CA18DET

[gearhead23]

I'm in the market for Pistons and Rods and I would like to get some feed back on the different rod styles(x-beam or I-beam) wich is better or just the pro's and cons of them and a few ideas on wich pistons have been proven by members to handle 22psi all the time.
Modified by gearhead23 at 7:56 AM 8/10/2007

[MeanGreenS13]

before dee blows this thread up... dont believe the 300hp BS thats floating around... use stock internals and freshen the motor up and your good..."

IF YoU MUST! pauter xbeam and CP pistons... waste of money imho though unless your going higher than 500whp

[themadscientist]

pressure is irrelavent, it's revs. You could blow a motor at 5 psi if you pegged it. Stockers are fine for about 90% of the builds people are doing right now.

[boost_boy]

pressure is irrelavent, it's revs. You could blow a motor at 5 psi if you pegged it. Stockers are fine for about 90% of the builds people are doing right now.

These guys are right "gearhead23". Your stock bottom end is capable of some extreme hp, but you got to do the preventive maintenance and have some good tuning done or it will all be academic. The name brand rods and pistons are good for bragging rights and extreme hp duties, but are not needed if your looking to sit around the 300-400whp area. Hope this stuff these guys told you sink in pretty good.

Dee

[MeanGreenS13]

im setting a rev limiter at 7000rpm for a litelw hile on my car to be safe and see if i need more... and ill adjust accordingly... start off slow is all we can tell you

but dont just drop 800 bux on rods man

[themadscientist]

To simplify it (I like simple) look at the forces involved. What will incresed pressure do? It will push down harder on the piston, then the wristpin, then the rod, then the crank. The forces imparted on the bolts are negligable; at that point it is just keeping the rod from shifting as all the force is pushing against the crank journal.Now the crank hits the bottom of the stroke and starts to swing back up. again the force is mostly crank to rod, this time the crank is imparting pushing force to the rod, then the wrist pin and on to the piston. The rod bolts are still pretty much just keeping the rod from shifting around.Now are you ready? here comes the moment where rod bolts come into play. The piston and rod are screaming up the cylinder toward the head and then STOP! we go the other way. At that moment your rod wants to punch the piston right out of the block and those two bolts holding the rod together are all that is keep that from happening. Now the higher the revs go the more force is applied to those bolts at the point where the direction of travel suddenly shifts. That is why revs are what kill rods not boost.Now in the situation of a rod with a dinky beam like a CA20 for instance whole rod is the problem. Boost in this situation will fold a rod beam in half at a certain point, probably before rpms stretch a bolt. The CA18DE and DET rods are short beefy little bastards and I would be shocked to see any amount of boost hurt them in that fashion.

[MeanGreenS13]

themadscientist, email me or IM me if you can i wanna ask about that turbo

[ch187]

tuning tuning tuning. the key to make power and making it safely. a poor tune will cause and pre ignition pre ignition causes detonation. think of this. if detonation occurs that means the fuel being injected as ignited before the chamber even sees spark. so if the fuel is ignited before the power stroke of that cylinder, say at the end of the intake stroke or beginning of the compression stroke, its going to make all that energy and nowhere to put it. except the piston. so your just putting enormous pressure on the wristpin, rod, its bolts, and eventually melt right through the piston. if the piston isnt at the right place when the fuel/air mixture combusts it will just explode causing the infamous ping. if youve heard that its already too late. at least thats what sense i can make of it. meaning if you tune it right, you can handle a lot more power because your not

[MeanGreenS13]

much agreed. Tuning is your key.

A GREAT EXAMPLE would be me honestly.

My green s13, had a ported and polished out GTI-R T28 with oversized wheels both sides. Flowed much better than originally. Anyway, prior to selling the car, i was still on 370cc injectors with CRANKED fuel pressure and as much timing as i could get, the car put down 318whp at 18psi with an 11.70 AFR

once i sold the car (to my cousin) we put some 550cc injectors, AFC Neo, Z32 MAF and HKS cams in the car, that same 18psi netted 352whp and 322wtq.

The only problem was i was a noob with the afc and left a few lean spots in the tune unknowingly. The afr was fine so I thought all was good... unfortunately without working knock sensors, i did not know there was detonation going on. 3 months later i got a phone call saying he was at the track wot and had a big bang and the motor stopped...

he popped a hole in the piston... poor tuning

if we had done the tuning correctly, it would probably still be alive today

**as a side not the motor now has crower rods, cp pistons, tomei top end and ARP everything getting ready to slap a T3T4 on it.. i have that T28 back =)

[dash]

MeanGreenS13who did your gti-r 'T28 upgrade' ?what rpm did it see 18psi ?I'm wondering if "drop-in" cams (~260 degree) would net a similar ~35hp (10+%) gain at the 300hp level for a ca18.

[MeanGreenS13]

i think what helped me most was going from BONE stock ECU with cranked fuel pressure, back to stock fuel pressure with an actual "semi" tune. Dropping in cams shouldnt net you a gain like that, i saw 18psi previously by 5000rpm, after injectors and "tuning" it came on about 4500rpm full boost... it wasnt the best setup but it worked... a friend of mine who is sadly no longer with us did that turbo for me.