hardcore4sure

I'm looking into buying a 02 Coupe and want to do LS6 heads and a 228 cam with a VR cai, ported TB and stock intake( for now) and LT's.possibly 4.10s. I'm on tight budget and want to know the actual gains between the two stg1 2.00/1.55 and stg 2.5 2.02/1.57 with a mild/medium sized cam like the 228-228 or the 228-232 115. I kinda want to keep the light weight valves but not at the expense of too much power. So what is the REAL diff. And what kinda power is being put down these days with similar set ups. Cam choice is to make sure I can pass Cali smog and maintain a smooth idle and drivability.

danielf

Do you have a stick or an automatic ? What gears do you have in now? What is going to be your target use for your project?

hardcore4sure

Stock gears ,6 spd , mainly a DD that can smash on Fords if the chances arise. Some quarter mile (goal is mid to low 11's traps in the 120's, dyno around 440rwhp 400rwtq) maybe some road racing. Mainly I want bolt on ZO6 performance in a coupe so I can take off the top on those nice summer days. So given the weight difference and tranny gearing of the ZO6 i figure a coupe would need the extra power that heads would provide to match the ZO6 with the same cam.If the stg 1's can do it great, or is the stg2.5 that much better to guarantee those goals can be met... Assuming of course I do my job behind the wheel.

All_Motor_C5LS6

0-2hp

hardcore4sure

Wow , you really think it's that small ? Lookin at the flow numbers between the two there is only about 2-4 cfm difference but figured there would be some proven reason to get the 2.5's. Or does it need bigger cam to really see the benefit?

Quick Shot xMLx

Essentially yes. Even the stock heads for these motors flow pretty good. If you search around LS1Tech you'll see plenty of examples of guys running smaller cams and something like AFR heads and they're all pissed because it didn't make that much more power lol.

hardcore4sure

Thanks figured that may be the case. I appreciate the input.

firefighter813x

IIRC TSP told me around 5rwhp or so. Call them and ask.

slowtealz28

You can't run as big of a cam with the 2.5's as the 1.0's. The 1.0 has a thicker deck.

TriplBlk

Good to know!

PRE-Z06

I agree, not that the OP is planning on it, but take a little extra off the stage 1s with free milling that TSP provides and the extra bump in compression will more than make up for the less than 10hp more the 2.5s might make imho

hardcore4sure

I was aiming at 10.5 cr like stock but started to consider shaving the heads maybe to 11.0. So you don't think the 2.5's could get a little compression bump with a cam that size without ptv issues. Not to be cheap but the extra $300 in price could get me most of the way towards a tpis 90mm LS6 manifold which will make more than 5hp.

c5mtl

i remeber making 405rwhp with afr 205's a 230/236 112 cam and a ported fast 90 and ported 90mm tb....car was an a4 with a big stall....wasnt very happy for the money i spent.....but it went 11.4 at 119........moral of my story ....dont chase those small hp differences between high end expensive heads and the mid range stuff.....again just my thoughts

hardcore4sure

Thanks guys I appreciate the input, all was useful. I'm not trying to be the fastest guy in the world. Just want to put together a nice smooth idling warmed over LS6, low 11 sec DD that will pass Cali smog on a budget. Kind of an oxymoronic goal but i think the stg1's shaved for compression and the tpis 90mm ls6 ,228ish cam and 4.10's should work real good together. Now I gotta get it, build it and show and prove at da track. Thanks again.

Trevor @ Texas Speed

The only difference between our PRC stage 1.0 and stage 2.5 LS6 cylinder heads is valve size. The stage 1.0 heads will use the stock 2.00"/1.55" valves, and the stage 2.5 will use larger 2.02"/1.57" stainless steel valves. The stage 1.0 LS6 heads can accomodate a larger cam because they have smaller valves, so it allows more room for piston-to-valve clearance. There is not a difference in deck thickness between the two heads; they use identical GM head castings. The actual horsepower difference between the stage 1.0 and stage 2.5 LS6 heads is 5-7 HP. The stage 2.5 is also a better way to go if you plan on forced induction or nitrous. The stainless steel valves will handle more heat than the stock valves will.

With respect to camshaft, your biggest limiting factor will be CA emissions. We have had quite a few customers in CA use our 224R 114 LSA cam and pass emissions. Anything with more duration is going to really push it. Our 228R makes an additional 8 flywheel HP over our 224R, so you're not giving up a huge amount of power. With a six-speed manual, you can expect our PRC stage 1.0 LS6 heads and 224R cam to make right around 420 RWHP. It does vary some from car to car, though. This is also assuming you're running long tube headers, good induction, and the normal bolt-ons that will help your new heads/cam package breathe. Additional compression is a great way to gain some additional power, and I consider it free HP and TQ! We don't charge to mill your cylinder heads because every set of PRC cylinder heads will be milled. If we are looking to retain maximum p-to-v clearance, the heads will typically get a .003" clean-up mill. The LS6's 64cc chamber size will net right at 10.5:1 CR, and if they are milled an additional .030" it will put you right at 11:1 CR. With a 224R cam, you won't have any clearance issues with the stage 1.0 or stage 2.5 cylinder heads milled .030". The cam is small enough that you will not have any issues.

What we can offer every customer is proven performance. We have an in-house Superflow 902 engine dyno, as well as a Dynojet chassis dyno. EVERY cylinder head and camshaft package is developed and tested on our engine dyno before it is installed on a vehicle and strapped down on the chassis dyno. We don't pick some lobes off of a chart and hope for the best. Some of our cams do use standard lobe profiles, but we will literally dyno the same duration cam changing nothing more than LSA and ICL. We want to see what works best with the combination. All of our cylinder heads are CNC'ed on one of our three 5-axis CNC machines, as well as valve jobbed on one of our Newen single-point cutter CNC valve job machines. We spend a LOT of time and money making sure our products are not only correct but also the best available. When you consider other cylinder heads like ones mentioned in this thread, keep in mind that higher price does NOT mean higher power. Some cylinder heads you will pay quite a bit more for just because they are an aftermarket casting. These will cost more money because they cost quite a bit more to manufacture vs. buying GM cores. We speak from personal experience on this because we have our PRC 215cc, 227cc, 237cc, and soon-to-be-released 245cc cathedral-port aftermarket casting cylinder heads, and we are getting ready to release the PRC LS3/L92 and LS7 aftermarket cylinder heads that we have developed from the ground up. All of our aftermarket castings do offer thicker deck surfaces, better piston-to-valve clearance, smaller chamber sizes for better compression without reducing p-to-v clearance, and our LS3/L92 cylinder heads will also offer smaller runner sizes for better port velocity vs. stock as-cast heads! I could go on and on. It's not just because I'm biased; it's also because I KNOW how much time, money, and effort have been spent to make our products some of the best on the market.

Feel free to give us a call. Any of our sales guys will be able to assist you in your goals. FYI, we currently have some spring specials on the PRC cylinder heads that you can see on our website! Stay tuned for our new website that should be up and running in the next two weeks!



Trevor
Texas Speed & Performance

hardcore4sure

Thanks for the detailed response I truly appreciate it, this has been a long time coming and your reply affirms my confidence that I'll be able to meet my goals ( of killing FORDS) with some of your touched up Factory GM products. That is why as soon as I get this car i'll be ordering from you. I've already spoken with Newtech about the cam and emissions and they assured me that plenty of cars have passed with there spec'd 228 cam. Again thanks guys for all of the informative responses.