Hi All

 

I have a Ke35 with a 4age 100kw in it. I have a full rebuild kit and am ready to strip it down and do the job. Before I do so, however, I need to ask is there anyway I can get a small power increase while I'm doing this?

 

I have been going through all the forum topics and have seen many about adding a turbo or supercharger, although, when it is all said and done it would probably be cheaper to just buy a 4agze half cut and start again. This all ends up being too expensive for me.

 

The real questions I need to ask then are: Can you buy different pistons to increase compression, like dome tops? Has anyone shaved the head? Are these bad ideas for this engine? Does anyone have any other ideas?

 

Like I said, I wouldn't mind a little bit more out of her, but I need it reliably and cheaply so if it can't be done its OK.

 

Cheers Craig

smallport 4age's are up around the 10.3:1 compression mark already.

 

this is a pretty good write up on the ol 4age.

 

http://www.billzilla.org/4agmods.htm

Thanks mate that website is great. Heaps of ideas and it will definitely help me out.

 

I suppose the thing I am wondering about now is valve clearance. There are cuts in the tops of the pistons to ensure that you don't get any contact, so if it is even possible to shave the head a little, how little are we talking?

I've been looking to try and find the actual figures for clearance, but not successfully yet.

can always port the head abit to make it flow abit better, cams, adj cam gears, better valve springs :yes: just to list afew things

So cam shafts and some head work seems like the go. What cams have people used that work well on the n/a engine? I don't want to go too far.

 

The website listed above says that anything above about 270degrees is getting pretty serious. I had a quick look on E-bay and there are some HKS 272 or 256 degrees for about $400 each. Is this an alright price and which would people recommend?

i don't personally know but i've seen alot of N/A 4age's using 272 degree cams

That website above also says that anything above 256 degrees needs a chip or after-market ECU. The 272s that you have seen running, did they have standard or new ECUs?

can't Give you definate answers for all of them but i'd say more than likely aftermarket computers aye

That's cool mate, I appreciate the information that you have given, cheers.

256 degree cams would still give it an angry idle though :)

the big tip on efi engines: if you change anything on the engine that changes the amount of power you are making (ie the amount of air into the engine) you NEED a programable ecu.

 

people will say "oh i ran 272's on a stock ecu fine", sure it might have run, but if you are only getting a 10hp increase when if you were using an aftermarket ecu with a GOOD tune you could be getting an extra 20hp. why bother with the standard ecu with an $800 pair of uprated camshafts if you arent going to use them to the full potential?

Ideas then for aftermarket ECUs? As far as I can see I can go the fuel and ignition, or I can go just fuel? Then the options also include a chip on the standard or a a completely new one.

 

I know that a whole new one will be the best option, although, the best is always the most expensive. Is one of the other options viable or good enough? What has been done?

I used an autronics ecu on my 20v st and reset vvt to lower rpm and it worked awesome!!

If you're talking a new computer and cams, or different pistons, then maybe selling and getting a GZE package isn't such a bad idea..... You'll have potential for more power later on as well...

Ideas then for aftermarket ECUs? As far as I can see I can go the fuel and ignition, or I can go just fuel? Then the options also include a chip on the standard or a a completely new one.

 

I know that a whole new one will be the best option, although, the best is always the most expensive. Is one of the other options viable or good enough? What has been done?

 

most expensive maybe the best, but you don't need the best to get the features you need for the 4age.

 

have a look at the new haltech sprint range, i think the base model is under 1000bucks. from what i could see that had everything you need.

 

also look into the gready emanage ultimate ($700ish i belive). that is a fantastic piggy back ecu. but its a bit more than a piggy back ecu, has some very good features. When the mods on my s15 require it ill be getting one of these, reliability and driveability of the standard ecu, with the ability to change everything through that emanage!