RWD and sensible power figure

[GTRgeoff]

You are kidding yourself. The amount of development Ben has put into his front diff, rear diff & transfer case to get the 495awkw to the ground hasn't happened overnight. He's also the first to admit that with a professional steerer his car has a couple of seconds up its sleeve. Arguably the gtst may be more entertainment value for some but if the fastest way around a track was the gtst then i think Fred Gibson and may have gone that route.

Well it wasn't Nissans flagship performer, and the engine capacity could have been larger but I don't think he had a choice. Remember Longhursts BMW was much lighter and faster on the tighter tracks.

[ferni]

Roy: yeah i would of loved to see you in your car around the track (probably beating me )

[GTRgeoff]

LOL at Gogira. Gotta agree. Troy, go the Rb25 DE with the GTR internals and 2350 (or 2530, bah turbos. leave the stats to others). Should be heaps, but maybe a bit toey for your granny road style.

[Roy]

Arguably the gtst may be more entertainment value for some but if the fastest way around a track was the gtst then i think Fred Gibson may have gone that route.

In racing where you need tyres to hold together for 30 laps there is no arguing about the merits of 4WD, especially permanent 4wd like the Grp A cars, (werent ATTESSA equiped.)

But the first part i agree, i want entertaining but not wasted....B-man, your figure is about what im looking for 320ish but with a 3L bottom end with a smaller housing so it may not have huge top end but would have a very capable midrange top end, almost NA style (Thats why they make BIG wastegates )

edited to fix my lousy typing/spelling

[benjiman74]

Well it wasn't Nissans flagship performer, and the engine capacity could have been larger but I don't think he had a choice. Remember Longhursts BMW was much lighter and faster on the tighter tracks.

Please tell me Nissans flagship performer that met the Group A rules of that era. The gtr obviously did and i assume the gtst would have to. I can not recall a single team racing the gtst in that intenationally recognised category. Sure at half the purchase price it's difficult to go past the value of the gtst but a better performing track car, i don't think so.

EDIT - Roy I apologise for the hijack. I've gone back and read the title to your thread and it specifically questions the amount of power you want to push through RWD so a gtr vs gtst debate is not helping your cause. I simply took umbrage at comments regarding placing Bens donk in a gtst would result in a quicker car. You obviously enjoy the engineering challenge although with respect to budget am i correct in recalling that you've already thrown $40K at this project? I wish you good luck.

[Sydneykid]

Please tell me Nissans flagship performer that met the Group A rules of that era. The gtr obviously did and i assume the gtst would have to. I can not recall a single team racing the gtst in that intenationally recognised category. Sure at half the purchase price you can't go past the value of the gtst but a better performing track car, i don't think so.

I have a heap to say on this but I need to point out to ben that the GTR had a 2.6 litre twin turbo homologated and the GTST had a single turbo 2 litre. Maybe the reason they raced them wasn't the 4wd, it might have been the extra 30% engine capacity. :wassup:

So after getting that one out of the way, let's move on to why I chose a GTST this time...

Roy has seen Ray Hislops Falcon (at Philip Island) it won the Improved Production National Championship. Keep in mind it rained for 50% of the Final race. That car has ~750 bhp from a 6 litre NASCAR based Ford V8 (bottom end) with Glen Setons EL V8 Supercar top end (heads injection, trumperts etc ). It runs on 245/45/17 Yokohama A032R's (the class control tyre) and weighs a good 1600 kgs.

This car proves that it is entirely possible to get ~500 rwkw to the road using a road legal radial tyre, not a racing slick.

I see no reason why a GTST at 1245 kgs (that's what ours weighs) couldn't do the same (or better) as long as it had the same response that the 6 litre V8 does. That's the trick, RESPONSE, it is simply useless having a verticle power band at that sort of power level, you couldn't drive it. It wouldn't be fast for one lap, let alone a 30 minute race. :spew:

Keeping the above in mind, that's why I chose an RB31DET (RB30 botom end with RB26 top end). That's why I picked 650 bhp as the power target. That's why I chose a spec (turbo included) that gives the best average power from 4,000 rpm to 7,500 rpm that I can engineer. That's why the engine will make 325-350 bhp without the turbo. The RB31DET is quite capable of handling 900+ bhp, several have, but the power band would only make the car slower. :thumbdwn:

So Roy, get into it, I need another R32 GTST @ 650 bhp to compare notes with.

[Roy]

You obviously enjoy the engineering challenge although with respect to budget am i correct in recalling that you've already thrown $40K at this project? I wish you good luck.

I like understanding and playing with things, but i hate spending money on it

The figure of 40k wouldnt be wrong, and my car is far from wildly modified, but its not a bad little jigger, and the money has been spent over 4 years of ownership, when things went, bigger and better went in...hence dead engine trying to suss out whats better (it may end up being bigger )... and as the car developed i slowly tried to keep pace with driver ability. :Oops:

So it has decent upgrades in major areas and i hate to throw numbers around that i cant substantiate (2rismo and Bu5ter wont be reading this ) but if i had been able to run around EC and Wakefield with my current setup before the engine expired; i am confident i would have been doing under 1:50s at Eastern and 1:09s at Wakefield....only reason i mention those times is that the 40k spent does mean the car goes well (by my standards) for an unloved 2L RWD

[B-Man]

Hmmm RB30 bottom end - noice :)

me is way jealous - If I had my time again, I do that

But hey - I have heard that the RB25 manual gearboxes aren't really matched (geared) for the power range of the Rb30 - is there any truth in this ??

[benjiman74]

I have a heap to say on this but I need to point out to ben that the GTR had a 2.6 litre twin turbo homologated and the GTST had a single turbo 2 litre.  Maybe the reason they raced them wasn't the 4wd, it might have been the extra 30% engine capacity.   :wassup:  

Good point, in that era the gtst was only 2.0l - for some reason i had rb25 in my head. With respect to the 4wd, on a dry track the difference may be negligible but we have all seen the dominance of the 4wd in the wet. In saying that, one of my favourite highlights from Bathurst was Glen Seton driving his rwd skyline in the wet a couple of years earlier.

You must ask yourself when Nissan sat down and designed a car to dominate the group A touring car class why didn't they go with a 2wd rb26. Obviously they found the attessa to be the consistantly faster combination. Despite its weight disadvantage over its 2wd sibling the runs are on the board and they kept producing and enhancing that system for over 10 years.

I believe that if Roy's car was equipped with the 4wd Attessa this thread wouldn't exist as the "sensible power figure" before the tyres fry wouldn't be an issue.

[Sydneykid]

I believe that if Roy's car was equipped with the 4wd Attessa this thread wouldn't exist as the "sensible power figure" before the tyres fry wouldn't be an issue.

No, he would be asking different questions....

"How many Brembo's does it take to stop 1.6 tones"

"$5,000 for 3 diffs, how many jobs do I have to work to pay for that?"

"Ditto $8,000 for a gearbox?"

"It needs 3 tranmission coolers, do Earls think I am made of money?

"It's understeering, does it need less front anti roll?

Or "more rear anti roll?"

Or "3% less front drive on the Attesa controller?"

Or "8% slower torque transfer?"

Or "has the extra 300 kgs weight in the front destroyed the front tyres already?"

We have 2 GTR's in the race teams and 1 GTST, I can tell you that it costs 4 times as much per season to run the GTR's and 3 times as much to build them in the first place. Then when we go to a new track, it takes twice as long to dial them in.

Why do you think Group A died? Because GTR's kicked everybody's butt? No, because the cost of running them was unaffordable. Nothing's changed ben, ask the guys who run fast GTR's how much it costs?

Maybe I look at it different than you, if I have $30K to spend building a Skyline race car, then a GTST will be faster than a GTR. If I have $150K to spend, then the GTR will be faster. But it won't be 5 times or $120K faster.

Well, that's the way I see it

[Merli]

The money is not an issue, I have just set my own goals, and being the technical type, try to do it better on a lower budget.

You just described the reverse snobbery that Gojira was labelling the GTRs vs GT3s comparison. The exact same thing applies to GTS-t vs. GTR my friend.

Everyone wants to beat a more expensive car with less outlay. It's human nature to try and one-up each other, especially those with bigger shoes

[DoughBoy]

Everyone wants to beat a more expensive car with less outlay. It's human nature to try and one-up each other, especially those with bigger shoes

Is that a challenge? Good thing I've bought a new car that cost under $10K, with the $3K worth of mods I'm going to throw at it let's race!

[Clint32]

good thread Troy, basically you have very similar goals as mine. My 32 will have 550-600hp out of the rb25/26 engine, this power was selected to give the best comprimise of power and respnce, ill see how it goes in a few weeks on the engine dyno then i need to get the rest of the car sorted so i can attack mallala and the drag strip.

But around 300rwkw is all you would wont is a street driven car that gets taken to the track, but if you can go all out on sus/tyres up tp 350 should be drivable i recon.

either way get moving so we can stick it up the GTR owners

[Merli]

Still i need Merli to tell me his GTR is quicker then his GTST

Quicker how?

1/4 mile? 60 foot? Terminal Speed? ET?

A lap around Eastern Creek?

What about Wakefield?

Oran? South circuit? GP Circuit?

What about just out of Turn 2 at EC?

What about around a skidpan?

From 60-100km/h in 4th gear whilst overtaking?

That's quite a loaded question you asked, but I hope that the GTR will be able to surpass the GTS-t in all the above catergories... If not, then more development will have to be done. As SK said, it's a lot harder to setup a GTR as compared to a GTS-t, so you're going to have to give me time to fiddle with things

[Merli]

Is that a challenge? Good thing I've bought a new car that cost under $10K, with the $3K worth of mods I'm going to throw at it let's race!

$3k worth of mods? Is that just for the water-air-IC?

[predator]

There is nothing wrong with buying a cheaper car and having more money to throw at it your way and the things that you would like to do to it..

The GTR is a more complicated system, there is no two ways about it.. which means more things that can go wrong. RWD is cheap, that is why its so popular out there. Hence when I sold my car the goal was simple - a cheap RWD and spending the money where it counts, and that is on the handling and engine.. If I had a lot more money I'd be throwing it at a GTR. That is all its about.. money... Sure I could probably just afford a GTR, but if its going to be sitting there waiting for my next pay cheque to fix it then where is the fun in that.. been there done that

anyhow, this thread has gone to Africa I think in terms of the original question - its back on the GTR vs GTST debate which is a little :zzz:

[Roy]

You must ask yourself when Nissan sat down and designed a car to dominate the group A touring car class why didn't they go with a 2wd rb26. Obviously they found the attessa to be the consistantly faster combination. Despite its weight disadvantage over its 2wd sibling the runs are on the board and they kept producing and enhancing that system for over 10 years.

I believe that if Roy's car was equipped with the 4wd Attessa this thread wouldn't exist as the "sensible power figure" before the tyres fry wouldn't be an issue.

Fair point about the 4wd and this post not existing....but this thread exists because i dont think 320rwkws would be an issue but there are ppl that know more then me saying/thinking the opposite and dont want to learn the hard way

Not slagging off 4wds, but the reasons why im yet to be convinced for the average mug punter wanting to enjoy a day at the track...you need more power in the first place to make up for power losses thru the extra diffs etc etc. Then you have more weight as a result of the 4wd so need more power to have the same power v weight ratio, now the GTR hides this very well unlike cars like the 3000GT, but in the back of my mind thats two issues that concern me before i start.

Then i look at the nature of corners and think in the slow corners where power down of 4wd helps, you first have to wrestle that extra weight under brakes, turn the extra weight then accelerate it albeit with better traction. On the quick stuff 4wd doesnt really help corner speed, it does help chassis balance if the bloke behind the wheel keeps trying to punch holes in the firewall with every throttle application. So again i could very easily be wrong...this is just the excrement from my thoughts whilst trying to sleep at night

But Nissan are not shy about the fact that they built a car to win the Grp A class...hence the R32 GTR. It did not run ATESSA that was road car only, the race cars ran constant 4wd as it gave more predictable handling, though i cant recall the torque split. The JGTCC cars didnt even even run 4WD, neither did one of their more serious attempts a LeMans class win with the GTR, though i cant be sure that the class rules didnt rule out 4wd hence the conversion to RWD of some racing Nissan GTRs.

Does Bens car run a torque split controller?

[Sydneykid]

not shy about the fact that they built a car to win the Grp A class...hence the R32 GTR. It did not run ATESSA that was road car only, the race cars ran constant 4wd as it gave more predictable handling, though i cant recall the torque split. The JGTCC cars didnt even even run 4WD, neither did one of their more serious attempts a LeMans class win with the GTR, though i cant be sure that the class rules didnt rule out 4wd hence the conversion to RWD of some racing Nissan GTRs.

Hi Roy, next time Terry has the ex Gibson R32 GTR out you should come along and have a close look at it. It has hydraulically adjustable 4wd torque splits. Same as ATESSA, but without the computer doing the thinking. The driver just adjust the lever, looks like a second handbrake, but with stops like a stabiliser bar adjuster. From, memory the 4 splits are like;

100% rear drive

5% front drive

10% front drive

30% front drive

Some people get confused with HICAS and ATESSA, the race cars never ran HICAS. But I have seen half a dozedn and they all have 4wd adjusters.

[Roy]

Quicker how?  

1/4 mile? 60 foot? Terminal Speed? ET?

A lap around Eastern Creek?  

What about Wakefield?  

Oran? South circuit? GP Circuit?

What about just out of Turn 2 at EC?  

What about around a skidpan?

LOL...couldnt care less about 1/4 mile, id have a cool 302 Capri if i did, No corner in particular, but all the corners that make up your typical circuit

So Eastern, Oran, Wakefield, Winton, Phillip Island, Sandown... the more tracks i drive on the more im gettitng a feel for what makes a car quick...

You just described the reverse snobbery that Gojira was labelling the GTRs vs GT3s comparison. The exact same thing applies to GTS-t vs. GTR my friend.  

Everyone wants to beat a more expensive car with less outlay. It's human nature to try and one-up each other, especially those with bigger shoes

LOL... yeh of course if you cant do it cheaper then just go buy the real thing first out and go on holidays with the money you saved and enjoy the UK summer Im not trying to one up one anyone, ok maybe Doughboy but his stocka with 3k worth of mods will chop anyone because he is Doughboy

I just want to mod my car, learn a few things along the way and have fun punting it around......if its quicker then other cars then sweet, im modding my car to go quicker so it makes sense that im going quicker then somebody, but my exerperience is that for light level mods the cars you have to be cautious of is S14/15s

Yeh id welcome the opportunity to look closely at any Ex-Grp A racecar. I read (there i go again read...no experience) that it was a fixed split that was changed for certain tracks... so thought it was a centre diff thing, makes sense though it would be adjustable in the cabin for changin conditions mid race and for setting up qualifying...perhaps evern the lunge for the 1st corner

[B-Man]

he he he

Merli is cruisin' for a brusin'.

He's got the confidence of the GTR within himself without trying it out for real he he ....

I hope you are right Andrew - the GTR is a monster ....

But the GTS-t is not too far behind - and with the combined efforts of B-Man, Buster, Doughy, 2Rismo, Sideways, et al you might be just eating your words 4wd boy

he he

Go the GTS-t ! ! !

Cheers,