Production Sports Cars, race the Zed?

[260DET]

"There is Richard, its called Production Sports Cars. There are even two levels of competition, 2F with limited mods and 2B where you can go further. But you still have to use the L series engine and no forced induction.

My old green car was still competitive over a championship in Queensland, and looking at the times of the current Queensland cars, I would be looking at picking up silverware if it hadn't met it's demise.

Only problem is you need deep pockets and a lot of cash to play in a car that is near 50 years old and be up the front. My S14 still owes me less than $15k for all the bits I have laying around and fitted. I just need the time to put it together, which is another couple of years off with my current work situation." Matt Ryeland.

Rather than clutter up the Bathurst thread here is a separate thread for anyone who is interested. In Q it's pretty well a MX5 benefit series so to compete is going to cost but any competition S30 is not cheap now, starting from scratch a Z33 or 34 would be cheaper but no one seems to have got one going well here, sourcing info and parts from the US would be the way to go rather than trying to reinvent the wheel locally. As for the S30 well it seems doable, if you want cheap racing then buy an Excel.

Edited November 23, 2018 by 260DET

[PZG302]

Gavin Clay has a 350 that is built to 2F and he runs pretty well in the Qld series and Greg Quince is/was developing a 370 in 2F spec for enduros, unfortunately he had an incident at the last round at QR and the car looks to be reasonably bent, I don't know any other details than what was up on bookface.

Both cars are very early on in development, but given time will be quicker than the MX5's. If I hadn't of started my build so long ago, I would have jumped onto a 350 for 2F, or the 350 that came up about 2 years after I started my build for 2B.

The MX5's are really only in 2F, there are about three or so in 2B, with a mix of Lotus, Porsche and Ginetta, the occasional Corvette, an R35.

Toyobaru 86's are also starting to come on board in 2F trim, and when the 86 series dies from V8 supertaxis killing it off, there will probably be a few more that turn up in either 2F or further modified to 2B spec.

As I said above, an S30 in 2B spec would still be competitive, but your pockets deep as the newer models are cheaper to strat with for a good base and the support is there in the aftermarket for cheap go fast bits. 

My old green car, before it got bent, with another 50 or so hp would have been up there still. To get that 50hp was a very big wad of fun tickets that I didn't have.

[260DET]

There was that drift spec 370Z for sale for ~$16,000 that I was keen on but too many projects. It had some good US parts on and MCA suspension, it's the engine that costs if you want to go serious racing. The only race 370Z that I know of is Lee Falkners but it's performance at Bathurst was disappointing, Lee relies on locals for his work so I suspect they are not entirely familiar with what makes a good circuit car. In the US fully developed 370's are quite competitive so the potential is there

For the S30 drop 20k on a full race engine, add top spec MCA suspension and off you go. Unfortunately a sound starter S30 will cost what, $20 k, so yeh, not a cheap exercise. But then again a Sc racer will cost too and just end up as Porsche cannon fodder so..........

[Cozza]

I quite liked the 350GT Skylines that we’re up at CB18. They supposively have a lot of interchangeable parts with the 370z, just a little prettier in my view.

they got down into the 2:39’s or thereabouts I think

 

[260DET]

350GT Skylines are a 2+2 aren't they, yes they do look good, not as crunched up as the 370 but more weight and a longer wheelbase.

[260DET]

Did a bit of checking on the 370Z engine, it's fairly highly developed as is for a NA which means that each step results in small gains, in NA form only conrods and forged pistons are required for the bottom end. I'd concentrate on weight stripping and improving grip, the best MCA suspension is a given so aero would be a priority. Current high end sports race cars are reasonably fast in a straight line but it's their grip that gives them their sensational lap times and they are heavy cars by our standards. The only requirement then would be a dry sump system, there are wet sump options available for our standards of grip.

Any thoughts?

[PZG302]

Aero is limited by the rule book. 2F is very limited over what came standard, and no race specials aero from memory. 2B is less restrictive, but wing sizes are small, 400mm chord width, 250mm above the rear boot or hatch lid and only as wide as the body, or a 150mm tall spoiler

Also, you need to decide on the class first, and then read the rule book, read it again, get someone else to read it and then build the car to meet the rule book.

2F, there is some scope for modifications, but not a lot, gearing for example, the diff can only use homologated ratios, so the favoured 4.3 may not be legal for 2F, but is fine for 2B. You have a fair few restrictions on susension location points and what mods you can make to the suspension in 2F, 2B is basically a free for all as long as you run the same type, ie struts for struts, multilink for multilink and so on, plus mounting points can be moved around a bit. 

2B you can go a lot further with modifications, which makes it a lot cheaper to do.

Having looked at drift cars and IPRA cars as a base for a Prod Sports car to replace the old Zed, you will end up throwing away a lot of the work done to comply and fix the car. For 2F, you are better off starting with a road car, for 2B a bare shell to build a car right.

I was taught something when I first started racing many many years ago and it still reigns true today......

"If you want to go tenths faster, spend your money on the engine. If you want to go seconds faster spend your money on suspension."

 

[260DET]

20 hours ago, PZG302 said:

"If you want to go tenths faster, spend your money on the engine. If you want to go seconds faster spend your money on suspension."

Could not agree more yet the engine invariably get's the $ over the suspension. The 280ZX has Murray Coote (MCA) three way adjustable suspension, worth every cent yet I don't know of any S30 that has such a suspension arrangement. Perhaps it's something to do with the fact that engine improvements give immediate results whereas with suspension it has to be tuned and grip levels explored, not nearly so immediate.

 

On the 370Z, it would have to be stripped completely and suitable MoTec engine management installed to handle the VQ37VHR's fancy electronics. The good thing is that the drive train is solid and suitable suspension components are available from SPL in the US. The worst thing about modern cars in general is their anti squat which reduces rear grip and often requires relocation of suspension pick up points to fix. Something in favour of the S30 and something addressed with my Z31 project car, don't know what the situation is with the 370Z.

[Brett240]

On 11/24/2018 at 8:39 AM, 260DET said:

But then again a Sc racer will cost too and just end up as Porsche cannon fodder so..........

group S has loads of Porkers these days, though a well built and driven Zed should see off all but the top handful of them. 

its an enjoyable category for the zeds too as your racing against period relevant cars. very restricted mods helps with costs ( though racing is never cheap ) 

Edited March 13, 2019 by Brett240

[260DET]

Really if you want close racing then Sc is it isn't it, an import 280Z seems like a good place to start what with the prices of S30's here now.

[Brett240]

Yep an import 280Z is exactly where'd I'd start if I were going from scratch 

Edited March 13, 2019 by Brett240

[gav240z]

I'd imagine the fuel injection can work quite well also with a few tweaks, dump the heavy bumpers and it's literally a late 260z body shell anyway (or S31)..Already has the L28 swap done too!

[hmd]

Group S porkers are yesteryear trend much like Sydney and Melbourne house prices.

 

The current weapons of choice in group S is 454 big block Vette or Pantera with Cleveland 351.

 

[gav240z]

I knew C3 Vette's wouldn't stay cheap for long... Grr... I like the Egg Crate grille early 70s look.

 

[gav240z]

Better video.

 

[Brett240]

2 hours ago, gav240z said:

I'd imagine the fuel injection can work quite well also with a few tweaks, dump the heavy bumpers and it's literally a late 260z body shell anyway (or S31)..Already has the L28 swap done too!

yeah its the S30 shell. I think triple webers would still be better than the fuel injection, though thats against the rules anyway. suspect the FI is better than the dual carbies on 240/260s. 

 

[Brett240]

1 hour ago, hmd said:

Group S porkers are yesteryear trend much like Sydney and Melbourne house prices.

 

The current weapons of choice in group S is 454 big block Vette or Pantera with Cleveland 351.

 

speaking of.... 

 

race  5 view from the datto, you can see the advantage the vette's and panteras have on open circuits ( especially over us  ).... Bathurst/PI they have it over the top porsches. I think the porches will still clean up at eastern creek and any smaller track. 

 

 

[hmd]

my qualy lap

 

[gav240z]

1 hour ago, Brett240 said:

yeah its the S30 shell. I think triple webers would still be better than the fuel injection, though thats against the rules anyway. suspect the FI is better than the dual carbies on 240/260s. 

 

I'm guessing you're restricted to the factory ECU? No aftermarket ECU's?

[Brett240]

9 minutes ago, gav240z said:

I'm guessing you're restricted to the factory ECU? No aftermarket ECU's?

yes, Bosch jetronic i think ( someone correct me if im wrong )  which is functional , though the nissan throttle body and intake is not as good as a triple weber setup. 

it still punches out good power, though we are short on most of the 3 litre Porsches, especially at 2.8 litres. the top 4-5 porsches have significantly more grunt, after that its a little more even. 

[OdinZ]

18 hours ago, Brett240 said:

speaking of.... 

 

race  5 view from the datto, you can see the advantage the vette's and panteras have on open circuits ( especially over us  ).... Bathurst/PI they have it over the top porsches. I think the porches will still clean up at eastern creek and any smaller track. 

 

 

Great start! Damn that Porsche was so skiddish.....I assume that is the same one that spun out too

[PZG302]

17 hours ago, Brett240 said:

yes, Bosch jetronic i think ( someone correct me if im wrong )  which is functional , though the nissan throttle body and intake is not as good as a triple weber setup. 

it still punches out good power, though we are short on most of the 3 litre Porsches, especially at 2.8 litres. the top 4-5 porsches have significantly more grunt, after that its a little more even. 

Yes but there are few tweaks that can be done and there are a few different throttle bodies that can be used and also inlet manifolds.

My green car ran a standard jetronic computer for a couple of seasons before changing over to the Haltech F9 when it was the gun computer. The guys that played with mine discovered a way to double pulse the injectors so it thought it was running teh V12 XJS Jag that that computer was also used on. There a few other ways to get more fuel out of the jetronic computer, such as dropping resistors, that I have no idea about, but those smarter than me do.

 

The throttle body I used was from a L20 turbo I believe, all I know is it was a period Datsun throttle body and only a couple of mm shy of the XF throttle body size that was the popular swap back in the day.

The inlet manifold I used was an N47, IIRC, very different in shape the ADM L28 manifolds in the runners and also the overall casting was very different. I have only seen my manifold and one other in my travels, but it still seemed to be a better thing than what could be done within the rules to the standard manifold.

[hmd]

 

it doesn't matter though, James Flett can get plenty power out of these engines.

What we need is more tyre and brake. we run 195/60 tyres whereas the 911 run 225/50 on the rears and the Vette and Pantera even wider tyres.

Edited March 15, 2019 by hmd

[Brett240]

1 hour ago, hmd said:

it doesn't matter though, James Flett can get plenty power out of these engines.

What we need is more tyre and brake. we run 195/60 tyres whereas the 911 run 225/50 on the rears and the Vette and Pantera even wider tyres.

agreed. i blistered a set last weekend. 195/60's are just too small for the speed and weight of an S30. you can watch the vettes and Porkers on all but the slowest two corners just drive away with mid corner grip, we are absolutely maxed out. 

im still in favour of getting rid of the 60 series tyre. 

[260DET]

A start for wider tyres/wheels would be to find proof that somewhere anywhere a dealer fitted wider wheels to a new car that was sold. I don't think that in the past Datsun racers were assertive enough with CAMS.