increasing power of a naturally aspirated engine

[Rockefella]

What is the replacment for displacement? You can always make more horse off a larger bore with n/a or a power adder.

The rear seats, air-con, airbags, and carpets getting thrown out, along w/ replacing steel w/ aluminum are a few replacements.

[QBridge]

Using a thinner head gasket will do the same at considerably less effort and expense.

But wouldn't it blow easier if it's thinner? How does a head gasket blow anyway, I don't know.

u got most but always remember, there is no replacement for displacement

I don't like that idea. What you end up with is a heavy engine with big displacement and low power/liter. Case and point - Most of the American cars.

[drakkie]

5-15% in chiptuning
5-10% in a completely new exhaust system,from the engine to the back,with more freeer flow of gasses.
10-15% in a special airfilter.
15-25% in a better injection system.NOS can easily be added then.

these are the easiest and cheapest ways to do it.

[whiteballz]

NAWZ! DAWG! roflmao.

i think if i wanted to increase performance of a car i would decrease weight, and then suspension/brakes in one hit, then work the engine.. for every 50kw added you need major brake upgrades from standard. (so says john bowe (aussie supercar driver))

[fpv_gtho]

for every 50kw added you need major brake upgrades from standard. (so says john bowe (aussie supercar driver))

You can only push that so far though remember, but in general it makes sense.

Another thing JB feels strong about is matching the suspension upgrades with the dynamics of the car.

[pimento]

Only thing that was missing engine wise was to use proper fuel. I've seen several independent reports that say Optimax gains a few hp but I don't remember if that was only on turbo cars.

To truly gain more power from higher octane fuel, you need to tune the engine to take advantage of it. Raise the compression et all, which is where the thinner gaskets and skimming of the head come into it. Of course, if you go too far, you'll end up needing to run it on AvGas (aviation fuel) which could get irritating when you're in the middle of nowhere and the little light comes on.

[fpv_gtho]

If its a modern engine it should be easy enough to have your 2 setups for your race fuels and standard fuels, although i wouldnt be surprised if you have to compromise on the ultimate setup to achieve that.

[hightower99]

and remember porting the intake and exaust will only lower your power and use up alot of money it is much better to use some body filler and fill up all the dead space in the intake and exaust ports to increase velocity and it costs next to nothing!!! I did it to my 3.8L ford V6 and gained 47.2hp (and the head treatment was the only thing I changed when I tested it!) it cost under 50$ to do!

[johnnynumfiv]

How reliable is having body filler in your intake? Won't it deterirate in the heat? Body filler absorbs water, and add the heat it could essentially blow apart.

[magracer]

use some body filler and fill up all the dead space in the intake and exaust ports to increase velocity and it costs next to nothing!!!

I had never ever heard of this!!!

It makes no sense to me to make your runners smaller to increase velocity if you get less oxygen in at the end. As johnnynumfiv said, there is a lot of heat and vibration in that area, so the body filler would end up inside your cylinders or in your exhaust making you lose power (or maybe your cylinders). Finally, I'm not sure how clean this fills would be, but I would say that most certainly they would destroy the quality of the flow.

Please enlighten our dumb minds with the results of your research (including some sources).

[h00t_h00t]

That can't be right, if it was true then the car would have come with tiny ports right out of the factory. Always remember when tuning a car:
The engineer that designed the engine is smarter than you.

[charged]

Never heard of bogging up inlet manifolds to increase velocity, matching ports to inlet to increase flow and different inlet lenghts, porting and polishing ports increase flow also. Thats a massive increase(47.2 HP) just from changing the volume of the inlet manifold

[PerfAdv]

Intake: Freer flowing airbox/element, larger throttle body, and port polishing intake tract to remove ridges/rough surfaces.
Exhaust: Freer flowing exhaust including better flowing cats. Headers, cat-back for max benefit.
Fuel delivery: Higher capacity fuel pump, fuel rail, and injectors.
Oils: Synthetics>less frictional loss.
Fuel: Higher octane race fuel.
ECM: Tuned to maximize power from new parts.

If you dismantle the engine there much more you can do. Stroker kit, blue-print buildup using race/performance rod, pistons, valves...

Now, by lightening the car you multiply the benefit of more pawr.

[johnnynumfiv]

You don't gain much from higher octane fuel unless you have a really high compression ratio.

[PerfAdv]

Some though if you advance the timing.