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Initial EFR 7670 dyno results

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Old 09-08-14 | 04:36 PM
  #26  
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Originally Posted by rx7 SE
Not to get sidetracked here, but the highest number efr 8374 I've seen have been from you which was 486 rwhp at something like 26-28 psi. A similar sized 6766 makes that at around 20-22 psi but give up some spool and the broad power band that the efrs are showing.

For example of 6766 numbers, post #43 & 48
https://www.rx7club.com/single-turbo...1023860/page2/
8374 would be a 6265 in precision language. Also the car has high RPM misfires, so PEAK HP numbers are way down. @ 5800rpms right before the misfires start you can actually see the torque curve is still climbing at roughly a 60 degree angle. It was probably on its way to 470FT lbs. HP is just torque x rpm. If the misfires weren't there it would probably be 550-600rwhp( assuming no other restrictions/issues).

Take a look at this link with a 9180( Which is roughly a 6868 PTE- Not that they make that size but for size comparison) make 57xrwhp @ 20psi;

http://blogdotturbosourcedotcom1.fil...vs-s366-91.jpg

I need to update the blog as I have a ton more info with more dyno sheets etc...
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Old 09-09-14 | 06:25 AM
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Originally Posted by Turblown
8374 would be a 6265 in precision language. Also the car has high RPM misfires, so PEAK HP numbers are way down. @ 5800rpms right before the misfires start you can actually see the torque curve is still climbing at roughly a 60 degree angle. It was probably on its way to 470FT lbs. HP is just torque x rpm. If the misfires weren't there it would probably be 550-600rwhp( assuming no other restrictions/issues).

Take a look at this link with a 9180( Which is roughly a 6868 PTE- Not that they make that size but for size comparison) make 57xrwhp @ 20psi;

http://blogdotturbosourcedotcom1.fil...vs-s366-91.jpg

I need to update the blog as I have a ton more info with more dyno sheets etc...
Wow, yeah keep the dyno sheets comin, that's good stuff
Old 09-09-14 | 05:40 PM
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Here is a JPG of the Excel sheet/graph I made using formulas for mph to rpm and hp to torque. It lost some resolution as I only graphed every 2.5mph.

Actually made a tad more torque than horsepower @ 419hp/423tq.

It is uncorrected Dynojet #s, but I ran the weather station stats and it is .983 CF so my #s are only 1.7% over the corrected values.

You can really feel that 300ftlbs @ 3,000rpm when you are driving/racing. I did some drag racing Saturday and I could bog the launch so I was starting with a roll on and still run low 12s. Best times were high 11s.

It was so nice to pull the V8s on shifts instead of dropping behind waiting for boost.

Click and zoom for larger image
Attached Thumbnails Initial EFR 7670 dyno results-efr7670x.jpg  
Old 09-09-14 | 05:44 PM
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What MPH?
Old 09-09-14 | 06:40 PM
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The only slip I have is for my third run and first 11 ever which was 11.9 @ 118mph. Spanked a C63 AMG with my 1+ sec reaction time (I'm no drag racer!)

My friend watching said I ran a 11.7 later as I got more practice. Didn't catch mph.

I think I will be able to get 119mph pretty easy if I haven't already and might squeak out some 120mph with a fan added to the IC for grid and practice shifting.
Old 09-09-14 | 09:50 PM
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of course i couldn't let that data just sit here... thanks for it BTW.

i pulled out your power at 6 RPM points

5000
5500
6000
6500
7000
7500

and added your results to my other 71 dyno power outputs each w the 6 data points.

your total power under the curve is 2379.

i then took the 5 runs above and below 2379. the ten averaged 2373. i averaged the ten which are the red line.

the X line point one is 5000 RPM, point two is 5500 thru point 6 which is 7500.

we have a new animal here.

the big question is what happens to the blue line after point 3 when you get your system running 100%.



howard
Old 09-09-14 | 11:37 PM
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120MPH is pretty good! I think I trapped 124MPH on my 07 GSXR 750( no drag launch, and I don't drag race bikes).. Thank you for sharing the dynojet graph with torque curve. Regardless if its over inflated numbers, its what MOST dyno systems use as base in the tuner community. All of my dyno charts that I have personally tuned have been based off of dynojet numbers, so I keep it consistent to compare.

That response( torque output) definitely beats the 8374.... Good autoX choice. We have a 7670 IWG FD kit leaving in the morning...
Old 09-10-14 | 02:50 AM
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he big question is what happens to the blue line after point 3 when you get your system running 100%.

Honestly, after I get my final tune I think the only difference will be a straight line drawn between 4,860rpm and 7,221rpm (the too rich to read on wideband area).

The whole concept for my set-up is being able to easily switch between pump gas boost and race gas boost- so I doubt I will ever put in the 21.75psi WG springs.

I still have to make the collar clamp for my MBC to bottom against on the high boost setting before I can turn the boost down (lazy!)

Sorry, for that bad news.

The good news is *only* 400rwhp Dynojet is still good for a 57mm turbo on a rotary. Plus, that spool!
Old 09-10-14 | 05:40 AM
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Very nice area under the curve.. that is the 1.02 AR housing right?

Does it feel like spools a lot faster than the 8374 with the .92 IWG housing?

Your intcooler setup looks also nice.. do you have a photo of the hood?
Old 09-10-14 | 06:02 AM
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Would you prefer this setup over the twins in carving through the mountains?
Old 09-10-14 | 08:33 AM
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Hot damn. The response in that video is incredible!
Old 09-10-14 | 01:19 PM
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Very nice area under the curve.. that is the 1.02 AR housing right?

Does it feel like spools a lot faster than the 8374 with the .92 IWG housing?

Your intcooler setup looks also nice.. do you have a photo of the hood?


Yes, the 1.05 AR T4 external WG housing.

Regarding the 8374 .92 VS 7670 1.05, we will have to wait for someone to do an in car video of 3,000rpm 5th gear pulls with the 8374 as I did (My stock tach is optimistic, subtract ~300rpm @ 3,000rpm).

I will take another video of the Haltech Engine data page while cruising/pulls.

The boost response at low throttle positions is really good which helps the engine feel like it has more displacement. I noticed right away that the car just drives around town at low rpms a little easier.

I do think the 8374 looks like it fits the rotary better as the dyno plot is still recognizable as a rotary engine (for better or worse).

I think the 7670 will appeal only to those who insist on the ultimate in turbo response without choking out the engine with a restrictive hotside or putting up with the "finicky" sequential twins.

Sadly, my hood is still a stock NA hood.
Old 09-10-14 | 01:51 PM
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Would you prefer this setup over the twins in carving through the mountains?

At pump gas boost on the EFR (10-13psi IMO) I don't think I would notice a difference between the EFR 7670 and sequential twins in my FD carving through the mountains. I have the secondary transition set seamless with the dual Hallman Pro RX boost controllers though.

I don't know who would cruise though the mountains on race gas boost (14-? psi), but I can tell you that even with *just* 19psi @ 3,000rpm the EFR torque is incredible compared to my stock sequentials and by the time it hits 26psi @ 3,300rpm I stop trying to even make comparisons to the sequentials and start comparing it in my head to an LS V8.

But its not a V8, the turbo still has to spool (albeit quickly) on throttle tip in.

Around town and in traffic I feel the sequential twins still have more torque from 1,000-2,000rpm.
As I stated before I think this could be largely addressed using the stock 3rd gen exhaust manifold as a quickspool valve with the EFR (but then you start to get into the exhaust heat soak issues just like the stock twins...)

You do get about 5-7psi boost free revving in neutral near redline and letting off like with the stock sequentials. I hadn't experienced that with my last single turbo set-up.
Old 09-25-14 | 12:50 PM
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What setting were you running for the 11.9 @ 118 mph? I ran a 12.0 @ 116 on my BNR @ 15 psi. I assume this was your 13psi tune.
Old 09-25-14 | 02:10 PM
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Nope, I am no drag racer!

On my old BNR @ 14psi-18psi *peak power didn't really change much as it was out of flow* (380rwhp on Dyna Pack & Dynojet- 325rwhp Dyno Dynamics) - I only ran mid to low 12s @ ~115mph.

I had to drive really aggressively to even get that. Good launch, flat shifts and a clean run.

On the EFR 7670 @ 26psi (419rwhp Dynojet- 369 Dyno Dynamics)- I only ran the high 11s @ ~118mph.

But, I could granny shift and get a so so launch and still run high 11s.

When I bogged the launch to 3,000rpm and missed 2nd I still ran a low 12. That is down to the 7670 response/torque.

I am sure I will get faster as I get better at the drag racing thing.

I assume this was your 13psi tune.

Nope, the EFR 7670 isn't making nearly as much peak power @ 13psi as the 60-1 since it is a slightly smaller and high pressure ratio oriented compressor.

13psi on the 7670 is ~275rhpw on the DynoDynamics from what I remember, but would be ~320rwhp on the 60-1.

Hell, the 60-1 really surprised me by making 295rwhp on the Dyno Dynamics at just 10psi PEAK boost. That would be ~ 330rwhp Dynojet @ 10psi from my experience.

But that lag... Peak power isn't where its at for the racing I do.

I wanted that LS V8 torque and the EFR 7670 (and race gas) delivered!
Old 09-25-14 | 02:17 PM
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What are your AIT's like running that much boost with that turbo?
Old 09-25-14 | 03:46 PM
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I didn't notice that IATs were abnormally high compared to my old low boost set-up. I will have to take a 4th gear log.

Last weekend was auto-x racing. I got to use full throttle in 2nd gear once for a second at the finish of each run

My Intercooler was still chilled to the touch on the coldside and warm on the turbo side after my 1min runs (I spray the IC with water before my run).

Obviously, it will take a venue like a hillclimb where it is 100+ degrees ambient and 3rd/4th gear full load to really see the higher IATs impacting the IC with heatsoak.

Its probably time for a vented hood to take advantage of my horizontal mount IC set-up as well as a fan on the IC.

I am doing an "enduro" the weekend after this which is 5 laps on a kart track (4 minute sprint race despite the name).
I am also interested in seeing how the IC and radiator handle full boogy at 26psi.

Well, the kart track is all 2nd gear with 3rd down the front straight, so it likely won't be full load/boost due to limited traction....

Ok, now I need a widebody to put the hurt on my cooling system!
Old 09-26-14 | 03:51 PM
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Thanks. It seems to be a tough choice between the 7670 and 8374! I know I want one, but I'm not sure which one will suite my goals better.
Old 11-02-14 | 06:23 AM
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Good read, I am also doing a 7670 on my FD (From Turblown). I too am shooting for response, as most of my driving is just traffic light grand prix (occasionally) and I daily drive it. The response seems phenomenal in the video! I was looking to see how much boost you were running, to see what I could expect. I didn't want to crank it too hard, being daily driven I need it to last.

What injectors are you running?
Old 11-02-14 | 01:24 PM
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Originally Posted by Enigmatic
Good read, I am also doing a 7670 on my FD (From Turblown). I too am shooting for response, as most of my driving is just traffic light grand prix (occasionally) and I daily drive it. The response seems phenomenal in the video! I was looking to see how much boost you were running, to see what I could expect. I didn't want to crank it too hard, being daily driven I need it to last.

What injectors are you running?

you can run any injector and be fine. The sweet spot for this turbo is 20PSI in terms of efficiency at our elevation (6,300 ft).

at sea level the sweet spot is 24 lbs ish.

at sea level, you can run the turbo down to 18psi and still be in a good efficiency spot. (2.2 pressure ratio).

up in high country we can run 14PSI and still be efficient.
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Old 11-02-14 | 06:05 PM
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Good read, I am also doing a 7670 on my FD (From Turblown). I too am shooting for response, as most of my driving is just traffic light grand prix (occasionally) and I daily drive it. The response seems phenomenal in the video! I was looking to see how much boost you were running, to see what I could expect. I didn't want to crank it too hard, being daily driven I need it to last.

What injectors are you running?


Probably asking about injectors as I stated I maxed mine on the 7670.

I was running 2x 720cc and 2x 1600cc injectors with an in-tank converted Bosch '044. We could have leaned it out quite a lot and then raised the boost as it was running richer than 10:1 on the top end.

I ran 26psi on race gas and 13psi on pump.

The 7670 doesn't make great power at low boost (like 13psi), but it does get full boost very early on. 10psi@2,500rpm and full boost just after that.

On 26psi it was an animal.
Old 11-02-14 | 06:05 PM
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I say was, because at the race I got a full day of practice Friday and Saturday and then Sunday it cracked the front housing pulling out into the street partial throttle in 2nd.

Haven't taken it apart to see what went wrong. It was full to the top with 110 as I had been running 110 and refilling all weekend.
Old 11-02-14 | 06:17 PM
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The EFR 7670 basically added a gear I could use on the short kart track if I wanted.

On the front straight I could shift 2nd, 3rd, 4th if I wanted and it ran the same time if I wound out 3rd to redline. On the short back straight I could shift 2nd to 3rd or let it wind out 2nd.

It is easy to let it rev out a gear as the torque is dropping so it doesn't get hairy.

Shifting early at 6,000rpm or so feels great as it puts you back in the meat of the torque, but then you have to add the time needed to downshift.

Basically, I found the EFR 7670 made the car fast no matter how you drove it- very accessible power band and quick into boost as well as recovery.

You can make "mistakes" on your shifting and not be penalized or if sections of the track dictate when you are able to shift you won't pay a penalty in power delivery in other sections.
Old 11-02-14 | 07:25 PM
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Here is a vid of a practice session on the kart track. I chose an early session as my driving is more entertaining before it gets faster.

https://www.youtube.com/watch?v=JSDd...ature=youtu.be
Old 11-02-14 | 08:15 PM
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Originally Posted by BLUE TII
The EFR 7670 basically added a gear I could use on the short kart track if I wanted.

On the front straight I could shift 2nd, 3rd, 4th if I wanted and it ran the same time if I wound out 3rd to redline. On the short back straight I could shift 2nd to 3rd or let it wind out 2nd.

It is easy to let it rev out a gear as the torque is dropping so it doesn't get hairy.

Shifting early at 6,000rpm or so feels great as it puts you back in the meat of the torque, but then you have to add the time needed to downshift.

Basically, I found the EFR 7670 made the car fast no matter how you drove it- very accessible power band and quick into boost as well as recovery.

You can make "mistakes" on your shifting and not be penalized or if sections of the track dictate when you are able to shift you won't pay a penalty in power delivery in other sections.

this is spot on here. When I ride in speedjunkies car its the exact same thing. wide great power in all gears, easy to drive, and I love how he can take a gear higher and smoothly pull through the corners. That little track would be perfect for this turbo. I couldn't imagine using a large turbo...the bigger turbo's in the thinner air here are worse to spool up. I think the smaller ones are better IMO.



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