New BW EFR Turbo Thread
Jan 24, 2011, 08:16 AM
#65
Got this link from nasioc. Looking good!http://forums.clubrsx.com/showthread.php?p=35892744
After playing around with the BW matchbot some more, it looks like a 7670 will pretty much fit all of my criteria in either the 1.05 or .92 AR. So I have a couple of questions, Geoff. Apart from the packaging/feature difference, what kind of difference would I see between the two trims? I'm assuming that the .92 will spool slightly faster and make a little less power up top, but at my target of 30psi on a built 2.0L, either option seems to be viable. How difficult will it be to fit the .92AR 7670 onto an Evo? I hate open dumps and the integrated wastegate and BOV appeals to me greatly.
Any idea if the 8374 will fit without major modifications? Any eta on when you will have the 7670 on your evo?You have to realize the setup is making 700 ft-lbs of torque and probably dropping boost like crazy as the compressor is out of flow. Look at it like this, let's say you turn the boost down to where it is making 550 ft-lbs peak. It would probably make 500+ ft-lb from 4750 to 7250. That's a pretty flat torque curve with a ton of girth.
Last edited by Geoff Raicer; Jan 24, 2011 at 12:06 PM.
Jan 24, 2011, 09:12 AM
#66
Evolved Member
iTrader: (5)
Join Date: Dec 2003
Location: Work - New York, Alaska, Mexico or the Caribbean. -Home - Tx Hill Country
Posts: 1,858
Likes: 0
Received 0 Likes
on
0 Posts
Dan - this is the fastest time attack car in North America, and #2 in the world. The powerband is far from horrible. This tq curve is a product of "over speed" condition and choke flow (rapidly rising shaft speed without increasing airflow). The definition of choke flow means: *IT IS NOT POSSIBLE TO MOVE MORE AIR THRU A 62.7MM HOLE* think about that, it doesnt matter if your turbo is an hta or a precision or an efr. A 62.7mm hole is only so big and can allow only so much air past. Once we start getting more turbos, especially twinscroll ones, then we can do more pertinent tests, and sure maybe even send a test unit out to you and sean if you wanted to try it out.
Jan 24, 2011, 12:16 PM
#68
i think i got that right.
Jan 24, 2011, 12:26 PM
#69
Evolving Member
Thread Starter
iTrader: (2)
Join Date: Dec 2009
Location: South Africa
Posts: 312
Likes: 0
Received 0 Likes
on
0 Posts
Is the graph's of single or twin scrolls?
here is his GT35R (purple line) vs EFR 8374 (green line) comparison:
no problem to order the shaft speed sensor along with the turbokit, we can supply the roadrage items too - just let me know what you are thinking about and we'll make it happen
I agree the 7670 is an outstanding fit to a 4G63 that doesnt need huge top end power. That is what I am running on my daily driver evo, however the .92 a/r with internal wastegate is extremely difficult to fit - impossible with the A/C compressor. I will have more info and pics on this in the next few weeks
Im waiting on turbos just like everyone else, but our customers are first and I'm at the end of the line. My R14 is waiting without a turbo, as is my evo. Right now the only turbos were getting consistently are the singlecsroll units
Dan - The powerband is far from horrible. this is the fastest time attack car in North America, and #2 in the world. Their cylinder head FLOWS and the entire system works to generate the numbers you see here. The dropping tq curve you see is a product of "over speed" condition and choke flow (rapidly rising shaft speed without increasing airflow). The definition of choke flow means: *IT IS NOT POSSIBLE TO MOVE MORE AIR THRU A 62.7MM HOLE* think about that, it doesnt matter if your turbo is an hta or a precision or an efr. A 62.7mm hole is only so big and can allow only so much air past. Once we start getting more turbos, especially twinscroll ones, then we can do more pertinent tests, and ill try to send a test unit out to you and sean to try out. Currently we can only wait as demand is outpacing supply
^^^ +1
no problem to order the shaft speed sensor along with the turbokit, we can supply the roadrage items too - just let me know what you are thinking about and we'll make it happen
I agree the 7670 is an outstanding fit to a 4G63 that doesnt need huge top end power. That is what I am running on my daily driver evo, however the .92 a/r with internal wastegate is extremely difficult to fit - impossible with the A/C compressor. I will have more info and pics on this in the next few weeks
Im waiting on turbos just like everyone else, but our customers are first and I'm at the end of the line. My R14 is waiting without a turbo, as is my evo. Right now the only turbos were getting consistently are the singlecsroll units
Dan - The powerband is far from horrible. this is the fastest time attack car in North America, and #2 in the world. Their cylinder head FLOWS and the entire system works to generate the numbers you see here. The dropping tq curve you see is a product of "over speed" condition and choke flow (rapidly rising shaft speed without increasing airflow). The definition of choke flow means: *IT IS NOT POSSIBLE TO MOVE MORE AIR THRU A 62.7MM HOLE* think about that, it doesnt matter if your turbo is an hta or a precision or an efr. A 62.7mm hole is only so big and can allow only so much air past. Once we start getting more turbos, especially twinscroll ones, then we can do more pertinent tests, and ill try to send a test unit out to you and sean to try out. Currently we can only wait as demand is outpacing supply
^^^ +1
Jan 24, 2011, 01:16 PM
#71
2.0L honda engine, T3 singlescroll .82 a/r for the GT35, .83 a/r for the EFR
you have to subtract the shaft and blade area to get the working area. as you mentioned tip speed absolutely has an effect on this. the compressor maps i previously posted showed the speedlines in RPM, but this one shows tip speed in m/s:
evodan - think about how if your car has wheelspin, the engine is accelerating and the tires are accelerating but the car isnt moving any faster (tires are spinning). this is the same thing, but with air and a blade, instead of tire and asphalt
evodan - think about how if your car has wheelspin, the engine is accelerating and the tires are accelerating but the car isnt moving any faster (tires are spinning). this is the same thing, but with air and a blade, instead of tire and asphalt
Last edited by Geoff Raicer; Jan 24, 2011 at 01:20 PM.
Jan 24, 2011, 01:26 PM
#72
evodan - think about how if your car has wheelspin, the engine is accelerating and the tires are accelerating but the car isnt moving any faster (tires are spinning). this is the same thing, but with air and a blade, instead of tire and asphalt[/quote]
Very nice analogy
that really helped me understand it, thanks.
Very nice analogy
that really helped me understand it, thanks.
that's very impressive regardless.
Jan 24, 2011, 01:58 PM
#75
so the answer will depend on how much gain does that specific setup get from the twinscroll configuration over the singlescroll. Typically that is in the area of 10-15% but every setup is different.
Since there are (2) dynosheets on this page of an 8374, one is singlescroll 2.0L (with very high VE) the other is built twinscroll 2.2L (also with very high VE). compare where they each hit 200lbft and 300lbft for comparison. You can see about 800-900rpm difference... some is due to the displacement, some is due to the headers, but when it all comes down to it, maybe half of that (400rpm) would be a reasonable guesstimate. Dont forget that the response is not measured on a dyno
Last edited by Geoff Raicer; Jan 24, 2011 at 02:00 PM.