~5.8° exhaust retard from knock pin adjustment?

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~5.8° exhaust retard from knock pin adjustment?

Postby athousandleaves » Tue Oct 08, 2013 5:35 am

As I'm sure everyone knows our engines are capable of producing more power with a 6° exhaust cam retard and the only way for one to achieve such a value is typically with adjustable cam gears.

Each tooth on the timing belt is 7.8° so just retarding by one tooth would be too much.

After reading through the bgb I noticed the section where they go into detail on the cam knock pin adjustment and how the first two holes are for +/-2° and the other two are for +/-5°.

Would it not stand to reason that if you retarded the cam by one tooth on the belt -7.8° and then aligned it with the +2° hole for the knock pin that you would have an exhaust retard of -5.8°?

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Last edited by athousandleaves on Thu Oct 10, 2013 2:57 pm, edited 1 time in total.
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Re: ~5.8° exhaust retard?

Postby built2run » Tue Oct 08, 2013 6:17 am

Or get a gen3 exhaust cam and retard by 2
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Re: ~5.8° exhaust retard?

Postby athousandleaves » Thu Oct 10, 2013 2:07 pm

Maybe I should.have titled this thread something like "TTE JDM TRD TIMING HACK!!! WOW!!!"

Most gen3 cams that come up for sale around here are almost as expensive as buying HKS or other aftermarket cam's so I was just trying to see what you could do with a fully stock engine to make the extra power...

Anyone else care to chime in or is everyone that dropped money on cam gears kicking themselves right now, lol!
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Re: ~5.8° exhaust retard?

Postby Landon » Thu Oct 10, 2013 2:32 pm

very curious to know. also curious how the 6" exhaust would work out.. lol
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Re: ~5.8° exhaust retard?

Postby athousandleaves » Thu Oct 10, 2013 2:38 pm

http://www.atsracing.net/Parts/Details/E-ATSCAMGEARS
15hp + 15lbft

Not totally stock as its 2.1L and has an aftermarket turbo but at least it has a dyno to go from. But the cams are stock and timing is the only thing they claim to change...
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby built2run » Thu Oct 10, 2013 5:13 pm

I can score a set of gen3 cams for 150, and that's not bad at all. Not to mention that the exhaust cam on the gen3 is already 4* retarded. But okay since that is too jdm tight hacking cams for you then that's cool.
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby underscore » Thu Oct 10, 2013 5:16 pm

Someone on CT.net did this recent, and apparently it worked quite well. I'm planning on doing this when I pull my engine for a clutch and timing belt change.

The fact that more people aren't doing this boggles my mind. I'd like to run Gen 3 cams, but this is free. Free trumps and kind of "deal" you might get on cams or gears.
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby athousandleaves » Thu Oct 10, 2013 5:54 pm

Well I figured it out and did it on one of my cars when I changed my timing belt. From what I could tell it did feel more powerful but I blew out a brake hard line so I haven't been able to really test it. :bangshead:

I don't get what you're trying to say built2run, I'm just suggesting a simple mod with the parts everyone already has. For the gen2 3S its probably the cheapest and best modification anyone could make *if* it works!

Underscore, would you have a link to that CT thread? I can search for it later if not.
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby built2run » Thu Oct 10, 2013 7:34 pm

I'm not saying it won't work, in fact I know for a fact what you want to do will work pretty well, and if you look deeper into it you can also re work the intake cam timing to further improve your performance

What I am saying is that if one wanted to do an upgrade to gen3 cams that would add a little more than the 10-15 you can get from the stock cams at optimal timing

I did that cam retard with stock cams like I mentioned before on my first built st165 but it had a gen3 head. So I went for a 2 degree retard and it did give a small improvement, now that being 6 degrees on a gen2 well that's going to feel a lot like a stock gen3 head while still keeping it with stock parts.
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby underscore » Thu Oct 10, 2013 8:20 pm

Here's the thread, basically the same thought process as you: http://www.celicatech.com/forums/showth ... sprune=365
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby klue » Fri Oct 11, 2013 1:41 am

you will get a bit more hp and tq. but i think its overstated to say 10-15 even more so to say that you can feel the difference in actual power. Would end up being more on the drive ability side. gen 3 cams are 200 at the most, and a drop in. the timing, duration, lift are all much improved over the gen 2 cam
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby built2run » Fri Oct 11, 2013 2:09 am

Thanks klue
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby underscore » Sat Oct 19, 2013 8:44 am

klue wrote:you will get a bit more hp and tq. but i think its overstated to say 10-15 even more so to say that you can feel the difference in actual power. Would end up being more on the drive ability side. gen 3 cams are 200 at the most, and a drop in. the timing, duration, lift are all much improved over the gen 2 cam


If Gen 3 cams are dropped into a Gen 2, what timing should they be set to? Is there any benefit to doing a 6* retard on the G3?
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby klue » Sat Oct 19, 2013 2:30 pm

No, the gen 3 cams should be installed straight up.

ex is retarded 4 deg if im not mistaken already
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Re: ~5.8° exhaust retard from knock pin adjustment?

Postby underscore » Sat Oct 19, 2013 3:11 pm

So there would be no benefit of using the 2* pin to bump it to 6?
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