Amen brother. it's disgusting the crap the sr and ka wagon riders dish out on the qr. it's like if you have a thread about a spec it just turns into a giant qr flame and then you find yourself having to defend it. o well.. once it's out as long as the sr and ka engines i know there will be just as many options.

 

Just wait... the QR is going to make it's way into the drag scene.. BIG time.. You don't think AEBS designed sleeves for this engine for nothing do you? I'm not saying squat.. but just wait and see... Let's just say that the work we've been doing with this, has gotten some attention.

Travis

 

hey travis,

glad you survived the storm!!

now down to business....exhaust pulse strength has almost no effect on turbo spool time. the only thing that siginificantly changes spool in normal operating conditions is mass flow. exahust pulse strenght has little to no effec ton spool time. how is it that 10.5:1 and 7.5:1 cr engines have the same spool time? becasue exhaust pulse strenght has no effect. your turbo is laggy becaue there just isnt enoguh mass flow trhrough the tubine to extract work out of. so the turbine has to wair for more mass flow (higher rpm) to generate enoguh shaft pwoer to drive the compressor.

nice project tho!!

 

EDIT: AND THE ENTHALPY BEATS ME BY REPLY BY A FEW MINUTES, MAKING ME LOOK LIKE THE CLOWN, HAHA



The number one factor to how fast a turbo spools is mass flow across the turbine wheel. pulses, energy, heat, velocities, all this crap doesn't really matter NEARLY as much as plain and simple mass flow. If all these things mattered, people would simply wrap and coat their exhaust manifold and all these different ' 500 rpm's worth of spool ' would be truths instead of sales pitches. Your ' little faster' won't be detected on the dyno, or on the street.


So what you're telling me is, you spent 4000 dollars on that motor to get it to do all of that, custom intake manifold, custom exhaust manifold, custom all this, let me ask you then.
1) How many hours do you have into this thing?
2) What is your Labor charge per hour? Maybe norlandt or some of your other projects can tell us if you don't want to give it to us.
3) Have you added that to the total cost, because the SR is a bolt together affair that holds power quite nicely.
4) I'm a firm believer that the SR can be built just as strong for MUCH cheaper, and without needing to have any customization done. Show me your costs, so my point can be completely valid.

Big horsepower is no longer my thing, I prefer flat torque curves, efficient turbocharger selection and cam choice, and response tune oriented motor builds these days. However, 661 isn't bad for spraying and boosting the hell out of it. Its a number higher than most, but what ended up failing on it, anyways? I've yet to see the threads rip out of this weak sand cast block the way many people say they do.

 

Mass flow is a big contributing factor... but transient response IS affected by the strength of the exhaust pulse. If it's JUST about mass flow, then how is it that a 1.3 liter rotary motor can spool a gigantic turbo much faster than a 1.3 liter piston engine could? The exhaust pulse coming out of the port on the rotary is much stronger than the exhaust pulse that comes out of a piston engine's exhaust port. Also, merge collectors take advantage of exhaust pulse as well..

We're talking price on the longblock? Right? I mean, I figure everything else, including manifolds, turbo, etc, would be teh same for BOTH engines. The QR bolts into the Sentra, so there's no added cost there. In reality, if you build the same calibur engine, you might spend a grand more on the QR.. that's about it.

You wouldn't see the SR pulling threads at 5 or 600hp.. I'm talking 4 digit power.. Yes, peak power isn't my main focus either... I'm not some 18 year old kid who's looking for a turbo "fix". But, the facts are the facts... The QR is a better design.

My S13 was the prime example of unuseable power.. I honestly didn't know what I was getting myself into when I built it. On the button, the car was uncontrolable. Off the button, it wasn't fun because of the lag. It broke several transmissions, and sheered all of the teeth off of the pinion once.


Travis

 

Doesn't a rotary fire on every rotation? Wouldn't that mean it puts out 2.6L worth of air in the 2 rotations that a normal piston engine needs to cycle?

Again with the pulling threads?? So the SR won't make 1400hp. Does that mean it's a bad motor? Should we all be buying Cobalts with the Ecotec 2.2L because they can make 1500hp?

 

Did I say that it was a bad motor?

I said that it's not better than the QR... which is what the debate is about.

Travis

 

you hit the nail on the head. rotary is a 2.6L , and spools turbos like it.

 

You saying the QR is better is not a fact, it's simply your opinion. What is better is subject to opinion, especially since you have had to do so much custom work , to make this motor produce even low horsepower in the SR world let's see this thing put out "4 digit horsepower" and then maybe we'll give you some credit.

 

So, you're saying that Die cast alluminum isn't better than sand cast? You're saying that 80 cfm more head flow at the same lift isn't better? You're saying that 3 times the oil pump capacity isn't better? You're saying that bed plate design isn't better than main caps? I thought that those things were understood in the industry as being "better"...

And, I'm not qualified to enough to argue with you about exhaust pulse and transient time, in the form of equation. What I DO know.. is that overall RPM where the turbine begins to get going, won't change with the strength of the exhaust pulse.. but, as I was taught, transient time, or the time from which the turbine goes from dead to full tilt, DOES increase with compression ratio increase, or a stronger exhaust pulse at the turbine. So, the RPM that it begins to come on boost, would be virtually the same.. but the turbine speed would ramp up at different rates.

Travis