This is a discussion on need advice within the Engine Modifications forums, part of the Tech & Modifying & General Repairs category; Originally Posted by shadowpr damn you. that just added another 1k to the build. That's what I like to hear...
The Hawk-Eye Alliance #90|The Blobeye Syndicate #0|The Stink-Eye Mob #0|N.E.R.D. Founding Member & #3
2012 Lightning Red WRX Sedan Stock...for now Soon to be OpenSource tuned by: Mattypants @ WTF Tuning
"If I have 10 ice cubes and you have 11 giraffes, how many pancakes can fit on the roof? Purple, because aliens donít wear hats" -Ying
If you're only looking for one build, I'd try to do it once / right. If you can handle letting parts sit, do that. If you're impatient, install them and see how long the stock block lasts on a conservative tune. If it doesn't work out, skip the cams. It'll still be a fun build without headwork/cams, but it won't be used to its full potential.Originally Posted by shadowpr
headwork/cams are a moot point unless you're going over 500whp IMO. I know matt disagrees strongly, but if you look at what I did... and what I made... and how much power my engine makes at 7000rpm... then you might rethink wasting money on cams/headwork
I think the point is that it will be easier to make more power if you consider the whole package. Easier means less stress on the engine/turbo. With the proper headwork you're looking at considerably more area under the curve with little to no extra strain on the engine.
Both if you can afford it. Cams will increase top end substantially, along with new springs and retainers you could push the rev limiter to 8500. Porting will give you power gains across the board, but more so in the top end where you need more air to continue making power.
Get the heads cleaned up a bit. If you do get them ported, don't go too aggressive with it; the 3071 doesn't require the airflow that larger turbos do.Originally Posted by shadowpr
I've only seen the two GTX3071 dyno plots (CA 91 / E85):Originally Posted by MainFrame
This car has ported heads, but is running stock cams. Obviously, with a set of cams, it's not going to drop off like it does here, but I don't know if you'd need to go to 8500, do you? I think 7500 would be about all I'd bother with.
I wouldn't say I disagree strongly, but Robin pretty much outlined my feelings on it. Higher VE makes more power easier.Originally Posted by Sinister
One big problem is that people "overbuy" cams, which ends up ultimately hurting them rather than benefiting them.
GSC S1: 268/266
GSC S2: 272/272
A mild set of cams (like the GSC S1s) is a great addition to a motor build; you will gain power everywhere in the RPM band, and are a perfect choice from anything from an 18G and a 35R. The 35R is where I think the tipping point is, depending on the end users goals. For someone looking for power everywhere in the rev range, stick with the S1s; for someone looking for top-end (e.g., drag), step up to the S2s.
I just wish that Subaru cams were as cheap as Evo cams (Evo GSCs are about half the price)
Last edited by EJ257; 09-22-2012 at 12:28 PM.
Well, I'm going to be responsible and sit on everything for a few months until I can afford the honey Badger.
I think I'll get some mild cams as well.
Is porting the heads a diy job? If not, I'll probably skip it to save money.
I really need to be done with the car and start concentrating on my future with my girl.
I tried replying earlier, but apparently, it got lost...Originally Posted by shadowpr
You can DIY head porting, but if you're unaware of what you're doing, you can easily screw yourself. I would leave that for a machine shop or leave them alone
While we're at it, +1mm valves are also something to consider.
^^ Absolutely not.
My engine builder tried to talk me into +1 valves. I did a ton of research on valves, and they are a completely moot point until the rest of the head has been p&p'd and cams have been installed with fairly aggressive lobes.
And at the cost of sodium filled exhaust valves... valves are a very expensive upgrade. I wouldn't touch them.
If you already have to replace valves then the additional cost is not bad at all. After I had my first set of +1mm valves installed (BC) with a radiused valve job they flow tested and I gained ~40cfm per cylinder (on otherwise stock heads). I don't know whether the gains were more due to the grind or the increased size of the valve. I could definitely feel the difference off boost once the engine went back together, and I could swear I gained a few mpg as well. On the 2nd or 3rd build one of the BC valves was burnt so I upgraded to Ferrea +1mm super alloy valves just paying the price difference from the BCs, but too many things were changed that time to tell if there was really any additional gain by going with the better valve.
Last edited by MainFrame; 09-23-2012 at 03:06 PM.
ok, at this point i think i have 2 options. keep heads stock and roll with it or
get the heads pnp'd, s1 cams, springs, valves and retainers.
thinking gsc s1 cams, gsc beehive springs with titanium retainers. need suggestions for valves and seals, guides, buckets and shims.