4G15 tuning and related info

venum · Posted: Thu Mar 02, 2006 8:40 pm Post subject: 4G15 tuning and related info

The purpose of this thread is to discuss modifications to the Mitsubishi 4G15 engine.

Found in the popular CK2A Lancer, both JDM and SDM, this humble 1.5L 4-banger has a lot of potential.

Also found in several early and recent Proton models, such as the Wira.

So please include your 4G15 tuning advice and experiences.

All experiences welcome !

I will start it all off with my initial and to date only modification to my JDM 4G15 DOHC:

and RPW free flow intake with an OBX cone air filter:

Click for full-size.

Dave · Posted: Fri Mar 03, 2006 7:54 am Post subject:

there are lightened crank pulleys, no trouble here since those engines are internally balanced
for the sohc engine, there are aftermkt cams also, i had one on my carbed 4g15
i also successfully bolted a 36 ratchet and also a 32/36 weber
in those days one couldn't buy aftermkt headers so i made one but now they are available
the ignition system is a distributor type and hence can be hooked up to a mutiple spark box for increased fire and use of a regulator or bigger jets can go a long way in creating more combustion
i also cut my dist cap and ran a sr/rb20 coil for more fire with excellent results
i pressed out 2.25" pipe(turbo thing nah) with small barrel so i still had some back pressure for torquiness
the stock wires don't last more than 80k km so i made some accel 8.8mm which also made a great difference
will post more as i remember

Rudman · Posted: Fri Mar 03, 2006 8:37 am Post subject:

Hmm..... *copies and paste dave's post for future reference*

Venum, Thanx for starting this thread on this particular engine....I know myself and others will benifit from this.

While mine is still bone stock, Dave U have me concerned about the stock plug wires lasting about 80,000km. My car is now approaching this milage... Shocked

U had to buy the Accel wires and make the ends yourself? U know of any wire sets that are already premade (properly insulated, crimped and fitting good?) Ractive, Magnacore etc...?

How about the cams? Was this a Mild or Wild cam? Think they might have cams for our DOHC application?

What about the lightened pulleys? Are they underdrive? What pulleys the aftermarket set replaces? RPW by chance? How much would it cost to get a set? How much extra HP the pulleys frees up?

Ok, I haven't been totally honest about not doing any mods........ minor things, but still noteworthy. I have replaced the stock air filter with a drop in washable one. While it may not produce the gains like Venum's OBX, its stock silent and definately a step above stock.

I have also replace the stock plugs with NGK Iridium 5's. Can't say I feel the difference but the 5 is definately the Heat range U would want to use for this engine. I have had no issues with cold starts or gas consumption. If anything, the gas consumption has slightly improved.....but my previous set of plugs were pretty worn.

O.k. I will shut up now.

Dave · Posted: Fri Mar 03, 2006 9:19 am Post subject:

i am talking about the c62a lancer, i had to make everything i did to that car, not popular and too early for the aftermkt to jump in

i am sure u can get ngk wires for it, i used accel in a l28 and worked excellent so naturally i turned to them, remember this engine had the plugs on the side by the exhaust manifold

cams has to be mild for good idle and also to maintain good street braking, my cus used some mild to wild and loss some braking

lightened pullies are limited to crank for now, don't know what developments took place

i always an a 6 series ngk cause of the detonation level and the 7.5k rpm i used to pull

btw, that intake is no good, the flexible rubber after the filter corrupts air flow thus slowing it and not being very efficient

i will shut up now, u have to pay for more info Laughing

Rudman · Posted: Fri Mar 03, 2006 9:46 am Post subject:

Dave, what flex rubber setup U talking about? Stock or Venum's one in the pics?

I mean venum got this from JUS4SHO, RPW and all...... aren't they a reputable brand from Australia?

What after market setup U pitching, that has straight piping right through?.... Smile

trinigamer · Posted: Fri Mar 03, 2006 9:54 am Post subject: Re: 4G15 tuning and related info

Dave · Posted: Fri Mar 03, 2006 9:54 am Post subject:

yup that same rubber hose after the filter in any system, ask yourself why filter have those folds?
they are out their to starighten the incoming air so that it flows faster and smoother with less turbulence

what happens when you put something in the way of the air flow that is starightened?

RPW is good stuff but their design sucks
i helped a friend weld two mandrel 90deg bends to get the same effect w/o the flexible rubber part and we extended the filter till it was touching the inner fender so that as little hot air would be caught by it
since then he isolated it so it now only gets majority of cool air

RA40-GTE · Posted: Fri Mar 03, 2006 11:11 am Post subject:

^^ what about that big "s" bend in the c62a exhaust...i thought that always made the car sluggish..
my c62 had a SRI with k&n and 2 inch pipes (straight as possible) and a resonator to quiet it down a bit..
32/36 weber was there for a bit too, worked well, but i dont think it was "tuned" properly, so i drank too much gas..that soon went, lol

top end improved a bit with the new exhaust i thought...ass dynos never lie lol Laughing

scooby · Posted: Fri Mar 03, 2006 11:19 am Post subject:

i have the same engine

shamo sold me an evo drop in K&N filter ......

How dif is that from what u have venum

ps this is now offically my favorite thread

Dave · Posted: Fri Mar 03, 2006 12:38 pm Post subject:

i maintained the same s by the tank, most late model systems use that style

32/36 should be jetted with 45 idle jets and 115(primary) and 140 (secondary) with the second sparayer blocked off
i got more mileage than stock and ran out 190km + on top with 7.5k rpm shifting

JUS4SHO · Posted: Fri Mar 03, 2006 5:27 pm Post subject:

i asked the reason for the folds they said it was to 1) prevent vibration, 2) prevent the bracket from braking
i did try a stright tube dale bit there was no noticable difference in performance and the bracket did brake, had to design and fab one my self

venum · Posted: Fri Mar 03, 2006 7:10 pm Post subject:

^^^ I concur

I have had this intake for ~ 6 months

the reason for the flexible middle tubing is just as JUS4SHO said

the filter has a support that bolts onto the tranny and supports the filter just where it connects to the piping.

when the engine revs there is vibration (normal vibration, my mounts good Very Happy

)

also when the gear is shifted into 1st gear, the engine shifts backward (towards firewall)

this causes significant movement of the engine block

the flexible tubing allows the intake setup to facilitate the vibration and movement

since one end is fastened to the tranny and is thus does not move, the other end is fastened to the TB, which moves with the engine

without the flexible middle piece the support will break and the filter will fall downward into the engine - no good there

you can see the double hose clamps on the neck of the filter

one clamps the filter to the intake piping, the other clamps the filter and intake pipe to the support, which is directly under the neck of the filter.

scooby your setup is different in that you are using your stock piping

my setup has the same size diameter intake piping if not slightly larger (3")

so it gives a better free flow

but the cone air filter design allows better air flow than the square design - to my knowledge eh, I could be wrong

Dave the flexible midle piece does introduce turbulence to the filtered air, which defeats (to some extent) the whole point of the free flow concept

a true free flow has smooth piping from filter to TB, with as little bends as possible,

those two 90 degree bends that I have do also defeat the concept in a sense.

these two limiting factors aside, the intake does serve its purpose, I do get a lil extra power

but trinigamer my low end power (torque) which directly is responsible for acceleration has improved, once the filter relatively clean. the overal response has also improved.

the mileage has been tweaked somewhat

if you driving calm then you will prob get a few more km to the tank, if you driving spirited, then you get a lil less

scooby · Posted: Fri Mar 03, 2006 8:37 pm Post subject:

i average $100 for 300km using priemium city runs

and 350 on highway runs somestimes more

hows that?

Rudman · Posted: Sat Mar 04, 2006 12:08 pm Post subject:

Yea scooby, for a 4G15, that sounds about right. 350 km for $100 (premium gas) of highway driving. Although, since I've changed my plugs and cleaned out my throttle body, I'm getting 350km with $90 to $95, and I have 16" rims.

U may want to consider having a look at these items.

venum · Posted: Sat Mar 04, 2006 2:26 pm Post subject:

^^ that sounding about right

although I have never spent more that $93.00 to fill up my tank

but that depends on how low you run your tank

I never tested the fuel light either

my average fill-up is $80.00

$90.00 when it run real low

and I get the same mileage ~ 350km

Rudman · Posted: Sat Mar 04, 2006 6:44 pm Post subject:

Interesting U should mention testing the fuel light. I don't normally run the car below 3/4 tank, but I decided to test mine a couple weeks ago.

I ran the car till the fuel light came on. The range of the car before the light came on is 425km. It took $111 in premium gas to fill up, or 37 liters. Assuming that the tank is a 50 liter capacity (that's what the manual says), that means there was a 13 liter reserve in the tank when the light came on.

Not that U should drive till the light comes on....... did it out of curiosity.... Smile

venum · Posted: Mon Mar 06, 2006 12:09 am Post subject:

425km

thanx for that info man

I still want to test mine, to know taht it wuking

venum · Posted: Mon Mar 06, 2006 12:26 am Post subject:

Tuners,

I need some info on Extractors,

They are reputed to enhance performance on an engine

I am considering this for my car

what are your experiences with this upgrade on the 4G15?

I would like to particularly gain an increase in low end power (acceleration)

I was advised by my mechanic that an enhanced exhaust system would improve the top-end (high speed) performance of my engine, however the trade-off would be that the low-end would suffer.

I believe that he was talking bout 4-1 extractor applications.

I am more interested in getting the car from 0-100 km\h in a shorter time, than carrying it from 100-180 km\h

since I do not drive at high speeds (beyond 140km\h) very often and have no interest in high speed upgrades on my car.

key word - low end power

the 4-2-1 extractor set-up is supposed to increase the mid-range torque. This is closer to what I want so I am thinking more along this line.

I haven't done much research as yet, just throwing out an idea for feeback and to hear your experiences in this matter.

Advantages and disadvantages, please share

I will update with my research findings as they come in.

blazing · Posted: Mon Mar 06, 2006 2:58 am Post subject:

^^aftermarket parts inc extractors for that engine are hard to come by, meaning you will most likely have to get one made locally, which is a hit or miss situation..
You better off slapping a tdo4-13g turbo on that which starts spooling at about 2200rpm.

Rudman · Posted: Mon Mar 06, 2006 1:55 pm Post subject:

Blazing, could U please elaborate on the tdo4-13g turbo. Is this part of a turbo kit for the 4G15's? Does it really make sense to turbo a 4G15? U talking moderate amounts of bost like 8 psi?..... I would really like to know more please.