Ive got a 2005 Blob with a SC360 turbo running about 345 Bhp , Its actually pretty quick as it is. Its supposed to be going in next month for a bigger turbo, FMI,headers ect ect to go for around 450 Bhp not sure what turbo they have me down for but i am wondering if i will get more turbo lag and spoil the drive

Has anyone else done this and wish they hadn't spent the money?

 

The car will spool slower (as in, it will make boost further up the rev range than on the sc36), and lag (the time it takes for boost to appear after you press the throttle *provided you are in the right rev range for boost to be possible* may be worse too.

However, depending on what you want out of the car, the bigger turbo may be more fun to drive, and it will definitely be faster in a straight line. Only you can make the decision of what you want out of the car, but there are lots of people who are happy with e.g. the sc46 and fmic (450+ hp).

Personally, I've gone the other way. I had a biggish turbo for my 2003 WRX (td05-20g), and I have now dropped down in size. I've probably given up about 50hp, but to me the power band was more important, and at the moment I'm happy with my choice (I'm probably not very typical, though...)

 

You will have slightly more lag but us mere mortals will not notice and it can be compensated for with a good map. Charge temps will be reduced and depending on the turbo and how you prefer the power and torque band, it could make for a fun setup. Having said that, power isn't everything. I've owned some high-powerd cars but a well set-up car running mid-to-late 300s is probably the sweet spot for drivability and fun factor.

 

If you like it feeling "punchy" from low ish revs, you may not like this change.

I went from optimised VF35 to an MDX turbo on my blob some years ago and hated it then went back to VF35.
There may well be better turbo options these days though, take advice from your mechanic.

 

Have to admit i am wondering if i could save a load of money and target say 380bhp , im sure the car would feel quicker at this level from what it now and could be enough for me as a road car. ATM other than the Turbo and exhaust i think the car is standard. What would i need to add to make 370-380 ish power

 

In my opinion You will feel more lag especially lower down the rev range moving from top mount to frontmount!...Well I did when I done similar upgrades to my Subaru back in the days, but as has been said above,it will have faster midrange so will be quicker once on boost when driving on motorways,but around town will feel slower to you,but in all honesty you are the only one that will know for sure as it is your carLet us know what you think once you go ahead with the upgrades.SJ.

 

Have you upgraded your brakes?As that would be paramount before tuning over 400+bhp.SJ.

 

Yes the brakes have been uprated not sure what they are mind, if they still feel lacking with the power upgrade i would certainly change them

 

as a comparison , my 2 litre sti jdm wagon has a bigger turbo plus more bhp than my fsti , the fsti would destroy it at a set of lights , plus the 2 litre had lots of lag ,my fsti v an impreza spec d that was tuned again and had more power than the fsti , the fsti was quicker off the lights and to 60 ish than the spec d , i like the upper range power of the bigger turbo in the wagon but it still proved to be slower than the fsti , plus again lots of lag , the mitsubishi fq400 on top gear was a good example it produced 400 bhp , but loads of lag due to the large turbo , so in real world driving the advice was by a less powerful and there fore less laggy model , similar situation to the subaru cosworth , my friend put a bigger turbo on his fsti along with the 2.5 engine not holding out , mpg was crap and lots of lag he regretted what he did to it

 

Well Did research today and found out when my turbo was rebuilt it got some hybrid parts fitted and it should be good for 400ps. with supporting mods. So going to try a remap with bigger injectors , maybe a bigger top mount and headers I have been offered a Process west top mount for £400

 

I’m almost certain you’ll get 400 out the SC360 with the right supporting work. Mine is the billet version and did 377@1.3bar on the 2.5 engine. The graph was lovely as is the car to drive.

I’ve tweaked the setup a bit for efficiency with better heat management and I’ll go again and I’m confident it’ll top 400.

 

Good to hear Mark. Are you on a standard top mount?

 

Yeah, standard top mount, blue (565cc?) injectors. Perrin filter, intake and inlet. 3” decat SCR exhaust.

 

Do you guys actually mean SC36? As in, the billet td05-16g from blouch/scoobyclinic? I think it will be very difficult to get 400hp from one, at least not unless running methanol or E85, regardless of intercoolers etc. The compressor wheel simply isn't big enough to push that kind of air volume, at least as far as I can tell.

@Nelzsti, you mention it has been back for hybrid parts? Do you know what wheel was fitted? That should give you a good indication of how much power you can realistically get out of the turbo. Has it been upgraded to an 18g wheel, for example?

 

I mean the SC360+ which is a blouch based turbo yes. Mine has run 370+ on different dynos
and the mapper was adamant it would do 400 with just a tweak.

im not guaranteeing it will do 400 but it seems likely going by what I’ve seen.

 

Switchable maps? Try 20% meth, you'll be surprised of the results.

 

Have to agree really,i can't see the SC36 making 400 bhp on pump gas alone maybe with some METH added you might get nearer that figure...370/380BHP is a nice drivable Subaru anyway you don't want a car that is too much of a hand full until you feel that you need or are ready for it.SJ.

 

Made a call to AET Turbos to confirm what i have actually got , they say its and TD05 with a 16 g wheel rated by them at about 350ps .. They say they can upgrade it to make over 400ps for about £600 I thought it was to good to be true

 

The 36 will be the limiting factor in you current setup, but going up turbos size will give more lag no mater what. But thats the trade off, peak vs spool. im guessing they are talking about an sc42. Front mount will make little no no difference, i actualy gained spool on my type r when it had a front mount fitted.

 

I am thinking to get the 18g wheel fitted not sure what that would be called SC38 ?

 

Tidgy you was lucky regarding turbo spool... When I first made the move from top mount to front mount I could feel a definite lack of spool up especially on the GO peddle,at the time I was even considering putting the top mount back on...i only really found a positive from the front mount once I checked my EGT were lower and the midrange power/acceleration had improved.SJ.

 

the last two digits define what its aimed at, so sc36 = 360, sc38 = 380, sc42 = 420. For the low to mid 400's i'd be looking at the SC42 myself

 

It very much depends on setup form my experiance, i;ve done the transition on 3 cars 1 reduced lag, 1 was more or less the same and 1 lost about 50rpm, smaller turbo's suffer from it more than larger ones of course.