hi all

i like to ask
if we not modify the internal parts,
no modification on compression ratio,
no change o internal parts and carburetor

just solely modify on external stuff
exhaust manifold, air filter,
ignition system, etc
overhaul

how much horse can we get


what is recomendation and steps to do this


hope experience user can give me some insight. :)
thanks in advance

You can get 85 HP "net" at the flywheel.

Here are the steps:
1. Replace the air cleaner with a new one. Any kind of new will increase HP.
2. Set points dwell
3. Set timing
4. Check and fix vacuum leaks
5. Check and adjust fuel level
6. Adjust idle air/fuel ratio & Idle speed
7. Adjust valves

For exhaust manifold, replacing with long headers/extractor *may* help (although you may need to rejet the engine). In any case for an A15 use 1.75 inch exhaust.

Adapting a weber 32/36 will give you more power than the extractors will.

Its not going to be much over standard. With all the external stuff done, perhaps 15hp at the flywheel, and thats being keen.
And most of those external mods wont do much without the internals to match. eg a huge exhaust will acutally hurt performance a bit without a cam and head work to match.

Beyond headers and a free flow exhaust (in reason) anything else will add realibility rather than performance.

are carbs condsidered external?? if you changed the carb to something mild, (small webber) then a few extra ponies, but still not much.

edit : dd you beat me to the punch, and I think you hit that nail on the head.

pretty sure changing to twin 40mm sidedraughts will give you the biggest leap in performance

cant see you upping the performance much at all while retaining the stock carby

wow,
Thanks dd, reuby, and pigdog for the reply.

So at most , i can add around 15 horse only..
so for average, maybe i can add around 8, 9 horse without internal mod..



i not planning to change the carb.. because i have the manual for the dch306..
and also because hard to find parts and labour at my country.. :(




btw... originally A15 have 80hp right?
or 75?
so end up i will be getting around 85 - 90hp
if lighthen the car more.. than will be a lively car... right? :)

The a15 in its standard form isnt a bad performer, but its isnt a deamon. that 80 is what the factory quotes from their test bench and its at the flywheel. In reallity, you could have a motor that performs higher or lower than the rated HP. That depends on many things like machining tolerences, contractor quality etc.

Dont get carried away with spending money on the external bits. If the carb is staying, then its really only exhaust and a good tune.

Yeah maybe 8-10hp which is again at the flywheel, minus the 30% parasitic loss through the drivetrain, and you end up with about 63 ponies at the wheels.

About lightening up, well you may want to consider your local laws about what interior/exterior bits you have to have as minimum. There isnt much to pull off a datto to lighten it up.

lightening off the interior does nothing to make the car faster

it might if you had a Psycho A15 (125+ horsepower) it might help

I noticed when I stripped out the interior of The (original) Defect it felt quicker - probably because it was louder with no hoodlining

A14 77Hp
A15 80Hp

So, the biggest improvement (without changing and modifying internal parts)
are changing the carburetor right?

with proper tuning, exhaust, intake
and a better carburetor,
i can gain about 15horse at flywheel..?



about lighthening..
i agree.. :)
after taking off the carpet and rear seat,
my car really feel very loud inside......

maybe there are more to strip.. like the door panel, etc etc...

theoratically, i feel that lighther car will accelerate faster,
and stop faster.

with proper carby tuned to the engine with an exhaust to match, it will make a fair difference over stock

dont know about hp figures, they are kinda pointless at the moment....but the above mentioned things will make it alot better to drive, it will actually use the power that it has if that makes sence

oic..
thats cool

since parts and labour are limited at my place.
i am cosnidering change the the carb from 3rd genertion lancer , its very common here.
its 1500cc lancer with mikuni carburetor.

will it give noticable improvement to the stock hitachi DCH carb?