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Originally Posted by flagg
Awesome news Judo. Would be good to have a 4bd1t convention one day and see how the different setups go IRL. :)
Does it count if the turbo is in a box o nthe back seat? :p
haha yes. I can't complain, mine sat in a box in the garage for over a year before I bolted it on!
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Originally Posted by isuzutoo-eh
In that case I can come with twin turbos. :p One up front and one in the back (seat).Quote:
Originally Posted by flagg
Dougal will be asking for a clean up of his thread soon. :wasntme:
Very keen to see how this goes, I nearly pulled the trigger on a BW turbo but then decided to hold off, then the AUD dropped, now I am questioning the need to go for the expensive option when I am not chasing big numbers. Comments on quality etc when you get it would be appreciated.Quote:
Originally Posted by Judo
Apparently the Borg Warner EFR6255 isn't available. I'm guessing demand wasn't high enough so they dropped it. Smallest one is the EFR6258 which Flagg has used.Quote:
Originally Posted by Dougal
The difference is relatively minor, but the 55 would be a bit faster spooling. Same compressor on them both.
I will certainly be posting all my stories as they are available. :)Quote:
Originally Posted by Jitterbug
Note the AUD affects the Kinugawa turbo prices too. The same one I bought on ebay was $100 cheaper a few weeks ago. When I messaged the seller about it, he apologised but said it was the exchange rate that caused the price jump, not his own price rise.
If you want to go real cheap (quality unknown?), this is a straight T3 bolt up (I was very tempted). But if you can see a brand name anywhere on that turbo, you're doing better than I! IMO Kinugawa is already ahead being that they have a name. :D
Isuzu Truck NPR 4DB2 4BD2 TB2568 Turbo Turbocharger 466409 0002 8971056180 | eBay
My source: http://www.aulro.com/afvb/isuzu-land...ml#post1714096
The TB2568 (4BD2T turbo) is the best of the stock turbos. But the TD04HL-19T should deliver a lot more low end boost and more boost. The TD04HL-19T can do 30psi to the rev limit, the TB2568 shouldn't.Quote:
Originally Posted by Judo
The EFR 6258 has also gone up in price quite a bit since I ordered mine (in USD, not just the exchange rate). Apparently there were some manufacturing issues that caused delays and I guess the price increases.
So I've finally had some time to crack the turbine sizing thing. Borg Warner use a number called Phi on their turbine maps:
http://www.turbodriven.com/performan...turbinemap.jpg
Garrett use "corrected mass flow" for theirs:
https://www.aulro.com/afvb/images/im...013/08/391.jpg
So here is how they work. Turbine power is essentially an arc centred around the lower left hand corner. So if you need say 20kw of turbine power, you'll have an arc which cuts that chart from top left to mid right.
Where that 20kw arc cuts the red line is where the turbine can provide that amount of power.
Every turbine like that has a lower limit where it can't get enough flow to start working and an upper limit where it's choked out and can't produce any more power. In between how much power it can produce depends on how efficient it is.
The crux of all of this.
The Borg Warner EFR6258 turbine starts at about the point of a Garrett GT28 turbine with a 0.64 A/R housing on it.
The difference is, the EFR is a lot more efficient so requires less drive pressure to produce the same turbine power.
Here is the GT2871 turbine map, max efficiency about 68%:
https://www.aulro.com/afvb/images/im...013/08/392.jpg
Here is the matchbot stock figures showing 75-70%:
BorgWarner MatchBot
This is why Borg Warner can get away with a larger turbine. The larger but more efficient turbines used on the Borg Warners can ultimately support more power for higher boost at higher rpm. But that said, even the T25 turbine can deliver backpressure below boost for the lions share of it's full load operation and can still provide enough boost to max out a standard pump.
At 750C EGT I'm getting 32psi drive pressure to produce 25psi boost at 3,500rpm with the 0.49 A/R T25 turbine. That's just over 33kw turbine power which is enough to feed 180kw of engine power.
I'm still crunching all these numbers, so don't get too excited yet. I also haven't visited the Garrett GTX range which should offer some competition to the BW EFR series.
Do you have any fuel screw left for those figures Dougal?
That is based on the 140cc max that Randy measured on his stock pump. Bsfc and power figures are conservative.Quote:
Originally Posted by flagg
I hope to bench test my spare pump one day.
After many more hours crunching numbers, it appears the 0.64 turbine housing just can't do it and anything bigger is even worse.
The gt22 turbine looks like the best one garrett have for our uses. But no numbers yet.