4g94 performance mods

P

Pen0014

New Member
Hey guys iv finally managed to get a bit more money together to spend on my ch. I'm thinking this time I'm after a bit more power for next time I end up at the lights next to a wanker in a commodore :p my engine is the 2.0L 4g94 and I can't find any threads dedicated to modifying this engine so that's basically what this ones for . I'm after a few stealthy mods that will give me some noticeable power but not get any unwanted attention.
I already have some sort of sports exhaust system (was on the car when I bought it) .
So far the only other things iv heard will give me the boost I'm looking for is a k&n panel filter and some sort of throttle body upgrade I don't know much about. Any help will be much appreciated :)
 
a new filter isnt gonna do anything, you need to change the set up of the air intake to only breathe in cold air. there are a lot of photos around of people making cold air intakes. a throttle body upgrade will also help, and you should get your whole exhaust modified with bigger extractors, not just a catback. also look into getting a lighter pulley. after those four, you should notice some difference.
 
CAI does bugger all, and lighter pulleys have the potential to cause more harm than good. The cheapest bang for buck is a set of high flow extractors, and cat-back. Throttle body upgrade will only see much improvement if you bore out the intake port to match the increased tb, and maybe a slightly bigger fuel pump...but thats getting a bit pricey.

Save your money....
 
I don't know much about the 4g94 but the common power mods which are aplicable to almost all engines are cold air intake, extractors and high flow cat (not sure if you have a full exhaust or not), larger throttle body etc.
There's not a whole lot more you can do for significant power gains without going down the high compression, engine rebuild path ($$$).
Do a search for any of the things I've mentioned and you'll find a heap of info on each one :)
Hope that helps.
 
Thanks do you recommend any particular brands of pulleys or cold air intakes ? Iv heard some can cause you to loose power which is something I don't want to do
 
charliem said:
CAI does bugger all, and lighter pulleys have the potential to cause more harm than good. The cheapest bang for buck is a set of high flow extractors, and cat-back. Throttle body upgrade will only see much improvement if you bore out the intake port to match the increased tb, and maybe a slightly bigger fuel pump...but thats getting a bit pricey.

Save your money....
Click to expand...

i strongly dissagree, and would say you havent done any of them, from 1st hand experience each of those mods are great for beginners and combined give a much lively engine
 
NA street mods list:
~Cold air intake = remove stock intake (cos restrictive as fk) run a 2.75"/3" hard pipe with silicone joins down behind one of the fog lights with a filter of your choice, could even relocate the OEM filter box down there
why do a CAI?: cos engine bay air is about 70-80*C, whereas ambient temp is 30-35*C, engine will perform alot better at ambient temp, better combustion, and in winter you will gain power cos air will even cooler making better combustion again, i guarantee if you make a proper CAI in winter you will feel it work

~Extractors = these replace the stock exhaust manifold, they are usually better flowing and better designed than the stock manifold, they will make the car rev up easier, and you will get better power from the extra flow in the top of the rpm band

~Exhaust = after extractors, go to the exhaust shop and get a 2.25" "Mandrel bent" catback, this is the optimum size for a street build 94, and choose a muffler other than a cannon cos cannons are super ghey
after extractors this will help open up your top end pwr a little more

~lightweight underdrive Pully = find them on ebay or rpw, they save about 4-6kg in rotational mass, which means engine will pick up quicker, the underdrive config of them means that the A/c and pwr steering will spin slightly slower (its okay not slow enuf to notice) but this also give the engine back a bit more power that those auxilliary pumps sapped out

~Throttle body upgrade= this will give slightly better acceleration, and much better top end flow thru the engine meaning top end power band will feel better again, make sure you match the intake manifold hole size to the throttle body size

~Lightened flywheel = similar to the lightweight pully, saving about 4-6kg again, makes the engine spin up faster, more responsive and accelerate faster due too less weight freeing up sapped engine power

~Heavey duty clutch = better launches, handles more power, better clutch response


well thats the main things
 
no need for heavy duty clutch, your not running over 150kws

Lightened flywheel, if your a beginner beware it can cause idle flux...

A science lesson behind CAI.

CAI (Cold air Intake), works on the principal that cooler air has slower moving particles, therefore they can become more dense, to which will increase the amount of Oxygen per Kg of Air. because of this increase in Oxygen, the combustion power per stroke will increase, giving more downforce on the pistons and increasing Torque relative to the increase in pressure.
CAI works similar to the principals of an intercooler, water injection or meth injection, where by cooling the airflow so more oxygen per kg can be fed into the combustion chamber at a given moment.

:)

on the other hand you could go for a subsonic turbo set up, however intercooler will still need to be present.
 
If I were you I'd sort out a cold air intake and some extractors and you're looking at a decent power increase for about $300 or less. I'd say those two are the best power:dollar ratio.
Then start looking into the other stuff a bit further down the track :)
 
Thanks for the advice everyone , ill start looking for a good set of extractors and some light weight pulleys , I'm nervous about the CAI as once I get my Ps I don't want to get my car put off the road constantly ( yes I'm still on Ls). Have any of you had much trouble with coppers and CAIs ?
 
All of the above advice is very good.... What questions were missed was how much you want to spend ? And have you done any suspension mods... I say do suspension this will get what limited power you have to the ground faster. Cost $1500 BN
60mm throttle body look at the Evo 7,8 or 9 these are cheap enough to buy $120
4g93 intake manifold bored ou to suit your now larger TB cost $50 - $80
Exhaust manifold I would look at a US company... Merrill performance by far the best value for money and they are cheaper Than any of the Australian ones.
Camshaft look at either a 4g93 or get a custom made price range from $50 to $600
Tuning talk to merrill he has a mate that does reflashed ecu and he is brilliant
 
I'm pretty sure the only thing defectable about a CAI is if it's not properly secured or if the pod is not covered
 
Thanks chowetime iv got king springs and planning a front strut bar and rear sway bar probably whiteline or cusco, will the evo parts simply bolt on or do they need to be modified ?
 
If you have the ch body shape the Evo strut bars fit with minor cutting or resizing of bolt holes nothing hard ... Not sure about rear sway bar fitting as they maybe different due to wad etc..as an alternative to white line and cusco look at Ultra Racing the prices are slightly cheaper but I think the quality is better than white line and as good as cusco
 
Just wanted to add re 60mm TB to fit 4G94, they can also be found in the Hyundai Sonata and are a bit cheaper to obtain if you go to pick n save / u pull it etc. If an evo one is preferred, then EvolutionM forum has a DIY thread on how to fit the evo7-9 TB.
 
chowetime said:
If you have the ch body shape the Evo strut bars fit with minor cutting or resizing of bolt holes nothing hard
Click to expand...

We actually tried this last week on a CH that was at the wreckers with an evo 7 strut brace because we were curious about it too. We found the strut brace clashed with the intake manifold and throttle body. This was on a 4g94 though, so wondering if fitment might be different between the g69 and the g94.
 
ohh ok I took into consideration that the intakes are about the same shape between the 2 G94 and G69 must be a slight difference... very sorry for misleading you.

we fitted a strut bar from a 7 and fitted it to a G69... the guy that took the evo brace did cut the firewall connection bar after fitment as he thought seeing as there is no true mounting point better off to remove it...
 
Res said:
NA street mods list:
~Cold air intake = remove stock intake (cos restrictive as fk) run a 2.75"/3" hard pipe with silicone joins down behind one of the fog lights with a filter of your choice, could even relocate the OEM filter box down there
why do a CAI?: cos engine bay air is about 70-80*C, whereas ambient temp is 30-35*C, engine will perform alot better at ambient temp, better combustion, and in winter you will gain power cos air will even cooler making better combustion again, i guarantee if you make a proper CAI in winter you will feel it work

~Extractors = these replace the stock exhaust manifold, they are usually better flowing and better designed than the stock manifold, they will make the car rev up easier, and you will get better power from the extra flow in the top of the rpm band

~Exhaust = after extractors, go to the exhaust shop and get a 2.25" "Mandrel bent" catback, this is the optimum size for a street build 94, and choose a muffler other than a cannon cos cannons are super ghey
after extractors this will help open up your top end pwr a little more

~lightweight underdrive Pully = find them on ebay or rpw, they save about 4-6kg in rotational mass, which means engine will pick up quicker, the underdrive config of them means that the A/c and pwr steering will spin slightly slower (its okay not slow enuf to notice) but this also give the engine back a bit more power that those auxilliary pumps sapped out

~Throttle body upgrade= this will give slightly better acceleration, and much better top end flow thru the engine meaning top end power band will feel better again, make sure you match the intake manifold hole size to the throttle body size

~Lightened flywheel = similar to the lightweight pully, saving about 4-6kg again, makes the engine spin up faster, more responsive and accelerate faster due too less weight freeing up sapped engine power

~Heavey duty clutch = better launches, handles more power, better clutch response


well thats the main things
Click to expand...

THIS!!! I've got pretty much all the above and more and it's very driveable idles well, accelerates hard and all the way to limiter. This and suspension mods are where to start out.
 
Samwise said:
If I were you I'd sort out a cold air intake and some extractors and you're looking at a decent power increase for about $300 or less. I'd say those two are the best power:dollar ratio.
Then start looking into the other stuff a bit further down the track :)
Click to expand...
So where in OZ can I buy some extractors & a CIA for my 4G94 for $300 ?????
 
You must log in or register to reply here.
Back
Top