View Full Version : OK, now you have your motor...now what
TRM02
11-15-2001, 08:12 AM
Ok I am getting closer to buying my 240 and I will be doing a motor swap on it and want to know how much PSI I can push on a STOCK s14 sr motor?
Plus anyone out there install stronger JUN pistons and rods? if so how are they and did the sound of the motor change?
S13Grl
11-15-2001, 08:48 AM
I really don't know how many PSIs can you run on a blacktop SR20DET, but what I do know (and what is covered in another topic here briefly) is that an S14 has variable valve timing. Variable Valve Timing can only take so much power before it will blow and of corse, that will damage your motor. I'm sure you're gonna wanna make your car fast...
I say you look at this topic:
Engine Swap (http://www.zilvia.net/forum/topic.cgi?forum=2&topic=841)
(Edited by S13Grl at 9:48 am on Nov. 15, 2001)
TRM02
11-15-2001, 09:10 AM
Yes you are right I have heard that also...This is why I am looking into getting stronger Rods and pistons...That should help aginst that...
kitoro
11-15-2001, 09:51 AM
all SR20s run 12-14psi stock before any real damage takes place. any higher, you need to change ur internals
don't push engine too hard either or else it go boom.
<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>
S13Grl
11-15-2001, 02:33 PM
Haha! And you don't want it to go "boom!"
KoukiS14
11-15-2001, 09:29 PM
Hey just a thought... I'm gonna do a budget-minded SR swap when it comes time (still a student kinda haha)..
Anyway... I'm gonna use an S13 SR probably...
How much HP can I expect with a mild exhaust like Remus, and intake, and at 10 PSI of boost? Anyone? Will stock tiny-ass sidemount handle this kinda extreme pressure well? =)
-Rob
tristarx
11-16-2001, 12:05 AM
Stock SR runs about 8psi. For safety, add in the Z32 fuel pump you can push to 10-11psi.
With intake, dp, mp, catback and 8psi, the stock setup I dynoed 200rwhp. If you push to 10-11psi, expect 215-220rwhp average.
If you get JWT rom tune, or SAFC tuned for 14psi on stock turbo, you will get average about 230rwhp. Any higher than 14psi we suggest you to upgrade to Z32 MAS and might as well add in a upgrade sports turbo to tame the boost down for pump gas street driven vehicles.
Tx.
Wayne
<a href="http://www.phase2motortrend.com
" target="_blank">http://www.phase2motortrend.com
</a>
mistert
11-16-2001, 12:33 AM
after 14psi you need a new headgasket and an FMIC. never forget, detonation management is the key. with our 93-94 octane pump gas, like tristar said, you'll have detonation management problems.
for an interesting article on raising the octane of your gas, look here: <a href="http://www.vtr.org/maintain/gasoline-octane.html" target='_blank'>http://www.vtr.org/maintain/gasoline-octane.html</a>
this should show you how to raise the octane of your gas past the 95 levels our japanese friends use.
the turbo in the s14 will handle 14psi, but on the s13 sr, that is really pushing it. with either cars you will begin to have streetability issues.
TUNING! DETONATION MANAGEMENT! these are key <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>
oberkill
11-16-2001, 07:45 AM
There is alot of misinformation in this string but it is all conservative info so that is good!!! LOL I am going to try and address them all but I dont know all the answers either!!!!
As far as changing the pistons and rods in the S14 that will beef up your bottom end to pretty good specs and if you resleave (SP?) you will be close to indestructable but that will do nothing for the VVT. If you are planning on building the engine up do NOT get a S14 you will have to disable the VVT and that is alot of the extra cost invloved in the engine. I would recommend a blacktop S13.
Stock internals will take up to 20 PSI no problem as will the head gasket but I wouldnt recommend running that all the time. :-) There is a guy in New York (Greaser) who is running a HKS ballbearing turbine with a completely stock SR (internal, headgasket, everything) except injectors and I actually saw him pull 320 RWHP on the UNN in June.
If you are running a SMIC you are pretty much limited to 8 psi. Also if you are running the Stock fuel pump you are also limited to ~8 psi.
I am going today to do a few pulls on the dyno to see what kind of injector duty the stocks are pulling. There are many people in Japan running 12-14 PSI on a stock SR but 14 psi should be pretty close to maxing out the injectors.
Hope that is helpful. I am going to document every part of my build up on the dyno with Air to fuel ratios so hopefully some of the fuzzy parts of what is and is not possible can be answered.
Alan
TRM02
11-16-2001, 08:24 AM
Alan, thanks for all the good info. can you tell me what a SMIC is? Also I just want to build up the buttom-end up so I can have a pice of mind on the motor...Running a bigger turbo I would like to get into the mid to high 12s with it on street tires...Wait can that be done with what I am saying I want to do?
ca18guy
11-16-2001, 09:02 AM
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from TRM02 on 8:24 am on Nov. 16, 2001
Alan, thanks for all the good info. can you tell me what a SMIC is? </td></tr></table><span id='postcolor'>
It's SMIC= side mounted intercooler, it's the stock location, it's pretty ineffecient you should'nt raise your boost past 10-11 with a stock intercooler.
oberkill
11-16-2001, 11:19 AM
Building up the bottom end is fine but if you spend that kind of money on internals you will most likely want to go with alot more boost than the valvetrain can handle. The stock internals are good for more than 450 hp as long as it is getting good oil pressure. If you are just looking for mid 12's get a good front mount intercooler, 3 in downpipe, 3 in dump pipe, 3 in exhaust and turn the boost up to 14 on the stock turbo or get a HKS turbo with an internal wastegate that still hooks up in the stock position. I think the 2340 does that but dont quote me exactly on that!!! You may need bigger injectors and some other fuel/air delivery upgrades but still works out alot cheaper and easier than Jun Pistons/Rods and you should have no worries about the engine.
Alan
TRM02
11-16-2001, 01:12 PM
Great, thank you all for your help on this...
HippoSleek
11-16-2001, 01:13 PM
Wow - some more FA names popping up... Thanks for putting some spice into the turbo arena <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'> Mostly, I agree with Oberkill (earlier numbers were conservative), but I think it's important to accept lower numbers unless you are willing to run at the breaking point.
I guess the question I am left with is are you looking for hp or et? If you want 12's, I think Greaser (found on FA and CSI - but in lurk mode on each) is one of the few to pull those kinds of numbers in an SR - but he did a lot of fabrication and used some exotic stuff (home made log manifold, TEC II stand alone engine management, and a fat GT-3037). He's got the power, but is running at a conservative sub 1 bar of boost. He keeps the boost down b/c, until recently, he had to make sure the car would get him home from the track!
I guess the point is that that is a lot of power out of any motor - especially if you want those times on street tires! I hear many stories about 13 flat (or thereabouts), but mid-low 12's is getting serious. For that, you are going to have to become very mechanicaly inclined (like Greaser), do an expensive bottom end build up, or accept the fact that it may be an expensive tow home.
TRM02
11-16-2001, 01:18 PM
I have also consider that...I think I am going to settle for low 13s
240S15DETE6K
11-16-2001, 03:02 PM
What h.p. will be possible with my S15 motor? It has a stronger bottom end (to fix the crank bearing problem?) conn. rods, etc. What kind of boost will be safe for the motor, and possible with the stock GT28 bb turbo (just got it and the manifold back from Swain Tech., looks great). I'll be controlling it with a Haltech E6K (currently modifying the wiring harness) so it should be in a good state of tune, and I've got a FMIC. Anyone have any hp / torque predictions, I'm getting a little concerned, I thought 300hp was easy? And about the 6-speed, does anyone know WHAT is breaking? Synchros, gear teeth, bearing failures? If I knew what the weak link was I could send it to be cyro-treated or something, maybe that would help? After reading the RB thread, I'm thinking of selling the S15 and getting a RB25 instead. Darn.
oberkill
11-16-2001, 03:05 PM
I agree the higher the horsepower the lower the reliability! Low 13's should be no problem. Make sure your fuel is OK (upgrade fuel pump) and turn up the boost, then its all about hooking up. I took my SR to the track this summer on a hot humid day and ran a 14.2 on 6 psi. I have a FMIC, 3 in exhaust, 3 in downpipe, 2.5 in dump pipe, JWT intake and thats it. That was on street tires without a tach!!! LOL the car was alot faster than I was driving it as I need alot more practice!! :-) Hope that helps!
I am going to find out what kind of HP can be had on a stock SR without changing internals but still keeping it reliable. I got a baseline today for the car and found a few problems that need to be addressed then I will go back and get another. I also have another SR that I am rebuilding torn down in my garage right now that is going to be the toy so I can kind of try out some of the bolt on stuff with the current engine and see what works!!! LOL I need a cheaper hobby!
Alan
Alan
oberkill
11-16-2001, 03:09 PM
On the S15 you should be able to get close to 300 hp at the crank with what you are listing fairly easily. The S15 has the same restrictions as the S14 in the valvetrain but 300hp is nowhere near its danger zone! I really dont have any experiance on the S14 or S15 engine so I dont want to give you bum info though.
Alan
HippoSleek
11-16-2001, 03:47 PM
On s15 gearboxes, I read it was gear teeth - particularly when drifting (which isn't exactly tranny friendly). As for the motor, IIRC Oberkill is correct about the same valvetrain issues, but I think the combo of the GT28 and stand alone set up should get rid you out of the big s13 set-back - turbo and tuning. I recall a trusted person (maybe Asad?) stating that the s15 should be able to make 350whp with the stock turbo (maybe clipped or something) and bottom end. Don't hold me to it though.
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