View Full Version : built sr feels slower than stock sr? lol
Options13
05-04-2010, 10:37 PM
ok so i took my friends stock sr for a spin the other day, at WOT aka full boost, his car seems to actually pull me back into the seat compared to my car
my sr specs:
S13 head, s14 bottom end
Apexi headgasket
S14 t28
Toda Racing Cams 264's
Toda Adjustable Cam Gears
Toda Valve Springs
Tomei Rocker Arm Stoppers
Denso Iridium Plugs
ACT Prolight Flywheel
Stage 1 spec clutch
z32 maf
hp255 walboro with nismo fpr
my friends sr has a stage 3 clutch, but i don't see that making a difference since my clutch isn't slipping or anything like that..
i checked for vaccum leaks, couldn't find any. when i give it full throttle it it builds up to around 6psi it looks like, and i know i don't have a vaccum leak.. my question is.. do my cams need to be timed in order for them to even add power? i swear full throttle feels alot better on my friends stock sr than mine, haha..
when im at WOT, my a/f reads around 11.5, and doesn't stutter or anything.. so i know timing has to be right on or close
S14DB
05-04-2010, 11:12 PM
Are you tuned?
Are you both running the same PSI?
Take them to a dyno?
Z33dori
05-04-2010, 11:21 PM
yea what are you using to tune your car?
all those mods, you need to be tuned. eitehr rOM tune or Power FC or something .... NOT SAFC ... fyi
Slammed Assassin
05-04-2010, 11:32 PM
you have to get a tune to notice the difference.
Options13
05-04-2010, 11:39 PM
enthalpy tune and yes both running stock boost 7 psi
gotspins13
05-04-2010, 11:53 PM
love the knowledge on motors here...
Z33dori
05-05-2010, 12:07 AM
enthalpy tune and yes both running stock boost 7 psi
is this an actual ordered rom tune? or one that u just bought?
Seems very similar to what is happening to my buddies car.
During the winter the car put down 290whp on stock maf... spring hit we put on a Z maf and now the car just dies past 5k and we dyno'd it at about 241whp this time. The car runs pretty nice a/f of 11.5-11.7, but the car isnt really tuned at all, atleast compared to how we had it before winter.
Maybe fiddle with your timing a little
FIlthy 24O
05-05-2010, 12:40 AM
take the cams out you have no need for them...i would run stock cams and you should be set...also what fuel pump on both?
Options13
05-05-2010, 01:04 AM
no need for the cams? what i should go back to stock?
we are both on high pressure 255 walboro's, i have adjustable cam gears, i was told i won't get much out of my cams unless they are timed perfect... this true? maybe thats why i am lacking power..
i forgot to mention in on a z32 maf, and i actually sent in my ECU to get tuned for z32 maf, and s14 t28, and told them the rest of my mods, the car cruises perfect at 14.7 - 15, but idles a little on the rich side? low to mid 13's... is that bad for my plugs? will it foul em out?
FIlthy 24O
05-05-2010, 02:10 AM
thats to big of a duration for your set up...i would go back to stock, i would also buy a new fuel pump something a long the lines of a supra pump or twin turbo rx7 pump. walbro is pretty much a stock replacement for usdm 240sx..lacking series fuel at full boost with turbo very dangerous..
Options13
05-05-2010, 02:17 AM
well, im not lacking any fuel at full boost, IF so, doesn't that have a lot to do with your tune? i thought hp255's were good up to around 400whp?
and if the duration is too big for my setup, could this be why my car feels more sluggish than my friends sr? i thought this shit's supposed to give you more top end..
FIlthy 24O
05-05-2010, 02:20 AM
they suppose but its just they have a really high failure rate...but its just my opinion for your set up and yes i think that is your major problem is with the big cams...plus whatever tune you have...the stock cams will be simpler and more "tuner" friendly.
VQMaxFan
05-05-2010, 03:27 AM
yeah you need to have the cams dialed in, there was a thread with someone having similar problems a few months ago and he had his cams dialed in and solved the problem.
Options13
05-05-2010, 03:39 AM
dialed in as in timed?
shiftdrift
05-05-2010, 03:46 AM
walbro is definitely NOT an oem replacement pump, it's good for some fun power.
lightsource
05-05-2010, 03:54 AM
i'll tell you right now, my car is/was faster than my buddies redtop with a t28, 3" dp/exhaust, 6puck, he takes off but I still power through with 10lbs t25, same boltons, headers, walbro and welded diff. It still feels like his car pulls harder and faster than my car.
This may sound really stupid but... It's because you're in passenger seat. You've gotten used to your car./IMO.
If not, maybe your cams aren't timed/dialed in ;)
ross.cottrill
05-05-2010, 03:56 AM
yeah you need to have the cams dialed in, there was a thread with someone having similar problems a few months ago and he had his cams dialed in and solved the problem.
wow,i cant believe your the only one who mentioned this.if you decked the head during all this workand the block surface you effectively shorten the area your cams haf to travel which would inturn throw off or "retard"your cams and hurt your power tremendously.i would invest in a set of cam gears and a degree wheel and have your cams dialed in.dont get rid of your cams,thats reterded.....jeez..
Future_gohan
05-05-2010, 04:46 AM
thats to big of a duration for your set up...i would go back to stock, i would also buy a new fuel pump something a long the lines of a supra pump or twin turbo rx7 pump. walbro is pretty much a stock replacement for usdm 240sx..lacking series fuel at full boost with turbo very dangerous..
You on crack? Walbro's arn't anywhere near stock.
S14DB
05-05-2010, 09:44 AM
Still think a real dyno is better then an ass dyno...
951's 330i
05-05-2010, 09:58 AM
Still think a real dyno is better then an ass dyno...
+1 msggglength
sean350z
05-05-2010, 10:19 AM
I don't understand, what's "built" about your engine? 264's at .5 bar is pointless, period. Cam gears, if not properly set up will screw with your timing.
Go back to stock cam gears and up your pressure and retune, then you'll beat him if that's your goal...
WISH ONE
05-05-2010, 10:22 AM
wow,i cant believe your the only one who mentioned this.if you decked the head during all this workand the block surface you effectively shorten the area your cams haf to travel which would inturn throw off or "retard"your cams and hurt your power tremendously.i would invest in a set of cam gears and a degree wheel and have your cams dialed in.dont get rid of your cams,thats reterded.....jeez..
by removing material from either block or head you are actually reducing combustion chamber size, although the amount is usually very small this would actually increase compression right?
S14DB
05-05-2010, 12:03 PM
by removing material from either block or head you are actually reducing combustion chamber size, although the amount is usually very small this would actually increase compression right?
He is talking about when you change the distance between the cam gears and the crank you change their phasing when the timming chain is the same length.
lightsource
05-05-2010, 12:06 PM
He is talking about when you change the distance between the cam gears and the crank you change their phasing when the timming chain is the same length.
Interesting. So... do you just get the timing chain modified? or it's only remedied with cam gears?
jspaeth
05-05-2010, 12:09 PM
Interesting. So... do you just get the timing chain modified? or it's only remedied with cam gears?
If you shave a significant amount off the head or deck, you either
1) Make up for it with a thicker HG
or
2) Accept the resulting higher compression ratio....but then with OEM cam sprockets, your CAM timing (mechanical timing) is slightly off, so you would use adjustable cam gears to dial them back in.
trsilvias13
05-05-2010, 12:10 PM
thats to big of a duration for your set up...i would go back to stock, i would also buy a new fuel pump something a long the lines of a supra pump or twin turbo rx7 pump. walbro is pretty much a stock replacement for usdm 240sx..lacking series fuel at full boost with turbo very dangerous..
any real facts/data to this?
I ran the stock oem fp and it read 50-52psi on a summitracing gauge. Switch out to a walbro 255l high flow and i had 65psi consistantly on same gauge, same fuel filter. Unless you have substantial data to back up your claim, please do not spread false information.
lightsource
05-05-2010, 12:18 PM
If you shave a significant amount off the head or deck, you either
1) Make up for it with a thicker HG
or
2) Accept the resulting higher compression ratio....but then with OEM cam sprockets, your CAM timing (mechanical timing) is slightly off, so you would use adjustable cam gears to dial them back in.
+1 thanks!:goyou::goyou:
Options13
05-05-2010, 12:57 PM
alright i'll get the cams dialed in by a shop and get back to you guys, and i didn't necessarily mean "built" sr, i just meant NOT stock
slider2828
05-05-2010, 01:46 PM
You have tomei poncams, you mostly don't need them dialed in. Also most likely passenger syndrome, when you drive, you feel less of the rush when compared to being a passenger...
Go get a dyno and dump the tune for a real ecu.....
Don't bother going to shops to get your cams timed, cause poncams 264s really is nothing.... overlap and stuff is pretty close to stock...
Also tires, diff, and driveline mods like flywheel and driveshaft make a huge difference... Weight of the car as well...
Options13
05-05-2010, 01:52 PM
tomei? i have toda racing cams
my gauge is reading -15 to -17 in/hg at idle, isn't it supposed to be at -20? or do bigger cams lower vacuum?
i double checked my timing today with a timing gun, unplugged my TPS, it idled at 1100, turned the idle screw down to let it idle around 800, and yeah its right on -15 maybe a LITTLE below
Options13
05-05-2010, 05:07 PM
heres a vid
YouTube - sr20det 264 toda's (http://www.youtube.com/watch?v=vIdStzXBGPc)
jspaeth
05-05-2010, 06:02 PM
tomei? i have toda racing cams
my gauge is reading -15 to -17 in/hg at idle, isn't it supposed to be at -20? or do bigger cams lower vacuum?
i double checked my timing today with a timing gun, unplugged my TPS, it idled at 1100, turned the idle screw down to let it idle around 800, and yeah its right on -15 maybe a LITTLE below
Cams make a HUGE difference in vacuum at idle, because of overlap
OEM cams I was at 20 in/Hg at idle.
Now I have HKS 264s....with idle at roughly 800 RPM, I am only seeing about 14-15 in/Hg.
Options13
05-05-2010, 09:03 PM
ok, today i was at a stop sign and from first to second i give it almost WOT, and all of a sudden i hear a gay ass loud clicking sound, the more i push on the gas the louder, but doesn't get any louder at higher rpms, my foot controls how loud the clicking will be, it does it at idle too..
sounds exactly like an exhaust leak, can gaskets just blow out like that? sounds like a BAD exhaust leak, almost sounds like im running open header
renegade_ewok
05-05-2010, 09:32 PM
Could have blown your exhaust manifold gasket and that basically ruins spool and power instantaneously....
Options13
05-05-2010, 09:35 PM
thats exactly what it sounds like, could it be because i tightened my new headers in to tight? (isis TUBULAR V2)
S14DB
05-05-2010, 10:34 PM
Gaskets that come with most manifolds are usually crap. Get a S15 MLS Gasket.
fcdrifter20
05-05-2010, 10:40 PM
thats exactly what it sounds like, could it be because i tightened my new headers in to tight? (isis TUBULAR V2)
nope, its just that most gaskets that come with the lower price kits are always cheap graphite, change them to the metal ones, and if you put the same gasket between the manifold and the turbo(the square one) change that out asap, cuz it will blow soon
Options13
05-05-2010, 10:40 PM
alright will do, hopefully the dealership has some tomorrow, gesus it sounds so horrible
slideways2004
05-05-2010, 11:08 PM
yeah if you used the horrible gaskets that come with the manifold, you are asking for trouble.
You should use oem s15 gasket for the head and a oem t25 turbo gasket. Both metal
Z33dori
05-05-2010, 11:27 PM
ok, today i was at a stop sign and from first to second i give it almost WOT, and all of a sudden i hear a gay ass loud clicking sound, the more i push on the gas the louder, but doesn't get any louder at higher rpms, my foot controls how loud the clicking will be, it does it at idle too..
sounds exactly like an exhaust leak, can gaskets just blow out like that? sounds like a BAD exhaust leak, almost sounds like im running open header
did your boost go down?
that is usually a dead give away, if you makes half or less the boost as normal at fool throttle.
Options13
05-05-2010, 11:40 PM
it definitely did feel like it lost some power, at first i thought it was pre-detonation, but im not even sure what that sounds like, i didn't feel any stuttering so i just kept driving it
i didn't give it WOT so i dunno if boost went down, but it def. has less power
brian3676
05-05-2010, 11:42 PM
From your 500 posts on other car forums about timing, im guessing your timing might still be a little off possably? Also i would get some NGK plugs, just the bkr6e are fine and there like $2 a plug. make sure you gap them right.
brian3676
05-05-2010, 11:45 PM
Gaskets that come with most manifolds are usually crap. Get a S15 MLS Gasket.
This is a good idea for sure! specially the gasket that comes with the isis shit. get a OEM one, for the T2 (mani to turbo) and the 5 bolt dump tube gasket. It will be well worth your time
Options13
05-06-2010, 12:02 AM
i re-checked my timing today, i let my car idle at 800, and its right on 15 degrees, with the tps unplugged
yeah i'll replace all the gaskets tomorrow, hmm this may have been why my exhaust sounded a little hondaISH
shit i even gave alex a call to make sure this wasn't pre-det.
brian3676
05-06-2010, 12:19 AM
i re-checked my timing today, i let my car idle at 800, and its right on 15 degrees, with the tps unplugged
yeah i'll replace all the gaskets tomorrow, hmm this may have been why my exhaust sounded a little hondaISH
shit i even gave alex a call to make sure this wasn't pre-det.
Yeah blown T2 gasket sounds like a old beat up car with rusted out exhaust, and will definitely make your turbo not spool as fast or efficiently.
Options13
05-07-2010, 12:07 PM
the t2 gasket was blown to hell, holy shit
my car is idling rich! its at about 12 on the wideband now, i don't see why the idle is getting richer and richer, i have no boost leaks.. when i unplug and plug in my o2 sensor nothing happens the reading stays the same, maybe i have a bad o2? anyway to test?
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