wow...................so what was this thread about again ?

-Ben

 

Then perhaps you'd care to explain why my naturally aspirated 396 LT1 makes 95 more horsepower at 2,000 rpm than Rice Racing's single turbo 13B?

Or perhaps you could explain why his 612 horsepower engine averages only 336 horsepower from 2,000-8,000 rpm, while my 647 horsepower engine averages 466 horsepower over the same range?

Or maybe why his engine averages only 132 horsepower in the band from 2,000-4,500 rpm, while mine averages 299 horsepower...

The answer to all of the above, by the way, is because my engine makes over 400 lb-ft. of torque from 2,000-8,000 rpm. It averages 486 lb-ft. over that range. Rice Racing's 13B only breaks 400 lb-ft. of torque from ~6,000-7,500 rpm, and averages only 316 lb-ft.

If you think that torque is irrelevant, or "a factor, but not the deciding factor", then you've obviously never seen the formula for calculating horsepower.

Horespower = Torque * RPM / 5,252

The reason I'm making 95 more horsepower than Rice Racing at 2,000 rpm is because I'm already making 250 more lb-ft. of torque. Period.

 

Something about someone doing what they wanted to with their own car, and a bunch of narrow-minded, opinionated ******** popping in to tell him that he can't...

 

You said it yourself, power is torque times rpm. Notice there are 2 parts to that equation, torque and rpm. Let me repeat that, torque A-N-D rpm. Torque is a factor but it is not the deciding factor, rpm is also a factor. It is possible to have an engine that produces half the torque but twice the power because it spins 4 times quicker. So it is entirely possible to have a lower torque engine that is quicker.

 

RPM may be the other variable in the equation, but you first dismissed torque as being irrelevant, and then as being relatively unimportant, when in fact it is the only variable that dictates how much horsepower an engine makes at a given rpm. More torque equals more horsepower at any rpm. Period.

 

Didnt read any of this...Just wanted to say...


Stupidest...
Thing...
Ever...




That is all.

 

I'm not sure why you keep pointing out I said torque is irrelevant, I corrected myself on that. All I can think is that you are trying to 'score point' agains me or something.

Torque is relevant but it is not the deciding factor. What is so hard to understand here?

 

All I have to say, is go tnt. It's cool that you're doing something different, and i'm even willing to wager it'll be pretty damn sick when you're done.

 

Awe man come on SR20DET in a FD......

 

Because I've heard the "torque is irrelevant" statement (excuse?) from more than one person who doesn't understand that the peaky, very narrow powerband of the rotary is directly related to the fact that small displacement engines can't produce large amounts of torque. And I've heard the same from another prominent Australian, whose single turbo 13B I used for an example.

Build an engine for torque and horsepower will follow, as the saying goes. An engine with a wider powerband is eminently more driveable, and in many cases, will likely be faster and quicker than one with a very narrow powerband, even if it makes somewhat less power, because the engine with the wider powerband will accelerate for a longer period of time.

Once the smaller engine is in its powerband, and if it can stay there, then yes, it will be very fast. But in order to stay in its powerband, the car must be very light, a very short differential gear is a necessity, and a close ratio transmission as well. A larger displacement engine is far more forgiving of weight and gearing because of increased low end torque. Try a single turbo rotary in a 3,400+ lb. car with a 3.07:1 differential and let me know how it works out.

 

god can we please stop with the ignorant comments about swapping out the 13b GIVE IT UP. christ im so sick of every other comment being"ohhh man u shouldnt do that to an RX7, keep it rotary" or any other sarcastic remarks. leave them alone i personally have more respect for these people for trying to be origional and do something different instead of the same **** everyone else is doing.

 

Can't resist...

Additionally, the lack of tourque in the rotary can be attributed to combustion pressure being applied roughly parallel to the rotational transmission line, as opposed to piston engines having an orthogonal pressure application. Inherantly more torque as the lever arm is twisted more effectively for a given combustion charge against an EXACTLY similar load (i.e. transmission and differential gearing being the same!) The V-8 is nice 'cause it has many more times the mechanical levers twisting the crank. That the rotory is able to produce the power it does is actually rather exceptional when seen in this light. Plus, you can rev the **** out of it with out exotic valvetrain components! The v-8 also has broader application of that torque across the rpm range than the four banger, i.e. less peaky, as was mentioned. I would have gone with a six banger, but the purpose of this swap is partially marketing on the originator's part. It's HIS car. Go buy it from him if you don't like it.

Ha HA! Now the flames can flow and I can get WARM in this damn autumnal wet!

 

The lower torque is due to the 270 degree expansion. Pushing over 270 degrees is like pushing against a gearing.

 

I have an SR20DET from a GTI-R in my 91' Nissan Sentra. :-)

 

Is it me or did that guy have a totally messed up launch?

BTW this thread reminds me of the time I posted a similar topic in the off topic forum. Back then a lot of people didn't approve of my swap-a-SR20DET into an FD idea.

BTW good luck with the project tnt

 

hello i just got an rx7 and wanted to put an sr in it. i was wondering if i could get some help or tips

 

wow....

 

Holy thread revival batman.....lol...

 

yea wow we are now approaching 6 years old on this thread. good job searching tho next time look at the dates from the previous posts and see that they are from 11/02

 

Lol

 

I know how to settle this, let's go to the people designing F1 engines, they'll tell us all how important torque is for the worlds fastest race cars!

Oh ****...
Wait....

F1 Engines make **** for torque, it's all high end power....

Who would've known

 

idk why everyone is bashing this Idea. I was about to do this same thing with my FC. The SR is a great motor a friend of mine lived over in japan and hes owns a RPS13 that he "snuck" over from japan. He bought a S13 hatch that has his dogbox and all his goodies with his blacktop SR. he will be pushing over 475hp on a 20g. nothing wrong with idea at all. I like seeing it is not another V8 swap and will later on have more torque then a rotary. the cost first off is higher then a rotary but parts are by far easier to find and much cheaper in comparison.


good luck with the build and post some pics

 

hey tnt how is your swap going sorry i dont feel like readin a million pages im thinking about doing the same swap just wondering what im getting my self into and picture would be aswome if you had them

 

Can u send me some pics of the swap

 

If u have pics that would help cuz I bought a rx7 fc for $100 its in realy good shape but bad motor. So i want to swap in a ka24de I have laying around from my s14 240sx.