Jump to content
SAU Community

Recommended Posts

EDIT: I just re-read what you wrote and you said "possibly", so I don't think they actually do :) You got me really excited then because that was one thing I didn't know about.

Yeah my bad they don't, however a few high end audis do have them on their V8 engines

  • Replies 250
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

Horses for courses. All the points made were moot about silly engine configurations and all that crap. Different racing styles/cars/sports require different torque/power/rpm setups.

Unfortunately there is no such thing as the perfect engine. So you just have to use what you have and try to make it the best you can in the real world. If you know much about racing, the kind that people on our level do, you aim for torque, not peak horsepower, especially in turbo cars like we all drive/race. In circuit stuff generally the guy with the most usuable average power does the best. Then its different for drag racing and so on.

But to the real point of this topic, E-wangs would be my response! People like to have big HP figures for the sake of E-wang comparisons. :)

PS.. variable length intake runners :) ??

I am pretty sure there were three versions of the heads on the CA18DET all with different runner design. I think most Aussie models have the two runners per cylinder heads and manifolds while I think the poms got the big port single runner CA's. I think there was also a version with three runners per cylinder.

Another example is the 3RZ-FE in my HiLux which has two runners per cylinder.

One runner will be longer and thinner internally to maintain/increase flow velocity, while the other runner will be short and fat for minimal restriction at high RPM.

Take notice of all engines you view and you will be surprised at how long this idea has been in use and how many makes and models use this.

Edit: Also have a look at the manifold on the Toyota 1G-GE/GEU/GTE/GZE, just to mention another.

Edited by RBceffy25

With all due respect to everyone in this thread, what is wrong with wanting a shit load of hp?

Some ppl like to go fast around a race circuit.

Some ppl like to go fast in a straight line.

Some ppl like to go fast sideways.

Some ppl like to go fast in circles.

Others like to make a lot of hp and have not much care for going fast around corners. What is wrong with that? They are no less of a fanatic than you or I. Why is it E-wang or Dyno queen when referring to these ppl? Each person gets something different out of their car. Who are we to judge how they enjoy it?

At any rate, who cares about hp or torque just enjoy your damn car!!

There isnt anything wrong with having alot of horsepower. However this whole topic has become about peoples opinions on the matter and it is a public forum....

Eitherway, its all good. :P

It is still interesting to discuss it.

absolutely

There isnt anything wrong with having alot of horsepower. However this whole topic has become about peoples opinions on the matter and it is a public forum....

Eitherway, its all good. :P

Yeah man, I'm just saying coz I hear it too often. I think the point I was trying to make was that it doesn't matter about hp or torque....at the end of the day if you enjoy how the car feels to you, then the number it makes on paper doesn't mean anything.

As for racing etc, yes it is more important to have the right setup for whatever event you take part in but for the general consumer I think the most important thing is how it feels to drive

Rolls pretty much hit the nail on the head with this arguement, i think alot of people dont understand the fact that if you had a car that can rev twice as much as another car, and had the first cars torque curve stretched over its rpm, that the second car could be geared (2:1 reduction ratio) so it had twice the torque at the wheels than the first car, also note that with its new gearing.. what hasnt changed versus its rpm?? its power output.

Both curves are pretty closely related and can both be used to interept a cars performance. All the people that are aiming for flat torque curves are still aiming for maximum average power, just looking at it from a different, less descriptive perspective, as the power curve displays the rate of work being done to move your car forward, ie your torque curve can start dropping off long before your power curve and long before its time to change to the next gear.

I am pretty sure there were three versions of the heads on the CA18DET all with different runner design. I think most Aussie models have the two runners per cylinder heads and manifolds while I think the poms got the big port single runner CA's. I think there was also a version with three runners per cylinder.

Another example is the 3RZ-FE in my HiLux which has two runners per cylinder.

One runner will be longer and thinner internally to maintain/increase flow velocity, while the other runner will be short and fat for minimal restriction at high RPM.

Take notice of all engines you view and you will be surprised at how long this idea has been in use and how many makes and models use this.

Edit: Also have a look at the manifold on the Toyota 1G-GE/GEU/GTE/GZE, just to mention another.

Theres a bit of a difference between engines with multiple runners per port, which are designed to keep velocity up whilst still maintaining flow, and those with variable length runners.

You will find that in a boosted application, variable intake runners are usually not bothered with, as the forced air stops the resonance and harmonics that you get in a N/A application. There is some pretty cool physics involved!

With regards to the other discussion, you can make extra torque by gearing, but not extra power :P

With regards to the other discussion, you can make extra torque by gearing, but not extra power :thumbsup:

so lower diff gears for eg, would show as extra torque on a dyno graph??

so lower diff gears for eg, would show as extra torque on a dyno graph??

Total tractive effort at the wheels yes, but an engine dyno shows corrected and calculated engine torque so that won't change. This is why you see diesel engines with really short gearing or 20 gears as you can make up for lack of torque by gearing, and they need all the tractive torque possible with their heavy loads, as mentioned you can't make up lack of power though. As always trying to picture this and understand what is going on is really complicated and confusing, took me a year or so to get my head around it.

Great article about it here http://autospeed.com/cms/title_Power-versu...48/article.html

Edited by Rolls

so because dynos are really only showing tractive effort and there alot of variables here making these figures somewhat misleading..Would probably explain why people are mainly hung up on power figures, cause few wheel dynos can actually give acurate readings..and even fewer people actually get their engine dynoed...

I used to have a v8 commy, my mate had a n/a13b mazda, driving in either of these you soon learn the difference between power and torque...well so i thought .. :thumbsup:

Edited by Arthur T3
As always trying to picture this and understand what is going on is really complicated and confusing, took me a year or so to get my head around it.

Hahah Yeah, its a pain in the neck :thumbsup:

To add to the discussion a bit of a comparison. Obvisouly only torque is multiplied with the speed reduction so wheel power = engine power - drivetrain losses (but not considered here).

power 400 kW

wheel speed 1000 rpm

engine speed 6000 rpm

engine torque 637 Nm

wheel torque 3820 Nm

power 300 kW

wheel speed 1000 rpm

engine speed 4500 rpm

engine torque 637 Nm

wheel torque 2865 Nm

power 400 kW

wheel speed 1000 rpm

engine speed 4500 rpm

engine torque 849 Nm

wheel torque 3820 Nm

To the people raging over "horsepower sells cars, torque wins races", quit hating on the saying...it's supposed to be ironic, not literal. It's just an old marketing adage poking fun at the very idea that average consumers care more about the big end figures than the more technical, not as widely understood unit actually responsible for delivering results - and ignore the fact that the two are actually related.

Also, what's with people quoting peak torque at low RPM?!? It seems to be the latest craze for marketing material given the swinging popularity towards turbo diesel engines etc. over the past few years. It does not tell a useful story about performance though, particularly with factors like turbo lag. You really need to see the rest of the engine specifications to make it worthwhile. It's about as useful as someone telling you their peak power...neglecting to mention they have a nice laggy T51 bolted on to a small displacement engine!

I'm a bit confused by your last statement? Having peak torque come on early as possible is a great thing and in a petrol engine is harder to do (compared to a diesel) and definetely should be highlighted as a good selling point.

All it says is that torque starts to die off after an early point in the rev range...even if it's not a rapid decline. It can suggest something about what type of engine it might be (low down torque diesel etc.), but the way people use it these days...is as if it's a performance benchmark in the daily driver and sports car...

Hmmm I dont think I really agree; let's discuss :laugh:

Can we use the N54 BMW engine as an example due to it being modern, award winning and something similar to what we own (with it being a 3.0L TT straight 6) and the fact I can relate well to it in this discussion :P

I have the sales brochure here with the BMW engine dyno graph.

Peak torque of 400Nm arrives at 1300rpm (sorry I said 1200rpm in previous posts, it was ment to be 1300rpm) and holds flat of 400Nm until around 5200rpm and then starts to drop off to 280Nm at 7000rpm.

Power is a peak of 225kw at 7000rpm.

Now to me that seems like a shitload of torque throughout the revrange for a turbo car and hence why every one (including my dad that has driven one) says you can bearly feel the turbos coming on and it just feels like a V8 down low, but keeps pulling to 7000 without dropping off like a V8 normally would.

So to me I don't really see why BMW mentioning the low RPM torque figure is a bad thing. Considering most consumers would assume a twin turbo 6 to have lag, mentioning this low down torque makes people go "Oh wow, thats quite a lot at 1300RPM for a turbo engine".

See kind of what I mean?

Edited by PM-R33

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Latest Posts

    • The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1680, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
    • Also, I logged some data from the ECU for each session (mostly oil pressures and various temps, but also speed, revs etc, can't believe I forgot accelerator position). The Ecutek data loads nicely to datazap, I got good data from sessions 2, 3 and 4: https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-2?log=0&data=7 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-3?log=0&data=6 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-4?log=0&data=6 Each session is cut into 3 files but loaded together, you can change between them in the top left. As the test sessions are mostly about the car, not me, I basically start by checking the oil pressure (good, or at least consistent all day). These have an electrically controlled oil pump which targets 25psi(!) at low load and 50 at high. I'm running a much thicker oil than recommended by nissan (they said 0w20, I'm running 10w40) so its a little higher. The main thing is that it doesn't drop too far, eg in the long left hand fish hook, or under brakes so I know I'm not getting oil surge. Good start. Then Oil and Coolant temp, plus intercooler and intake temps, like this: Keeping in mind ambient was about 5o at session 2, I'd say the oil temp is good. The coolant temp as OK but a big worry for hot days (it was getting to 110 back in Feb when it was 35o) so I need to keep addressing that. The water to air intercooler is working totally backwards where we get 5o air in the intake, squish/warm it in the turbos (unknown temp) then run it through the intercoolers which are say 65o max in this case, then the result is 20o air into the engine......the day was too atypical to draw a conclusion on that I think, in the united states of freedom they do a lot of upsizing the intercooler and heat exchanger cores to get those temps down but they were OK this time. The other interesting (but not concerning) part for me was the turbo speed vs boost graph: I circled an example from the main straight. With the tune boost peaks at around 18psi but it deliberately drops to about 14psi at redline because the turbos are tiny - they choke at high revs and just create more heat than power if you run them hard all the way. But you can also see the turbo speed at the same time; it raises from about 180,000rpm to 210,000rpm which the boost falls....imagine the turbine speed if they held 18psi to redline. The wastegates are electrically controlled so there is a heap of logic about boost target, actual boost, delta etc etc but it all seems to work well
    • hahah when youtube subscribers are faster than my updates here. Yes some vid from the day is up, here:  Note that as with all track day videos it is boring watching after the bloopers at the start.  The off was a genuine surprise to me, I've literally done a thousand laps around the place and I've never had instability there; basically it rolled into oversteer, slipped, gripped and spat me out. On the way off I mowed down one of the instructor's cones and it sat there all day looking at me with accusing cone eyes as I drove past. 1:13:20 was my fastest lap, and it was in the second session, 3rd lap.  It (or me!) got slower throughout the day as it got hotter.      
×
×
  • Create New...