How to squeeze more HP

[philipplim]

Hi sifus.
i know that this question is asked plenty of times but i think no one can give me an exact answer
So iam kindda like doing a reseach on this thing..so if u guys (anyone have comments, pls just write it here)

iam using a 1.8 sohc mitsu engine which i have converted from a 1.6.
iam wondering if i were to change to a dohc head, either 1.8 dohc turbo or normal NA head, wat is the difference in terms of power. ( for those convert the similar process, 1.6 or 1.8- plz leave ur comments here, really wanna know the result)

if i were to have done the convertion, lets say iam running on a 1.8 dohc NA engine, how much Hp can i get cause i know my engine now (sohc) carries bout 100-110 Hp or maybe less than that. if i were to lets say squeeze all the hp out from all this mod below, wat is the estimate hp u guys thought of.

1) head convert to dohc
2) FPR compromise with SAFC tuning
3) mivec throttle body + gsr intake manifold
4) open pod filter
4) 4 2 1 extrator
5) adjustable cams ( twick abit the degree)

just leave ur comments here..
thanks guys for the help..just wanted to know the fact of the things above and also the Hp squeezed out..and maybe u guys have better idea.

cheers
phil

 

[chelnick]

dude... the mods you mention will most proberly set you back around... ermm roughly an extra ... 30hp???? maybe less though

price is going to be quite high as well.... in the region of 2k-3k...


from sohc to dohc will not bring you that much difference in Hp... but effienciency is better(save more petrol)

cause even N/a 1.8 4g93's are only about 110-120 Hp on the wheel....

if you want to follow the N/A path... you can do the mods you said + some additions...

but to get to most kick from your mods.. i would suggest you turbocharge your engine... or get a 1.8gsrt.... ;) the latter would be better ...less problems :lol:

eheh... don't shoot me kay.... i'm just stating my oppinion... and my words may have mistakes :P

 

[JINEIL2EN]

the most easy way is pump in Shell V-power & add som fuel add like AfterBurn.....etc....

 

[Yong_5290]

juz asking...

is there a adjustable cam???

'5) adjustable cams ( twick abit the degree)'

of coz...turbo charge is better than na...nothing beats the G-Force...hehehe...

but still...comes down 2 individual preference.....there r some who wan 2 put Mivec head on 1.8 block also....

but if got budget...go all the way 4 GSR 4g93T....

i c b4 dyno chart tat a stock GTi DOHC 4g93p...114hp on wheel

i might be wrong too...juz my 2 cents

 

[taqu]

Do u mean adjustable cam = adjustable cam pulley? Adjustable cam pulley on SOHC won't give u much power. I guess the mods u listed below might give u about 10-15% increase. U want more?

1. Camshaft - I don't know whether there is a camshaft for 1.8 SOHC
2. Port & polish engine head - Same as above
3. Exhaust mods - the usual mod, enlarge exhaust size & change muffler/bullet
4. Quad trottle bodies - big power gain but very difficult mod

 

[philipplim]

Sorry guys make u all misunderstood..
its the adjustable cam pulley..not the cam..
by the way, i know normally u guys will suggest me to swap a gsr engine but i think for time being NA is still the suitable engine for me.
lets say i do all the mods..but i install a turbo kit into it..will it give me more hp..lets say an estimated Hp from u guys..

can leave out supercharging cause i think it wont be cheap anyway.thanks for replying

cheers
phil

 

[taqu]

Turbo doesn't like quad throttle bodies and vice versa, having both items in ur engine can be a very challenging task.

 

[philipplim]

lets say i have the mods of:

1) head convert to dohc
2) FPR compromise with SAFC tuning
3) mivec throttle body + gsr intake manifold
4) open pod filter
4) 4 2 1 extrator
5) adjustable cams pulley ( set degree)

Plus a bolt on turbo kit from a gsr..

wats the hp i can expect..boosting at (.5 to .6 ) without changing internal components)
cheers
phil

 

[taqu]

Dude, if u want tu turbocharge ur stock 1.8 SOHC, might as well dump all the mods u've listed and go straight to turbokit. Better save ur money for that turbokit project. A turbokit running at 0.5-0.6 bar, if tuned well, can give 40-50% power gain. Note "well-tuned". What u might want to consider when boosting to 0.5-0.6 bar :

1. An intercooler is necessary
2. Compression ratio is safe to be reduced using thicker head gasket
3. Use a good FPR, if u can find rising rate FPR it's even better
4. If u wanna use SAFC for turbo, don't use TPS, mod ur SAFC to utilize ur MAF/MAP sensor instead
5. U may need to find another MAF/MAP sensor
6. Ignition is critical in turbo, so u also need something that can adjust ur ignition timing
7. Most probably u'll have to change ur injectors too
8. Ur must ensure ur cooling is sufficient since ur engine will produce upto 50% more heat

Wanna boost higher that 0.6 bar? Must change to stronger pistons/conrods, or use GSR piston/conrods. A GSR engine already have all those things above sorted out, but it's ur choice. Good luck, oh yes, a good tuner/mechanic helps alot too.

Plz shoot me if I'm wrong :lol:

 

[philipplim]

thanks for the reply..really appreciate it..
so a normal turbo kit produces bout 40 to 50% of the engines performance
thats good enuf...but i think there are plenty of thing i need to consider in putting this bolt on thing. from injectors to engine managements..
anyone out there runs a successful bolt on turbo kit on any car, just place ur comments here bout the maintenance and stuff...doing r&d on all this things

cheers
phil

 

[L2TurboFool]

your mods which you stated above,i doubt it will give much hp outta your engine.

it would be better to get a turbo kit.
or if you would like to keep it stock,better! :lol:

looks like your opting for a NA engine all the way...
if you want to keep it NA,go for port and polishing(stage by stage),change your pistons(forged),changed headers and exhaust system,change your cams.