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Old 08-31-2015, 09:35 AM   #1176
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Quote:
Originally Posted by bettner12 View Post
A little teaser pic from Headgames.




They look pretty, but I'm going to have to question their philosophy on duration here. Lol!
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Old 09-26-2015, 03:34 PM   #1177
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Forgive my naivete but what's is so wrong with sticking with OEM cams for ~400hp builds?

My impression is that most aftermarket cams have significantly higher duration which is
great for top end i.e. racing, but is not conducive toward low end & response for daily driving where ppl with 400hp cars spend vast majority of their time.
(I concede that ppl with 550hp+ racing engines need S2-S3 cams to get the best top end but that is not what I am after.)

Why not just stick with OEM cams and save $1K+ to put toward a better turbo, other mods, etc.

For full disclosure, I am presently building a motor to go with an EFR 7163 TS turbo for use as a daily driver. Several builders & tuners have recommended S2 cams (Cosworth/GSC/Kelf..) all appear to me to be more risk & trouble than they are worth
for my daily driving objective. If anything, I was thinking of the smallest Tomei 256 poncams but my builder is unenthusiastic about them so, I am thinking of just sticking with the OEMs for their optimum low end response, and giving up a few hp on top, if at all...

Constructive feedback & comments are greatly appreciated - thanks.
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Old 09-26-2015, 05:16 PM   #1178
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Quote:
Originally Posted by il1 View Post
Forgive my naivete but what's is so wrong with sticking with OEM cams for ~400hp builds?

My impression is that most aftermarket cams have significantly higher duration which is
great for top end i.e. racing, but is not conducive toward low end & response for daily driving where ppl with 400hp cars spend vast majority of their time.
(I concede that ppl with 550hp+ racing engines need S2-S3 cams to get the best top end but that is not what I am after.)

Why not just stick with OEM cams and save $1K+ to put toward a better turbo, other mods, etc.

For full disclosure, I am presently building a motor to go with an EFR 7163 TS turbo for use as a daily driver. Several builders & tuners have recommended S2 cams (Cosworth/GSC/Kelf..) all appear to me to be more risk & trouble than they are worth
for my daily driving objective. If anything, I was thinking of the smallest Tomei 256 poncams but my builder is unenthusiastic about them so, I am thinking of just sticking with the OEMs for their optimum low end response, and giving up a few hp on top, if at all...

Constructive feedback & comments are greatly appreciated - thanks.
I would think a s1 cam would be a good fit. I installed two seperate set of cams and had no failures..along with everyone i know irl running aftermarket cams. The cams have been updated anyways and are now free of any issues that may or may not have been there. With your turbo 400whp should be super low boost conservative stock engine able numbers. So i wouldnt worry about cams unless you plan on going larger in the future in which case you should do it now rather then later.
http://realstreetperformance.com/Sho...STI-04-07.html
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Old 09-29-2015, 02:20 AM   #1179
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I'm still on stock cams, but planning on 272ish cams as soon as I make up my mind about who will build the motor... With my turbo (ATP 3076), the car feels naturally aspirated below 3k RPM anyway, so losing a little power down there hardly matters to me. In that range I'm just putting around regardless. It just doesn't make sense to optimize for that, it's already a lost cause.
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Old 09-30-2015, 06:17 PM   #1180
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Yea, that's how my cars feels too - NA until ~3K, then the power starts building up fast.
Ah, what I will not give for a bit more down below!

I was thinking of going with increased compression but that's not a good idea in California with our crappy Cal 91... I wish I was back in N-Jersey where you guys got nice 93
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Old 09-30-2015, 09:38 PM   #1181
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Quote:
Originally Posted by il1 View Post
Yea, that's how my cars feels too - NA until ~3K, then the power starts building up fast.
Ah, what I will not give for a bit more down below!

I was thinking of going with increased compression but that's not a good idea in California with our crappy Cal 91... I wish I was back in N-Jersey where you guys got nice 93
sounds like you need a displacement increase
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Old 09-30-2015, 10:09 PM   #1182
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Or to understand how a turbocharged vehicle works
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Old 10-01-2015, 01:49 PM   #1183
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Come'on guys, I explored all reasonable options and discussed it with several top builders & tuners.

A displacement increase brings with it a lot of issues - the EJ25 is already at its max, the 2.5L is an afterthought for the US market -
it was originally conceived as a 2.0/2.2.
I'll need to go sleeved and all the components are much more exotic/expensive.
To do it right will probably add 3-4K to to build with minimal gains.

And, the longevity of such an exotic engine is TBD - for racing apps I would have no hesitation but for a daily driven ~550+hp engine with expectation to last over 60K mile lifetime this is not reasonable...

Has anybody considered the Quick Spool Valve - google QSV? the theory is tempting
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Old 10-01-2015, 03:06 PM   #1184
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Quote:
Originally Posted by il1 View Post
Come'on guys, I explored all reasonable options and discussed it with several top builders & tuners.

A displacement increase brings with it a lot of issues - the EJ25 is already at its max, the 2.5L is an afterthought for the US market -
it was originally conceived as a 2.0/2.2.
I'll need to go sleeved and all the components are much more exotic/expensive.
To do it right will probably add 3-4K to to build with minimal gains.

And, the longevity of such an exotic engine is TBD - for racing apps I would have no hesitation but for a daily driven ~550+hp engine with expectation to last over 60K mile lifetime this is not reasonable...

Has anybody considered the Quick Spool Valve - google QSV? the theory is tempting

If your worried about longevity i wouldnt worry or look into a qsv or any form of spooling quicker. It will only lead to less engine life imo. Low rpm high load situations are not good and are pointless to try to gain the idea is to bring power on smooth and draw it out not spike the **** out of it at 3k and then where you actually need the power it will already be gone.

Only reason to use a qsv imo is if the turbo is large enough that you cannot create a powerband without a reasonable rev limit.

A better turbo will also help you something along the lines of a efr or bullseye spool a lot better then stock location 30rs.


Sent from my iPhone using NASIOC
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Old 10-01-2015, 06:49 PM   #1185
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in general this is correct but in my case, with the SS 7163 spooling up ~4K, to high for daily driving apps,
if a QSV can reduce it by 350-400rpm, which it has demonstrated it can do,
this will make a lot of difference.
The gen 2 of the QSV has not had any failure, if you don't count those who use unti-lag which burns everything in its way
the establishment is definitely against it but the facts are solid - this approach will be adapted sooner or later...

Last edited by il1; 10-02-2015 at 02:06 PM.
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Old 10-01-2015, 07:27 PM   #1186
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i like the QSV idea. it seems to work well in other platforms. but that's for another thread...
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Old 01-24-2016, 12:37 AM   #1187
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.....
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Old 01-24-2016, 12:39 AM   #1188
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Originally Posted by Power-Division View Post
I wanted to make sure Dom had the same theories before I addressed these.



1: Lobes too centered/buckets wont spin:
Stock Subaru cams are offset just so slightly, as are GSC cams. Our lobe placement is within 0.25mm all the way down the cam compared to an OEM unit. This is just our tolerance, we typically see +- 0.1mm. That’s just manufacturing of a cast cam vs an assembled cam like the OEM(we do not know what the tolerance from Subaru is on their lobe placement) The lobes are wider, by 1.25mm. You do have to take in account there is some rough casting on the sides of the lobes, so every lobe may measure different with a set of calipers if you want to check for yourself, but remember we are only concerned with the ground section, which contacts the bucket. A slightly wider lobe was used to help deal with the extra pressures associated with heavier valve springs and loads that come with 11+mm of lift and higher RPMS for extended times. These are race cams, not OEM replacements, these differences are required. We have not seen one bucket, either posted on here or sent in for inspection that has shown signs of not spinning. All of the damage to the buckets was done in a dished or circular pattern. When a bucket doesn’t spin, it creates a straight wear pattern.

2: Metallurgy:
Metallurgy is a tricky one. As you said this can be a whole host of things.
Our blanks are a made from a chill cast method. This allows much deeper hardening on wear surfaces, in our case a lobe and journal. Chill casting is a really good method for a camshaft and one of the most common. It allows the lobe and journals to have deep hardened areas, but allows the core of the cam to stay ductile and keep toughness. Our blanks are made for our profiles; we can use the same blank for an S1, S2 or S3 profile(S1 and S2 have the same peak lift). We keep the rough lobe shape very close on an S3, this is why many customers that have asked for larger profiles we have had to tell we cannot do it. Our cast blank simple won’t allow for it. With a larger rough blank comes the risk of getting very thin hardening layers when ground down to an S1 profile.
Run out, on journals and base circles are something we hold very tight. Most OEMs allow for 0.025mm on the outer features, and 0.050mm in the center. The cam shaft Dom sent us originally had as follows.
Journal 1: 0.0066mm
Journal 2: 0.0019mm
Journal 3: 0.0064mm
Journal 4: 0.0046mm
We flag runout at 0.010mm across the shaft, we will allow up to 0.025mm runout in the center.
Base circle runout:
Lobe 1: 0.0137mm
Lobe 2: 0.0131mm
Lobe 3: 0.0111mm
Lobe4: 0.0093mm
We know from this that the cam is not bent. Ductility and core issues can be found during grinding, we push pretty hard on the journals, if you are going to get runout or a bend, its on the center journal that doesn’t have the steady rest engaged yet.
Hardness on a chill cast core cannot exceed 60c Rockwell. The casting process wont allow for it, just the nature of the method. Soft lobes are also almost non exsistant on chill cast, again just the method that is used, and why it is used by so many for camshafts. On the various cams sent back, we tested the base circles and points on the lobe. There was a range from 50c to 55c Rockwell on all the cams. That is right in our range for call out. The OEM bucket is usually in the 55-60C range.
Not one cam had a harness below 49c Rockwell. I have seen the results of a soft lobe on other applications, usually in older V8s. All of the lobes wipe down, and do not damage the tappet they were riding on; this is due to the softer material being weaker than the hardened tappet. In almost every case on the Subarus, there is massive damage to the buckets as well. That is a huge sign to us that the lobes were not “soft”
Porosity can cause wear, we have seen that in other applications as well. Typically you see porosity as pin holes in the wear area, or a cavity found during grinding and machining as material breaks away from contamination or air pockets. We have not seen any porosity in any of wear areas of the cams that were sent in for inspection. All of the wear areas had build up and smearing, but not voids or cavities. Porosity usually only affects a very small area, I would not expect to see porosity large enough to cause wear all the way across an 11.5mm wide lobe without being visible to the naked eye. From my understanding of casting, chill casting actually helps reduce chances of porosity. In high porosity prone sections of a part, they will use a chill to disperse porosity and reduce stress.


3: Lobe Profile:
I could agree there is something to this, but only if it were just our Profile. We have seen damage on the S1, S2 and S3 profiles. I don’t know which and how many different failures are on other aftermarket manufacturers, but we all know that between manufacturers there are very different profiles. We have seen this occur in completely stock, unopened EJs as well. I know of 3 off hand that had the same damage to the bucket and lobe. Does the OEM profile have a problem as well?
We run very similar profiles on other flat tappet engines, and have never had lobe wipe failures on those applications(except for a few that were found to have coil bind during inspection).
Are you going to come out with a stage 3 billet cam for the dual avcs EJ25?
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Old 01-25-2016, 08:04 AM   #1189
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Quote:
Originally Posted by mattistrouble View Post
Are you going to come out with a stage 3 billet cam for the dual avcs EJ25?

Maybe try calling or pm'ing them......not posting in a thread called "stop buying their product"...

And the answer is yes and yes. I heard a rumor that IAG and possibly Outfront had a set or two.

I know that they will be manufacturing more in the next month or so.

Last edited by vwown3d; 01-25-2016 at 08:16 AM.
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Old 01-25-2016, 04:32 PM   #1190
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Originally Posted by vwown3d View Post
Maybe try calling or pm'ing them......not posting in a thread called "stop buying their product"...

And the answer is yes and yes. I heard a rumor that IAG and possibly Outfront had a set or two.

I know that they will be manufacturing more in the next month or so.

lol


Yes they are, I have a prototype set for my 15 STI.
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Old 01-25-2016, 10:47 PM   #1191
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Oh yeah???? Hmmmm
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Old 01-26-2016, 12:05 AM   #1192
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Quote:
Originally Posted by Junior2JZ View Post
lol


Yes they are, I have a prototype set for my 15 STI.

How do you like them?
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Old 07-28-2016, 10:28 AM   #1193
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Has anyone had any issues with the new GSC Billet S2 cams?
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Old 07-28-2016, 10:58 AM   #1194
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Lol, I'm still running my s3 old school non-billets
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Old 07-28-2016, 12:17 PM   #1195
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street car factory has had a cam failure with the new billets.
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Old 07-28-2016, 01:39 PM   #1196
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let the hysteria ensue again
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Old 07-28-2016, 04:08 PM   #1197
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We have run non billet GSC S1 cams in our 2.1L stroker for about 6 races. 8000 rpm redline with soft limit at 8100 and hard limit 8200. Driver was on limiter at end of back straight at Road Atlanta every lap in 4th gear = 165 mph. Also saw some street driving.

This race started from pole and led all https://www.youtube.com/watch?v=bCb8houXMug

www.CarmaCars.com

Car ran great until it ate the 5 speed ring and pinion...
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Old 07-30-2016, 04:20 PM   #1198
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My S3 Billets failed as did our other shop car.
Mine barely made it 50-60 miles, the race car made it 20-25 passes.
Another customer in the shop with failed billet S2s as well
Dwarne on here as well had a S2 billet fail within 500 miles.

The tried placing the blame on my car lifting a head at 1050+whp.. My car was running and worked perfectly unless I was trying to run 48-50psi of boost and then it would push a little coolant so it was taken apart. Upon tear down to do some headgaskets and new orings the cam was found to be failing already.

My car is running again this time with Kelfords and we inspected them after a dyno session with 0 issues. I also ran the same Kelfords all last season without a single problem. Kelfords are not billet or anything fancy.
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Old 07-30-2016, 06:10 PM   #1199
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Just as another data point, I had S1 non-billet cams, which outlasted my first build at 5K miles; I'm near 5K miles on a second build, second set of non-billet cams and still running strong.
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Old 07-30-2016, 07:51 PM   #1200
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There are so many variables. S1 probably has a profile that does not accelerate the valve as quickly as an S3 cam, and different cam makers have different profiles as well. We don't know anything about the lifter surfaces. People are not doing hardness testing on many of the cams. The springs are not usually mentioned. The break in lube and type of oil - zinc content, etc. are not discussed. RPM history is not usually mentioned.

This thread is interesting but what are we learning? NASCAR people are using tool steel, case hardened cams with DLC coated tool steel tappets. NASCAR rules have made life very hard on the engine builders when it comes to the valve train. They have responded with superior components. Would be great to hear from some experienced builders, but they are usually fine when the other builders are having fits.
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