Author | Topic |
Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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40c DIY FCD for 1JZ
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Thu, 22 April 2004 02:48
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Ok, I've had a look around the internet at DIY fuel cut defenders, and the easiest one I've found is very simple, & involves soldering up a zener diode between the MAP signal wire & earth, which bleeds off any voltage over 4.3, efectively capping the MAP sensors output before the fuel cut.
Besides the obvious dodgyness of using a FCD, does anyone know if this will work ok, specifically on a 1J?
I'll only be pushing it up to 16psi I reckon, & with a bottle of octane boost & the 1Js naturally rich A/F ratio I'm not too worried about blowing up the motor, but I would like to know if anyone here has tried it, or if anyone here can think of a reason why it might not work?
BTW, yep, the diode costs 40c.
Now that's my kinda mod!
[Updated on: Thu, 22 April 2004 02:53]
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Location: Adelaide, SA
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 03:48
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BigWorm wrote on Thu, 22 April 2004 12:18 | Ok, I've had a look around the internet at DIY fuel cut defenders, and the easiest one I've found is very simple, & involves soldering up a zener diode between the MAP signal wire & earth, which bleeds off any voltage over 4.3, efectively capping the MAP sensors output before the fuel cut.
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So effectively you're telling the fuel management that it is only getting X psi boost (and supplying the correct amount of fuel for X boost) when really it's getting X+Y psi? I know the 1jz's run rich at the top but unless you are sure it won't lean out it could be a recipe for diasaster.
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 03:54
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Yep, that's right, I know I'm asking for trouble etc.
Lucky I didn't mention how it's still running the standard cressida fuel pump!
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Location: Adelaide, SA
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 03:56
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It's probably the same as the soarer! My 1jz has been working fine with my NA MA70 fuel pump (which I'm pretty sure is the same as the Turbo one)
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Location: Brisbane
Registered: November 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 07:03
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A fuel cut defender is only a good investment if you have a car running safely around the maximum boost that just occasionally touches fuel cut. if you are doing it to run considerably higher boost than standard you've got rocks in your head
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Toymods Social Secretary
Location: Sydney
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 07:57
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lol... you could always use a logarithmic pot!!
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Location: I wanna go Hawaiiiiii.......
Registered: November 2003
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 14:49
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The Zener diode FCD has been tried and used successfully by Celicamad and i think Craig (GIHOOK) with mixed success. Best talk to them about the mod.
To use a FCD is not dodgy at all really, many fast cars rely on this technique to make serious and reliable power. Matthew's (from Magic Performance) big single 1jzgte powered RA23 for instance, 2nd fastest time over all at dubbo nats this year, factory computer and injectors + FCD.
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Registered: June 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 22 April 2004 21:48
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Quote: | To use a FCD is not dodgy at all really...
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Unless something goes wrong, ie. actuator line blocking/coming off and the boost goes through the roof, buy buy engine!!!
What you really need to be able to do is raise the boost cut rather than eliminate it!!
With older cars (like my old 323gtx) they had separate boost cut solenoids, with those you use to bleed off some of the boost (as you do to get more boost anyway), this way the boost cut still works just at a higher psi, so you still have some protection.
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Location: Newcastle, NSW, Australia
Registered: May 2002
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Toymods Social Secretary
Location: Sydney
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Fri, 23 April 2004 03:12
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yeah sounds liek a worthy design grant... pretty damn basic
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Fri, 23 April 2004 16:37
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Sweet, thanks for the help guys, I might do a bit of testing with the multimeter before I go plonking the diode in, then I'll most likely have a go at making the adjustable one instead.
Damn the long weekend double demerits! I wanna try & sort it out by this wednesday....
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Location: Auckland, NZ
Registered: April 2004
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Re: 40c DIY FCD for 1JZ
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Fri, 23 April 2004 20:18
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I don't suppose you guys would want to post in a diagram of how to build and wire in that adjustable FCD with the two diodes and a POT? I'd be keen on building one if the 1G ever hits boost cut, and no doubt will come in handy when I drop the 1jz in....
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Location: Montrose, VIC
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Sat, 24 April 2004 22:54
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Only a few issues:
1. By the time you add another zener AND a pot, the cost might be pushing the $1 mark...
2. Make sure you check it out with a wideband, and possibly try one of those nasty non-linear (rising rate??) pressure regs as well, that way you can get away with a bit more boost, at least until timing rears its ugly head. Which, who knows, maybe you can get around by 'fooling' the air temp sensor. Ahh, I love dodgy mods
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Location: Phils
Registered: December 2003
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Re: 40c DIY FCD for 1JZ
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Sun, 25 April 2004 15:25
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Grant wrote on Fri, 23 April 2004 08:11 | The DIY FCD actually uses two zeners and a pot so you can adjust it to just above the boost cut. I've made quite a few over the years at customers request and all seemed to be happy with them. The last two guys I built them for were using HKS FCD's but had continual trouble with them (not uncommon with the HKS ones). They fitted the cheapy FCD and were rapped.
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do you have any diagrams for the cheap FCD you design?
kindly share it to us.
thanks,
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Location: UK
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Sun, 25 April 2004 16:27
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4.3 volts is around 11psi, and youre hoping to run 16? rich or not.. very very risky.
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Mon, 26 April 2004 01:40
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BigWorm wrote on Sat, 24 April 2004 02:37 | Sweet, thanks for the help guys, I might do a bit of testing with the multimeter before I go plonking the diode in, then I'll most likely have a go at making the adjustable one instead.
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Mon, 26 April 2004 07:25
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Well, I just spent the day doing some testing, & with the multimeter hooked up to the map sensor I found it was putting out about 3.9V at 11psi, and was hitting boost cut at 4.37-4.39V, which was 13.9-14.1psi.
Because the signal was so close to 4.3V, I decided to try out the single diode, but it didn't work at all. It was as though the computer knew I was trying to mess with it, & it wouldn't go much over 10psi, with power dropping off over about 75% throttle, & going up when I backed off a bit. Very wierd.
I guess I'll have a go at the 2 diode & a trim pot method, hopefully that will give better results.
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Location: UK
Registered: May 2002
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Location: Wollongong
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 27 April 2004 02:15
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Manny has done a heap of testing on the MAP sensors I believe. I remember seeing graphs and everything. I'll have to hunt around for it.
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 27 April 2004 10:05
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Well I went out today & got the parts necessary to make the 2 diode & a pot setup, & guess what, the parts cost me 22c! Even cheaper than the single diode!
I've put it together & wired it up, now I'm gonna go out & try to set it up & test it in this crappy wet weather...
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Location: Phils
Registered: December 2003
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Re: 40c DIY FCD for 1JZ
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Tue, 27 April 2004 10:51
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BigWorm wrote on Tue, 27 April 2004 20:05 | Well I went out today & got the parts necessary to make the 2 diode & a pot setup, & guess what, the parts cost me 22c! Even cheaper than the single diode!
I've put it together & wired it up, now I'm gonna go out & try to set it up & test it in this crappy wet weather...
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please post the results
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Location: Brisbane
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 27 April 2004 11:50
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yeah.. keep us updated
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 27 April 2004 12:44
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That worked a treat! The best 22c I've ever spent!
It took me a while to set it up, as I was only adjusting it a small amount at a time, but eventually the fuel cut disappeared. I re-adjusted the pot back up a little bit but hit the cut again, so adjusted it back down a little & there it stayed, with the fuel cut no more. At first I was only running around 14.1, then slowly wound it up. I am controlling the boost with a Blitz SBC iD-III which is making things pretty easy, & I ended up setting at about 15.2psi, with only a small amount of gain to kep spiking to a minimum.
I'll probably set up another boost map with a bit less boost & a bit more gain for comparison, although the extra response has just resulted in alot more wheelspin on launches in 'preliminary' testing, but is much better for daily driving.
Now can everyone please pray the rain holds off tomorrow??? Eastern Creek MUST stay dry!
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Location: Perth
Registered: January 2004
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Re: 40c DIY FCD for 1JZ
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Tue, 27 April 2004 15:14
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Abit off topic, but still kind of relevant to the situation.
How do you have your boost controller setup in the engine bay ?
I have a Blitz Dual SBC on my 1jz, and all i can get it to do is spike the boost up to about 16psi only to have it drop back down to 11 - where it was before the controller was put in. Fiddling with the gain has only resulted in the drop off becoming a bit more slower than before.
Any Ideas ?
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Wed, 28 April 2004 07:50
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That's strange, is this in 3rd or 4th gear? 1st & 2nd won't hold as much boost, and the gain shouldn't really affect it once it's hit peak boost, so prolly best to leave that off until the boost is stable.
Mine's set up in the far right hand rear corner of the engine bay, next to the brake booster, so the length of the hoses to & from the compressor & wastegate is a bit longer than I'd like, but it still seems to work quite well. I have the 2 compressor lines linked, & the 2 wastegate lines linked, then connected through the solenoid unit.
I don't know what else to suggest, apart from the obvious, like triple check the hoses are all the right way round, there's no leaks any where, etc
How do you adjust the boost, with a 0-100 scale?
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Location: sunny coast, qld
Registered: October 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 29 April 2004 01:56
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silly question but, is fuel cut the same as boost cut on a 1jz?
How do these mods sound?
600*300*75 FMIC
twin pipes into 3" exhaust
air filter
S-AFC II
speed cut defender (high diff ratio)
oil catch can (gen 1 1jz)
celicamad boost controller (if boost is not already up about 14psi)
$1 FCD
ANyone know if the S-AFC II has an inbuilt speed cut defender?
anything else?
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Location: I wanna go Hawaiiiiii.......
Registered: November 2003
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Location: sunny coast, qld
Registered: October 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 29 April 2004 07:37
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hmm ok then. The only reason I said that was because I remember readint about people with twin pipes, FMIC and nearly hitting boost cut. Can't remember who it was though.
I will get a celicamad boost controller though. Who wouldn't with all the great feedback they get.
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I supported Toymods
Location: south of the big smoke
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 29 April 2004 11:37
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joel are u running duel dumps? cause temps must be getting pretty damn hot at 16psi?
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Location: Brisbane
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Thu, 29 April 2004 11:49
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Im lookin at getting a celicamad boost controller soon.. when im back in the black
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Toymods Board Member I supported Toymods
Location: Turramurra, Sydney.
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Fri, 30 April 2004 05:26
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Craig, nah it's just the standard dump, but I havn't actually pushed it to 16psi yet, the most I've had it on is 15.2, and even then I'm never on full boost for very long at all, maybe 5sec at the most.
Engine temp hasn't suffered noticably, the 2 14" thermos keep the temp pretty well in check. I also had to recently install a new temp guage (cheapo $30 mech. type), as the bloody standard one didn't budge from normal op. temp. when the fans stopped working. And even with the original sender unplugged & removed from the engine, the original temp guage still pops up to standard operating temp when the car's running!
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Location: newcastle
Registered: June 2002
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Re: 40c DIY FCD for 1JZ
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Sat, 01 May 2004 12:09
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o.k yeah mods
well definatley dumps and an airbox (not a dumb podfilter in the enginebay .....interheater )
use a ss commodore one they are cheap and VERY high flowing and the stock paper filter has proven to perform as well as ANY aftermarket one
3 or bigger exhuast .
big fmic .
THEN power is made by bringing the boost on sooner in the lower gears .
IE you should be running the same boost in 1st as 4th .
1js (stock ecu)DO NOT like running more than 16psi .the seems to be a map issue as you can run 16-17 psi midrange for a short period of time with BIG gains .
although running more boost makes more PEAK power performance is lost with the engine running VERY rich in the midrange .
MORE PEAK POWER BUT MUCH SLOWER
The ultimate boost curve for a 1j is boost to SNAP to 16-17 psi then slowly fall off to hold 15 psi until redine .
this needs to be done the same in all gears .
i actually design my controller to do this and the BEST results have been achieved using this setup .
So if you can find a way to get the electronic to work this way then im sure you will notice a BIG peformance gain .its worth trying anyway
P.s long lenghts of hose will actually cause a small spike .
this will be actually for a duration eg 1 sec .so the spike will be most noticeable in lower gears
this is not actually a bad thing
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Location: sunny coast, qld
Registered: October 2002
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Re: 40c DIY FCD for 1JZ
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Sun, 02 May 2004 01:27
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thanks mate!
will follow that advice.
I already have a pod filter so I think I will get a seperator thing made up to keep the hot air away from it.
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Location: Sydney
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Sun, 02 May 2004 02:48
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The Apexi S-AFC does not work as a speed cut but will work as a boost cut defender (work well too)
I know some one (me:D sorry not steeling the thread) that has a S-AFC for sale in the for sale section make him a good offer and he might include a GReedy speed cut defender in the deal
ohh make sure you get a celicamad controller i have one and would not swap it for any controller on the market anyone who uses anything else is nuts (i've used a few controllers in my time!!!!) they are SO freakn accurite its scary...electric one are accurite cause they keep corecting the boost, celicamad controllers simply just work....
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Location: Brisbane
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Sun, 02 May 2004 11:22
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i was just thinking of enclosing where my pod filter is and running CAI to it...
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Location: newcastle
Registered: June 2002
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Re: 40c DIY FCD for 1JZ
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Sun, 02 May 2004 12:51
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we have PROVEN 10h.p so about 7 kw @ the wheels on a 30 degree day GAIN by enclosing pod and adding 3 inch cold air pipe
P.s thanks to all those giving my controllers a wrap .makes the 2 years of model after model worth it
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Location: Kita-Ku, Sapporo, Japan
Registered: January 2003
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Re: 40c DIY FCD for 1JZ
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Sun, 02 May 2004 13:17
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just readin the thread, and this is not exactly a 40c mod but....
is the JZ MAP a relative or absolute pressure sensor?? what voltage is it at atmospheric pressure??
i think a relatively simple way to fool the ECU is:
if stock MAP goes to 5V at 1BAR
get MAP sensor that has same volts at atmospheric, and goes to 5V at 1.5 BAR (the MPX4250 goes to 1.5BAR boost and is about AUD$30 from www.digikey.com)
this way the EXU sees 2/3rds of actual boost, as determined by MAP sensor. (ie boost is 50% more than it thinks)
then, raise fuel pressure by 50%. this way fuel delivered for same PWM is 50% more than the ECU thinks...
for vacuum? i assume that the stock MAP goes to near 0V at 1bar vac. so does MPX4250. even for vacuum, the ECU will see 2/3rds actual boost and the increased fuel pressure will still work.
you still want the fuel pressure reg to be vac referenced, with 1:1 ratio, but base pressure be 50% more (ie 50% higher pressure everywhere.
doable?
Cya, Stewart
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Location: Brisbane
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Sun, 02 May 2004 14:00
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celicamad wrote on Sun, 02 May 2004 22:51 | we have PROVEN 10h.p so about 7 kw @ the wheels on a 30 degree day GAIN by enclosing pod and adding 3 inch cold air pipe
P.s thanks to all those giving my controllers a wrap .makes the 2 years of model after model worth it
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what materials did you encxlose it with?
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Location: sunny coast, qld
Registered: October 2002
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Re: 40c DIY FCD for 1JZ
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Mon, 03 May 2004 05:11
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and what size twin pipes are people using?
will be getting them in about a week.
thanks
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Location: Brisbane
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Mon, 03 May 2004 11:22
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i heard they are 2.5 that merge into a 3 just before exhaust
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Location: newcastle
Registered: June 2002
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Location: sunny coast, qld
Registered: October 2002
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Re: 40c DIY FCD for 1JZ
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Mon, 03 May 2004 22:25
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re these dump pipes from Lilford exhaust: is it just the flange with a U bend and another flange with the sharp left and sharp right or is it the whole distance one like you have?
Are these made for a specific car, because I doubt my car would have the same clearance as a jza70/jzz30.
thanks again for the info.
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Location: south east - melbourne
Registered: March 2004
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Re: 40c DIY FCD for 1JZ
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Tue, 04 May 2004 00:31
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celicamad wrote on Mon, 03 May 2004 21:37 | My
POI the factory cressdia 7m airbox with font mount 3 inch duct to it flows 90% as good as pod or ss box ...filters are expensive and you cant hear the blow off valve through them
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WHATS WITH THE filtersexpensive , u mean pod filters ?????
and cant hear the bov through the filter , if u can hear the hissing / faint gushing noise from the pod flter doeasnt that mean that the compressor surge is still returning back through the turbos via the afm and out the pod
so what the use of a bov being there , when theres still compressor surge
just query , no offence to u bro , as i thought if the recirculating bov was there u wouldnt hear the compressor surge coming out the pod
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Location: newcastle
Registered: June 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 04 May 2004 08:47
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no factory Cressdia filters are expensive compared to $6 commodore ones .
the factory cressida filter is a large quite thick paper filter .
Through the commodore airbox you can clearly hear the factory bov at the air intake at the front of the car .the resonation chamber and filter on the stock Cressida one considerably reduces this noise and it can barley be heard .
i think your misundestanding what compressor surge actually is. the air being vented by a bov is simply pressurised air .
turbos simply spool up faster when they dont have to spool up against the pressurised air . this sometimes casues compressor surge if the compressor is attemting to spool up against trapped pressurised air
the noise is simply bov venting to intake. air does not exit the intake just the sound of the bov opening . 1jz are not afm
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Location: sunny coast, qld
Registered: October 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 04 May 2004 09:09
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i rang Lilford exhausts today and they told me the dumps are 2.5" from the turbo that join to a 3" pipe and they are about 30cm long. I told them I was told about them from some Toyota Nationals people but I don't know if that changed their price or not. They quoted me $420 which I think is alright.
However, they said they were to fit a supra and I am a bit hesitant of paying that much money plus postage to QLD when I don't know if they will fit in my Corona. I think I will get custom ones instead.
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Location: Sydney
Registered: May 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 04 May 2004 12:41
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Celicamad: on a side note, I was wondering if you knew which wires I would need to put a fuel cut device on a 3rd gen 1G-GTE, I want to be able to run 15psi without the hitting of boost cut on night time drives etc.
I used to hit it late at night but ran alright during the day when I ran it in the celica and that meant I had to adjust the bleeder valve accordingly.
also I'll be getting one of you boost controllers once I get the motor in the corona and up and running.
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Location: newcastle
Registered: June 2002
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Re: 40c DIY FCD for 1JZ
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Tue, 04 May 2004 13:05
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do a search on here for a user captain chaos this is craig he is the wiring man ask him he put me on to them .i simply cant remeber which wires go where with out pulling out my glovebox
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Location: south east - melbourne
Registered: March 2004
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Re: 40c DIY FCD for 1JZ
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Tue, 04 May 2004 22:46
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yeah thanks mate ,
i thought the bov noise was actuallt the bov not doing its job properly and the excess pressur was travelling back to the turbo and out the afm via the pod
used to happen in my exa when there was no bov on it and that was definitly compressor surge as there was nowhere for the pressure to vent and it came right back at the turbo , and out the afm
can i also ask , in my 1g-gte , (its a stocker) whenever i let go off the accelerator pedal after flloring it , it makes a whistling noise anyone know what the hell it is , as these engine have no bov from factory
is there some kind of over boost valve or something n the 1g-gte
cheers
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Location: I wanna go Hawaiiiiii.......
Registered: November 2003
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Re: 40c DIY FCD for 1JZ
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Wed, 05 May 2004 00:19
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Anyone who wants to trial a celicamad boost controller in sydney can pm me to arrange a time. I am home this weekend, and happy to fit and tune a controller for those interested in buying. I am in Chatswood.
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Location: Brisbane
Registered: July 2002
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Re: 40c DIY FCD for 1JZ
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Wed, 05 May 2004 08:15
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Chris Davey wrote on Tue, 04 May 2004 19:09 | i rang Lilford exhausts today and they told me the dumps are 2.5" from the turbo that join to a 3" pipe and they are about 30cm long. I told them I was told about them from some Toyota Nationals people but I don't know if that changed their price or not. They quoted me $420 which I think is alright.
However, they said they were to fit a supra and I am a bit hesitant of paying that much money plus postage to QLD when I don't know if they will fit in my Corona. I think I will get custom ones instead.
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sucks doesent it?.. i think ill have enough room though
can u tell me the pricing on custom ones when u get it done?.. cause i might have to.. over msn to me aswell.. as i might miss posts
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