Hi Mac, just been reading about your car....you HAVE been busy :D

 

 

As you posted, you have a change of turbos on the way: Garrett T28s. Just wondering what influenced your choice?

CFM? Pressure? Robustness? The T28 is a roller bearing design which usually increases the spool-time...I presume this is a worthwhile trade-off for the improved flow?

 

What allowances need to be made in the map? I would assume the T28 has a faster response "on boost" and so increased fuelling would be required at this points in the map, or am I incorrect?

 

Sorry about all the questions, just not well versed in the charecterstics of garetts....esp in relation to Zeds ;)

 

Thanks.

You mean BB turbos decrease spool up time?

Originally posted by TopLess

You mean BB turbos decrease spool up time?

 

yes, that IS what he means :D

LOL no he doesn't - he's obviously been in my car with my massive lag - I HATE having to wait until 1300rpm for possitive boost :( :D :dance:

 

There is a common misconception with BB/RB turbos that they spool earlier. From my experience this IS actually the case, however, what they say is that they come in HARDER and FASTER they do not spool earlier. BB turbos are the way forward - why sit in the past with old technology when there's far better stuff out there?

 

CheerZ,

 

Andy

Bottom of the page T4;)

 

 

 

http://www.angryturbo.co.uk/turbo/turbo.htm

400bhp? EACH? :eek:

Originally posted by Dave Marley

400bhp? EACH? :eek:

 

Oh YES:D:dance:

at 40 gazillion RPM. :D

 

oter than that, nice turbots mate. :)

Originally posted by Jezz_S13

at 40 gazillion RPM. :D

 

oter than that, nice turbots mate. :)

 

I knew you would like em Jezz:bow: :bow: :bow: ;)

are they the MD240's

better turbos spool up faster, but bigger turbos spool up slower.

yup, my T34 hybrid spools up much faster than my old T28.

Thanks Mac.

 

Roller Bearing turbos do take more to get going, but once they go, they GO GO GO! :D

 

Will you be running modified exhaust headers too?

Roller bearings are near bomb proof(only Timken ones:D i used to make em;) )the roller is profiled to match the profile off the race bearing,its the strongest way,the amount of loading they can take is way way greater than ball bearings,but its allso the most expensive to manufacture(SKF(Japanese) our biggest competitor were close but never could match the load/stess/destruction test as they could never get the heat treatment right,Timken bearings=the best in the world:D

 

ps,they hold the world record for load/stress

Tony,

 

no-ones been able to tell me, maybe you can?

 

Does a roller bearing turbo run at a lower operational temperature? I had assumed that it was a little higher than standard, due to the increased friction etc etc, but no one has been able to tell me for sure?

 

Presumably if they DO run at higher temps, no matter how efficient the compressor is, then some of this will be passed on to the charge????

 

Or is the difference simply insignificant?

mmmmm,good question Steve,had me thinking of years back when making them,but i think i am correct in that they run cooler,there is a greater contact area,ie,roller length/size moving around the cone raceway,but becouse the roller is actually taperd and that its surface mirrors the profile of the cone raceway you end up with less friction/heat,.plus with a Taperd Roller Bearing the rollers are seperated by being enclosed in a floating cage,not like ball bearings which are allways touching each other and wearing out quicker,eventualy over time the ball becomes non round and struggles to move causing heat to build up,i have seen some of these just lock up like being welded together becouse of heat.Another thing is that being heat treated the surface of the cone that the taperd bearing runs against is very very hard,and will never ever wear out like a ball bearing and can withstand amazing amount of heat,hope this helps:) Tony

Sort of! LOL

 

 

Thanks Tony.

Originally posted by Turbo_Steve

Thanks Mac.

 

Roller Bearing turbos do take more to get going, but once they go, they GO GO GO! :D

 

Will you be running modified exhaust headers too?

 

 

How do you work that one out Steve when they spool much faster?

 

Will be getting custom made manifolds too;) did you know this is one of the largest BHP gains? you can achieve up to 100bhp by changing them;)

Originally posted by MAC 1

Will be getting custom made manifolds too;) did you know this is one of the largest BHP gains? you can achieve up to 100bhp by changing them;)

That's a lot of extra bhp! Do you gain that much using one big sticker, or lots of little ones? ;)

RB's just need more gas flow to get going. Whenever mapping I find they just don't come on so early, no matter how much advance you run or whatever mixture you use. Of course this COULD be a problem with the headers, but I doubt it.

 

Typically with Hybrids, you're looking at the most efficient SMALL turbine & housing possible, mated with as large / high flowing compressor as possible.

 

I assume, this big compressor requires more inertia to get going, despite the more efficient turbine. However, once that has been overcome it reaches optimum speed very quickly.

 

At least that has been my interpretation.

Originally posted by MAC 1

Will be getting custom made manifolds too;)

Eh, what?! Where from, how much... and when can I have some? :) Is this an SE (whatever) thing?

Originally posted by 51x

Eh, what?! Where from, how much... and when can I have some? :) Is this an SE (whatever) thing?

 

YES! give them a call Si;)

Oh FFS Ian! You can't do this to me! It's touch and go whether the engine will be back in my car for the rr-day as it is... I can't go ordering a set of fannymolds - I'll NEVER get it back!!! Still, if I don't get them at least I've still got /something/ I can do to my car when it starts feeling slow again ;)

 

You bastud... I'm looking forward to seeing how your car comes out :D