hi all..me friend has a 2004 uk sti...a quick list of upgrades are sc46,800cc injectors,full 3inc militec with sports cat,syvecs ecu,fmic,cone filter,gt spec headers...he had it mapped twice at different rr's where on 1 it made 420 and other it made 410 both at 1.6bar,on v power plus...done by duncan graham...shouldnt the sc46 be making 450ish?...i no its not duncan thats the problem so what could be holding it back? or are the figures correct? cheers.

 

Turbo is more suited to 2.5 engine

 

Is the engine healthy?

 

cheers zippy....so the figures are about right then?

 

engines done around 62000...runs completely fine,im no expert but its like a rocket ship

 

That sounds about right at 1.6 bar, up the boost to around 1.8 and you should see closer to the rated figures.
As you already have a syvecs, get a second map done to run a 20% meth mix and that will net you another 40bhp or so, cheaper than v-power and safer running for the engine.

 

cheers dubzy...is 1.8bar still safe?

 

20% METH would get him closer to 450hp, nothing else to improve on what you've said.
Trev

 

sports cat may also be holding it back at that level

 

..

 

1.7-1.8 should see 450ish and 2 bar plus meth around 500 me thinks.
P.s get a better mapper

 

There are plenty of SC42s/MD321Hs that don't make 400bhp and plenty of SC46s/MD321Ts that don't make 450bhp. 410 - 430 is more typical.

 

And then there's some others that make over the quoted figures, it's all down to right supporting mods down to the very last details and creating the best flow for all to work together.
Quality of certain parts make a difference too, example, if you use some modded injectors etc you may not see the full benefit out of them and maybe holding you back but you don't know this yet as you think they are oversized for application.
Certain sensors like 3-4 bar map sensors needed, always buy 1 bar more as typically they don't make it.
There are loads of variables, like right fuel flow too, correct air flow, oil flow, gas flow etc etc.
Lots of people just fit the supporting mods (basic parts) and it don't give them numbers that are expected of.
And of course a good mapper is needed also as a finishing piece.

Banny has thought me a lot in the small little bits that most don't bother with, even different ecu's will give different results.
Well let's hope all that quote pays off on my build otherwise I'll slap myself

 

All very true, but most just bolt bits on and hope for the best!

 

Exactly my point, and forgetting the little bits that think they don't matter.

 

seems like a reasonable spec list, Does it have a good quality turbo intake hose? (Something like perrin or samco?)