Wossner forged pistons

[robi1000]

I'm into process of buying new forged pistons. For now it looks that I get the most for my money if I buy Wossner.

What do you guys think of Wossner pistons?

Also for those that do not know I need them because I have a head with 34mm valves and my current pistons can't handle that. I've sent an email to Wossner and got the following reply:

Piston kit Inlet Valve-Pocket Ø/ depth Outlet Valve pocket Ø/depth

9034Dx Ø36 / 2,6mm Ø31 / 2,6mm

9037Dx Ø34,6 / 5,1mm Ø32,6 / 4,1mm

9034 kit has 11.2 CR and 9037 kit has 12.5. Which one should I choose? I have head with bigger valves, some porting and cams. 34 has bigger inlet valve pocket diameter but is not as deep as 9037 kit whic has 4.1mm deep pockets but they are a bit smaller.

Also Stan if you could send me an offer via PM for your pistons.

Cheers

[stan]

I'd go with the 12.5:1.

I'll have to double check the price, as they went up last month

I'll pm you tommorow (if i dont, pm me as i will have forgtten)

[robi1000]

Some pictures:

9034 pistons (11.2:1 CR):

http://www.moj-album.com/slike/10833367/yQtRwaSas7vVYMe7.jpg

9037 pistons (12.5 CR)

http://www.moj-album.com/slike/10833367/MUUMUngw3RffO3nS.jpg

Also are they going to be ok for everyday use? Any precautions using forged pistons?

[stan]

No will be fine

Ive got a set of used Wossner 11.2:1 pistons, they are in 83.5mm, if you are lookign for a cheaper alternative. Thy have only done about 4 hours dyno use.

[robi1000]

What is the optimal CR for Catcams 5502225? Can F7R engine handle 12.5:1 CR without pinking in lower revs at WOT? I really have to know this because I'm after every bhp I can extract from this engine. Somehow I think I'll get noticably more power with higher CR pistons. I'm after the highest CR at which engine doesn't detonate. What is your experiance guys?

[stan]

You can safely run the 12.5:1 pistons, so long as its mapped nicely.

You gain about 2% (in theory) for every unit the Cr is raised, so going from 11.2 to 12.5 would THEORETICALLY net you about 2%.
So if your engine is making 175bhp with 11.2:1 pistons, it could make say 179bhp with the 12.5:1.

[robi1000]

Well I guess I'll just take 11.2:1 ones. Just a practical question. How it's then with the fuel? I usually fill it with 100 octane, but if I want to go on a seaside and there would be no 100 octane petrol available, would 98 octane be enough? Or will it detonate?