Best handling RCR

[Big-Foot]

Originally Posted by OC_

All this hypothetical mumbo-jumbo!
Well, I think there is no real way to tell unless someone goes out there and drive it around the same track that an original one did. I can find some lap times on-line from back in the day, but I don’t know if an EXACT comparison is even possible since a lot of the tracks have changed over the years.

But for now; until we can race the old and the new side by side, we can compare specs. I think the most relevant specs to compare would be weight and power. Along with something a little more subjective like, what the car does at the limits.

I’m really interested in how these cars perform on the track; because if I get one, I want it to be a total track car.

Here’s something of interest: a Porsche 917/10 lapped the Nordschleife in 7:31:40 in 1973
While a new Z06 did a 7:42.9

But the tracks have changed over the years and the Z06 had a 2km shorter distance on the modern track…
I think back in 1973, Nurburgring had a full fledged jump…

Not only have the tracks changed but the Tires, brakes and shocks are exponentially better than they were back in the day..

Not sure you would ever get a valid comparison unless you were to get an original and a replica side by side on the same rubber and same brake compounds as well as shocks..

[Keith Hardy]

Drivers! You forgot the Drivers!

The originals had some mighty fine pedallers with grande cojones in the '60's. The best of the best. They must have been worth many seconds a lap....

[Ross Nicol]

Well I'll be bold and say that these replica cars (made up of lots of parts, some sourced many fabricated by hand or machine) are never going to be really fast straight off. Consider my cars evolution it has taken four years of continuous development to get it to handle, go and stop well. Now I'm not an idiot and I can drive ok but you wouldn't believe all the minor & major things that have had to be improved in my car to get it to be race fast.
Here are some examples.
Gearshift upgraded 3 times
gearbox changed ratios not good
Intake manifold upgraded (sticky throttle )
Throttlecable changed from push/pull to pull only
Rear view mirrors shifted to improve rear view
Brake rotors uprated to 2 piece
Brake pads changed to pads with more bite
Spherical bearings in suspension replaced after Teflon fell out
Brake master cylinder for rear changed due to poor initial choice
Front caster altered to lighten steering
Complete realignment of rear suspension to correct problems inc engineering work to complete
And this is only a sample

Now these things are improvements I have made to the car after it took to the track for it's first race.
Fran knows his cars will go through this process too and as none have been finished yet refinements (which have yet to be identified) will have to be made to get it really fast.Of course then we will probably be reading lines like- which car is faster RCR, RF, DRB,CAV etc .
I will be interested to know the all up weight of the RCR GT40 though Fran I guess you'll be hoping it'll be light with that alloy chassis.
Ross

[Gregg]

Originally Posted by ross nicol

Well I'll be bold and say that these replica cars (made up of lots of parts, some sourced many fabricated by hand or machine) are never going to be really fast straight off.
Ross

Ross, I have to disagree with you. I don't see how you can broad stroke all replica's based upon your RF. I've looked over your list, and I don't know how many components you sourced and selected yourself, but I believe what will make the car "fast" is it's original design, not that you continued to put better parts on it. Theoretically, if you started with grade A parts, there would be no need to upgrade later on. All you would have to do is fiddle with the geometry, tires, etc. Typical stuff. Lets take a look at your list.

I believe the following have nothing to do with the design of the car and if better choices were made up front on the initial build the car would have been fast or at least faster out of the box.

gearbox changed ratios not good
Intake manifold upgraded (sticky throttle )
Throttlecable changed from push/pull to pull only
Rear view mirrors shifted to improve rear view
Brake rotors uprated to 2 piece
Brake pads changed to pads with more bite
Spherical bearings in suspension replaced after Teflon fell out
Brake master cylinder for rear changed due to poor initial choice

Unless of course the design limited you from using high quality brake rotors, calipers etc. I know that RCR was using AP brakes and I believe now Wilwoods.

Gearbox and ratios are up to the customer. Can't fault the car because the customer wants to go with an Audi box instead of a zf/porsche.

I don't have to mention the engine or its components for obvious reasons.

I would contribute the following to the manufacturer which would limit the car:

Front caster altered to lighten steering
Complete realignment of rear suspension to correct problems inc engineering work to complete

I am on the fence with this one:

Gearshift upgraded 3 times

I have met both Fran and Robert. Now Robert was a pleasant gentleman, and history has proven him to be a lousy business man, but in my opinion, Fran is infinitely smarter than Robert was or could hope to be. Better looking too. Robert may have edged him out on the accent though. My two cents.

Keep up the racing updates.

[Keith Hardy]

Originally Posted by ross nicol

Gearshift upgraded 3 times
gearbox changed ratios not good
Intake manifold upgraded (sticky throttle )
Throttlecable changed from push/pull to pull only
Rear view mirrors shifted to improve rear view
Brake rotors uprated to 2 piece
Brake pads changed to pads with more bite
Spherical bearings in suspension replaced after Teflon fell out
Brake master cylinder for rear changed due to poor initial choice
Front caster altered to lighten steering
Complete realignment of rear suspension to correct problems inc engineering work to complete
Ross

That sounds like the first hour at '66 Le Mans!

[David Briggs]

There are lots of things to consider in this arena, but major factors are tire and brake capability and the engine rules that the original cars operated under. Very few of our cars have the cap on displacement they had back then and I doubt that many of our cars would run full throttle for 24(or even 12 hours), we also have the advantage of knowing most of the tuning and set up tricks that were not shared when these cars were current technology.
The original cars were very beefy and with todays tire and braking capability the car would have to be even stronger(and heavier), but back then they raced at around 2000-2200 lbs and my CAV is about 2800. Dan Gurney would probably still have the edge!

[Ross Nicol]

I didn't intend for this to become personal because you have to admire anyone who has the intestinal fortitude to take on the manufacture of these cars when so many before them have fallen. describing a car as being fast is a relative thing and many drivers of GT40 Replicas built for the road will of course describe their cars as being fast. In my case fast is a comparison I make when I drive on the track against a competitor in say a GT3 Porsche where he has the race bred vehicle with all the data to have it go fast out of the box. When I can consistently match his time and he is known to me as a good driver I will then say my car is fast.
A lot of handling gremlins will never show up in a car only driven on the street and they don't necessarily make the car unsafe either,but they most likely will hold it back from being fast on the track.The Items I listed comprise a sample only of the alterations I have made to my car to make it track fast.Pulling them apart and analyzing them separately will not prove anything.By the way when your driving fast on the track very small things can affect you.For instance a corner I was taking on saturday was quite tight and add to that a little understeer and I had my hands on the wheel banging on my thighs. Is it because the race seat brings my thighs too close to the wheel? the ratio of the steering? or some other reason.
Anyway to percieve these things prior to driving the car is not possible and in no way a reflection on the cars build quality.I'm looking forward to meeting Fran one day but I dunno if he's better looking than me!!!! I think I'm older than he and that could work against me.
Ross

[Scott Calabro]

It WILL be interesting to see the G TECH DATA from a completed RCR chassis......
S

[Straight 8 Racing]

As part of the process of building my R.F. (#117) we had a computer based analysys done by a young man who has subsequently gone on to work for Williams in the UK. He used a programme called SusProg3D Version 4.76B
It took about 3 days to measure the car and obtain the relevant data to put into the system. The end result is a set of co-ordinates(X,Y,Z) that defines every pick up point on the car. By inputting required roll centers it adjusts the pick up points accordingly. It also plots the theoretical dynamic roll centers as the car moves through its motions. I use the word theoretical as we have not yet turned a wheel but it is getting closer (Or thats what they tell me in the workshop !)

[Fran Hall RCR]

Scott..
to satisfy your insatiable hunger for G tech data ,why not let us know what you achieve with your RCR.......

Ross,Gregg,

I appreciate everything that has been said.
I come from a data acq. background and completely understand the nuances of dialing in a race car.
There is no one thing that will make a racecar faster....."good" testing and "good" development is the only sure fire way....
The other issue is that a car set up as a street car will not make a good race car and visa versa.....end of story....you cannot have a compromised situation.....
Most all race cars would be so nervous on the street that they require intense concentration to keep them in a straight line......ever watch the hands on a Le Mans driver.....they are in there for long stints and they are always on the move.....(no mere mortals there).....

Numbers are for bench racing and the pub/Golf Club.....IMHO

Race results and smiles per mile are far more important....

At the end of the day a measure of how successful a car is can only be quantified by the enjoyment the owner receives in the building/fabricating/showing or driving of his own car.......

[Scott Calabro]

Hi Fran !
I knew you would be lurking in the shadows....you took the bait! Currently I am in the process of my eng/axle build, but don't fret, RCR is very high on the list. When I'm ready you will get a call.

LOL,
S

[Gregg]

Ross, sorry if my post came off personal, it wasn't meant to. My apologies if I offended you. I agree as to what you say regarding handling gremlins and the definition of "fast" as it relates to you. You've set a very high benchmark in the Porsche GT3. I hope you achieve your goal. Going fast down the straights is one thing, going fast around the curve's is another. Based upon the amount of money Porsche has spent on R & D and refining there cars over the decades, I believe all replicas are at a disadvantage, especially out of the box. Now as far as street fast is concerned, I'm waiting for Ron McCall to finish his car and hopefully get a ride in same. Hey Ron, how much longer?
As far as the beauty pageant between you and Fran, well distinguished is a good quality. Just please don't post any pictures of the swim suit portion.

[Ross Nicol]

Absolutely no offence taken by me Gregg, the personal bit I was referring to was your reference to Fran and RL. As you can tell I hate these threads like this one that have silly titles, which is why I used the smiley "flogging the dead horse" after my made up title " which is the fastest car". If I was Fran I would reply all RCR cars handle brilliantly in response to this title.I certainly would not win a beauty contest Gregg and you'll notice I've cleverly disguised my facial lines in my Avatar
Regards Ross

[CliffBeer]

I would tend to agree wholeheartedly with Ross here on the notion that even a well engineered replica car is going to need a whole boat load of testing and modifications to make it fast on the track. True, part of this is modification to evolve the car from settings which are more optimal for street driving. However, in my experience, the bulk of the work is simply to test and prove the basic mechanics all work together in a reliable and predictable fashion, and, measuring settings and comparing outcomes. Ross' experience here is essentially this (I think, hope you agree Ross).

And, ultimately, no matter how well a car is engineered on paper and built (kudos here to Fran's very high quality and well-engineered products), there is going to be a ton of real-world testing and modification necessary to make it perform optimally for street or track. Anyone who has any experience at all with the prototype testing processes performed by porsche, ferrari, etc. knows this painfully well. Unfortunately, for us gt40 fans there isn't a ton of data out there for any one particular variation (gtd, cav, rcr, etc.) although I do note that there is a pretty large contingent of our UK brethren who have dialed in their cars for track use - seems to be a lot of gtd's with a few RFs over on the other side of the pond.

Net, the post-production testing and refining can be a whole lot of fun too!

[Lynn]

Cliff,

What you have just said is true and, not only does it apply from one type/make of car to another, but it also applys to each and every individual car regardless of who makes it.

One need look no further than all of the comments we hear week in and week out from the roundy-round guys on setting up each individual car. Now I know that when these cars are built, side by side, they go to the nth degree to make them identical, yet each car has it own character and must be individually set up and tweaked. They also react diffferently to the same environments of temperature, track condition, etc., etc. And, while they can have similar starting points or trends can be used to point the way between seemingly identical cars, the absolutes are seldom, if ever, the same.

[Ross Nicol]

Ah thank you Cliff and Lynn, the process your describing is exactly what I've been up to for 4 years and been trying to describe probably not very well, in my earlier rambling.I am gob smacked that anyone interested in these type of cars is not aware of the process of track testing and the continuous development of a race car. The English guys have certainly been at it a long time and would have quite a bit of data for their cars no doubt. I would predict a significant lap time difference between any undeveloped car (recently finished) and mine.If you don't believe me enter your car at a track day and try and stay with a Porsche GT3. When you get to the first corner you'll realize what I'm talking about. When you find you're 5 to 10 seconds a lap slower, stand on the start line and time a car after it goes past for the difference between you and he. It's a large distance and that's per lap, so you'll be lapped in just a few laps. That's very depressing when you think you've got a fast car. Of course you can stand and look at your newly completed GT40 Replica, contemplate its pedigree and salivate over it's beautiful and sexy lines, but don't think that it is going to handle well enough to win a race without a lot of development.
Ross

[Jac Mac]

The Bullshit stops when the Flag drops and so far I think Ross has got more bragging rights than most of the other Wannabee's. Hope Ron is not having his Lola Halfshafts sourced from same place as the JH.

Jac Mac