Can anybody tell me the differences between these engines? STi's run another 1000rpm over a uk car don't they? I have a uk99 that run's just under 300bhp and am wondering what to do next and what will be stopping me going further (and don't say 3rd gear )

 

The UK and WRX engines I believe, are the same internally. Extra power of the JDM WRX comes from mapping to suit domestic fuel grades etc. The STi engine is stronger internally (some would argue at that!!) by the use of forged pistons,rods etc as opposed to cast items in WRX and UK. Some STi versions have hollow valves (sodium filled?) which also allow higher rpm (reduced inertia).
At approaching 300bhp you should start to consider the integrity of the std. internals?
JohnD

 

Doesn't your boss know?

You need serious power to strip 3rd gear

[Edited by alanjack - 7/29/2003 6:12:54 PM]

 

Oh no you don't

PS Or as someone once said ...."You learn from your mistakes"

 

Or you must be a bad driver

[Edited by alanjack - 7/29/2003 6:23:09 PM]

[Edited by alanjack - 7/29/2003 6:24:12 PM]

 

Alanjack;
Doesn't your boss know?

Sometimes he appears to know just about everything, but gets sick of answering my endless questions!!!

JohnD;
At approaching 300bhp you should start to consider the integrity of the std. internals?

Yes thats what I was thinking, but am not sure of where to start.

 

Heads are different, cam profile is different, blueprinted engine...Erm... just a couple of differences

JohnD, serious question.. why would you question the integrity of the internals at approaching 300bhp??

I must beg to differ on this, how many 300+ uk cars do you know of that have let go at all?? how many 300+ uk cars do i know of that are fine and in one peice?? quite a few..
There are a few uk cars with std internals running 350bhp, no reliablity probs, as long as you take care of your engine.
I dont want to start a slaggin match but there are people who come on here as 'newbies' and will listen to comments like that.
It was a while ago that 300 was seen as the breaking point of uk cars.

And just for info, John banks had over 400bhp on std internals.. Not sure how long it would have held together though

 

Tweenierob;
Heads are different, cam profile is different, blueprinted engine...Erm... just a couple of differences.

What, all three engines are different?

 

Sodium filled exhaust valves, different cam profile, forged pistons, not sure of the details on the lifters.

The STi engine is a fair bit more detonation resistant both in terms of not detting in the first place, and allegedly standing up to it better if it does.

8000 RPM rev limit allows lower gearing to suit bigger turbo.

Seriously, your main limit IS 3rd gear.

 

Sure heads, cams etc are different from WRX to STi you dont get extra power persae from just stronger components! Those stronger (and lighter in some cases) components allow you to extract more power with safety and it was the safety (mechanical integrity) aspect I was emphasising. Sure it's easy to get the UK unit above and beyond 300bhp without delving inside and spending money on bits that don't actually produce more power but surely It's not a lot of use having an engine capable of delivering bar-room braging amounts of power if you have this little voice inside saying "careful, not too often"
If the standard unit was fully capable of 350-400bhp in safety, why do STI build their engines with such expensive components? You pays your money --------- .
JohnD

 

So for now I will be leaving my internals standard, with new turbo and front mount I should be in the region of 320-330 bhp, so next question, what to do about 3rd. STi box? uprated gearkit? any thoughts?

 

Is my third gear or lack of it causing you concern Cord? UK boxSTibox V's torque no contest Torque wins.
Just think about what you're doing.

I'll give you some advice, first time your gearbox falls to bits in anyway, get a decent replacement and one that is GTEED.

Save you money in long run.
Tell Steveo to get on the case and get me some prices

 

Steve is already on the case but there are a few options and I want somebody else to confirm what I think.

 

What do you think, I have P Mail