Does anybody know the lobe centerline angles for the helix cams? The lift and duration are listed as pretty much the same as the HKS 272s, but I have no reason to think that the lobe centers are the same.

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I havent found it yet, but they do seem to respond to about the same amount of cam timing on an 05 VIII I am doing right now. What would lead you to believe its not the same? Differing results or something else?

JB

 

Oh, I don't have evidence to think they have different centerlines, but everybody seems to have chosen different centers for their '272' duration cams. While gruppe-s advertises them as being just like the HKS, I'd like the get additional input.

Are you running them straight up or with adjusted gears?

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I had asked this same question a while ago, and never got an answer.
I have run mine at -4,-1 and -2, -2 with good results.
Of course, I was not doing an apples to apples comparison with HKS cams, so who can really say.
I have them at -4, -1 again; it seems to have the smoothest idle, similar to the HKS findings.

 

Good info. Thanks.

Anyone else?

d

 

-2/-2 and now going to -3/-3 just to see if we can gain anything. Higher altitude car so I am looking for some easy advantages where I can get them.

 

How high? I'm at 6000' and routinely take the car to 11000'. In two weeks we have an autocross in at lot at 9000'.


chronohunter and JTB have had success running +1/-3 to get earlier spool on HKS 272s.

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Only 2500, but its hot and dry air right now. You are obviously ALOT higher than that but the spool doesnt look bad with the -2/-2. I am thinking it will definitely get later the more it goes (duh common sense) but I am looking for the balance between spool and top end right now. If you are looking for low rpm torque for auto x, then advance is your friend. Let me run some numbers in my sim program and I will PM you some settings to play with.

 

I appreciate it, but the cams haven't gone in yet. I'm waiting till the end of the racing season, so talking about them keeps me from running out and installing them.

offtopic: it definitely gets laggier as you go higher. the only that would be worse than the lag would be not having a turbo at all. While I'm thinking about it, another thing I worry about is idle. With the stock cams, I only get about 10 in.hg of vacuum. With the A/C on that drops to about 6-7.

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Holy schnikeys. Stock at sea level is like 17-18, with an HKS 280 exhaust its 15.5, and I'll let you know when the S1's finally make their way into the motor.

 

Trust me, I realize. It's one of the reasons I want hard numbers on camshaft. I don't expect idle without fuss.

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Has anyone contacted Gruppe-S directly and asked for them to get the cam specs???
Seeing as they sell a cams/cam gears package, you will want the cam specs to set the gears correctly.
Or do they think that cam gears are just a bling item ??

 

I called, but they don't know. They are going to try to find out from Helix directly, but I'm apparently the first person to have asked this question...

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I'd get the gears with the helix cams. I found out the hard way that they overlapp a bit too much without gears. There isn't enough knock supression. I'm going to go find out this weekend how much of a difference it makes with gears.

Probably going to try the HKS -4 -1 method. We'll see what kind of numbers it puts down.

 

I asked GruppeS the same thing and the guy couldnt give me an answer. I have had my 272's for months now and haven't got around to installing them yet. I'll probably install them this week.

I was going to try -4/-1 but maybe -2/-2 is the way to go? Whats the difference?