[_Mozz_]

http://www.k20a.org/forum/showthread.php?t=103374&highlight=zof484

Its the same setup you have commented.

Best torque was on low lobe and there is over 200hp under vtec.

It is all in your post as per why the DC4 are over cammed on a K20.


Back on the 3.2s,

I belive the 3.2 cams are not as "balanced" when it comes to Intake lift vs exhaust lift, as the 2.2, 4, 4.5 and even 5.

 

[w00t692]

yeah i remember now. Ported cylinder head, high compression, flat valves, ported intake manifold, 3.5" intake and E85. I thought this might've been on a stockish k20. Still really high vtec point though... you're also revving to 10k, so a camshaft like you have there was definitely needed.

 

[zof484]

It is all in your post as per why the DC4 are over cammed on a K20.


Back on the 3.2s,

I belive the 3.2 cams are not as "balanced" when it comes to Intake lift vs exhaust lift, as the 2.2, 4, 4.5 and even 5.

Well if you look at it at that point then yes.

I think its just good designed cams. Not only high lobes but low ones too.

I still have lots of area from 6500-9500.
Why best torque cant be on low cam?

 

[zof484]

you're also revving to 10k, so a camshaft like you have there was definitely needed.

:like:

 

[_Mozz_]

yeah i remember now. Ported cylinder head, high compression, flat valves, ported intake manifold, 3.5" intake and E85. I thought this might've been on a stockish k20. Still really high vtec point though... you're also revving to 10k, so a camshaft like you have there was definitely needed.

Well if you look at it at that point then yes.

I think its just good designed cams. Not only high lobes but low ones too.

I still have lots of area from 6500-9500.
Why best torque cant be on low cam?

You are mean to gain torque on the High cam, not loose torque.

What max VTC are you running ?
Do you have a limited cam gear or is it just limited by ECU?

 

[Fg2_FrAn]

It is all in your post as per why the DC4 are over cammed on a K20.


Back on the 3.2s,

I belive the 3.2 cams are not as "balanced" when it comes to Intake lift vs exhaust lift, as the 2.2, 4, 4.5 and even 5.

A lot of other cams on the market also possess varying lifts between intake and exhaust. I personally don't see why not

 

[_Mozz_]

I am not criticizing the cams, I am just curious about the specs.

In theory, DC 3.2 have way to much exhaust lift compared to intake lift than needed.

This will put extra unnecessary work on the valves.

We have 35mm Intake valves and 30mm Exhausts valves for a reason (OEM).
Look at even to most extreme Ported K series heads, the intake valve can go bigger, the exhaust valve stays the same.

 

[zof484]

You are mean to gain torque on the High cam, not loose torque.

What max VTC are you running ?
Do you have a limited cam gear or is it just limited by ECU?

I have dynoed and tuned maybe like 10 different k20a2 setups and on
8 of them torque curve stays pretty flat after peak. With stock, dc4 and custom cams. Only on bp2 cams torque was climbing on high cam.
On other setups it stays pretty much flat.

With dc4 we tested high cam on 45 but best was 6500-8500 on 40
and 8500-10000 on 30. Low cam was on 30.

Its limited only by ecu.

 

[K20EF8]

I have dynoed and tuned maybe like 10 different k20a2 setups and on
8 of them torque curve stays pretty flat after peak. With stock, dc4 and custom cams. Only on bp2 cams torque was climbing on high cam.
On other setups it stays pretty much flat.

With dc4 we tested high cam on 45 but best was 6500-8500 on 40
and 8500-10000 on 30. Low cam was on 30.

Its limited only by ecu.

What are the depths of the valve reliefs on those wiseco pistons... 45 seems like alot for an aggressive cam like the dc4

 

[_Mozz_]

I know then on K motors we see the torque stay flat (slightly decreasing) after peak. What Its not normal is seeing vtec actualty drop on high cam. It can suffer a drop at Vtec point, but will climb to hit peak after that.

Also not usual ist to run less VTC on low cam than on hi cam.

You dont happen to have the composed dyno for cam angles power figures when tuning?

 

[zof484]

What are the depths of the valve reliefs on those wiseco pistons... 45 seems like alot for an aggressive cam like the dc4

Im not sure how deep those are.
Those are Blueprint "custom" wiseco pistons so i guess reliefs are little bit
deeper than on the shelf pistons.

With 50vtc there was still 1,25mm v2p clearance but v2v will contact on max vtc.

I know then on K motors we see the torque stay flat (slightly decreasing) after peak. What Its not normal is seeing vtec actualty drop on high cam. It can suffer a drop at Vtec point, but will climb to hit peak after that.

Also not usual ist to run less VTC on low cam than on hi cam.

You dont happen to have the composed dyno for cam angles power figures when tuning?

What do you mean by this composed dyno?

Why everything have to be usual?
If it will work with those vtcs i will use those even if its not usual.

 

[BlackNDecker]

Why everything have to be usual?
If it will work with those vtcs i will use those even if its not usual.

:up:Atta boy!

Thanks for sharing your results:up:

 

[_Mozz_]

Im not sure how deep those are.
Those are Blueprint "custom" wiseco pistons so i guess reliefs are little bit
deeper than on the shelf pistons.

With 50vtc there was still 1,25mm v2p clearance but v2v will contact on max vtc.



What do you mean by this composed dyno?

Why everything have to be usual?
If it will work with those vtcs i will use those even if its not usual.

A dyno with diferent runs for best power on Low cam 5, 10, 20, 30, 40, 50 VTC and same for Hi Cam.

That is what you do to find best power line and Ideal VTEC crossover, correct?

 

[zof484]

A dyno with diferent runs for best power on Low cam 5, 10, 20, 30, 40, 50 VTC and same for Hi Cam.

That is what you do to find best power line and Ideal VTEC crossover, correct?

Well we dyno and tune each vtc (0,10,20,30..) on low cam then same thing on high cam. After that select right vtcs and vtec point.

Then we try small changes in fuel, ingintion and vtc if there is
still some hp available.

Some setups like different afr so we test all of those kind of things
in the end.

 

[_Mozz_]

Well we dyno and tune each vtc (0,10,20,30..) on low cam then same thing on high cam. After that select right vtcs and vtec point.

Then we try small changes in fuel, ingintion and vtc if there is
still some hp available.

Some setups like different afr so we test all of those kind of things
in the end.

Thats what I was talking about. Do you have the dyno sheets for those runs?

 

[zof484]

Thats what I was talking about. Do you have the dyno sheets for those runs?

No. I only take final curves on the paper.

My home would be full of different vtc dyno sheets if i would print every
single one.

Okay. Lots of offtopic.

I think L S I should show us dyno sheets and topic starter should
try those cams.

Maybe those will work good with your setup.
You never know.

 

[L_S_i]

No. I only take final curves on the paper.

My home would be full of different vtc dyno sheets if i would print every
single one.

Okay. Lots of offtopic.

I think L S I should show us dyno sheets and topic starter should
try those cams.

Maybe those will work good with your setup.
You never know.

Here you go mate. In my opinion its not a great setup since its low on torque, altough its a street racing car and its a top end car, and its definatly fast, but for e in a road racing car it would suck, not a big fan since its got even a deep at 6k almost impossible to ditch at least in this setup ( Its better now after rasing the vtec at 6,3K but dont have the graph). I believe the dip is cause by the overcammed setup, mostly because the diference between the intake and exhaust cam size, you woudnt have this in a bigger displacement engine for sure.

Its a 87 mm 11.7 k20 , Cai injen , rc440, kidd racing header and 3" catback



Uploaded with ImageShack.us

 

[gtimportfanatic]

hmm.. i wonder what this would really be like on a higher compression k24

 

[Fg2_FrAn]

So I finally installed these over the weekend. All I have to say is WOW.
I was on a decent set of skunk stage 2's before which made great power up top but flimsy on the low side due to safety(tensioner) reasons. These puppies feel like they've picked up power all across the board.

I'm looking forward to dyno tuning in the next couple of weeks. For now she's on a safe street tune by B.R.I.A.N. I will report back as soon as I get some dyno time.

 

[763k24]

Im about to put these in and will let u know when i do.. Not much help right now but just wanted you to know your not alone

Highly interested in running these with my setup. Did a couple of searches online and didn't really find ANYBODY that used them. I guess it's because they're too big for stock bottom k20s but must people that go 2.4 run 12:5 which is perfect compression for the stage 4's. Well, I'm kind of in the middle LoL. My setup is the following:

- k24/20 Frank 11:5:1
- 5 angle valve job cylinder head
- Ported bowls (Type-R style)
- Backcut valves
- Supporting mods with 3" intake/exhaust

Any feedback from anyone running these would be greatly appreciated.