Rezlo

S-afc actualy works well for small injector upgrades for those on a serious budget, I wouldnt go more than 15% larger though, anything more and your fooling the MAF signal really messes around with timing.

I have had a few GTR's and S14's that show high knock figures for no reason, one in particular was a SR20 S14, on the Kmon is was silent, ran a very safe map in it, yet the PFC D-jetro would show up to 50-60 on decel and even at idle would hover around 15-20, at wot it would often hit 95, I went over every squar millimeter of that engine bay, not a single thing loose or contributing. 6 months later I did an engine build for more power, same thing with knock, did not change. Eventualy I replaced the knock sensor at a regular service and it dropped to about 3-4 at idle and 15 odd on decel with 50-60's at WOT (usualy see 25's to 30's on similar setups) I then replaced the complete knock harness from sensor to ECU, didnt make a difference. I even tried to switch out the PFC's with its sister car running identical setup and still the car im mention would always read close to double, What I did notice though, if you run a hard core twin plate or tripple plate clutch it can be a very good contributer, SR20's knock sensors usualy go balistic right before/as they chow the teeth off 3rd gear as well. Not saying somthing is wrong with your driveline, just that it could be somthing a little futher down the line thats causing your odd readings. Good luck, hope you find the problem.

There is no real doubt that street = stock, race = exhaust removed, full race = both When in the US we did this to a few high HP mitsubishi's, but each time we used a custom piston design for open camber usage. What effect do you think using the regular style RB piston which is clearly been design for quench pads has on maintaining the correct swirl and fire path? Yes a correct setup will be a lot less likely to detonate due to the open chamber, but in the real world where the 2jz can make 1000hp+ on the stock quench padded head (near identical in design to the RB) is it somthing that is really worth while unless the vehicle is a fully dedicated race car that really is pushing the limit? I know I wouldnt bother

RB25's hydro lifters would sound like 24 rocks in a tin can if they were not getting decent oil press, Good chance you botched the install but as per most of the people here, rather get it sorted asap preferably by a pro, oil problems and engines = expencive.

Just for interest for those reading, Max power per each of the below? GT35 .63 GT35 .82 GT35 1.06 GT35 .78 TS VS: T04z T4_Divided .70 T4_Divided .84 T4_Divided 1.00 T4_Divided 1.15 T4_Divided 1.32 T4_Undivided .61 T4_Undivided .70 .81 A/R T4 Undivided with 3" V-Band outlet .96 A/R T4 Undivided with 3" V-Band outlet

I need a set of rear calipers in good condition, Anyone have a set? cheers

been more than 18 months now since I went with the Nismo supercopper mix twin plate, best clutch I have ever used! and as with all things car I landed up with 150kw more than antisipated in the power department... The Nismo clutch feels no pain when the T04z is at full tilt. I stripped it out last week to change the N1 oil pump, clutch after 20 000km's of abuse still looks like new. Still running as smooth as stock and the only con is a tiny little bit heavier than stock clutch, probably within 10%.

I guess some like to voice problems it to work out why it failed... something along the lines of learning from mistakes/ not wanting to repeat them,,, I think the only mistake made in this situation was me being cheap ass and buying a N1 when I should have paid another $400-500 and got a decent pump.

Do you think there are more N1 pumps in use than stock pumps? because a simple search will show boat loads more N1's fail than stock... fantasic "upgrade" as you call it... Basic stats are given, from a simple search, this simple searching showed loads of random failing N1's.. I am yet to see more than one random failing name brand pump...

So you do feel that there are more N1 pumps on the road than stock oil pumps? Because there are far more people posting N1 failures than stock, almost 10-1 ratio. I would like to know if any of you guys have links to HKS, Jun or Greddy pumps that have just totally randomly failed without any other damage which could have contributed to the failure? I have found only one case of a totally random name brand pump failing that is not attributed to bearing/crank destruction due to possible out of balance or damper requirement etc. Also if anyone has remains of any of the name brand pumps inner and outer gears I will happily pay air mail so I/we can have it tested at the same university as the N1, stock and SR20 is being tested at. After all actual facts will speak volumes… but until I have hard material facts I am treating it as a rubbish pump till proven otherwise,

TiTAN, as mentioned, if it was ballance, mashing limiters and/or dampers causing pump fails the bearings would be mashed long before the pump as with all other pump sets that share the same design. Most N1 pump faliures when caught in time show no signs of bearing dammage at all... Some right away some only after 40k km's. From adv search across 19 international forums over the last 2 weeks, each case is unique in description and username and date range. 23% - Standard RB pump on short pump drive 6% - Standard RB pump on full pump drive 68% - N1 pump (not specified which diameter) - 3% - Greddy, HKS and Jun 1% - Tomei – only 2 cases found 5% and less can easily be chalked up to build issues/ballance "external factors" in my opinion, Use it, don’t use it… but it definatly isnt 50/50... Obviously sales volume also would dictate the above, that said I would guess there are just as many if not more stock pump w/ full pump drives running around as there are N1's. Sydneykid, you are one of the only "builders" I know of that still using them. I am glad youve had success and value your input greatly... Unfortunatly there are many performance renound RB builders all having the same faluires all over the world for no apparent reason... I should have the metrology results back shortly on the remains of the N1 I removed from my motor as well as a stock RB25 pump and a stock SR20 pump.

A leaking seal? which seal? the less pressure you place on the pump the less likely it is to crack. Unless you ran out of oil I dont see how a leaking seal would break an oil pump... Effectively a leak is like comparing a single turbo to a twin turbo setup, the only thing different that would happen at the pump is the pressure relief valve will stay a touch closer to closed at higher RPM and when cold, doesn’t effect the load on the pump.

One thing for sure, that ACL head plate works really well, I use it on all my race cars.

Where from? My advise, change the pump before it breaks... seems to be more a case of "when" rather than "if".

Factory dry sump as most 911's have been It is on a moving engine dyno

RB N1 vs stock SR20, both outer pump gears are identical in OD, pump drive on the SR20 is about 3mm smaller than the RB, which means the actual inner pump gear on the SR20 is 3mm more beefy, probably why it doesnt crack... SR20 has a 2mm narrower gear due to reduced oil volume needed. And its got nothing to do with power, there are RB N1's failing 150-200wkw earlier than SR20's running stock pumps.

Torsional vibration and harmonics are generaly worse in an I4 due to firing order and cyl sequence, also one of the reasons most I4's have ballance shafts to try help NVH Large crank movement = toasted bearings, SR20's run main bearings pretty easy if not 100% dead on ballance when running over 400wkw yet dont break oil pumps running a near identical drive setup & dimensions to the RB... Rb on the other hand comes out with bearings looking like brand new yet oil pump is scrap metal, The RB pump is driven not even 3-4mm from No:1 main bearing, pump gets damaged from movement but bearing isnt touched? There is no way to have rotational vibration / whip without it running out of center.

If the flat pump drive setup was a bad design the SR20 would destroy oil pumps as well, yet they can run to 8500rpm all day every day on a stock oil pump, To add to that, Harmonic damper to protect your oil pump? tell me how if a 700hp RB25 with stock harmonic damper has such bad harmonics, enough to crack and oil pump, how is it that the main bearings still look like brand new? hell they dont even look like the motor has ever ran and she has over 20 000km's since I built it. I am chalking N1 pump drama down to either poor quality control (in material and/or manufacturing) or poor material spec

Would I use or sell another N1 oil pump? NO! Bloody obvious why the N1 pumps fail, the narrowest area of the lobe is right on the contact flat edge where it contacts. Lucky big ends and mains still look like brand new and there is no other dammage. Will change bearings as safety obviously.

There is nothing wrong with the pump drive setup as used on RB's. If this was such a bad design the SR20's would also grenade

Yes 20 random cases in 5 minutes of searching... and as somone mentioned, most people wont like to admit their motor had issues even if it was due to bad quality parts. I suppose its my own fault, buy a cheapy N1 pump and hope it will last was a dumb idea on my behalf.

While we are totaly off topic, anyone know of a good ballancer for an RB25 specific belt setup,

I have found around 20 cases already all apearing to be "for no particular reason" over a few other international GTR forums. I think material testing will tell a lot.

Im off the group buy with the pump Fastrotor, last one is yours!, got a good (damm good) deal on a drysump. Cheers

I dont got the last one ;-)