360C VS 360GT VS 360N-GT (VS GTO-spec)

I'm familiar with the Challenge car but - can someone outline the differences in spec, performance and race format between it and the rest of them etc..... the whole thing is starting to get more than a little confusing.

Thank you

Manu

 

I'm sure the racers here can add to this but essentially:

360C - road car decontented, more or less standard engine. straight thru exhaust. c 400bhp. All F1 gearbox. No spoiler (unlike the 355C)

360GT/N-GT - race car upgrade, much lighter, engine substantially upgraded, but has to run with restrictors. Circa 430 bhp. Difference in GT vs N-GT is just different regs, one runs F1, one runs 6 speed. Spoiler on the read deck.

360GTC - revised version of the 360 GT, now with 445bhp, aero now based on the revised aero from the 360CS road car, new spoiler at the back with a 6 speed sequential gearbox (a true sequential @ 50K for each box, NOT an F1).

GTO spec, not sure about personally. Perhaps someone else can fill in.

Pic of the new GTC w/ spoiler:
Image Unavailable, Please Login

 

Bizarre spoiler the way its mounted to the side fender panels.
How do you open the engine lid?

Given the F1 is a true sequential, I am not sure what this means. I know from other sources that its different, but how is it different???

 

The way I understand it, the F1 is not a sequential gearbox. The electro-hydraulic F1 mechanism actually moves the shift linkage between gears in the H-pattern just the way a human would. A sequential is a simple pull back or push forward to change gears.

Gary

 

Well, just like the paddles, you could easily set up a stick where push forward does what right does and push back does what left does... or vice-versa.

Sooo, if I understand right, the difference is NOT how its actuated by the human, the difference is in how the gears and linkages in the tranny itself are set up. Sooo, I am guessing that, unlike the traditional tranny where you can go from 4 to 2 without engaging 3, the sequential tranny would not have that option. If so, why is that a good thing?? In what way is it better?

 

What are these cars capable of sans restrictors? could they be streetable with these near 500 hp outputs?

 

As I understand it Gary is right, sequential boxes were invented so that it was impossible to go 5-2 instead of 5-4 etc. The advantage in GT over F1 is no electronics or hydraulics to go wrong, and I'm sure it is permissible in N-GT where previously only the 6 speed is.

Just been watching the british GT racing on Speed channel - there was a 360 racing there which looked like a regular 360C (stock wing mirrors and aero kit) but it had a rear wing fitted. Perhaps this is the GTO spec?

 

- ergonomics - location of the shift stick end is always the same - middle
- faster - think about going from 2nd to 3rd forward->right->forward compared to only pull back
- simple - can't mis-shift compared to H pattern

gearbox is operated by a drum that rotates and operates gear selction forks through complex groves - similar to motorcycle

F1 cars also use a drum mechanism - but use electro-hydraulic operation

there are mechanical units that simulate the sequential shift with normal gearboxes - saw one for Porsche

 

The main reason for sequential is speed of shifting.

The F1 system electronically closes the throttle (sometimes partially) on shifts, even though your foot stays down. This is to give time for the synchros to work, and to break the load momentarily so the many dogs can engage. The F1 system takes about 120+ ms to shift on average.

The sequential system has no synchro's, and only 5 or 6 dogs on each gear, so it can be smashed straight into the next gear instantly. The throttle stays wide open and only a brief ignition cut breaks the load. The sequential system takes about 40 ms to shift. Over a lap, that has say 10 gear changes, the advantage is 80ms per shift on average, or 0.8 seconds per lap. It also gives clutch control back to the driver for starting and recovery, but is not used on shifting generally.

The only down side to sequential is the possibility of driver abuse damaging the engine, and it's sensitivity to being set up by the mechanic properly.

The 360 Challenge engine is completely standard to a Modena, only the AC is removed, and thermostat too.

There have been several specs of N-GT engine, running 2x 30.8mm restrictors in FIA spec, they have between 427 and 435 BHP @ 8700rpm. The GTC has more revs and power....445@9000rpm.

The GT engines are surprisingly only slightly modified inside. The only real performance increase coming from new pistons and camshafts. Tiny amounts of port matching (already very good) and oil pressure lowering give fractions of a BHP. They only use 102 RON fuel.

The GT F1 gearboxes are only slightly modified too....with gear ratios and a bit of weight removed from various places. All synchro's are still used and the hydraulics are std.

The GT cars have a wider front track, gained purely from wheel offset.

There are hundreds of other detail changes, far too many to list. I was lucky to spend two weeks working at Michelotto assembling the second of our 5 cars from them.

The biggest difference between the race and challenge/road version is the installation techniques...where proper race theories are used on the GT, and not road style fixtures and fittings.

 

Phil,

Thanks for your wealth of info on these cars. I am not sure if you remember but we were having a discussion about hp on a 360 GT with and without restrictors and I had stated that a mechanic at our local Ferrari dealership (Ferrari of Washington which ran the #33 GT car) told me that without restrictors the GT car could easily make well in excess of 500 hp.

Well you correctly stated that this was inaccurate and after talking with Glen Marquis head of Washington Motorsports he indicated that at most the engine would make closer to 480 so you were indeed correct.

Just wanted to clear that up.

Also, are you all having any involvment or interest in running the new Maserati GT cars that Ferrari of Washington and Risi are running in this months Daytona 24 Hour?

Wondering what your take is on this car. It seems helplessly outclassed and I am wondering why they are racing it.

See my thread in the racing section at:

http://ferrarichat.com/forum/showthread.php?t=5429

Regards,

Jon P. Kofod
www.flatoutracing.net

 

Thanks Jon, I don't usually make up stuff in my posts....not here anyway!

No, the Maserati is not very interesting. We have two Trofeo's in the workshop that have done a few races this year in our Nations Cup Grp 2. They're a little slower than our modified Challenge in std form on Australian tracks. I did a load of work to one to try and find some time, but politics meant it never even tested.

They are both back to standard now and up for sale at Maranello Motorsport.

Just as a note, the wing on them is the exact same one as the 2000 Michelotto 360....like we use on our Challenge cars.

The Trofeo Light is too much slower than the 360 GTC, so It'll only ever do well in a mixed category where it can steal an advantage somehow.

 

How many times do I have to tell you that that's a load of bull???

 

Interesting. I assume you mean 10 upshifts (half the shifts will be up and half down... the time savings on downshifts will have minimal direct impact on laptimes). To be clear, though... even with 10 upshifts, that's 0.8s of acceleration that's lost (but you'll be coasting, not stopped)... which mathematically might mean a few mph at the end of each straight... but somewhere less than 0.1s per lap in laptimes. Your laptimes will not be 0.8s less! (Unless your car halts movement during each shift.)

But in a business where much will be spent to gain 0.1s per lap, there is no doubt that 40ms gear changes will be preferred over 120ms ones!! And that could make a huge difference when trying to complete a pass.

And thanks for all the info in your post... very interesting, indeed.

 

So GT and N-GT are broadly similar - and GTC??? (GTO I believe is a challenge derivative for the British GTO Championship, I *think* so anyway...)

Any more thoughts on the original question?

 

Dearest Aircon.......

As I said earlier, the advantage is 0.8s/lap in my theoretical example, and yes Brian, it is a 0.8 advantage of gained acceleration and not outright lap time.

Interestingly, the (ACO rules) manual H pattern 6 speed 360 N-GT is about 1 second a lap (Donington) quicker than an F1 set up, and the sequential that Veloqx first fitted was about 1.5 seconds a lap quicker again at Donington, that's about 2.5 seconds quicker than F1 at Donington (1.10.00 ish lap). There were a few other minor developments between testings (maybe 1 second, max), but the drivers all communicated the huge gains sequential gave in not only actual time, but racing strategy, lines and new overtaking opportunities.

I can't explain why the sequential equipped cars are even faster than the theory suggests they should be, a combination of higher gained speeds, greater driver feedback and control, less time wasted taking up transmission backlash, and less tyre sidewall load cycles between shifts, lighter gearbox internals.....maybe. Who knows, but the stopwatch doesn't lie either.

 

ha...i knew you'd waste no time commenting after mentioning it to you this afternoon! So what you're saying now is that the 0.8 of a second overall that you save in changing gears amounts to 1.5 seconds a lap? Very interesting. I think we should all go out immediately and install sequential gearboxes into our cars!

 

As Phil is most likely aware of as well, this theory proved correct in the European Touring Car Championship as well. The FIA rules there allow for either...

1) A stnadard H pattern gear shift (factory supplied unit)

OR

2) A sequential gearbox BUT with the addition of 30 pounds ballast

The BMW's chose to use standrd H pattern and the AutoDelta Alfa's tested their cars at the beginning of 2003 with both the H pattern and the sequential with added weight.

The two tracks they performed the tests at (think it was Mugello and Fiorano) proved that even with the added weight the sequential was worth about a second per lap.

Alfa ended up winning the drivers championship. Only perceptible difference between the BMW and the Alfa was front wheel drive vs. rear wheel drive and the different gearboxes.

Regards,

Jon P. Kofod
www.flatoutracing.net

 

That doesn't seem plausible... were the gear ratios different?
I'd be inclined to think those "few other minor developments" had a bit more impact than estimated.

The stopwatch doesn't lie... but given other changes were made, the real cause-and-effect could be very unclear. Think of the time found between F1 qualifying runs with minor little tweaks.

In your list here, I could see greater driver feedback being a bigger win in head-to-head race performance, but not much in testing lap times. Lighter gearbox would be a possibility... is that the purpose of the 30lbs of ballast? Or was that intended to be a penalty for the advantage of the superior tranny? The others in that list may all be real, but they could be (over-)accounted for in the theoretical model by lengthening the gear shift delta a few ms. Even if we double the "coast" time delta, we're still talking less than 1.6s of acceleration, so no way we're getting anywhere close to 1s a lap... maybe a quarter second.


Also interesting is that the 6-speed was a second faster than the F1. Of course, since there were a second or so of other tweaks somewhere in there, that could be easily written off as due to the other tweaks. Its a shame they didn't test that in full isolation... would have been interesting.

 

I'm beginning to speak out of school now, but to help clarify further, Veloqx ran 3 360's, and they were not all at the same level of development at the same time, but they did all run on the same tracks at the same time on a a number of occasions. The drivers had all cross-tested and their relative speed to each other is well recorded....the development estimations I have made are a very well educated guess, and I know personally 3 of the drivers involved (Davies, Simonsen, Lockie).

I stand by my report of findings and estimates, but will admit to being slightly at a loss to fully eexplain where all the bonus time comes from.

Yes Brian, some ratio changes are involved too, but this again is included in my knowledge from the 3 cars overlapping in development.


Aircon....yes, even you would go better with a sequential.....I've booked you in for next week, don't disappoint me by not showing with your deposit for parts..........!!

Now, what about some hi-flow air filters, for the icing on the cake???

Fun over....Manu, the relative performances are very similar in terms of acceeration, The N-GT cars have much better downforce and particuarly front grip, so their cornering forces are up to 2.25G according to our data. A challenge pulls about 1.8, and road tyres give much less.

You'll also go even better without "canvas revealing" flatspots on your tyres.............

 

80ms is 0.08 seconds, not 0.8.

 

errrrrrr kickus, ideal name mate

hows your maths......0.08 multiply by 10 shifts/lap= 0.8/lap

Thanks for reading anyway.