Hi all, being the first s2 car I got to grips with Im a big fan of the FZR. Iwas actracted to the GTR cars mostly and I found my love with this one because I like the mid engined setups.

Having looked at all the figures for the GTR class cars, the FZR stands out to be the quickest, and for good reason, I think it should be.

However, Gazing over the engine specs turned up a perculiarity that i just cant ignore anymore.

The 3.6 Litre produces in excess of 500nm of torque. I believe that this is an unrealistic figure. Now I cant seem to find much information about the subject so I'm not sure if this is a reasonable figure but I dont think it is.

You will notice that on the best side of production spec engines, the big guns often cough at anywhere between 100-105nm per litre of displacement.

Fisrtly I make reference to the Australian V8 Supercar series. I've heard (and it appears to be about right) that the 5 Litre NA V8's used in the series produce around 430-440 lb-fts of torque, which equates to around 580nm, boiling down to around 115nm per litre. Pretty racey stuff.

The second reference I make is to the 1998 Mecredes Benz CLK GTR car which runs a massive 6.9 Litre V12 and Produces around 770nm of torque which rounds down to an easy 111nm per litre of torque.

Now I cant seem to find much info about the subject but from my quick browsings, the 3.6Litre FZR shouldnt be producing anymore then 440nm (120nm/litre x3.65Litre displacement). 500 odd nm seems definately out of the question, thus making the FZR too quick a car. As for the FXR and XRR, well they are turbo so no argument can stand without knowing the boost pressure.

Scawen, was your aim to model the FZR's engine as if it was supercharged? If its just a "tie over" until superchargers are introduced then ok, otherwise I think it needs some rectification. We really needs that supercharger for next patch

Well, these cars are produced and designed by SEV, the motors are made by SEV and the drivetrains are too. They are just that perfectly engineered, they can even make an 2.0L 4 cylinder engine with 490 bhp and 600something Nm torque.

Look here...

http://www11.porsche.com/uk/mo ... ities-pmsc/technic-intro/
http://www11.porsche.com/uk/mo ... t-technic/technic-engine/

I know it shows no more than 405nm, but it's perfectly possible without forced induction

Quote from ajp71 :

Look here...

http://www11.porsche.com/uk/mo ... ities-pmsc/technic-intro/
http://www11.porsche.com/uk/mo ... t-technic/technic-engine/

I know it shows no more than 405nm, but it's perfectly possible without forced induction

What's your point? Sketchy already said that the FZR could probably put out 440Nm in real life.

Quote from ajp71 :

Look here...

http://www11.porsche.com/uk/mo ... ities-pmsc/technic-intro/
http://www11.porsche.com/uk/mo ... t-technic/technic-engine/

I know it shows no more than 405nm, but it's perfectly possible without forced induction

FZ50 GTR, 3.6 litre flat 6, 503Nm torque @ 5267 rpm
Porsche GT3 RSR, 3.6 litre flat 6, 405Nm torgue @ 7200 rpm

What's wrong in this picture?

Yeah, it might be a bit torquey. An extra ~14% torque isn't a massive issue but it could help balance the field out a bit more. We know the LFS engine simulation is to be improved, I suspect this would be one improvement. The famous quote "there is no substitute for capacity" was talking about torque, not power.

since the FZR is a race prepped car u shouldn't compare the engine to a standard one.

send that bog standard GT3 to a famous engine tuner (guys who prep engines for le mans ; 24hr spa ; ALMS ; ...) and have a look at its torque figure then

The Porsche GT3 Cup car is pretty comparible to the GTR cars in LFS. It's a purpose built race car with a stripped interior, rear wing, roll cage, etc. Very similar to the LFS cars.

http://www.rsportscars.com/eng/cars/911_gt3cup.asp


The FZ has more torque and more horsepower. The torque even comes in over 1000 RPM lower in the powerband. It has more horsepower, but needs an extra 800 RPM to get there. It also weighs 100lbs less.

I'm sure the FZ is modeled after a real world car, but the question is which one?

The engine of the 911 GT3 RSR is a race engine, not the stock engine in other 911s. It is based off of the engine from the 911 GT1 from 1998 I believe. Basically the 911 GT3 for road use exists for homologation purposes (as in sports car series (lower than prototypes) you can't race a car that doesn't exist for sale on the road). It's not the same engine as the 911 Carrera.
So basically the GT3 IS a race prepared car and can be directly compared to the FZ50 GTR in terms of power.

i know it isnt a standard carrera engine,
but i also dont think the top teams using these engines use it as is..they send them to a highly specialized tuner who gives the engine a good tickle. intake,exhaust,ecu,internals and so forth.


This is not just a cup car (standard as built by porsche) but a heavily tuned version of it as used in top GT races.


Thats my take on it anyways

The GT3 Cup can't be tuned. It's sold as is and used as is in series like the Supercup.

As for the GT series, I tend to believe that teams like Alex Job Racing tune the cars themselves rather than sending them to 3rd party tuners.......
http://www.alexjobracing.com/

That's a bit O/T in the discussion tho. So to get back to the point: I do believe the figures of the FZR are unrealistic. Since we cannot tune the engines in LFS, it would just sound logical to me that the "stock" specs of racing engines would be used.In fact it's not really the max torque output that bothers me but the RPM at which it is available from a NA engine. It would look more realistic and then since the 2 other GTR cars currently present are turbos it wouldn't be that hard to match them rather than match the turbos to an unrealistic NA.

Quote from Bob Smith :

The famous quote "there is no substitute for capacity" was talking about torque, not power.

Absolutely right, As torque is the direct force that an engine produces at the flywheel, where as horsepower is a measure of efficiency at "applying" that torque as RPM rises, which is, for the moment at least an area where some of the S2 simulation aspects (regarding engine specifications) are a bit slack, almost as if the figures were a bit of a rush job to get S2 balanced. Now I'm not complaining about that, but it is something that I would like to think scawen has some awareness of and will pay some attention to within the beta process of S2.

Quote from Noccy :

since the FZR is a race prepped car u shouldn't compare the engine to a standard one.

send that bog standard GT3 to a famous engine tuner (guys who prep engines for le mans ; 24hr spa ; ALMS ; ...) and have a look at its torque figure then

Being that the GT3 RSR uses an already race prepped engine, the figures should be atleast comparable, which IMO they aren't anywhere near.

Now I dont have any knowledge in the area of FIA regulations regarding engine tuning, nor any "real" knowledge or experience in engine tuning, but we need to consider the fact that since horsepower is a measure of efficiency in applying torque, its very possible to increase. Using lighter and stronger parts with advanced ignition timing and good tuning, increasing engine horsepower is an almost easy task (atleast with production engines). In many cases its simply a matter of building an engine that can acheive and sustain a higher RPM and adjusting timing (ignition, camshaft/valve timing) so that the engine can continue to rev harder for longer.

Torque production is an entirely different matter, as it is the measure of power that the combustion cycle creates and turns into a revolving force, "efficiency" plays a far smaller role in producing maximum force. There is only so far you can go, and it has been shown that the FZR exceeds what is really possible with todays tech without using special fuel additives (legality in some regulations?) or something along the lines of methanol or nitrous oxide.

So you could send that RSR engine along to an engine tuning specialist and he could (provided he didnt have to stick to any tuning regulations) improve the horsepower by a sizeable amount. I wouldnt say that a 50% increase in horsepower is impossible, but providing the same combustion fuel was used a 50% increase in torque most definately would be

Quote from Nick_ll :

In fact it's not really the max torque output that bothers me but the RPM at which it is available from a NA engine.

This is another very valid point and is another aspect where the engine specs need some more polishing. The powerband seems far too even and flat for such a highly tuned engine. Being one who used to play around with LFS tweak and minimekanic alot, I quite enjoyed modelling engines and seeing what figures I could come up with in game and how they would translate to on road perofrmance. Playing around with powerbandwidth and RPM settings allowed you to make "almost" anything in the real world. For anyone familiar with LFSTweak Pro, apart from minor changes to these values, the GTR class cars and engines (FO8 not so much) look like they have just had the "engine power" value increased, effectively having the equivalent of increasing the compression ratio of then engine. Buts its obvious that the compression ratio for these cars is just set unrealistically.

It all boils down to what are balanced cars to drive around the track (providing some great competition), but its not upto SIM standards, or should I say the standards that LFS is moving towards (it really is a fantastic sim).

Basically, being forced induction, the turbo cars are more often then not going to kick the NA motors in the pants when it comes to torque/weight ratio. Where the NA car would shine is it abilty to rev hard and just keep on ticking. In other words, a remodelled FZR needs to be placed among competition where its horsepower and abilty to be in its power curve is what keeps the car up to pace.

Shame it aint a diesel, would but out a heck of a lot more than 500nm!!!!, my roadcar puts over 350nm out through the front wheels .

Dan.

yeah those deisels really know how to talk, but can they walk the walk?

Quote from Sketchy :

yeah those deisels really know how to talk, but can they walk the walk?

On the road they can , not so much on the track yet, a local racing team entered one in Le Mans 24 the year previous, nearly 1000nm of torque, didnt last the race though......, but give it a few more years...

Ok, sorry for the tangent

Dan.

Actually to see where diesel engines are really at you only have to look at a few of the sportier production variants and have a look at there figures.

Manufactureers these days can get 100kw plus out of 2.0L Non turbo diesels... or so I thought, I cant remember the car model, but I swear I read it in a magazine and couldn't keep my eye of the fact it was a non turbo diesel.

Maybe time for LFS to include a diesel car?......

Dan.

Yeah... right...

At least not before they include an 8 Litre 16 cylinder with quad turbos... haha oooh yeah :eclipseeh

Quote from Sketchy :

Actually to see where diesel engines are really at you only have to look at a few of the sportier production variants and have a look at there figures.

Manufactureers these days can get 100kw plus out of 2.0L Non turbo diesels... or so I thought, I cant remember the car model, but I swear I read it in a magazine and couldn't keep my eye of the fact it was a non turbo diesel.

That must be some kind non production test car, since VW Golf 2 litre Turbo Diesel (the most powerfull version) only produces 103kW. Golf may not be the most highly tuned off the turbo diesel cars out there, but 150kW from 2.0 non-turbo diesel engine sounds unbelievable.

And anyway I have the impression that Diesel engine without a turbo is pretty much useless anyway.

Quote from geeman1 :

And anyway I have the impression that Diesel engine without a turbo is pretty much useless anyway.

It is, diesel engines have big, big breathing troubles, which is why they MUST have forced induction.

Dan.

I don't see the problem with the fzr engine giving 503Nm torque, afterall I'm sure with the correct engine design and tuning it would be posible to get 503Nm from a 3.6 litre flat 6. Boxer (flat) engines are almost devoid of vibration which means it doesn't need any balance shafts or crankshaft counterweights. The only thing they need depending on the engine is a larger flywheel to counter some rather large torsional (twisting) forces out which is why some boxer engines seem to be slower to build revs than you'd expect.

I think lfs has got the fxr just about right, what I'd like to see though with the fxr is a sequential turbo, where you have a small turbo running at boost all the time, and a larger one cut in at about the point the current one does, this single change would make such a difference would make it much more drivable on the south city tracks and wouldn't hurt on tracks like aston national either.

Indeed I think the rules at the moment are that 1000 vehicles with the same technical specifications as the race cars are based on have to be made / sold before they can race. So the cars can basically be as mad as the manufacturers want they just have to be road legal and it's easy to fill a waiting list with 1000 names for any new fast, exclusive, expensive road car.

rant over.

Quote from Sketchy :

Yeah... right...

At least not before they include an 8 Litre 16 cylinder with quad turbos... haha oooh yeah :eclipseeh

noboddy wpuld eer make such a car... <img>

The FZR is still perfectly possible IMO. You could change the torque and powerbands with ease when you are race modifying a car. People should understand the difference between:

A production engine (S1) - tuned or not whats basically road engine is never going to be producing anywhere near the peak power the engine could get as it's not setup for heavy track use.

A race tuned production engine (UFR, XFR, FOX, GTRs) - taking a production engine and striping it down. In some cases you keep just the block. Depending on series regulations, budget and the time the engine must last they'll often be dry sumped and have everything removed you don't actually need including alternators and so on. In club racing many injection engines are actually raced on carbs because that's what there allowed. These engines are often limited by ECU mapping, intake sizes and so on. Despite appearing low power these engines are very highly stressed to get the maximum power out of whatever limits they are given. A lot can be changed in cam profiles, look at the Chevy V8 in the back of F5000/hillclimb cars, very peaky with almost no torque.

Racing engines (FO8) - can be similar to a car using just the production block. Very peaky almost no torque. Not used as often as they used to be as the costs of building a purpose built block are great + production materials are so much better than they used to be + also very expensive to maintain.

Despite it's production block the FZR/911 GT cars will share very little with the racing engine and with a peaky cam can be completely different. My guess is the FZR is a more highly tuned engine with a less peaky cam.

Quote from Jakg :

noboddy wpuld eer make such a car... <img>

I don't know if that was sarcasm or ignorance (it sure wasn't English anyway), but the Bugatti Veyron is such a car.

I'd rather see a 1.5 litre V16...