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tercel613
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![[*]](./images/reveal/default_icon.gif) posted on 25-7-2010 at 05:29 PM |
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engine power question
i boosted my JDM 5efe engine it now has all forged internals with a 9.1:1 compression, custom intake manifold with 75mm throttle body, custom exhaust
manifold i have 5efhe cams... turbo is a t3/t04b ... 650cc injectors and 255lph fuel pump. i'm using megasquirt for engine management
the head is the stock 5efe one with a 3 angle valve job
i was on the dyno last week and can't make power to the original redline of the engine (7400rpm)
at 9 psi the power would drop drastically at 6900rpm, at 15 psi the power drops at 6400 rpm.... so the more boost i run the earlier the power drops in
the rpm band....
my tuner thinks that the car "sounds and acts" as the valves are floating (what confirmed his idea is when we turn up the boost the power falls down
earlier in the rpms...) the tuners other idea could be a valve not sitting properly at high RPM and he says there isn't really anyway to test that
aside from taking it all apart...
but all the other turboed tercel/paseos i heard of never had valve springs not being strong enough at any kind of boost level causing them
issues???
i just wanna make sure i don't take things apart again to change the valve springs if i don't have to.... i just had the engine completely rebuild
200km ago...
what do you guys think would cause that???
thanks
alex
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mulberry
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| posted on 25-7-2010 at 06:31 PM |
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Trevor or sleepyrz can confirm this but the valve springs should be the same as the 5EFHE valve springs. Were the 5EFHE cams shimmed properly??? When
the car is revved in neutral does it go all the way to 7200RPM?? What is the A/R for both the compressor and exhaust housings?? Do you have a pic of
the dyno graph that you can post?? The pic of the dyno sheet will offer some more clues especially if it shows the AFRS.
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tercel613
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| posted on 25-7-2010 at 06:39 PM |
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the cams were shimmed buy the engine builder.... i haven't rechecked them but the valves aren't tiking..... so i'm guessing its fine??? i haven't
tried revving it in neutral but driving it and on the dyno it does go to about 7200 its just that after 6400 it slows down like crazy and almost
sounds like floating valves....
this is the specs of the turbo:
GARRETT T3 / T04B "S" trim (130-350 HP)
TURBO SPECIFICATIONS:
compressor wheel: 48.4 / 69.9 mm 48 "S" Trim
compressor housing: 0.60 a/r T04B
center section: oil cooled journal bearings
Turbine wheel: 68 trim (stage1)
Turbine housing .63 a/r upgrade
i can't figure out how to attach a pic of my dyno sheet???
thanks
alex
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tercel613
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| posted on 25-7-2010 at 06:44 PM |
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here's a link to the picture!
http://www.redliners.ca/forums/attachment.php?attachmentid=3223&d=1279985067
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mulberry
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| posted on 25-7-2010 at 07:41 PM |
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| Quote: | Originally posted by tercel613
the cams were shimmed buy the engine builder.... i haven't rechecked them but the valves aren't tiking..... so i'm guessing its fine??? i haven't
tried revving it in neutral but driving it and on the dyno it does go to about 7200 its just that after 6400 it slows down like crazy and almost
sounds like floating valves....
this is the specs of the turbo:
GARRETT T3 / T04B "S" trim (130-350 HP)
TURBO SPECIFICATIONS:
compressor wheel: 48.4 / 69.9 mm 48 "S" Trim
compressor housing: 0.60 a/r T04B
center section: oil cooled journal bearings
Turbine wheel: 68 trim (stage1)
Turbine housing .63 a/r upgrade
i can't figure out how to attach a pic of my dyno sheet???
thanks
alex |
To attach pics you will need an account with photobucket.com and upload the pics with [img]
If I remember correctly only "P" trims were used. That turbo seems a bit large for a 1.5. I can give you turbo specs that have worked and produced
300+ wheel horsepower on a fully built engine with CP/Ross pistons and Pauter/Eagle connecting rods.
T3 50 Trim/Stage 2
Turbine Exducer diameter 49.53mm
Turbine Mayor diameter 63.75
Compressor Exducer diameter 46.23
Compressor Mayor diameter 59.94
Turbine housing A/R .48
Compressor housing A/R .42
If the valves are floating they will float when you dry rev the car in neutral. If a valve was not seating properly you should have a slight misfire.
You can change the valve springs without removing the cylinder head. You will need an air compressor to pressurize the cylinders once the cams have
been removed. Set the car to TDC, make sure it is on the compression stroke, then remove the cam cover and cams. Use a piece of cardboard to number
and mark where each cam cap comes from to ensure they are replaced in the correct order. With the engine set to TDC, fit the airhose to number one
cylinder after removing the spark plug. Once the cylinder is pressurized, you can compress the valve spring and remove the retainers and valve spring
locks which are called collets. Change one valve spring at a time for the number 1 cylinder. After changing all four and making sure all four
retainers are locked in place, remove the airhose and the number four spark plug and fit the airhose to the number 4 cylinder. Follow the same
procedure as the number one cylinder. After changing the springs for the number four, you will need to turn the engine to have the numbers two and
three pistons at TDC and follow the same procedure. Use a set of new valve springs for a 92-95 Toyota Paseo. If you are not comfortable changing the
valve springs without removing the cylinder head then by all means remove the cylinder head and have your tuner change the valve springs. After market
valve springs like Cruise springs are not necessary unless using uprated cams.
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tercel613
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| posted on 25-7-2010 at 08:25 PM |
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i think too the turbo is too big considering when the power comes in but i think it'll just make even more power after 6400.... so i don't think
that's my main issue for power loss at high rpm???
so you think it is necessary to change the valve springs???? if i'm gonna change them i'll put cruise ones in.... don't i need to have an engine
builder to check the base spring pressure and stuff??? isn't it more complicated then just installing them??? i've changed valve seals on my old
tercel before so the labour part isn't really scaring me... i'm more worried about making sure all is perfect and all is fine... but the engine
builder had checked all the valve clearances like 200km ago when the engien was build... so as long as i put the shims back in the same spot changing
the springs doesn't affect clearances or anything right?
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tercel613
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| posted on 25-7-2010 at 08:27 PM |
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tercel613
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| posted on 25-7-2010 at 08:58 PM |
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i also have a video where you can hear the engine change sound at high rpm and you also see the engine stop "torquing/ rotating" when it's on the
dyno....
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t_cel_t
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| posted on 25-7-2010 at 09:43 PM |
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well it looks like you are going way way rich after 6000rpm, 11-11.5 really?
its probably drowning in fuel.
need to have it around 13, maybe dipping down into the upper 12's.
[Edited on 7/26/2010 by t_cel_t]
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mantafelix
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| posted on 25-7-2010 at 10:43 PM |
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Tu est qui? Peut-etre que je te connais... Ton tercel a l'air vraiment clean!
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tercel613
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| posted on 26-7-2010 at 03:15 PM |
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well i think 11.5 is fine for turbod engine.... 13 is more for an N/A engine.... no???
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t_cel_t
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| posted on 26-7-2010 at 03:29 PM |
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well actually your almost dipping down into the 9s, you can see the big drop in power as you get below 11.
look at other dyno graphs of other turbo cars and you will see that they never go that low.
ex.
[Edited on 7/26/2010 by t_cel_t]
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mulberry
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| posted on 26-7-2010 at 06:11 PM |
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| Quote: | Originally posted by tercel613
i think too the turbo is too big considering when the power comes in but i think it'll just make even more power after 6400.... so i don't think
that's my main issue for power loss at high rpm???
so you think it is necessary to change the valve springs???? if i'm gonna change them i'll put cruise ones in.... don't i need to have an engine
builder to check the base spring pressure and stuff??? isn't it more complicated then just installing them??? i've changed valve seals on my old
tercel before so the labour part isn't really scaring me... i'm more worried about making sure all is perfect and all is fine... but the engine
builder had checked all the valve clearances like 200km ago when the engien was build... so as long as i put the shims back in the same spot changing
the springs doesn't affect clearances or anything right? |
As long as the shims are returned to the correct bucket new springs will not affect the clearance. The installed height of the Cruise springs may
change the clearances. If running other than stock cams then you should check the base spring pressure.
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mulberry
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| posted on 26-7-2010 at 06:16 PM |
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| Quote: | Originally posted by tercel613
well i think 11.5 is fine for turbod engine.... 13 is more for an N/A engine.... no??? |
With 650cc injectors 11.5 is really rich, the target should be closer to 12.2 but do not go above 12.2.
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tercel613
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| posted on 26-7-2010 at 07:52 PM |
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so you think i should replace the springs???? and if i'm reinstalling the 5efhe cam on the 5efe head then i don't need to have the base spring
pressure on cruise valve springs rechecked???
thanks alot for the help....
alex
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