GTA hillclimbmonster

Saying hello overhere!

Sorry for my english skills, i'm still learning....

I'm reading in this Forum since long time, now i think the time has come to give something back, so i'll share my project, hope it will be interesting to one or another.

I found Martin Faulks (he's my holy PRV-engine grail) by this Forum!
(thanks and hello to Lee
I've been talking to him very intense since a year, and we've been talking about all the possible options very detailed.
As we know he knows the history of the PRV, he knows all the differences between older and newer variants, he knows the head castings, what has been optimised over the years, what parts of what variants are best, so exactly the knowhow we need to build a proper race engine. There are a lot of people that like to sale parts, there are also good enginebuilders, but anybody is really experienced in powerfull prv's, Martin does it from his heart and with huge enthusiasm, he explained me every detail until i understood, also background info and beginner questions, no matter how often i re-asked, that's what i've been searching for, because i also have to be able to service the engine by myself after building!

Hmm i stop talking of people that could listen, do you, Martin? If you are here "hello" and thank you very very much!

So we figured out the best option for my hillclimb racer, quickly said it will be a forged bottom end crossbolt-block with 73mm crank but 2.5l liners, very light forged pistons, fully worked heads, twinscroll BB turbo, twin ext. wg, doubleslip headers and...and...going further into very important details later, but it will fly for sure!!!
Challenge is to stay single-turbo just because i love it, never seen a real powerfull one, and i don't want to add any unnecessary weight and complications to the rear end. I will also not set the turbo to the back of the engine.

Something about the car first, yes it's a broad one, but a beautiful one and for racing only, so i think it should be allowed that it looks like that.

I've seen an over 400hp GTA like that on a hillclimb in france and felt in love, so i started working on mine. For first the broad body does weight less then oe, because every part we mounted was replacement of a heavier oe part, fenders etc. lot of non-sight carbonwork and very thin polyester, took me a couple of years of work and money, i'm not gaining loads of money, but i was ready to invest a huge amount of time, don't want to do a budget solution





Next thing i'll post is my experiences about suspension and tyres and show the new brakes. Engine related i'm about to create the manifolds at the moment, will show some pics soon.

Hope that i'm welcome and that others maybe can profit of my experiences.

Cheers
Chris

Hi Chris ,about time you said hello on here
How are things going ? Not heard much of late .

Welcome to the forum. Car looks great, can I ask what wheels they are - not seen them on a GTA before

Now this is what I am talking about! Awesome!

Hi Turbohead, cool looking car you have, well done.

If you are going to hill climb then maybe you should come over to the Prescott "La Vie en Bleu" meeting in 2013 to compete with our plucky Brits, it would be good to see your car over here if they have a suitable class for it to compete in.

Hi Chris

Welcome to the forum from me too, hope you have fun on here and make some good Alpine friends

Thank you for your kind words, they are very much appreciated. It's been a pleasure chatting to you, but remember I talk from my experience, there are many other ways of doing things, and different ideas too.. I never stop learning as well

Hope putting your project up on the forum brings a big smile to you, and enthusiasm to keep going too. It's nice to get some encouragement from like minds and fellow enthusiasts, especially after all the hard work! Well done keep it coming!

Enjoy!
Martin

This looks brilliant, any plans to bring it to the uk for any trackdays/events.

John.

[phildini]

After looking at those pic's I now have a stiffy!!

That looks the absolute mutts nuts mate. Love it.

Waoo that looks amazing...

well done and welcome to the forum

Looks awesome. Good work!

Thank you guys for the compliments, gave me a really broad smile! And thanks for welcoming me!
I was a bit afraid that the oe-keepers will throw my car into the "crap-thread"

Hi Lee yes it was quiet, lot of thinking and theoretical work, but things start coming together now, a kitchen full of parts, and full of enthusiasm to start putting together

Martin, i love to prototype and try out things, and practical experience and loads of theoretical know how is a must, you prove me that you are the man for that engine!
And i have never ever seen a guy that explains me the way you do, without charging money for the time it needs, that's worth more than gold, thanks for having nervs for me! When ever you want to come over you can use the car as yours!

Racing in UK, yes would be great with you guys, but i think lack of time will not allow me the next years. I also don't know about international racing class and laws, the car is built in accordance to the rules to do hillclimbing in swiss for first, groupe E1 formula-free, over 3lit, and i need the NAT. racing licence. E1 rules are very liberal except the FIA cage in this lit. class.
With the car, i actually think international racing should be possible, because safety rules are not too lazy in swiss, full FIA cage is required, jealous how simple and light rollcages seem to be allowed in UK. But on the otherside i've seen pics of a race-gta that came off the street rolling over and that looked veeeery scary even with a cage. So i thought go for it and add a bit of power

Wheels are "Kerscher" mostly known from the BMW edge, 8.5x17, 11x18
they vwhere expensive but i love the look and how it runs on them, and they are pretty light for the size, will tell more later...

short afternoon break for the brakes.


Kit from Ress, btw. rims where also already fitted to Ress cars, needed some tweaks to fit. 6 pot and 306mm for the front, i decided not going too big, think it does not need endless force to brake a car of that weight, i think these should be good stoppers for me and short hillclimb race periods. Needed a 25mm spacer for my very flat rims, don't know how it suits with other rims, but i can give you measures if interested. Everything fitted, also done new metall-brakelines all round, mounted new sealrings inside the mastercylinder. First i thought it's not necessary (mastercylinder), all worked fine, but they where very hard and broke like plastic when removing them, good feeling to have it done! Would advise to others too that want to scratch the limits!

I think i let it be good with just the front-kit for the moment and do some testing.
Plan is to fit A610 calipers with 300mm one-piece discs to the rear if needed, to keep it payable and simple.
Brakepads, will tell my experience after testing.

Suspension is a Spax adjustable from Simon with stronger Eibach-springs. Took me a while to setup, i'm very happy with it, even it's a one for the lower pricerange.

Quickly said:

Tyres and trackwide was the best improvement i've done. There may be people talking of overtyring. My personal experience is, with the oe setup, that it shoves a bit over the front at first, but then the back takes over very quickly, violently and surprising. With the new setup, the understeer thing is almost eliminated, back comes around more or less from the beginning of breaking out, but very much more controllable broader neutral range. Car is standing on streetyres but driven on 215/ 285 semis what's a huge improvemen at it's own.
I'm sure, same improvements could also be done in a less broad (tyre/car) combination as some of you surely know.
And yes i know there are also bad effects of my version because of heavier wheels, powerloss of broad tyres and and, but i love the solution as it is.

So Body was done, suspension also, front brakes ready to test, will tell you about the cage-adventure at next...

Have a nice afternoon!

Hello

Raining overhere..aaarrrgh...sooo time to work on the car tonight!

Cage story:
Heigo is the best known cage builder overhere, and had a cage listed, so i asked them, and was talking to the "ASS" no ass, AutoSportSchweiz, who makes the rules overhere. They told me that the car does have a full FIA cage to allow me to start in my groupe, with a not road-legal car in this literclass.
So i asked Heigo for a homologated cage. The one they had listed, needed some adds, because the FIA rules had changed over the years, things like double "A" pillar and double door struts where required, so resulting in a heavier cage. Anyway safety first. It weights around 50Kg. So they had to do a new DMSB homologation, happy that they had a GTA there to do this, so i did not have to bring mine over. I think they list the homologated cage now.
Fitted spot on when mounting!
It was an expensive thing, but perfectly mayde and i don't have to have an eye on FIA cage rules changing, very happy with it at the end.



Cage sorted, then i started to talk to Martin, motor, motor, he said noooo, gearbox first! Good, well spaced ratios for hillclimbing, stronger inputshaft, LSD, as important as the engine, but not so sexy because it's hidden in the box , Martin showed me his ratio calculations and i've seen how important it is. So i thought one built do it good, saved money while the months where passing by, my lovely wife payed the bills and looked thast i have something to eat in the evenings , finally i had the money together, Martin managed me the parts, it was a real bargain! I'll show the details as next

Gearbox:

We all now the weaks of the internals, broken by the high torque US and Lotus V8's, repeated again:

-flexing to breaking inputshaft and or coupler
-overhanging, small diameter, not proper centerbored 5th gear end

As we all know, the ratios don't really suit for hillclimbing, especially the gap between 1st and 2nd

6 or 5 speed GTO internals are out of my cash range, but Martin managed something perfectly to me.
Still a two piece, but stronger material, and bigger shaft, and nice ratios, 3:1 and 1.94:1, 1st and 2nd cut on it.
Decision for 3rd is not finally made (think oe will be fine), 4th and 5th will be atmo ratios, even i'll not need these gears often.

So strenght of the shaft solved

Uprated clutch spline, no undercuts etc, to avoid flexing and a new stronger coupler.


To shorten the whole thing a bit 3.89 final gear


Aaaaand LSD!



Think this should give a very fine payable serious gearbox!

Clutch will be organic M3 single disc clutch or a smaller 2 disc AP clutch will tell later.

Now what i really want to do, if one of you already have done this, please tell, help or finding a solution together would be great:

I want to fit a hydraulic center release clutch bearing to throw out slave cylinder and fork. This would be a nice thing on a un1, simpler solution.
I've no bellhousing in front of me to have a look yet.

Anybody done? Possible?
Some advise would be nice!!!