Steve

Inasnt, have you had a look in the for sale section? Munro is selling his HKS 2835Rs pretty cheap, esp considering that they are nearly new. I have seen a review of them in Zoom or HPI and they seem like a pretty good turbo, and will definately get you to 250rwkw.

Warpspeed, are the RB25 and RB26 condors the same length. I would make sense to me but I have never been told for certain, and am having trouble finding the specs on the net. Also, would RB26 rods fit on an RB25 bottom end - might be cheaper than aftermarket forged for my power applications (600bhp) - as from photos the RB26 ones look alot thicker at the neck near the little end. Also, do you know why nissan use less overlap on the RB26? Is this offset by the increased lift? Some really nice info there, any chance of posting a link to Meggalas site and the specific page, as I couldnt find it. Sorry for yet more questions, you've certainly been very helpful so far. Cheers Steve

Xeron, too short for what? I was under the impression that shorter stroke meant more rev friendly? Is that a bad thing? Cheers Steve

Yes things are starting to stray a bit, time to move on. Apologies to all.

Have you heard the word patronising? I finished school 20 odd years ago, and yes I have rebuilt carbies, so yes I know what a venturi is, and what the venturi principle is as I also studied physics. And the pressure drop is only present IN the ventur not before or after, what is your point. Then again please dont reply. If you dont want to contribute why the hell are you posting, the only thing I have seen so far from you is a desire to blow wind up your own arse. Comments like " i have played with more gtr's and gtst's than i reckon many of you have even seen so y when i lend my opinion do you all get shitty I own a skyline i work on skylines all day ..." IMHO, anybody that needs to make a comment like that without knowing the company you are in, please. Ok, so in keeping with your above, you are a skyline mechanic - please tell me where you work, as if I ever need any major work done, I dont want to visit you - you'll tune my car so that you blow holes in the pistons, then you'll try and give me homework when I ask a question. Then,and this takes the cake, after refferring to the vast superiority of a F1 engine to a shitty old RB25, you comment that the whole problem with the RB series ie the bore is too small? WTF Where did you come from and please go back Another quote"..have you ever spent any time on a flowbench ..." I am asking a question, if you have had comparisons for an RB engine before and after you have filled up the ports to make them smaller great - I would have loved to hear about it. Or even if you could have answered my question with pure scientifice theory that would have been fantastic. I have seen acutal results on a flow bench of an actual head that was ported - and do you know what, they removed material, ie made the bloody thing bigger not smaller. If you have so much wonderful experience,and can do it so much better than the japanese, perhaps you should consider a consulting job with Nissan. I am sure that they would love you to come along and sort the problems they are having with such a crappy donk as the RB series. The whole world could benefit, becuase arguably there arent alot of better engines around than the japanese develop. Another one "..in exhausts the slower the air moves the hotter it gets explain that cause i can if u like but you brought up the exhaust thing you prove it!..." I dont need to prove anything, and in fact I am not sure you are speaking the same language - I didnt acutally bring that up at all. Do you acutally read what people post or just pick out the small words so you dont get confused? Just my 0.02c

PS, ski boat and bbq sounds pretty cool, and nightcrawler havent you heard of internet cafes....j/k

NIghtcrawler, I dont care, organise it and I will come. If you need any help with the committee thing, if I can help I will. Steve

Drift Spec, if you are going back in for a balance, I would ask them to check that they are using max adjustment on the front. The kit is supposed to allow +/-0.6 deg, or a bit over 0.30'. I would have expected your camber coming back to about 1deg,15'. Might be worth checking/asking?

BigDatto, you say that these catalysts lean out fuel - wouldnt this be pretty dangerous when already running mixtures on the edge? Have you heard any reports of people using these in modified cars. At well over the $1 mark for 98ron, these sound interesting, but when you include the cost of a new tune, or perhaps a rebuild due to detonation - I am a bit scared:) Cheers Steve

Peewee, decreasing the hole that the air has to move through would necesitate the increase in air pressure to move the same amount of air in = hotter air charge = more prone to detonation etc. On the exhaust side, well the increase in power from the change to an aftermarket exhaust speaks enough there. The practice of increasing port size and improving flow characteristics is a well known one that is proven, port reduction will restrict flow - all other things being equal. The least resistance to getting the air in and out, the better, no? I really cannot see how restricting air flow can increase power potential?

If bigger were better, wouldnt pistons be 3"+ thick at the crown? I was under the impression that to strengthen ringlands, you placed rings further apart, not increased the amount of metal beside them. Anybody else heard of this?

This might help clear things up for anyone wondering about trims and fitment, http://www.hksusa.com/categories/more.asp?id=1092 Hope it helps Steve Munro, I am bloody amazed that these havent gone yet, they must be close to the bargain of the century - perfect singly for a 2 to 2.5L and they sell new here for over $5K each!

Some more great replies, thanks all. Warpspeed, for someone who describes something as difficult to put into words, you did a bloody good job - its all alot clearer. Sort of explains why all the wear is being done at the top and bottom of the stroke, loads increase as the energy is trying to transfer with poor mechanical advantage. Have I got this right. Also asks the question, how much more efficient would an engine be if there wasnt the loss of energy here, then again I suppose it also has some positive features too? Cheers Steve

Yet more interesting replies, thanks again. Raises another question, how would you reduce to the point of insignificant the damage to big ends by over acceleration of the piston? Xeron, I think I am missing something here, I thought it was mentioned that shortening the rod to increase stroke commonly causes excessive rod angle? Can you explain how a longer rod causes the piston to dwell longer? And how stoke length is made up at the bottom of the stroke? Sorry for all the quesitons, but this really flies in the face of my really basic understanding of physics as it applies to the geometry of the internals. Sorry there are so many questions here, but understanding how things work helps me remeber:) Cheers Steve

Just for comparison sake, I got some brake cleaner, cost $9 and gave the AFM a quick squirt (a couple of seconds) and it was like new. If you are having idle probs, it may be more than jsut the AFM, check all hoses that are connected to the plenum/intake pipework, make sure none of the clamps are loose, and check all hoses for damage. Ihad a small crack in a thin piece of rubber pipe where my boost guage was connected, as well as a couple of loose clamps. Sorted these and idle problems disappeared. Also you could try cleaning your AAC valve, as these sometimes cause problems. it may be worth doing a search about idle, as a few people have had similar probs.

Dont know in sydney who would sell them, but if you contact your bridgestone head office, they will be able to. Full name Bridgestone Potenza RE540

How is this poor piston design. It is used to enable oil to cool the pistons - further removing the chance of detonation. I find it interesting that an engine design that has stood the test of time, been modified to high degrees, with great reliability, produces high output reliably in stock form, has an at the time unbeaten track record and you call it "such poor design". Can you explain this please, as it flies in the face of all thought currently being expressed on GTRs? I am more than a bit confused also, you own a skyline, join a skyline forum and then start slagging off the cars? This forum is for use constructively, if you have an opinion, why cant you back it up with facts or personal experiences - instead of just making wild claims? I am not having a go, but I do believe that perhaps you are missing the idea behind this forum, and the reason people come here - to hopefully be able to learn something and share knowledge - not provoke arguement and disrupt threads started by people trying to gain knowledge. Have you had a look in the Wasteland? If you want to have a go at skylines, why not pop in there, I am sure you will find people willing to further discuss it.

Warpspeed, thanks for a really excellent reply - it has certainly helped my understanding a bit, and helps explain why some people can get much better hp figures than others with stock engines - it all relies on how you make the power, not how much power - is this on the right line? Your reply also reminds me of where I have heard MEP - Corky Bell, I should have remebered, but glad I asked the question, alot of interesting stuff in your reply. Raises another question, hope you dont mind, you mention 4000FPM when talking about piston speed? Is this for Feet Per Minute? Also, is there a simple formula (or a complex one) for converting this to RPM - I take it, this will be number of pistons and length of stoke dependant? Thanks again Steve

I was under the impression that the main damage caused by pressure in a well tuned engine was at TDC and BDC and effects bearings and conrods??? Anybody shed further light? Warpspeed, can you explain MEP? Cheers Steve

I believe so.

Well, I found a guy in brisbane who will highflow 6 injectors to 500+ (within 1% of each other) for $400, includes cleaning and new o rings and has a turn around of 2-3 days. Still not sure though whether to go Sard new as I can get these for about $800 new (customs willing) Anybody have any thoughts Steve

Isnt this the problem with going colder - they work at a higher rpm and better for bigger hp but you get a trade off. Perhaps you could a. Change them frequently.... b. Get the car down to the plex more often c. Driving around in first - only in built up areas of course.

Thanks for the replies, all sound good. so go the exhaust side adj cam gear and leave the VVT in place. Rev210, I am seriously considering going to a 3L when the bottom end dies, and supercharger/turbo combo - just for something different. this will also mean the removal of the VVT. For now I want to optimise what I have and then move on. I have been considering too many directions at once of late I think, so I just want to get the top end sorted first. And see where things take me from there. Cheers Steve

MFX_R33, no, I have a HKS 3037S56T going on soon. Steve

Either totally ingnorant, or one hell of a dry sense of humour. I doubt the latter. thats a really funny story, thanks. Steve