Hks Cams Which Ones?

[Steve]

No valves or port work, stock head

Yes, reset base timing, re-tuned gained a bit of power up top, but lost midrange. I didnt push the point too much, cos the tuner wasnt cheap (mick stanic, used to work for tilbrook and tuned John Munros 9 second GTR)

[ike]

Going by Gavs power curve after adjusting cams the slope is the same on the way up so there is no improvement in response

But the max is higher for sure which is good for straight line stuff .

Each to their own.

I like response so will stick with the solid pulleys.

[ike]

I'd reccomend basically the opposite.

Putting cams gears on from the get go saves money in double tuning. By cam gears first then cams makes more sense if not only because on all the RB's from 20/25 & 26 gains can be had with stock cam timing changes, this is well proven.

Depending on the engine setup it is possible to go backwards at the '0' mark with aftermarket cams (I noticed this on the GTR with stock turbos) this is because they are designed around an intended engine spec and setup. Perhaps a certain type of compression / valve size / manifold / turbo spec / head porting etc.....

Bottom line is that if you are too broke to afford a few hundred bucks for some cam gears, re-consider the ownership of a GTR or RB26 equipped car.

I am not broke mate just a bit cautious as a matter of fact I am starting a collection of em. nice r32gtrvspec coming from Japan soon to compliment the 33.

[rev210]

Going by Gavs power curve after adjusting cams the slope is the same on the way up so there is no improvement in response

But the max is higher for sure which is good for straight line stuff .

Each to their own.

I like response so will stick with the solid pulleys.

You have to learn a little more about reading power graphs.

Response on the cam change would absolutely be night and day.

Notice how the curve is dramatically effected once full boost is reached (these are pretty big turbos). Once the turbos are on boost all the way to redline there is a bucket load more power. This is your power band , on the track you setup gearing and drive the car within this area.

The average power is 532rwhp with the cam adjustment instead of only 501rwhp, that is the average power all the way through that engines effective power band.

If the two graphs represented two cars the cam adjusted one (the one with cam gears) would absolutely destroy the guy who didn't bother in any gear for accelleration. Around a track this would be far more pronounced than at a drag strip.

This example spells out very clearly what you should be doing to capture 'response'.

[ike]

You have to learn a little more about reading power graphs.

Response on the cam change would absolutely be night and day.

Notice how the curve is dramatically effected once full boost is reached (these are pretty big turbos). Once the turbos are on boost all the way to redline there is a bucket load more power. This is your power band , on the track you setup gearing and drive the car within this area.

The average power is 532rwhp with the cam adjustment instead of only 501rwhp, that is the average power all the way through that engines effective power band.

If the two graphs represented two cars the cam adjusted one (the one with cam gears) would absolutely destroy the guy who didn't bother in any gear for accelleration. Around a track this would be far more pronounced than at a drag strip.

This example spells out very clearly what you should be doing to capture 'response'.

As I said mate its only on the top end , bring boost earlier equals more response . Power curves are easy to read but it all boils down to what you want rev210.

But I'm not talking about drifting or drag racing I started this thread for a rapid road driven car around the twisties and you have twisted it all around to the life in the redline

Another bloody topend pissing contest

[Steve]

every single kilowat is not what you are after its being able to control the power curve shape that is good. You get more than single kw's and more importantly better 'average power'. Peak power isn't as valuable.

I think you miss understood where rev is coming from - he is the first one to scoff at 'peak power' heros

[rev210]

As I said mate its only on the top end , bring boost earlier equals more response . Power curves are easy to read but it all boils down to what you want rev210.

But I'm not talking about drifting or drag racing I started this thread for a rapid road driven car around the twisties and you have twisted it all around to the life in the redline

Another bloody topend pissing contest

I am not talking about a drag car either.

You aren't reading it right buddy. Think about the corresponding torque of each curve. The torque curve on the cam timing adjusted curve is substancially above that of the non adjusted one.

Well before the redline Gavs cam timing adjustments are proving thier worth.

What I am reading in your post is you are examining the peak horsepower value and suggesting that I am pointing to it as a be all and end all. I am not. I am telling you for your own good that unless you understand 'average power' delivered over the entire power band you are not seeing what you need to in this graph. Increasing the length of the power band is one good way to up the average power and torque but, the other way is to fatten the power curve across the effective power band.

I found an old dyno of some initial adjustments of cams on a stock turbo GTR, low boost and conservative timing and fuel. The lower amount is the '0' settings. I ended up with more power everywhere. The very top end is deliberatlly 'lopped off' as it was a very old motor. As you can see there is more 'response' in this example again. If I had the other graphs I'd post them for you too.

Although I am being a little argumentative I only hope to help you out with some of my experience and often poorly atriculated understandings. I really would like to see you get the most from your car for what you want and I can't tell you how valuable cam gears are even before you get cams.

[si]

If you're already changing the cams then get some adjustable pulleys. Here is a Quote from SK from rev210s old post that i found. Have a read He was talking about poncams there but it should still apply to the hks cams.

This has not been my experience with GTR's, they ALWAYS benefit from adjustable inlet and exhaust camshaft pulleys. The more extensive the mods, the more they benefit and no two engines are the same.

[ike]

I am not talking about a drag car either.

You aren't reading it right buddy. Think about the corresponding torque of each curve. The torque curve on the cam timing adjusted curve is substancially above that of the non adjusted one.

Well before the redline Gavs cam timing adjustments are proving thier worth.

What I am reading in your post is you are examining the peak horsepower value and suggesting that I am pointing to it as a be all and end all. I am not. I am telling you for your own good that unless you understand 'average power' delivered over the entire power band you are not seeing what you need to in this graph. Increasing the length of the power band is one good way to up the average power and torque but, the other way is to fatten the power curve across the effective power band.

I found an old dyno of some initial adjustments of cams on a stock turbo GTR, low boost and conservative timing and fuel. The lower amount is the '0' settings. I ended up with more power everywhere. The very top end is deliberatlly 'lopped off' as it was a very old motor. As you can see there is more 'response' in this example again. If I had the other graphs I'd post them for you too.

Although I am being a little argumentative I only hope to help you out with some of my experience and often poorly atriculated understandings. I really would like to see you get the most from your car for what you want and I can't tell you how valuable cam gears are even before you get cams.

Back from work saw your post.

Yeah the torque curve is higher but I didn't mean the absolute peak I mean the curves are the same for a while until the adjusted curve leaves the other behind giving a peak torque increase and also when averaged out is obviously more but it is not broad. Whereas you old dyno sheet it shows your adjusted cam moves the whole slope over to the left and on top of the non adjusted curve this is what I meant by improved lower response across the board. Correct me if I am wrong but say we had 2 of gavs cars one adjusted one not would they not accelerate the same till the curves part ways (in one gear). Your old gtr with the adjustment shows gains (Fatter)over the whole curve which is what I personally would want from adjustable cam gears. When I bought the cams ( just recently) I translated the hks jap site and they say with these particular cams the dowel has been reindexed for the best position (Same effect as installing adjustable pulleys) and that adjustment is not necessary when used with there GTSS turbos on an otherwise stock engine with free exhaust and inlet.

Theres a lot of different cam grinds out there and they react differently to adjustments .

I think we are on the same path I hope. Plus I will always listen to experience such a yours its just I want to see proof such like your dyno . As long as it is the same dyno same day . I take it they were stock cams.

What I would like to see is a car like mine with hks cams and gtss turbos and adjustables with dyno charts . Have not found any as yet so my car will be the mule.

Will install the pulleys and cams soon and see how it all goes .

Cheers

[rev210]

hi ike,

The difference in fuel we use here as opposed to Japan makes for a very big difference in tune not only in fuel but, also in the timing maps. These alterations make for the need to have access complete adjustment to these cams that were most likely optimised to 104 octane fuels and the burn characteristics.

[Swiper the Fox]

ike, Gav and rev210 are well versed in this field...id recommend that you read what they say carefully as their knowledge may save you some time and net some gains to your setup. Good luck with it and keep us informed of your results.

I too have had marked gains by correctly "dialing in" aftermarket cams with vernier gears in both response and outright power.

[ike]

hi ike,

The difference in fuel we use here as opposed to Japan makes for a very big difference in tune not only in fuel but, also in the timing maps. These alterations make for the need to have access complete adjustment to these cams that were most likely optimised to 104 octane fuels and the burn characteristics.

Hi rev210 your right mate never thought of that one cheers

[rev210]

no problem dude.

Let us know how the setup goes.