Z turbos

[Jon]

Anyone on here had any experience at turbocharging Z`s?? Im running welded n balanced crank already. Im gonna have to spacer-plate the head as running Zthou pistons at 998cc on Z1B lump which is waaay above the 8:1 compression rate. Not sure what size spacer I`ll need tho to bring compression back inline with standard??

Ive got n read all the books etc on the subject but not turboed a bike before. I know ideally I should run some nice wiseco slugs, but Im looking at really low boost system (7-8 psi max). I was originally thinking draw through, but now Im siding towards an intercooled blow-through setup with some gixer CV carbs probably. Should increase reliability and driveability over old Mr. Turbo setups.

Basically Im looking for any suggestions/input. I also need to find out the size of the restriction that the Mr. Turbo kits came with in the oil pump exit to boost the oil prerssure through the take off to the turbo oil feed. Too small and you starve the engine of oil, too large and you dont get enough psi of pressure to the turbo seals (which need waaay more than the Z`s standard pressure). Suppose I could make some sort of adjustable restriction and have couple of gauges to measure oil pressure in both directions.

Why turbo an already v.quick n light Z harris?? Just fancy the engineering challenge as ran out of things to do to her and havent done a turbo instal yet. Not looking to increase the power to stupid levels, just love the idea/look of turbo bikes. As I say low boost only with intercooler and some sort of water/alcohol injection setup too.

[Pasc]

Jon, can't tell you too much as I've not built a zed turbo. If I did the oil supply to the turbo would be a major concern. I've not heard much praise of the restrictor kit although others might tell you different. I've seen a few that have a separate oil supply and electric pump to feed the turbo but this method will obviously mean extra hardware to mount on the bike. Good luck and keep us informed of the progress

[Pigford]

Jon, I'm not going to be any practical help, BUT, go for it
Couldn't think of any finer mod for a Zed

[london calling]

Jon,have a word with Steve Cundall.He's got a Turbo'd fuel injected GPz and a rather distinctive jacket to go with it.
Look out for Big Green Bus on this massageboard.

[Jon]

Ok cheers for that n cheers for the support so far. Gotta get moved house n all that crap outta the way first, but wanna do it somepoint soonish. Just ran outta other things to do to bike really. Fancy doing a turbo install as its about the only things Ive not done before.

Turbo oil feed is my main headache at mo tho what with Z`s infamous low pump pressure.

[Jeff Saunders]

I've run a turbo'd Z1 for the past 3-4 years. The draw-through configuration is easier to install, but less efficient.

I did upgrade my setup to a 42mm flatslide mikuni carb, modify the oil pump and sump, and install a dyna 2000 to gain the retard settings needed to avoid detonation.

The 42mm flatslide is a great carb for the street - it allows for around town riding and is very responsive in the mid-range (unlike the junk Zenith carb in my bike originally).

Oil to the turbo is critical. I run a Mr Turbo reducer in the oil fitting behind the barrels.

DO NOT run an oil cooler - this reduces the oil pressure to the engine / turbo - a big no-no.

You can add a 40 thou copper base gasket - that will reduce your compression about 1 point.

Cast pistons are very susceptible to melting - and turbo bikes run hot - damn hot. After a spirited run, I park my bike outside to cool off - it scares the heck out of me with just how hot the engine gets.

[Jon]

Now your just putting me off.

I run a BIG cooler at the moment to keep the engine cool enough! If I cant run a cooler with a turbo setup then its gonna have to be a no-no. Temperatures before I made the cooler take-offs and installed the big cooler were frightening! Never mind the huge temps of the turbos pressurised air. Hence I was thinking a blow through so I could run a nice big intercooler too. Yeah draw through is simpler n all, but tryna keepo temps down. No cooler tho means no turbo setup Im afraid. Maybe I should chase the nitrous route instead.

[Jon]

There must be a way of modding to run a cooler too. Been looking through my stack of pics n theres loads of Z turbos with oil coolers too. Do you think theyve managed to bosst oil pressure somehow, or just taking the risk??

[chrisNI]

There's a cooler on BGB's and he's done over 20,000 miles with the turbo on the engine....

[Jeff Saunders]

The Z1 oil pump is the issue - you need optimum oil pressure to the turbo, and have some left over for the engine. Some bikes run a separate electrical pump to push oil through the cooler - easily done with a take-off on the underside of the sump. I too have seen bikes with oil coolers on - but talk to all the people in the know, and they will tell you the same story - no cooler. If you have a modified deep sump you'll have more oil in the system.

Engine temperature will always be hot - that's where you have to run a retarded ignition - 10-12 degrees retarded from stock - this step alone will help significantly.

Water/alcohol injection can be used to cool the engine AND produce more HP.

If you were in a hotter climate, I'd say look at an electrical oil pump - but temperatures in England are less than this region of the USA in the summer - we get a good number of days in the mid-to-high 80's and some days in the 90's.

[Jon]

I can see the modified sump in your picture. Take it its just a welded on alloy affair to increase sump capacity?

I was considering water/alcohol injection anyway to help out with charge heat. Hence my route for intercooled blow through too. Yeah I like the minamilism of the draw through, but like the idea of intercooling too. Saying that only running 7-8 psi I shouldnt really need it.

I`ll look into the electic scavenge pump idea also tho.

Another thing I was going to ask is about headers. I know the merged equal length setup is best for cylinder scavenging and outright power, but is the `log` type setup so bad?? Reason being Im doing all the fabrication myself and this seems an easier route if I do go draw through. Gives a shorter route to turbo too which must help with responsiveness.

Yeah Im doing it all DIY. Reason being Im permanently skint, live in the middle of nowhere, and I like to show what can be done on next to no budget. The bike only owes me ?2500 so far including buying it.

[Jon]

Ok change of direction. Thinking along the lines now of an Eaton M45 supercharger. Pop up on Egay quite regularly for sensible money.

Self contained oil for bearing lubrication so no oil pressure probs to worry about and can keep oil cooler. No complicated exhaust headers to worry about neither. Also gives me the option of an intercooler setup. Good freinds with couple of engineers than can helpout making up crank take-off plate for pullys, etc. Rest of it I can do myself really.

Physical sizes seem ok, but got plenty of open spaces on that bike anyway. More research n techy drawings required methinks.

[Rich]

Just run a dedicated electric oil pump for the turbo Jon, feed it from the sump and return it via clutch housing.

[Big John]

I'd go for a supercharger it'd be less common than a turbo.

[Pigford]

Boy-O-Boy, this is a soopa doopa thread!
TURBO's SUPERCHARGER's NITROUS

Heaven

Wish I had the skill/nerve/cash to go that route too Jon