of thing .

best thing about blow through is a) tickover is very stock ,with a suck through the fuel condenses and loads up a big slug in the housing at low rpm .b) best distribution.c)also , you can use an intercooler with blow through , i have a big one on the 500 , and i estimate it makes around 25 % more power .

,re blowing into a single carb ,then a log plenum ,with suck through  the turbo mixes the fuel and air , so it has a better chance of staying in suspension ,and so getting a better equality of distribution , you wouldn't get this with the turbo> carb> log system , making a manifold that would feed the 4 cylinders evenly within the space available would be a challenge .

having said that ,my 400/4 with a suck through , and a box section plenum ,was great , just poor tickover and no intercooler ,, stil made 85 bhp when the clutch gave up ..you get a little bit of intercooling running the fuel through the turbo.

regards
robert.

[hotdog]

Yes fueling would not be optimal with turbo - HSR42 carb - log intake manifold.
Intercooler would be good, I'm not planning on running my afr near destruction. In saying that Bamboozlers intercooler (link above) setup looks good.
I guess I'm just trying to get out of having to run an oil scavenge system for the turbo by mounting it above the crankcase....but might have to concede that its a better way to go, as most systems are setup this way.
My calcs I got from Joe Hailes book on turbocharging motorcycles, he reccommends 80% VE for a high performance street motor..? so at this point I'll stick with that figure, I don't want to over turbo it and have unacceptable lag time (I.e. have a coffee/scratch my arse while waiting for it to boost). I'll have a look but I'm confident the td04 will fall into that range. Please explain your theory on your VE some more, Haile recommends a VE of 94% for a race motor .....to be continued.

P.S. anyone got the lowdown on CV carbs that fit without too much modification....cb750/900f..?

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[ivanhoew]

my 500 still uses a gravity drain , hold on theres a vid somewhere..

re VE .big topic .  i would say joe is speaking of low bhp/litre bikes .any engine around 100bhp/litre na is well over 90%.but see how 80%ve calcs work out for you ,and if its too stifled at the higher rpm , you can allways change turbo .

[hotdog]

Bike looks good, what model is it.?
 I do understand where your coming from with the VE, however I think the cb750's  are a little shy of 100hp/ltr. Even the 1000cc guys have trouble getting above 90hp.

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[ivanhoew]

is that 95 at wheel?

[hotdog]

........its on a wheel dyno..?

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[hotdog]

Just bought a set of Honda CBX750 34mm CV carbs for this project - slowly collecting parts....apparently they fit ok with some fiddling around. 

[ivanhoew]

........its on a wheel dyno..?

 ah , no what  i meant hotdog , was , if that bhp was the power at the wheel , or , bhpw , that does not include any drive train losses , so the engine itself may be making 10 to 15 odd bhp more power at the crankshaft , so 105 to 110 bhp . therefore above 100 bhp/litre .

some dyno's measure at the wheel , some add a percentage  ,or do a real coast down test like my one does ,so get an approximation of the losses . on my 500 , it had 115 bhp at wheel , and 135 at crank . that was a twin roller dyno .


 oh , and the bike is a 500 honda twin ,from 1999 , mounted in a cagiva mito 125 cc chassis.

[Retro Rocket]

Just bought a set of Honda CBX750 34mm CV carbs for this project - slowly collecting parts....apparently they fit ok with some fiddling around. 

I just bought a set of those too, the guy threw in the rest of the bike bar the engine and frame for nothing...

[hotdog]

Yeah I saw that, hopefully not too much mucking around to fit them. Have to better than running the PD's I have here...

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[Retro Rocket]

Yeah I saw that, hopefully not too much mucking around to fit them. Have to better than running the PD's I have here...

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

Another guy on the forum had the 34CV's of a CBX on a CB750 and he said they were superb once set up, very light throttle too, he ran a modified stock airbox ......

[hotdog]

Anyone have comments on the td04-9b for sizing..?

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[hotdog]

Yeah I saw that, hopefully not too much mucking around to fit them. Have to better than running the PD's I have here...

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

Another guy on the forum had the 34CV's of a CBX on a CB750 and he said they were superb once set up, very light throttle too, he ran a modified stock airbox ......

Wasn't that terry's "Goldie"

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[Retro Rocket]

Yeah I saw that, hopefully not too much mucking around to fit them. Have to better than running the PD's I have here...

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

Another guy on the forum had the 34CV's of a CBX on a CB750 and he said they were superb once set up, very light throttle too, he ran a modified stock airbox ......

Wasn't that terry's "Goldie"

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

Yes, if you have a look at pics of that bike you can see the airbox is modded where the old stock velocity stacks went in ...

[hotdog]

Yes I saw the alloy sheet added to the top of the box.
This project won't need the air box mod, but a plenum to carb setup will be required.

Follow me on Instagram - thelumpycam

Follow me on FB - The Lumpy Cam

[hotdog]

Quick update - been gathering some parts...lots more needed. Drifted away from the CV carb setup - you'll see.

F2 (410) head



Arias 70mm (970) 10.5:1 pistons - hoping c.r. should work out with these k pistons and f2 head.



ARD Maggy - this might go on the k2 yet.?



Cyclex super rods



Cooler



Mikuni hsr42 carb



Rajay b25 turbo, I've already stripped this and its been peiced back together - have a full kit on order from MrTurbo





NOS morris industries 19"-18" wheels



Now the ugly part - either make something from this - k0 and k7 + bottom ends, or find a more complete suitable donor.....seriously considering importing a u.s. bike if one can be had cheap enough....offers..?







Later alligators....

Instagram - Lumpy Cam Motorcycles

FB - Lumpy Cam Motorcycles

[Retro Rocket]

Nice collection of bits there Dale.   

[754]

You have some seriously. Nice parts there.. Did you find the Morris mags over there?