BLUE TII

iTrader: (9)

djseven It's making 240ish rwtq at 3500 rpms. This is phenomenal no matter how you dissect on a turbo that is capable of 600rwhp.


I agree. If I had to choose a ~550hp single turbo EFR 9180 might be the one.

I just always look at a chart at 3,000rpm/55mph first to see how much low rpm power the turbo makes and your comparison to a sequential twin FD was off the mark.

If it was made in jest along with the NA 20B comment I apologize for the argument it sparked, but not for correcting your statement with a factual post.

EFR turbos don't need hype as their great results (as shown above) speak for themselves.

*I know, ironic as reading my posts it really seems like I am hyping them constantly. I swear, I am just stocked on the EFR results on rotaries.*

djseven

iTrader: (56)

t-von

iTrader: (8)

There you go being delusional again. Not everyone measures performance based on illegal street racing. It's also funny how you're the one that introduces this comparison to the thread, yet you expect someone like myself who actually owns a NA 20b to no respond? Since you have ZERO experience behind the wheel of a NA 20b allow me to share another forum members off boost experience.

In response to Gordons post on another thread, Monsterbox said this:
Monsterbox was obviously joking about not needing a turbo. I personally then commented

Monsterbox then relied:
Lasty what you keep refering to low end is actually the mid range. Low range is off idle-3000. Mid range is 3,000-6,000. Top end is 6,000-9,000. Below 3,000 that engine make less torque than a 20b. Those are the facts.

BLUE TII

iTrader: (9)

Yeah, the reliability and tip in torque response off the apex from the NA 3 rotor is what has me dreaming of that build.

I look at dyno charts of NA 20B cars though and I keep thinking "will I really be happy with half the torque?"

I think I need to just keep racing my 108rwhp 4 speed auto RX-8 until I forget about torque and then build an NA race engine.

Its like driving a V8 race car versus looking at the dyno chart of one.

You think OMG this thing must spin tires like crazy with all that torque and then when you drive it on slicks you realize the engine revs up so slowly in the real world it can barely spin the tires faster than it accelerates the car in the lower gears. Definitely not a bad thing, just weird.

rx7 SE

iTrader: (5)

Wait, what?

t-von

iTrader: (8)

A turbo 13b will always make more torque in the mid to upper range vs a Na 20b however, it's that tip in response the instant your foot touches the accelerator that tells you something special is going on with the engine. Some things you have to feel and simply just can't put numbers on.

djseven

iTrader: (56)

....and that is exactly why I'll never understand why I even acknowledge your posts. You got me though, from 1000-2500rpms the NA 3 rotor is marginally faster than a stock twin FD.

I'm done with Tvon. Great to see someone post numbers and post final proof that the entire EFR line is truly ground breaking on a 13b. Nice work.

rx7jocke

and thats when you put the efr on a 20b.....dyno comin this summer :-)

rx7 SE

iTrader: (5)

I think I know what you're getting at. The ITB's on the s54 in my e46 m3 gave a very direct feeling to the car, something that a turbo interferes with. I would imagine an N/A 3 rotor would be something like that but even better.

I think you would agree that outright performance would go to an efr 13b, but the subjective feel is in favor of the 3 rotor. Would be nice to have both as weekend warriors.

j9fd3s

iTrader: (3)

we could put numbers on it, although its not as simple as a dyno chart.

t-von

iTrader: (8)

I think everyone should get the chance to experience what it feels like. It's hard to put in words but having an engine that immediately responds to throttle inputs is something special.



I completely agree about the efr 13b. It took what 20+ years for a really nice single series to finally come out and make a 13b less of a dog down low. Bottom line is it all comes down to preference. There's a reason some prefer a NA Porsche Gt3 over a 911 turbo. The Gt3 is designed to give more of a direct/more purist feel than the 911 all because of it's NA engine. It's not always about the hp as some try to make it out to be.

t-von

iTrader: (8)

Very true. As for me, I'm perfectly satisfied with driving around town and not having to rev over 3,000 all the time to get the car moving. Most just don't understand that there's more than enough low end to just motor around without the car feeling sluggish. Efr9180 on a 20b is what I really wanna see.

thewird

iTrader: (8)

The pulls were to 8,500 RPM where the rev limiter would hit. Peak torque was around 7,000 RPM. There is a chance the tires were spinning as Moe's car only had 235 tires and I had to strap the car with short straps just to pull the car down to grip and lower the tire pressure.

The engine is a custom half-bridge I experimented with. The dip down low was pretty consistent from low boost to high boost through the whole tuning session and I take it as a cause from the port and not the turbo at all. I think with a more torque focused port, even if its a bridge would have a much flatter torque curve and more bottom-end but that wasn't the focus in this build. On the highway, the turbo hits 10 psi easily at 3,000 RPM pretty instantaneously. Here is a video of one of the pulls...


I put the dyno graph in speed mode because for that particular pull the dyno lost the tach signal for a little bit which you can see so with speed mode you can at least still see the HP completely. The pulls did start at roughly 3,000 RPM in 4th gear and I more or less punched it and pushed the log button on the dyno at the same time. For comparison this is a dyno from last year on an old school Garrett T04Z turbo with a very torque focused large streetport...



As for the people who keep saying n/a is better for response, they just don't understand a proper efficient turbo setup. It's basically RX-8's all over again, yah they're peppy and feel awesome coming into throttle but then you continue to put your foot down and.... nothing... thats all you get lol. And if you really care about that 1/8 throttle tip-in response, all you have to do is build a high compression engine and keep the boost under 14 PSI and your fine without AI (with proper tuning). It would make the turbo spool even faster, naturally make more power at less boost, and if you can get power hungry you can always run injection or switch to E85. People are too closed minded, they can only see one way of building an engine/car when there is a million ways to skin a cat and get the results you want. Some people like n/a, others like turbos. I'm a tuner, I like turbos so I'm biased

thewird

t-von

iTrader: (8)

Seriously lets not try to assume you know peoples build intentions ok. At heart I'm still a turbo guy (always have, always will be). I'm a DIY extremists. I went NA with my 3 rotor swap because I had zero buiding/modifying experience with turbos and felt going NA was the safest way to really learn what's going on with the engine and be my own turner. You have to understand that when you've mastered buiding an NA setup, learing to maximize the power delivery increases your overall knowledge level. You simply just can't turn up the boost to make more power. Along this NA journey, I've learned more than I thought I ever could. Now that I'm close to mastering that knowledge, I'm updating myself on the latest turbo goodness as I will be putting one on in a couple years. You see turbo charging my 20b has always been my intention. So as you can see, this is my way of skining that cat.

thewird

iTrader: (8)

Turbo porting and N/A porting is not the same on a rotary. What could be highly optimized and efficient on an N/A may not be ideal with a turbo. As for tuning N/A, yes its ridiculously easy, 25/15 degrees of timing with 13 AFR is your tune from 3k and up WOT, maybe add a degree or 2 of timing at 7k RPM if your ports are small.

I think a 9180 EFR 1.45 would be a deadly on a 20b response wise and still make 700+ rwhp. I considered it for a while but I've already told myself who am I kidding. I'm not going to be happy with 700 rwhp anymore and am aiming for 800-900 rwhp at this point in time in the next iteration of my build.

thewird

t-von

iTrader: (8)

Your absolutely right but I was more or less getting at mastering intake runner length design. Tuning an NA may be easy but, buidling your setup to maximise the torque curve though out the entire rpm range is what's very difficult with NA.That can't be done with the factory intake manifolds. Build for top end, you typically lose low end. Build for low end, you lose top end. I'm trying to build for both and that's why my 20b doesn't use the factory oem intakes. My engine is a 9 port with full size pp's and has shutter valves in the intake I built.


Not happy with 700whp????? I don't know how you guys do it. The 500whp 20b I rode in back in 2004 scared the hell out of me. Lol!

j9fd3s

iTrader: (3)

i have done a bunch of turbo cars, some with tunable ecu's. i built a PP engine a few years ago, and i'm really glad i did. i learned a LOT about tuning. the PP engine is really vocal about what it wants, as far as fuel and timing are concerned. it really made me tune it.

just because it doesn't have a turbo, doesn't mean it can't be a worthwhile experience.

rx7srbad

THIS

thewird

iTrader: (8)

You get used to the power pretty quick when its primary use is a track car with slicks. On the street yah its pretty pointless with normal tires. I remember taking a buddy for a rip and half-throttled it to about 200 km/h, figuring at that speed there should be grip in 4th gear stepped on it fully and the back-end kicked sideways at that speed... So yah pretty silly on the street, on the track its more "civilized".

thewird

Slowx7

does anyone know the actually highest number the 9180 set up has made? I poured through a few of the pages haven't seen anything concrete except that video

thewird

iTrader: (8)

Here's a car I tuned a couple of weeks ago, 17 psi on pump gas... I didn't build the engine, only put it in and did the turbo install and whatnot so don't know about internals other then its an rew with some kind of not too big streetport.





thewird

ZoomZoom

iTrader: (2)

Now you understand what all the LS swap guys are talking about. The linear power is much easier to anticipate and is easier to drive near the limit. All the trash talk about swaps around here you would think they are bad things. Only bad thing about them is they are home made and lack refinement. If an OEM made an FD3S with an LS3/LS7 it would probably be the best car ever made by nearly every metric.

Of course that's my opinion....

KNONFS

iTrader: (14)

How does the boost pattern looks like in this dyno chart? I am guessing that boost is not rock solid across the board?

thewird

iTrader: (8)

Boost is flat, its being controlled by twin 38mm Tial wastegates.

thewird

KNONFS

iTrader: (14)

Thanks for the info! Was asking because of the hp/tq drop off around 7k rpms.