ALFAGTV6.COM

[kevin]

Got stopped by the local cops with the race today. They hummed and haahed(eish) about the worn semi slicks then tried all the lights and the hooter. The exhaust started to scare them but they let me go. Probably because I was not on my cell phone which is the only thing they fine for here. I was on my to put two 'resonance' tubes in the 50mm sections just to take an edge off the sound as some tracks dont allow you to pactice on a Sunday if its seriously loud.
Basically got a 50mm perforated pipe and wrapped fiberglass packing around it then put a 63mm outer pipe over it. Made two of them 400mm long. Car sounds quieter but still dam loud . There is only space for one box and ground clearance is an issue. Pics to follow

[kevin]

2009 plans are to work on suspension try make it more adjustable including front AR bar, getting my camber gain correct without comprimising my roll centre height whenI start playing with my adjustable upper control arms.
Also like to replace all bushings to spherical and rose joints.
Engine is perfect so nothing to touch there(to much power if anything). Brakes are perfect. New gearbox should be ready at end of January. Propshaft is trouble free . Lighter clutch assembly will be looked at(Barry).
Bottom line is also to improve driving.
This car will end up as a 'road legal' dedicated race car .
Just a sideline note. When this car had a 2.5 12v motor in you could run a whole season of trouble free racing as very low budget(just fuel and entry). Its only when you add another 80kw then the problems(costs) start.

[GTV27]

Your cops are friendlier than ours - we would be royally reamed for the side pipes, let alone the volume. Is the muffler a common chamber or separate all the way through?

[kevin]

GTV 27, the muffler has two pipes straight through and the they are wrapped. It is in a common chamber but there is no crossover effect due to the wrapping. I have tried to read up if the v6 needs to have a common chamber and feed off one bank but due to no conclusive evidence I went with two seperate pipes. I have gained another 13 kw but that due to many other factors ie mapping, new intake, Short exhaust but i ave not gone backwards.(same dyno). The car definetly has a very different sound with two individual pipes.
Had the exhaust off today checking all the headers I had made to make sure they are all correct. (I swear this is the last time to make these.) These headers fit easily with studs in heads excepth on right bank the no 3 pot, the studs need to be slslightly shorter. Some other pics off templates etc

[Zamani]

Kevin,

I don't think there is anything you can do about the sound pressure level. It's either you have:

1-smaller pipes
2-more bends
3-baffles in the muffler

None of these seems to fit the goal of a race car.

Maybe what you can do is fit a vacuum activated valve where under full load (0 vacuum) the valve opens and you get full noise, and under partial load the valve shuts off the exhaust leaving only 1 pipe open to flow.

Or get an electronically activated one.

If you look at the E36 328i and E46 330i their rear muffler has such a valve for one of their outlets. This is vacuum activated I think.


I have an electronically activated one. At the track it just dumps exhaust gas to the road.

[kevin]

Z, the sound level is perfect at moment without compromising power which there is no lack of so everything is staying as is. Have a look at these headers on a proper race motor. My headers are good for fast road not like these equal lenght one on video. This big bore make 50kw more than my race motor !! Check out the brakes when dawie reverses car off dyno. SA style. Look at other links on this.
http://www.youtube.com/watch?v=8JC91b8DQag

[kevin]

Looking for some pics on rs rear anti roll bar on 75 or GTV6. I have an origional autodelta adjustable one which I bartered it from Barry. Whats the easiest way of puting one in as I never have thought about taking it out during the countless times I have removed the gearbox. Its one of the last things to complete this so called budget race car. Touch wood, reliability has been pretty good on last two track outings. Big race tomorrow so hopefully can get footage as taking video camera along.

[kevin]

We have just had two races , 21 march and yesterday. All in with practice that was eight heavy sessions.
Good news is I have done my first propshaft inspection after a year of racing(with the 24v motor) and the front coupling is looking as new as the day I bought it. The coupling cage has proved an absolute must for reliable racing. Also this same prop did two years on the 2.5 motor.
Conclusions. The prop can take an absolute beating with the cage. No need to modify anything. Having said that my centre coupling was looking rather tired so i ahve replaced it with a thicker BMW one which is 28mm compared to 23mm.
My first plan was to machine the bm coipling down but after finding hidden spacers around the tubes under the rubber this proved impossible. The spacer just ripped the rubber open. I did try various machining methods which did prove dangerous after dodging a flying coupling coming out the lathe!!
I ended up cutting 5mm out the prop and welding it up again(proffesionally done)
Here are some pics of condition of coupling and my second method of maching down coupling.
The bm coupling is far superior as it should be with 20yrs more development than the old alfa one.

[kevin]

If I could have got an Alfa centre coupling in South Africa I would have used it but as no supply I used the bmw one. Only reason.

[MD]

So Kevin, you got an original Alfa Coupling in the front in a cage. A modified BMW unit in the centre. What's in the rear of the shaft?

[kevin]

Rear is standard Alfa coupling. I dont jump kerbs when racing and get the wheels airborne as coming down breaks cv's and couplings. Thats the only area where I am conservative other than that i am fourth fastest of forty cars. I know Barry put one of those cage on the rear coupling which is a good thing to do.

[TRC Magazine]

Hi Kevin,

I chatted with the guys about you diff at the Race Retro Show over here in March - Have you got it fitted yet?????


Andrew.b

[kevin]

Not yet, hectic start to the year and two races close together. Also being trying to help mates get their cars on the track. I must get my fiberglass doors and bumpers on , saving of 60kg as well.
I ruined a new slick(bad circuit) in my first heat on saturday and did not have a spare so i ran my semis in the second. Even though they are both 15'' (semi 205/50) its amazing how a fraction of difference(obvious) in tire circumference can effect your ratios so much. Could not even get into 5th on main straight at Midvaal on semis while on fullslicks I was 4000rpm in 5th.
Anyway I am searching for the last 1.5 seconds at swartkops then I will be happy.
Thanks again for set up advice.

[ar4me]

I was 4000rpm in 5th.

You are probably better off in 4th. If that is a pattern, it may just be your 1.5 sec
Jes

[Mats]

I was 4000rpm in 5th.

You are probably better off in 4th. If that is a pattern, it may just be your 1.5 sec
Jes

Or third..!