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South america gets a different roller rocker engine as opposed to the one the USDM gets. I’ve said it many times before on the forums but for the sake of the post... here it goes again. South American (JDM?) roller rockers engines come with 7.2k rev limiter from the factory.
A friend of mine who’s swapping a high port SR20 to his GA16 powered B13, lend me his ECU (A11-B20 B57) This ECU came from a ’91 NX and he also pass me a 22680-53J00 MAF (91-94 I think). Well I plugged both things on my 2002 OBD I Japan made P11 and Voila! 7.5K rev limiter on a roller rocker engine.
We tested this setup on two cars, one bone stock 98 P11 and mine 02 P11 (same engine though) Both saw the benefits of the higher redline (and different timing map too 3500-3800 low port flat spot/surge was all gone!).
I got this ECU on my car for over a month and revved the piss out of it. Although there was always the concern of valve train damage, I always shifted first at 7.5K. Just on two accidental occasions I hit the rev limiter, nothing happened but I did not want to push my luck.
So this got me thinking about valve springs on the different NA valvetrains available for the SR20 (excluding VEs of course).
The following information was extracted from the FSM of the respective models
The high port SR20DE information got it from a N14 FSM, from the NA section (RNN14 is there too) it’s stated on the list below as B13
The P11 FSM that I got from a dealer here in Chile and the B15 FSM available on line recently (B15forums).
Heres the information available on the SDS section on each FSM about valve springs
Free height is in inches, Pressure and limit is in pounds at 30 mm, except on the P11 which is at 27 mm. Valve lift is on mm.
BTW valve spring part number for my RR P11 is 13203-2J200
I'd love to hear opinions about it. By making a rule of three (I don't know if you call it that) but on proportions to the height, the P11 springs pressure are the same as the b13's measured at 30mm (not 27)
Which is the part number for the B13 and B15 springs?. So we can compare
Is this enough information to determine if the P11 & B15 RR is capable of 7750 considering the similarity with the b13 springs? Remember mine saw 7.5 no prob
Thanks and sorry for the long ass post.
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Claudio in Chile 2003 Nissan Primera GXE
The last of the P11s
Boost, NOS and displacement... Find a replacement for that!
Hey Claudio..
Remember that the Primera GT (P11) revs untill the 7.5k mark with the RR SR. The main difference between that engine and ours is the GT intake cam, the exhaust and the ECU...so no problem there...but to 7.75k
Well this is what I know about US and JDM roller rocker motors. I know the US motor uses top feed injs while the JDM motor uses sifr feed injs. I might be incorrect but the 3 JDM roller rocker motors I have got had side feed injs.
As far as going from 7200 RPMs to 7500 RPMs I see know problem because most car companys leave room as far as safty goes. 91-94 SE-Rs rev limiter is 7500 RPMS and you can move it to 7950 RPMs even with bigger cams. 95-99 SE-Rs use a rev limiter of 7100 RPMs and only do this because of smaller cams so the rule of 7950 RPMs still remains.
As far as the roller rocker motor goes I would get the JWT cams for your car and also get valve springs and retainers for it to. Then I would send out the comp to JWT and have the rev limiter moved up to 7950 RPMs like they do on the regular comps. Even though I would still shift the car at 7500 RPMS with the JWT cams and valve springs and retainers. It would still give you room for a small error in shifting.
In conclusion I think 500 RPMs over the stock rev limiter is a safe area but might be usless becasue the power is falling off to quick up top with stock springs and cams.
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So Andreas what about that post that you made not to long ago about the 98-99 SR20DE Rocker Arms and the 2000-01 Lifters with some upgraded springs and retainers? What would you rev that setup to well over 8k? Im getting ready to rebuild my engine and Im thinking about searching for these parts. So if this is a proven setup I would like to get the part numbers so I can get these exact parts.
Originally posted by Andreas Miko but the 3 JDM roller rocker motors I have got had side feed injs.
Mine has side feed too
Quote:
Originally posted by Andreas Miko
As far as the roller rocker motor goes I would get the JWT cams for your car and also get valve springs and retainers for it to.
I have S3 but without JWT springs and retainers. On that note I was looking at this: http://www.sr20deforum.com/showthrea...threadid=43515
and saw that the outer spring part number is 13203. I that the same as mine? (13203-2J200). There's an inner spring too 13204. Do you think it's possible to install the inner spring plus retainers from the VE to the roller head? If it is, I'm sure it'll be a much cheaper way of letting the roller head rev to 7750.
Quote:
Originally posted by Andreas Miko
In conclusion I think 500 RPMs over the stock rev limiter is a safe area but might be usless becasue the power is falling off to quick up top with stock springs and cams.
Besides the S3 I have all the bolt ons too (minus flywheel), so I think I'm making some power up there. The original question came up because I'm buying a used JWT comp with the limiter set at 7750. I don't want to kill the engine by getting carried away on the shifting.
I'll shift at 7500 or less but what if I accidentally went any further Will the springs be strong enough to avoid valve float? Will the rocker arms be thrown away? Roller rocker arms seem heavier than the solid type. But my valves are a tad shorter (less mass to move) than B15's valves. My springs have the shortest free height of the bunch but have the same stffness as the B13 at 30mm. Is that better or worst for preventing uncontroled valve events at high RPM?
Sorry for asking too you many questions but I wanna learn!
There should be no problem installing JWT C-series valvesprings in a roller head, if those spring specifications are accurate. Seems to me that this has been tried and succeeded, even (Dre?). I also seem to remember that installing C-series springs on a high-port engine with S4 cams netted some nice (3+) WHP gains...makes me wonder if JWT S3 Roller cams would work nicely with C-series springs and gain as well.
Claudio, is your GX' ECU connector the same type used on B15s, or the same type used on B13s?
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Originally posted by CowboyDren There should be no problem installing JWT C-series valvesprings in a roller head, if those spring specifications are accurate. Seems to me that this has been tried and succeeded
Yes sure, Disco Potato (C1 I think).
Once I installed regular S3 to my roller engine (I know, I know..) The car run great besides 7K hesitation, other than that the car could be run just fine. I think you can put 91-99 cams on a roller head just by switching cams and rocker arms.
Quote:
Originally posted by CowboyDren
Claudio, is your GX' ECU connector the same type used on B15s, or the same type used on B13s?
OBDI Blue conector. That's why I'm using a 91 NX ECU.
It amazes me that:
- NX ECU has mechanical speedo, mine it's electronic... but it works.
- NX has external coil, mine It's internal... but it works
- My P11 has no EGR nor AIV but as you've already guess... it works
- NX has Air Regulator mine doesn't. Here is a lil problem but nothing intolerable. When the car is warming up if you drive right away it tend to hesitate at part throttle but push it a lil' further and it's gone.
Spring wise I think JWT springs sure are an option. But what about the inner VE springs? If it can be done I'm sure It'll be much cheaper. Here in Chile we can go to either importer of Nissan automobiles (MARUBENI or CIDEF) and with just with a part number and a liltle twisting I can order pretty much anything from Japan. It takes long but all the importation hassle is up to them, not me . They qoute me like 5 bux per spring (not in stock though) That's dirt cheap! Retainers shouldn't be too expensive.
Finaly, another primera from south america, claudio, im from venezuela, i have an primera,"98 , and my engine has roller roker, i dont know if the last engines had change that 01 02 in US, i got 2 engine, one bad and the other runnig, i will take some pic of it. about throwing that speed at your engine, do you know that water pump on sr20de cavitate around 7K, SportCompact car said that they do around 6500, what about vibrations at that engine speed, Have you think about lighten you your crank, i know that the 02 comes with a lighter crank,and what about lighten flywhell?,
im, in Maracaibo, if you can try to aviod Caracas, here the politicals problems are verry bad this is on all around the coutry, Caracas is the hell, you can even die there between gunfires, terrorist bombs, if you come here go this places Of course Maracaibo,Margarita, and near by we have the most beautifull island ARUBA, is small island but is the best of all, Netherlans, italians,bunch of us, girl girl... beaches an the most pleasent place on heart. Is verrynear by Venezuela about 30 to 25 minutes from caracas or maracaibo
do you know that water pump on sr20de cavitate around 7K, SportCompact car said that they do around 6500
I got UR pulleys that's suppoesed to take care of that problem. Anyway but I think that WP cavitation is more of a concern when taking the car to the track. I drag race every once in a while other than being a weekend warrior.
Quote:
Originally Posted by primerap11
Have you think about lighten you your crank, i know that the 02 comes with a lighter crank,and what about lighten flywhell?,
USDM RR has the lightest crank of all SR20s. I don't know for sure what kind of crank my car has... but probably is that very same. So no I wouldn't ligthen it any more than is already is. I'd like a Fidanza Flywheel though :-)
Hey I have a usdm G20 (2002) could I do these performance mods as well? Are the ecu harnesses different from obdl and obdll vehicles. I was also told about how I could not use the jwt cams becuase the roller rocker cams have 2 less counter weights. Same goes for the ur pulleys. I am also concerned with valves becuase I am going to turbo my motor and I diffinatly need to have stronger valves and springs before I do so. Is there any place that makes performance engine internals for the roller rocker sr20's?
I've turboed a few USDM RR motors... I can say this for sure.. the power falls off big time after 7K. I dunno it's it's the springs letting the valves float.. or if the cams just suck.. but it loses power after 7K. I've turned them to 7500rpm though.. and have had no problems. Also, I've had a RR motor that made 380whp with just the addition of S3 roller cams and low copression pistons (and turbo of course).
i have a 94y 2L head (200sx se-r i think) in my b14 sentra with turbo and all the works. i recently broke all the rocker arms and i was wondering if its possible to put roller rockers, rr lifters and rr cams in a non rr head. would i need anything else besides these things?
Thats on the track
