Gt HP boost Options

[devilsden97]

Whats the best bang for your buck, to increase your hp in a 5S-FE motor?(totally stock) How much HP upgrade should i be looking at? (with whatever your suggestion is.) And does putting Super or Premium gass really effect hp enough for it to matter?

[Silver94CelicaOw...]

I know I've probably said it before, but if any of you are serious about making more power with the 5SFE than go to MR2OC and read their stickies....its excellent knowledge.

I've picked up on a few things just for the hell of it even though I dont intend to build up my 5SFE.....I'm bored, so I'll write up a list of things to consider for others. Most guys get impressive power gains from combinations of these sorts of mods-

--------------------------------------------------------------------

Camshafts. Most serious builds use a more aggressive camshaft profile to enhance the mid-top end power curve. Webcams as well as some machinists that frequent those forums can make an excellent camshaft for not too heavy of a price.

Head Shaving. I just read of a guy who had his cylinder head machined down like 1/8" or so, and it boosted his compression a good deal...his MR2 puts down just over 135 WHP with that and P&P, Intake, Exhaust and header, etc. so obviously something worth considering if you know of a good machining shop.

Header, Exhaust, Intake, and De-Cat. I put these all together because they all correlate to freeing up the stock restrictions and can all be improved upon with aftermarket items. Exhaust? Custom. Header? Custom again, but other FE block headers usually fit with modifications. But this is pretty much square one to making the 5S perform any better.

Individial Throttle Bodies(?) Think of the 4AGE's and motorcycle engines that use ITB's and it makes sense. But this is a tough one considering you need to rig something up electronicly since your one throttle body has been multiplied by four and intake manifold butchered to fit them all. One guy sold his MR2 just as he was rigging up Honda sportbike throttle bodies on his, but never got finished I dont think.....damn.

Fuel, Spark, ECU. Aftermarket ignition will be a good move if you introduce any more fuel, and more fuel plus the means to adequately ignite it quickly and completely will produce more power. Fine tuning of both the air/fuel ratio and timing of the engine will optimize output any engine, and certainly helps on the 5SFE which uses crude electronics to manage the engine anyway. MSD ignition, Apexi SAFC 2 or standalones (Emanage, Megasquirt...etc.) with the guidance of a dyno or wideband O2 sensor will best fit the bill.

Engine/Head. The obvious. If you blueprint the block, port and polish the head, get upgraded valves and springs, high compression pistons, forged rods or cryotreated rods and crankshafts....etc....you'll be not only strengthening the internals but providing a good (albeit expensive...) foundation to produce more power due to the increased compression, or if your crafty more stroke or displacement. Again, this requires a machinist or engine builder with the right tools.
The biggest kink in the 5SFE's performance is its head design, so getting the head fully ported and polished with a 3-angle valve job with improved springs and valves will help.

Clutch & Flywheel. No, it doesnt actually make more power, but a lightweight flywheel and firm clutch will handle the extra power even better and plant it to the road quicker with less drivetrain loss in all likeliness.

MAINTAINENCE! Keep your 5SFE well lubicated and change oil before you see its getting old and dark with a good synthetic oil like Mobil 1, or Royal Purple (read a non-biased article in Modified about how superior Royal Purple synthetic is due to its abundance of additives that gasoline manufacturers of oil dont care about...so I give it a thumbs up. ) Redline, Pennzoil synchromesh, or other brands of trans fluid for smoother shifting, clean fuel filter, timing belt, spark plugs and wires, and other routine maintainence should come FIRST. Your engine wont care if you have a sick camshaft profile if you have a leaking headgasket and bad compression, along with those fouled spark plugs you've had for 8 years.

-------------------------------------------------------------------------------
So anyway....that's my rant regarding power upgrades for the 5SFE. Bottom line- Money. If you want to do it right, you need to buy good parts just like any other upgrade and tune them as best as possible. N/A power is more focused on what makes a engine produce power and improving upon it, so it wont be cheap but there are some more cost effective ways to bring about an improvement. Just tune it very well, have it built strong and correctly with good parts and drive the crap out of it.