This any good?????

Post by **Coops** » Mon Jan 11, 2010 11:29 pm

Been offered this charger, it seems to be home made, or i maybe wrong.
this ok for my 4.6 or not?
the internal ratio is 4.15:1
i'm told the housing and imppeller are from a GT35 turbo
the gears are straight cut

kiwicar · Post by **kiwicar** » Tue Jan 12, 2010 6:54 am

Hi Tony
I have a couple of concerns, firstly the size of the pully on the front, it is presumably that size to get it spinning fast enough, I think it may slip unless you can use a bigger one, that will mean a bigger bottom pully which could end up very big to get the necessary ratio. with the internal box ratio of 4.15:1 and say 2.5:1 on the pully, you will have it spinning at 72K revs at 7k on the engine. from what I remember turbo impellers run with boost from about 50k to 90 to 100k. I'll try and find the right map for this housing and it's flow against revs and see how it comes out.
Any ideas what it has run on before? what bottom pully it ran with and why it is being sold on.
Best regards
Mike

ChrisJC · Post by **ChrisJC** » Tue Jan 12, 2010 7:18 am

Gonna be noisy too with straight cut gears.

Chris.

topcatcustom · Post by **topcatcustom** » Tue Jan 12, 2010 9:44 am

Whats with the quick release air fittings screwed in too?

kev_the_mole · Post by **kev_the_mole** » Tue Jan 12, 2010 10:05 am

Will second the awful bloody noise problem and you'll probably need a toothed belt drive. I assume the quick release stuff is for the oil feed to keep the whole shebang cool. You might need an oil cooler as well!

SuperV8 · Post by **SuperV8** » Tue Jan 12, 2010 2:06 pm

What's the overall diameter?

I've found most centrifugal superchargers a lot larger than their turbocharger cousins. Because they generally turn slower. 50K - 60K.

Rotrex use a smaller housing which is more in line with turbo size but they turn a lot faster than the big Vortechs and Paxtons.

I don't recognise the gearbox.

I'm using a procharger C1. This also has a 4.7 ratio gearbox and the max impellor speed is 80,000rpm. I'll find out if it uses a straight cut gears?
http://www.procharger.com/models.shtml

Tom.

kiwicar · Post by **kiwicar** » Tue Jan 12, 2010 4:01 pm

Hi Tony
I have had a look at a couple of compressor maps for the GT35 .7 AR hosing, and provisionally I recon this doesn't have enough flow at low pressure ratio for what you want, I am assuming about 12 to 15 lbs of boost at 7k revs (to give you 3 to 4 lbs at 3.5k revs). I think it is intended to work with somthing requiring about 18 to 25 lb boost and about 2 to 2.5 litres capacity
If it is seriously cheep you could buy it for the gear box, get a bigger howsing and drive pully and Robert is your mothers brother!
Best regards
Mike

Post by **Coops** » Tue Jan 12, 2010 4:48 pm

he's asking £400 for it,
reason for sale he said its too big for his v6 rover 827.

kiwicar · Post by **kiwicar** » Tue Jan 12, 2010 7:32 pm

Hi Tony
Having spent my time usefully at work today hunting around compressor maps and doing add-ups, I think this will produce the wrong combination of boost and flow for your engine, too much boost at too little flow. I would like a little more time to check my maths but I recon you want a T76 housing and compressor with an AR of .96 (this is the bit I need more information for and some more time to check my maths), assuming a starting point of that gearbox of a 4.15:1 ratio then you want to drive it with a toothed belt giving a further gaering up of 1.9 to 2.2:1 as I said before assuming you want to end up at about 12 to 15 lb boost at 7000 revs. you could try and use that one as it is but you would to limmit max revs to 6k and gear it up to 3:1+ on the belt, and drop the compression to about 8.5:1 otherwise it will over boost at 6K and still strangle the engine low down. He is right about the 2.7 engine, if he is not going for a high boost solution, it will give too much boost for that lump aswell as I posted earlier I recon it is intended for about 2 to 2.2 litres and 2 bar of boost.
Really it is only of use to you for the gearbox, and I recon if you have access to a mill and lathe you could make one up for less than £400 and you would then be able to buy a housing and impeller for a T76 and build your own (I would buy some helical cut gears for it if you are doing your own)
Best regards
Mike

Post by **Coops** » Tue Jan 12, 2010 7:49 pm

thanks for looking into it Mike,
looks like im gona hold back until i can find a proper one.

stevieturbo · Post by **stevieturbo** » Tue Jan 12, 2010 8:14 pm

Aside from whether it fits or not....the fact its a DIY would steer me away !!!

f**k knows if its of any use at all, or has ever been used !! Although fair play to someone for making it !!

But you'd probably buy the likes of a Procharger P1SC from the US fairly cheaply second hand.

kev_the_mole · Post by **kev_the_mole** » Tue Jan 12, 2010 8:36 pm

Tone,

If you want to do it I've got the gears!

http://www.transdev.co.uk/pages/gears/gear_main.htm

Cheers,

Ian

Post by **Coops** » Tue Jan 12, 2010 9:06 pm

kev_the_mole wrote:Tone,

If you want to do it I've got the gears!

http://www.transdev.co.uk/pages/gears/gear_main.htm

Cheers,

Ian

stop trying to tempt me

SuperV8 · Post by **SuperV8** » Tue Jan 12, 2010 9:11 pm

Just realised i'm now helpful or confused....

Think its the later...

kiwicar · Post by **kiwicar** » Wed Jan 13, 2010 11:04 am

Go on Tony, build your own, you know you want to

Mike