New BW EFR Turbo Thread
Jul 5, 2015, 03:45 AM
#3106
I assume this is Arnold from PPT?
424whp on a DJ I would assume? No way in hell a .64A/R 6758 makes 424whp on any pump plus meth car on my dyno. If your dyno is the same as the local DJs here, figure ~16% less corrected power on our data vs theirs. If you take 16% out of 424whp, that is 356whp which is pretty darn par for that we get on our 2.2L EFR 6758 .85 kits on pump kits plus meth. IIRC, pump on the .64 was a 320whp on the 20vt 5 cylinder. If you are "doing" 356whp on our dyno on 93 plus meth, then yes, I think you are right, 40-50whp with e85 is right on track to our test results on that housing of being at 420-430whp L&S, roughly 440whp MD or 475-485 DJ.
9a was a 92.8 stroke/144, which is significant for how it spools vs a 86.4/144 rod ratio.
The .64 is hands down going to outspool the .80AR. Anyone that says otherwise is mistaken. The data is virtually in this thread that I have posted in the last 2 pages. I own a dyno, I am a decent engineer, decent calibrator, and I am meticulous about testing to get scientific data that is repeatable. I don't have anything to gain by hyping up the EFRs. There are some sizes I like, there are some sizes I like other manufacture's offerings better. All I am doing here is presenting the data. I'd look at the deltas to see what kinds of gains are being had, then plug your current data into matchbot with the same delta change of 400-500rpm and see if you can stay out of surge. Not just for your Arnold, that carries for 4g63s or whatever.
I know and deal with surge all the time, these QSVs on the EFRs have not shown any signs of surge on a 2.2L i5. We always monitor and check TSS on all of our testing, and you see surge on those lines. I can stall a QSV device'd engine with the absorbers on my dyno and still not invoke surge. The majority of the reason is because VE is relatively poor and because turbine efficiency is relatively poor. This is clearly presented in shaft speed data if mapped to Matchbot.
Hope that helps
Cheers,
Hank Iroz
424whp on a DJ I would assume? No way in hell a .64A/R 6758 makes 424whp on any pump plus meth car on my dyno. If your dyno is the same as the local DJs here, figure ~16% less corrected power on our data vs theirs. If you take 16% out of 424whp, that is 356whp which is pretty darn par for that we get on our 2.2L EFR 6758 .85 kits on pump kits plus meth. IIRC, pump on the .64 was a 320whp on the 20vt 5 cylinder. If you are "doing" 356whp on our dyno on 93 plus meth, then yes, I think you are right, 40-50whp with e85 is right on track to our test results on that housing of being at 420-430whp L&S, roughly 440whp MD or 475-485 DJ.
9a was a 92.8 stroke/144, which is significant for how it spools vs a 86.4/144 rod ratio.
The .64 is hands down going to outspool the .80AR. Anyone that says otherwise is mistaken. The data is virtually in this thread that I have posted in the last 2 pages. I own a dyno, I am a decent engineer, decent calibrator, and I am meticulous about testing to get scientific data that is repeatable. I don't have anything to gain by hyping up the EFRs. There are some sizes I like, there are some sizes I like other manufacture's offerings better. All I am doing here is presenting the data. I'd look at the deltas to see what kinds of gains are being had, then plug your current data into matchbot with the same delta change of 400-500rpm and see if you can stay out of surge. Not just for your Arnold, that carries for 4g63s or whatever.
I know and deal with surge all the time, these QSVs on the EFRs have not shown any signs of surge on a 2.2L i5. We always monitor and check TSS on all of our testing, and you see surge on those lines. I can stall a QSV device'd engine with the absorbers on my dyno and still not invoke surge. The majority of the reason is because VE is relatively poor and because turbine efficiency is relatively poor. This is clearly presented in shaft speed data if mapped to Matchbot.
Hope that helps
Cheers,
Hank Iroz
so inflating numbers is somewhat counterproductive for me. We made 609awhp on a GTX3582R on a 1.8T (stock stroke, cams, stock intake/tb amazingly) 33psi/E85. To say it made 511awhp (which is subtracting your 16%) is a bit much. We rolled with a 2015 GTR with some mods as well as an M5 with mods and soundly pulled on them like a 600whp vehicle should. Have the vids...But great work you're doing there. We obviously share in our enthusiasm for this on technical levels.
Lets rephrase that, would you trade 1k of powerband where you're up averaging PLUS 12-15whp and torque for 3.5k of powerband where it is on the average MINUS 25-30whp on power and torque?
Last edited by altrix99; Jul 5, 2015 at 05:22 AM.
Jul 5, 2015, 09:48 AM
#3108
Hank, you have lots of EFR experience where I have none. I am building my first EFR 6758 car right know. I would have sprung for 7163 if I was buying new but got the snail for free. including both .64 and .85 vband housings. The car is 94 summit with A/T. (early expo RVR). build is 100% daily driver so response is of paramount importance. my goal is ~430-450whp dynojet at 25psi on E40 fuel. pump plus eth spray. (actually 380-400 through a/t but is equal to 430-450 5spd) the only place I am actually concerned about response is in first gear rolling from a dead stop. as all other scenarios the trans will downshift and be insta boost. I am using a cast stock manifold as from my experience nothing will spool faster. The engine is 2.2 at 9.4 compression. But cams will need to be kept very small so the car can idle at 600rpm smoothly and not creep forward at a stop. I was going to start with the .64 a/r housing but reading your text from last few days you have my thinking maybe I should start with .85? I also wonder how well the factory pop off valve works? I see no one commenting anywhere on how well they function. if you can share your thoughts I am listening.
Jul 5, 2015, 02:46 PM
#3109
Evolved Member
Jul 5, 2015, 10:23 PM
#3110
Evolving Member
Jul 6, 2015, 07:49 AM
#3111
The other half of the benefit that doesn't translate as well to dyno plots is the increased transient response.
But the bottom line is this: For applications where the driver rarely falls out of the power band and isn't on and off of the throttle much, the open scroll setup looks to be the winner with the additional top-end power. But for those of us willing to sacrifice a little top-end for better spool and powerband, twin scroll is still the way to go.
It's good to have options. I'm just glad that there are still multiple shops (CBRD, Hypertune, Full Race) willing to put in the R&D to bring us these products.
Jul 6, 2015, 09:13 AM
#3112
If you go back and look at the STI charts (yes, I know, apples and oranges) the low-end difference is actually quite substantial. It's up a full 50 ft/lbs of torque at some points before peak boost is reached.
The other half of the benefit that doesn't translate as well to dyno plots is the increased transient response.
But the bottom line is this: For applications where the driver rarely falls out of the power band and isn't on and off of the throttle much, the open scroll setup looks to be the winner with the additional top-end power. But for those of us willing to sacrifice a little top-end for better spool and powerband, twin scroll is still the way to go.
It's good to have options. I'm just glad that there are still multiple shops (CBRD, Hypertune, Full Race) willing to put in the R&D to bring us these products.
The other half of the benefit that doesn't translate as well to dyno plots is the increased transient response.
But the bottom line is this: For applications where the driver rarely falls out of the power band and isn't on and off of the throttle much, the open scroll setup looks to be the winner with the additional top-end power. But for those of us willing to sacrifice a little top-end for better spool and powerband, twin scroll is still the way to go.
It's good to have options. I'm just glad that there are still multiple shops (CBRD, Hypertune, Full Race) willing to put in the R&D to bring us these products.
When you're up in the powerband, as far as transient response is concerned, you'll actually have better response with less restriction. You'll make more power per psi
Last edited by altrix99; Jul 6, 2015 at 09:15 AM.
Jul 6, 2015, 01:36 PM
#3114
EvoM Guru
iTrader: (1)
Like the LLR Evo. English tested the 1.12 and 1.28 AR housings, identical results except less back pressure (6psi less per John Bradley on the 2nd page) on the 1.28. Twin scroll setups need a larger AR T4 housing to work. If CBRD is testing T3 twin scroll stuff, that could explain why. T3 ts volutes are tiny..
https://www.evolutionm.net/forums/ev...4-744-a-2.html
Last edited by letsgetthisdone; Jul 6, 2015 at 02:15 PM.
Jul 6, 2015, 01:51 PM
#3116
On the new QSV housings... I love the technology. I do like the concept but I have a feeling that when conditions change (weather, altitude, etc) you'll need to 'tune' them to suit. Certain turbos will also not cooperate with the quicker spool as you'll run them off the map. I deal with TDI's with VNT tech. When you throw in a larger turbo, you have to play around exhaustively with the VNT actuator because when they are closed and you decide to mash the pedal, the tune/mechanics do not respond quick enough and what do you think happens? MASSIVE SURGE. You almost have to ease into it to make sure you dont overspin the turbo early. Oftentimes you have to live with the surge if you want to drive it the way you want it...
Jul 7, 2015, 05:49 AM
#3118
Newbie
yes i agree! and why we select EFR 1.45 a/r for high boost evo turbo when you're really racing, how often are you between 2.5-3.5k? I think the 3.5k-6k range is more frequented when you're actually going through the gears and racing the car...... The only race you'll win convincingly is if you're racing from stop light to stop light, through traffic, in auto-x and very windy roads/tracks with not many or short straights where you're rarely standing on it and barely in 3rd gear...
But the bottom line is this: For applications where the driver rarely falls out of the power band and isn't on and off of the throttle much, the open scroll setup looks to be the winner with the additional top-end power. But for those of us willing to sacrifice a little top-end for better spool and powerband, twin scroll is still the way to go.
Jul 7, 2015, 07:16 AM
#3119
But when you're really racing, how often are you between 2.5-3.5k? I think the 3.5k-6k range is more frequented when you're actually going through the gears and racing the car.... In a drag race situation, everything being equal, you will lose to the high powerband car. On a hwy pull going from 3rd to 5th/6th redline, you'll lose to the car with the higher hp car that spans 4000rpm's...
The twin-scroll option is what makes these larger turbos a realistic autocross option for our tiny motors in the first place, which is why I like it so much. The results show up in the dyno plots (+50wtq down low!) and the STI build I linked previously was used for autocross. The STI driver swears by the increased response of the twin-scroll setup. I'd be hard pressed to give up that low end and transient response for an extra bit of HP up top for an autocross setup.During spool-up, the primary goal is to get to peak boost quickly, not to limit backpressure and optimize power output at partial boost.
Take the concept one step further and you get the quick spool valve that EFR is working on.
I haven't really examined the EFR QSV pictures too closely, but I wonder if there's any way that would fit in an Evo 8/9. A twin scroll 7163 with QSV would be a perfect autocross setup.
Jul 7, 2015, 07:30 AM
#3120
you guys are killing me with all this exhaust housing talk . the subi making mad power on the 7163 has used both housings with dyno graphs. you only have to look there to see which powerband suits your driving style. trying to convince someone your preference is correct choice is a waste of time.
there was a race team upgrading to 7163 turbos so they put twenty 6758s on ebay for 450 each or make offer. I bought ten of them for 3350 shipped. resold nine quickly for a 2k profit. the bonus was sale number nine where the guy wanted to buy new exhaust housing. so ended up with both size exhaust housings to try. plus the turbos have the alloy center. win win everywhere for me..I am keeping my eye out for next year when they upgrade again lol
Must be nice to come across a free EFR turbo.
Last edited by 94AWDcoupe; Jul 7, 2015 at 07:41 AM.