Thank God!

Seriously, thanks for that.

Oh yeah, it looks like the 74mm efr turbine wheel is 87 trim which I think comes out to about 69mm for the turbine wheel exducer. The trim info is in the BW EFR "Technical Training Guide" pdf.

 

Thanks 03white.

 

damn it... wish i could do 'evo-talk' like some of y'all in here... 'google: sae turbine'

 

fyi - 2 indycar races completed so far - all 2012+ Indycars use a 100% off-the-shelf EFR rotating assembly, the same exact turbine and compressor wheels / shaft / bearings that every aftermarket customer will receive. The wheels are literally 9180 and 6758s. The only difference is indycars weld the twinscroll housing to their headers, so there is a different inlet. for the twin turbo chevrolet and lotus engines, they get an external WG t25 housing for the 6758s (this is so teams can not cheat and raise the boost). same center sections however. some photos:

you can see the penske dampers and the twin EFR 6758, stock center section complete with internal wastegate mounting holes in these 2 photos:










chevy twin turbo:






Lotus twin turbo here:









Honda is running the single twinscroll turbo:











note: honda is the only team using "header bags" to contain the heat. chevy and lotus just use raw or coated tubular fabricated headers.

note2: these cars use E98 and low boost so do not require an intercooler

 

I have learned something here. Thanks! Why then does the same A/R in a twinscroll have such a large power deficiency compared to a smaller single volute? I would think the area being the same/bigger with the pulses better seperated would be more efficient and yield MORE power not less. Teach me!

 

Geoff... what are these header bags made out of? Are they commercially available?

 

I guess now we know who's been sucking up the supply of EFRs.

l8r)

 

I was thinking the same thing... interesting how the pro teams don't seem to have a shortage, but most of the commercial customers who have already paid for their turbos over a year ago still don't have them.

 

As a/r gets larger, turbine efficiency at the low end increases, while turbine efficiency at the high end decreases. This is counter intuitive becuase the housing:wheel combo flows more at the high end, but spools later. effectively - there is no free lunch you cant put a 1.5 a/r on a 60mm turbine wheel and flow as much air as efficiently as an 80mm turbine


agreed - ive posted this previously also, the divider wall is NOT used in A/R calculation!

yes- the 7670 and 7064 are smaller than the 8374 so give much more room and you can fit the stock radaitor fan even. I have some photos posted of this on my evo i can post up if it helps you

correct

we have heard this from other well known shops also, whereas some shops seem to love them. to each his own

cant wait for you to get it on track, the setup will blow your mind

poor man's evo6 radiator!! well done, this needs to become a sticky in its own thread... you just changed the radiator game for evo owners. rockauto is going to get a flood of orders for these mirage rads haha

+1

 

I cant say how the mirage radiator will work for certain. Its full width, but its a single 5/8" thick core. Stock is double the capacity. Go buy one and test it out, if it works for you in az, were all good!

 

i could be wrong. but guys using 1/2 sized rads are not ''as big'' as a full size rad. maybe it is double instead of single. my thought is the single rad has double the surface are then the 1/2 sized rads. i bet they hold nearly the same amount of fluid. so IMO it should work fine. but i could be wrong.

 

I agree, but sometimes what works in our brains doesnt work in the real world.

 

i am a victim of that every day haha. but its a good thought. i dont think it will cool as well as a stock rad but it will cool better then the 1/2 rads used. so its in the middle. or maybe its in the trash. who knows

 

"Also NOTE: The BW turbo was a divided turbo on a divided twin scroll header. The PTE was an undivided turbo! There goes that theory! " quoted from SP.

 

Thanks Geoff! Please post or email me some pics of 7670 installed!

Believe me, I can't freaking wait!!!!! The first race of the championship was 2 or 3 weeks ago and I was going nutttss!!