Hi guys, finally picked up my car this morning after waiting 3 months at Cotton Competition for a power upgrade.

I was originally running this spec / SC360 16g turbo at 345 ps
Standard pink injectors/ Standard intercooler / Standard intake / Standard ecu/ Carbery rom

My Expensive upgrade is/ AET GTX3071R with 11 blade billet wheel and 7cm housing

Process West Top Mount

RCM Headers with up pipe

ID 1050 injectors

Fancy cold air intake, i forget the name

Initial thoughts on driving the car home was not that good really , firstly the car wasnt as smooth as i remember and feels like all the shove is much higher up the rev range. It spools up nice enough but i was expecting more torque lower down. It does feel fast when you rev it out but not sure its as much fun to drive as it was before. Pisser really,, Maybe i need to spend more time behind the wheel to get used to it

 

"..maybe a mapping issue.." my thoughts too.

 

Yeh might be a good idea to get it checked out . Having been driving it about this afternoon, its a bit lumpy at low revs, in both high and low boost, although low boost it much better

 

What power did it make? If it’s on a 2 litre then I’m not sure there’s much you can do about the huge amount of lag. The gtx 30 Is a 500bhp plus turbo so unfortunately I doubt it can be sorted. My current 340bhp blob drives miles better than my old blob with a sc46. Chalk and cheese tbh.

 

Not a clue what power it makes as they dont have a dyno. I bought that turbo off a recommendation on here, someone else has one on there 2 ltr and was singing its praises .
Its Cumming on boost at about 3k, it doesn't feel laggy at all

 

I take it that it’s a standard position turbo ?

I have a Gt3076R with all supporting mods and it made 426bhp on my 2.0l after thinking it would happily make over 450bhp and its laggy as hell but it’s been like that for 2 years now and don’t drive it as much as I should, I know I’m gunna get comments that it should of made more and so on I know that but not sure why it didn’t only thing I can think it would be was the fact it’s a Mamba unit

Will be looking to change mine soon and go for a rotated set up or maybe something like the RCM precision billlet that’s capable of 500bhp and advice on turbo choice would be helpful

Await all the stick now haha

 

Yea my SC42 tinkered by Owen Development had very little before 4krpm. Peak torque around 5k on an engine limited to just past 7 was pretty useless great if on the drag strip & a WOT only car.

400 would be my sweet spot on a road car using all the standard issue parts that have been available for years.

The other option would be a nice twin scroll borg warner efr series aiming for around 400-420bhp, something not done so often

Going big turbo on my 2.0 was a dissappointment

 

Yes so they say its mapped for the mods, but i do know he had loads of trouble mapping it.

 

Anyone any idea what Scooby Clinic would charge to dyno it and tweak the Mapping?

 

The sc42 is touted by almost everyone as the best thing since sliced bread for the 2.0 (or at least it was when it was launched). It is interesting that you found it laggy!

I have looked at a bunch of dynoplots over the years, and I think it looks laggy as well, because at the end of the day we are trying to drive quite a big turbocharger with a small engine, so this will never end with low spool point and low lag (IMO). I also scaled down my power ambitions for the same reasons. Although my car was on a td05-20g, the spool point would have been somewhere in the vicinity of the sc42, and on twisty tracks and twisty back roads, I just don't think it worked that well. Great on straight A-riads, but not with the type of driving I enjoy.

I currently have my favourite turbo on the car and it's somewhere close to your power level. I have tried UK spec td04, td05-20g, td05-16g, sc36, JDM spec td04, and finally a td04HL-19t hybrid. I keep flirting with going back to a td05-16g billet,but I don't want to loose any of the brilliant spool that makes driving twisty roads a joy.

There are two things I'd like to try: twin scroll (but then there's so much that needs to be changed), and a variable vane geometry turbo. I think a VNT turbo could be a bit of a holy grail, offering decent spool, and also enough exhaust flow to support more power than our current turbos.




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Yea folk get hung up on the wording lag is the wrong word i used there but its what everyone would describe it as

The SC42 i had was closer to a 46 had a very high boost threshold. Above 4krpm

But once in that threshold up above 4k-4500krpm it is responsive so not really laggy in the true sense of the word.

The problem is most folk split hairs when talking about these especially after dropping best part of 2k into a turbo.

Then you get the folk who quote how much boost it makes at 3krpm when really it's still dead on its **** compared to a modern motor.

On a 2.0 with a big turbo if managed 300ftlbs @ 3krpm i'd say your doing well.

But for reference and i know it's apples & oranges but my mapped 140i BMW made closer to 500ftlbs closer to 2krpm & pulled all the way through to redline & ran times that i could only dream of even when i had 450+ bhp in my impreza the 140i stock would have kept up with it due to how poor the responce was.

I now have a 2.5 fozzy sti and the low down torque it has is pretty impressive compared to the 2.0 but is still a total dinosaur engine.

 

Interesting, so you ended up back in a Subaru...

 

@Nelzsti It was probably me that mentioned it as I run that turbo and it's fantastic on a road car, I'm on a 2.1 though and there is a noticeable torque difference of around 60ft.lbs iirc. Mine makes around 460bhp now. Who mapped the car for you? If it's lumpy down low then it does sound like a mapping issue. Mine ran like a bag of nails after my first map which is why I took it to someone else and the difference was night and day. I did read something on here long ago that the RCM headers are not recommended below 400bhp and car make the drive lumpy (although you should be making that now). I run the RCM headers with a Harvey Smith trick uppipe. You're a long way from me otherwise I would've said come over and have a drive of mine.

 

Can't fit 3 dogs 4 people & a mountain bike in a 140i

Always wanted to try a Fozzy Sti tbh & didn't have any reason to choose one over an Impreza 1st time round. After driving this 2.5 i think i've been turned to the dark side.. the low down torque & driveability is incredible compared to the 2.0 Sti I've had.

I reckon with an SC42 or better yet a good modern Twin-Scroll setup the 2.5 with 400bhp would be hard to match as a great daily road car spec.

 

Heres the estimates from AFP when mapped

Fozzy Sti




2.0 Blobeye on VF35 with FMIC stock headers & up-pipe
vs
2.0 Blobeye on SC42 tinkered by Owen Developments
Gt-Spec Header - Harvey 3 bolt up-pipe




2.0 Blobeye on SC42 tinkered by Owen Developments
Gt-Spec Header - Harvey 3 bolt up-pipe

V-Power vs 20% Bio-Ethanol





2.0 Blobeye on SC42 tinkered by Owen Developments
Gt-Spec Header - Harvey 3 bolt up-pipe


20% Bio-Ethanol vs 30% Bio-Ethnaol




AFP usually overestimated by around 5%

Torque on the 20% E run was overcalculated due to dip in road.

Below 4200rpm the stock VF35 was killing the bigger turbo car and this showed on the road, nothing brake boosting couldnt fix in a side by side race but out on the road it became worse unless giving the car absolute death.

Compare the the 2.0 to the fozzy 2.5 & it shows the fozzy has it down low.

VF35 again but with rpm to compare torque.

 

You need to be making at least 300ftlbs to get these shifting if u ask me so compare that figure on each

2.5 Fozzy 300ft,lbs @ 3k rpm
2.0 VF35 Sti Blobeye 300ft,lbs @ 3600 rpm
2.0 Sc42 OD V-Power 300ft,lbs @ 4200 rpm
2.0 " " " 20% Ethanol 300ft,lbs @ 4100 rpm
2.0 " " " 30% Ethanol 300ft,lbs @ 4000 rpm

For comparison my 140i had almost 500 ftlbs by 2k rpm
&
Mates Golf R made 400ft,lbs by 3k rpm.

 

Interesting read guys. I’m running the Sc36 on my ej25 and I like the way it drives @380hp.. I’d like more power but have always worried about compromising the drive for a few pub talk numbers.

 

The new engines are incredible compared to our old tractor engines tbh... Even the new Subaru engine is probablya lot better from a tuning point of view.

This is partly why I gave up on even trying to achieve big power tbh - if you want power, you might as well just buy a new car and a remap. It will be faster , likely better handling, safer, more economical, more reliable etc etc, because 20 years of development. I still like Subaru's, but there's no denying that modern machinery is better in many ways.

 

Do you have a graph for that setup ?

I'd really love to see what a Twin Scroll does on a 2.5 if sized correctly to make around 400bhp

 

 

It does frustrate me when people compare modern cars with an impreza that's over 15 years old. Comparing a 140i with a Blob STi is like comparing my scooby with an Escort RS turbo or 309 GTI, there's just no comparison as cars evolve over time.
Are modern cars faster, in most cases yes as they have all the driver aids to make you go fast. The trade off is that the more driver aids you have, the less involving the drive. I find new cars a bit boring if I'm honest...

 

So 300ftlbs @ 3250

250 rpm isnt a bad sacrifice for the gains but it gets worse the larger turbo you go for.

 

[QUOTE=adam.pah;12094512]It does frustrate me when people compare modern cars with an impreza that's over 15 years old. Comparing a 140i with a Blob STi is like comparing my scooby with an Escort RS turbo or 309 GTI, there's just no comparison as cars evolve over time.
Are modern cars faster, in most cases yes as they have all the driver aids to make you go fast. The trade off is that the more driver aids you have, the less involving the drive. I find new cars a bit boring

Compare it to a 2.0 VAG unit from same time & 300 ftlbs @ 3krpm is easily done with around 370bhp

Our 2.0 can't come close

You can't measure fun......

 

VNT has a lot to answer for there i'd imagine

 

Afaik there's very few petrol engines using that tech i know the 911 turbo does but definetly not a SEAT Leon or tht level of VAG car.

So in those cases VNT has nothing to do with it.

Twin scrolls maybe but then compare to a 2.0 Sti twinscroll and its not exactly life changing

 

The sc42 is a lag monster on a 2.0 ej
if Anyone tells you any different they be telling lies

 

[QUOTE=SmurfyBhoy;12094515]Are you suggesting that seat leon running comparable power is more fun to drive than an impreza?

 

[QUOTE=adam.pah;12094525]I says you can't measure fun.....

 

[QUOTE=Jamesfromrugby;12094529]Yep the good old 2.0 VAG engine at it again.

 

[QUOTE=Jamesfromrugby;12094532]Followed one of those round a track once and, even though I was in a much more powerful car and his was standard, I was surprised at just how hard he could push it and how composed it was. Something that really stuck with me to this day.