Camshafts and Boost!
 

So, I'm looking to do some custom cams for my '13 FRS-

Stage 1 Sprintex 210 Kit (non IC)
Tomei EL Header
Perring 2.5" Resonated Exhaust
On E85
12.898@110mph

I'm shooting for 11s, trying to squeeze every bit of power out of it. Has anyone figured out what the optimal lift and duration etc is for a mild FI camshaft set?

I would also be interested in seeing if there is any merit to the HKS claim that you have to use HKS/Custom pistons with their cams, or why that is if it is indeed true.

I'm also curious if i'd need more fueling for this setup. Obviously would require a retune. not going to buy $1400 cams for this car either.

What cams are not over 1K that are available?


Also.... when you increase lift you run in to piston to valve clearance issues. Most cams with higher lift will need different recesses in the piston to accommodate that.


Depending on your retune, depends on fueling. Most simple cam swaps by themselves do not merit a TON of horsepower but it will change the powerband, and impact every aspect of air entering and leaving the motor (exhaust requirements, possible boost loss/gain). Your tuner will be able to let you know on fueling.


I doubt a cam swap and retune will get you to 11's. You are far from that.

^ What he said. You can not add anything worth doing as far as lift goes without pistons

FIFY
"Optimum" turbo cams would be significantly different than "optimum" s/c cams for any car. The biggest differences would be duration, overlap, and timing.

Since there's no concern on the exhaust side of a s/c'd engine (besides evacuating it quick enough), you can cam it like an aggressive N/A engine and it will respond/perform accordingly. The HKS cams are designed that way; ideal for N/A & S/C. A little more lift, a little more duration, (tune controls overlap), and the geometry doesn't allow anyone to go much bigger without changing the heads.

The valve pockets in the HKS pistons are deeper to maintain the same p-to-v clearance as stock when using HKS cams.

Haha may as well go with a HKS or Trust (Edit: AKA Greddy if your not a car guy) Stroker kit

Says trying to squeeze every lsst bit of power out of it...


Non intercooled :bonk: :lol:

:confused0068::lol: I missed that ahahahahha!!

Much better investment to get the IC before you do cams hahahhaha!!

Fixt

is there significant difference between "optimum" root s/c cams and "optimum" centrifugal s/c cams?

In a 3000hp Pro-Mod - yes. Boost characteristics and efficiencies are drastically different and these engines only have 1 stick to control all the valves. Timing is set when the cam is installed and never changes from 1000 to 10,000 rpm. So at this level, yes, they are definitely different.

In a 300hp FA20 - no. 4 cams + AVCS allows you to make a grind "optimum" over a wide range by changing timing on the fly. You don't have that capability in a lot of other engines, like a 500ci 3000hp Pro-Mod engine. Obviously, we're also not pushing the thresholds of physics like we are in the other example and there are a few other reasons it would be very difficult to measure a difference, but ultimately AVCS is a cams greatest asset for being ideal over a broad range.

This. OP what are your 60' times?

1.9-2.0 on all season tires with a slipping clutch.

here's two slips, both of these going into 5th gear instead of getting a taller tire for better gearing

its coming with the tax refund, just thinking about what else I can do.

If youre going to try and extract all the power you can, first, dont try and draw more power from a parasidic loss of boost into the engine. The right turbo on this car will make more power everywhere, secondly due to mathmatics, physics and simple plug and chug, intercoolers help immensely for improved SAFE power, transient response among other things.

So if you want to 'squeeze' all the power you can out of this engine; intercooled turbo, oil cooler, passive aero (dual purpose). Depending on power goals, built motor and race gas/e85.

Then think about cams or a stroker kit. Thats kind of where it would fall in terms of performance gains.

The head units on this engine are super tight and compact so you wont find any seriously aggressive cams for this car without running alot of interferance.