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AVCS conversion. What else to do?

Old 01 April 2016, 06:44 PM
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cardinal.sin
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Default AVCS conversion. What else to do?

So I'm planning on a AVCS conversion on a 2.1 CDB. I've just bought a pair of big port AVCS heads from this forum. I'm just wondering what's beneficial to be done at the same time.
My thinking was these options;
1. Vernier exhaust pulleys (expensive nowadays!)
2. Porting and polishing as required
3. Painting of engine (looking pretty tatty)
4. Is it really worth doing an engine rebuild at this point? Engine has done 10k since the stroker kit went in about 5years ago.
4. Anything else?

I'm already running syvecs, planning on a JTI AVCS conversion loom and clear cam covers (purely to keep an eye on the visual state of the cambelt). I'm obviously going to do fluids, filters and gaskets.
Currently sat at 380-420bhp depending on whose rollers you believe with ported V6 heads and SC42, I'm doing this conversion to widen and flatten the torque curve to make it more responsive and usable on the road. It's obviously going to need a remap but I was going to up the boost because I'm currently limited by the OEM map sensor.
Money isn't growing on trees for me at the moment but I can stretch the budget if it means I don't have a weak point in the engine.
Thanks in advance.

Last edited by cardinal.sin; 01 April 2016 at 06:46 PM.
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Old 01 April 2016, 06:54 PM
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JGlanzaV
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Originally Posted by cardinal.sin View Post
So I'm planning on a AVCS conversion on a 2.1 CDB. I've just bought a pair of big port AVCS heads from this forum. I'm just wondering what's beneficial to be done at the same time.
My thinking was these options;
1. Vernier exhaust pulleys (expensive nowadays!)
2. Porting and polishing as required
3. Painting of engine (looking pretty tatty)
4. Is it really worth doing an engine rebuild at this point? Engine has done 10k since the stroker kit went in about 5years ago.
4. Anything else?

I'm already running syvecs, planning on a JTI AVCS conversion loom and clear cam covers (purely to keep an eye on the visual state of the cambelt). I'm obviously going to do fluids, filters and gaskets.
Currently sat at 380-420bhp depending on whose rollers you believe with ported V6 heads and SC42, I'm doing this conversion to widen and flatten the torque curve to make it more responsive and usable on the road. It's obviously going to need a remap but I was going to up the boost because I'm currently limited by the OEM map sensor.
Money isn't growing on trees for me at the moment but I can stretch the budget if it means I don't have a weak point in the engine.
Thanks in advance.
Big valves, double valve springs and cams etc.... if not doing this then there is no point to having the pulleys

What version is your car? You will need to consider the inlet manifold on some models.

Personally I wouldn't bother with clear cam belt covers. You have never needed to see the belt before, why now? And the fit on them is ****e....

As for remap why wouldn't you fit a new map sensor at the same time? Saves another map tweak later down the line....
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Old 01 April 2016, 07:00 PM
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cardinal.sin
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Originally Posted by JGlanzaV View Post
Big valves, double valve springs and cams etc.... if not doing this then there is no point to having the pulleys

What version is your car? You will need to consider the inlet manifold on some models.

Personally I wouldn't bother with clear cam belt covers. You have never needed to see the belt before, why now? And the fit on them is ****e....

As for remap why wouldn't you fit a new map sensor at the same time? Saves another map tweak later down the line....
It's v5/6 JDM sti, I believe the inlet and exhaust manifolds will bolt straight on.
I don't fancy spending up a grand on valvetrain when I'm sticking with standard cams for now, seems a big cost for not enough reward.
I was thinking clear cambelt cover because I'm going to have to get covers from somewhere. Is the fit on them really that bad?
As for the remap, yeah I was going to upgrade at the same time, I was just indicating that boost will probably be upto and maybe exceeding 2bar.
But cool, thanks for the input
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Old 01 April 2016, 07:04 PM
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JGlanzaV
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Originally Posted by cardinal.sin View Post
It's v5/6 JDM sti, I believe the inlet and exhaust manifolds will bolt straight on.
I don't fancy spending up a grand on valvetrain when I'm sticking with standard cams for now, seems a big cost for not enough reward.
I was thinking clear cambelt cover because I'm going to have to get covers from somewhere. Is the fit on them really that bad?
As for the remap, yeah I was going to upgrade at the same time, I was just indicating that boost will probably be upto and maybe exceeding 2bar.
But cool, thanks for the input
Yes as long as you already have a ph2 car then it all bolts straight on.

I would be putting cams and valves on all at the same time. You are doing half a job putting the avcs in and not releasing it's full potential only to later on down the line pull it all apart again to do it.

Let's face it you will do it sooner or later once you get used to the power so just get it over and done with now 😉

Yes the fit on clear ones is never right. Wouldn't waste the money on it!
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Old 01 April 2016, 07:22 PM
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cardinal.sin
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I see what you're saying about power but I'm really not chasing numbers, an extra 2000 (I'm guessing) for cams, pulleys, springs etc seems like diminishing returns. But, that is purely based on me thinking that cams don't limit airflow enough to warrant the upgrade at this level. Can they spread power that much? Especially when I consider that the same 2grand could be spent on a different turbo if outright power was a priority in the future.
I'm not being argumentative btw, I appreciate the feedback.
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Old 01 April 2016, 07:34 PM
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Originally Posted by cardinal.sin View Post
I see what you're saying about power but I'm really not chasing numbers, an extra 2000 (I'm guessing) for cams, pulleys, springs etc seems like diminishing returns. But, that is purely based on me thinking that cams don't limit airflow enough to warrant the upgrade at this level. Can they spread power that much? Especially when I consider that the same 2grand could be spent on a different turbo if outright power was a priority in the future.
I'm not being argumentative btw, I appreciate the feedback.
Yes cams are something I would look into before buying a bigger turbo.

The figures are irrelevant you are looking for drivability. I have spent a lot of time, money, effort, and research into effectively making my car slower (was 550hp)

Now with my 2.1

AVCS
278 cams
+1 exhaust valves
Double springs
Retainers
Etc etc

I make 497hp, but am nearly .3 of a second faster over a 1/4mile than the last spec.

I am also making 497 at 1.6bar as opposed to 517 at 2.1 bar on the previous set up. And can rev out to 8.5k where as you will be revving to 7.2ishk...

I was pulling out 3 car lengths on a blob with 477hp every time he changed gear.

Drivability is king, ignore power figures, and I cannot recommend enough doing the cams etc first
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Old 01 April 2016, 07:48 PM
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Oh wow, that's both very impressive and exactly the kind of user feedback I'm after. You Sir are a star!
What turbo are you/were you running to get those figures?
So go on then, what cams are good value? Lateral don't post prices and RCM seem overly expensive. Who else does them? I'll talk to my engine builder and mapper about valves and stuff but is it worth buying stuff from the states? I read a while ago that some bargains can be had.

EDIT to say that I'm really not wanting a higher HP turbo, I find the SC42 has power too high up in the Rev range already considering the tailoff at the top.

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Old 01 April 2016, 08:05 PM
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I've heard the clear cam covers can melt?
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Old 01 April 2016, 08:08 PM
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Originally Posted by cardinal.sin View Post
Oh wow, that's both very impressive and exactly the kind of user feedback I'm after. You Sir are a star!
What turbo are you/were you running to get those figures?
So go on then, what cams are good value? Lateral don't post prices and RCM seem overly expensive. Who else does them? I'll talk to my engine builder and mapper about valves and stuff but is it worth buying stuff from the states? I read a while ago that some bargains can be had.

EDIT to say that I'm really not wanting a higher HP turbo, I find the SC42 has power too high up in the Rev range already considering the tailoff at the top.
+1mm exhaust valves help, don't bother with inlets engine tuner have tested them and found them to be fine. Supertech are good value, I got the whole supertech kit for less than 1k iirc.

The avcs will help with low down torque and spool.

Cams I am using gt spec cams that engine tuner have sourced for me, 278 on my set up but you might find you could go with something a bit less lairy.... Engine tuner do good prices and will be able to advise on spec a bit more.

I can't comment on my tail off as I am still building power at 8.5k, but that can't be wholly attributed to my heads etc my Gucci exhaust manifolds will be helping a lot with that.

Concentrate on making the car drive better, build power sooner, hold onto the power for longer and even though the headline power may not be as much, you will have a much faster car that is more drivable and will be considerably more responsive
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Old 01 April 2016, 09:22 PM
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I'd look at some inlet manifold spacers. They're not going to make a huge amount of difference to the headline power but should help to keep intake temperatures lower. If you've got the heads off anyway they're not going to take much time to fit, or cost much money, and may help prevent knocking.
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Old 01 April 2016, 09:27 PM
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Originally Posted by Cambs_Stuart View Post
I'd look at some inlet manifold spacers. They're not going to make a huge amount of difference to the headline power but should help to keep intake temperatures lower. If you've got the heads off anyway they're not going to take much time to fit, or cost much money, and may help prevent knocking.
For a proper set your talking over 100. Use the AS Performance ones that have machined in o rings so you don't need to use 2 sandwiched gaskets which look gash.
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Old 02 April 2016, 08:59 AM
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Originally Posted by JGlanzaV View Post
For a proper set your talking over 100. Use the AS Performance ones that have machined in o rings so you don't need to use 2 sandwiched gaskets which look gash.
How about an oil catch can? Again, not going to make a huge amount of difference to the power, but a good supporting mod if you're going to be looking for big numbers.
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Old 02 April 2016, 12:00 PM
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Originally Posted by Cambs_Stuart View Post
How about an oil catch can? Again, not going to make a huge amount of difference to the power, but a good supporting mod if you're going to be looking for big numbers.
Yep with out a doubt
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Old 03 April 2016, 05:33 PM
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You may have done this already, but if you're going to take the heads off then I'd look at a decent silicone turbo intake pipe (samco, perrin, other makes are available).
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