Ok, the rumour is that they can break. What are the best/best value replacements? How much? Who sells em?

 

Would it not be worthwhile doing the pistons at the same time? (I understand that this would put the cost up though...)

But I would be interested as well... so BTTT

David

 

I believe the rods on Sti are the same as the others but it is the lightweight pistons that allow the increased rpm limit. (maybe wrong of course)

No idea what aftermarket rods people are using I'm afraid.

 

just as an aside if u do replce the rods, ive read somewhere recently (CCC I think) about a new coating Keronkite or something which 'hardens' the piston and can resist the ill effects of detonation much better, cost was approx £25 per piston, I have no experience of the product but might be worth looking into...

Cheers

 

GGR do some light weight con rods - not sure if they are any better but they aren't too expensive at 200 notes.

 

I believe there are pro's and con's to coating pistons

Pro's
Resist det for longer
Transmit less heat to oil
Maintain more heat in combustion chamber(good for N/Asp)
Lower piston expansion

Con's
Piston top face runs hotter promoting det at a lower pressure
Maintain more heat in combustion chamber (not so good for turbos)

Back to back testing would be the only thing to convince me to have it done.

Andy

 

hi there are quite a few options with conrods
1/weisco - good but expensive
2/toda racing
3/jun auto/
4/crower
5/Bpm motorsports etc etc
all the above a quite expensive
I have investigated another option which is the sti version 7 rods which are forged and cheap- they will fit earlier engines
but the only issue is the bolts which are unique to the rods
A must is ARP bolts which I dont think are made for these rods yet
Im sure its a matter of time though
regards

 

Cheers Andy F its alaways good to learn something new, i hadnt considerd the thermal properties

 

I think that the coating would reduce the piston crown temperature, due to the insulation material on top. What this would do however, is transfer more heat into the other areas of the combustion chamber, eg head face and more importantly the valves. Dave, the car I am enquiring about upgrading ( a friends legacy )already has forged sti pistons, but we are going to build another engine for it with the Cosworth pistons out of the last engine we built which **** a big end. ( in under 2000 easy miles, but thats another story which i have told ) We will be looking to hit the 2 bar mark, for a blast up the 1/4, and so far with a stock MY98 UK motor at the minute ( fitted with sec hand sti pistons ) are running 1.7 bar with no apparent problems. Since rods seem to be a concern, my frined is going to upgrade these for the next engine. The current engine is more for trial purposes, and lasting up very well despite some abuse.
If it aint broke, dont fix it...but all this talk about rods does raise concern........

 

tell me about it... I like the idea of sti 7 rods.... I need to have words with my dealer.. (car dealer stupid..) and get some sti 7 rods.. I used to always walk around the parts room / floor and workshop, as it was easier for me to get what I wanted and then for them to decide how much...

I need to speak to someone in the know about recommended pistons and rods as he said you wouldnt guess what they are out of.. so if you are reading then you could mail me and tell me

David