Turbo Options - 450BHP - 550BHP
 

Hi Guys,

Looking into Turbos's and options avalible.

My current UK Wide track is running 320BHP, with a Dynodynamics Map.

Current Mods that came with the car:

• Cobra Turbo Back Exhaust
• Haywood & Scott Downpipe 3>2.5
• High Flow Fuel Pump
• Fuel Tank Top Seal - no idea what this is?
• Pro R Panel Filter

Looging to get my car to 450bhp - 550bhpm, runinng on fuel only (no meth) - I have been told the car can handle the power?

I want the car to be drivable under normal conditions in town etc.., and want to keep the lag to a minimum... is this possible? i know ther eis a trade offm however tying to understand this.,

I understand i need injectors, and other bits however for now just looking at Turbos.

Thanks

Came across these two...


http://www.streetracersgd.co.uk/index.php/shop/product/724-gt35r-turbo-kit-for-subaru-wrx-sti-stock-location-internally-gated

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F 293158869621

MDX 555. ,,,,,,

Also reading up...car is safer to run near 420bhp..

Is this right? Or can I push more?

Dont want to blow anything..and avoid the lag at all costs...

If you want to avoid lag dont go for that power level, stick an sc36 on there and have a quick spoiling 360bhp.

Already on 320bhp.and the car feels slow..however that is because I have a f10 m5..and my brother has a 410bhp ttrs.. so wanted something with more power..

There has to be a way to achieve say 450bhp..or near abouts without Lag?

Ir is Lag the trade off for power powt 360bhp?

Build one of these to avoid lag....

2.1 stroker
2.35
2.5

What is this? And what are the costs involved?

They are just different engine builds, the 2.35 is for mega power 600+bhp. A popular choice is the 2.1 stroker from engine tuner it uses a 2.5 crank in your 2.0 block with uprated pistons and rods. They can take an awful amount of abuse and the extra displacement will help with spool. Speak with alan Jefferies @ engine tuner about their drive in drive out price. They also do their own mapping which is handy.

The 2.5 would be your best bet to reduce lag but only when built correctly, in std flavour they are complete ****e but once forged they make the best fast road engine with bags and bags of torque. You can use your 2.0 heads on a 2.5 block so you could offset some of the cost by selling your bottom end.

Shreksta is right ,,having just gone from a forged 2.5 running over 500bhp back to a 2.0 running 340bhp ,,,, my 2.5 spooled better than the 2.0 ,,,, 2.5 was running a forced performance red @ 531bhp ,,, the blob eye 2.0 is running a VF35 @ 340bhp ,,, the difference is night and day ,,, the 2.5 spooled a lot better from low down due to the extra displacement

As the yanks say............there ain't no substitute for cubic inches :)

Comparing a modded nearly 15yr old Scoob to a TTRS and an F10 M5 is your biggest issue.

I don't know for sure but i'd bet lots of money on the newer cars having variable vane geometry in their turbos and will almost certainly have shorter exhaust paths from engine to turbo in comparison to the Subaru. These two factors will nearly eliminate lag and there's next to nothing you can do about it.

I'd be looking for a roller bearing turbo instead of the SC36. The likes of the SC42 if you can get one as i don't think SC do them anymore. Or as was first suggested very similar to the SC42 as they're all garret cored the MDX-400/450 would be similar in response. along with the MDX from turbo dynamics there's the MDX321H (400ish) and T(450ish) from Lateral Performance are much in the same as the previous mentioned turbos.

I would not be buying some old ass spec turbo as thing have moved on since then, you need to be getting a turbo that has been developed in the last year or two.

other things that help spool are a Samco intake pipe :)

I seemed to be getting mixed responses from people I have spoke on to..

Some have said 500bhp is possible on standard internals..some say the will become a ticking time bomb...others said the wide track can handle the power..

Some said 450bhp is not even possible unless a bigger turbo is modified...

There are allot of Turbo choices out there..the one in my 1st link was on ebay and down from £1800 to £1000.

So this is going to be tricky...I think..

Go twin scroll :thumb:

I dont think you can put a twin scrol turbo in a UK spec single scrol car? UK is twin scroll...right?

Any turbo car will be laggy, simply because the turbo has to spin up to speed once you stomp on the accellerator. The bigger the turbo, the laggier it will be, generally speaking, but there are as above some things you can do to make the car feel less laggy.

In a random'ish order:

- have a smaller turbo. This will probably make less power than a bigger one, of course, but it will spool up quicker than the bigger turbo all other things being equal.
- have a bigger displacement engine. 2.5 will outspool a 2.0 (all other things being equal). The TTRS is also 2.5 litre, IIRC, and the M5 is what 4.5 with a twin turbo? Displacement here makes a difference :)
- twin scroll turbos (this is where the exhaust runs from two cylinders are kept separate all the way to the turbo, and fed into two separate exhaust scrolls (actually this may be a lie, but at least there's two separate holes for exhaust gases to enter the turbo)). This works very nicely indeed to reduce spool times, and quite possibly lag too.
- don't run big aftermarket headers (exhaust manifolds) - a lot of them make spool worse. There's an up-pipe (which on the subaru fits betwen the exhaust manifold and the turbo) from ASPerformance which is tapered to a smaller diameter near the turbo, and this is supposed to make several hundred RPMs difference in spool compared to e.g. the overly large aftermarket headers.
- Some turbos come with "billet" wheels - basically the wheels are made from a lump of aluminium, rather than cast. Sometimes these wheels are lighter than the cast ones, and have slightly different shape, which can aid spool / lag / power.
- Keep the stock STI intercooler - a FMIC will increase lag, and the stock intercooler is good for 450 at least, depending on turbo.


Basically, as we have quite small engines, it's dificult to achieve high HP numbers without noticeable lag. You can learn to drive around it, but at the end of the day, you cannot change the laws of physics. To make a lot of power, you will have to shift a lot of air, which necessitates a big turbo, which will feel more laggy than a smaller one. All the other stuff is IMO just fiddling around the edges of the problem - yes, some combinations of parts will make the issue slightly better or worse, but you wont get away from the lag unfortunately. Even your M5 will have some lag, but it might be so small that you cannot really feel it (but then again, you might, if you were used to driving the E60 M5 with its V10 normally aspirated..)

I have a td06-20g with a billet wheel (single scroll) on my 2.1. It's laggy, and spools late. Twin scroll probably makes it much better, but... still a large turbo :)

Btw, spool point = the RPM where a turbo starts producing some level of boost at full throttle. Lag = the amount of time it takes for a turbo to spin up and produce boost, once it's past the spool point.

A large turbo will generally be both laggy and spool late, where-as the opposite is true of the smaller turbos (generally)

Thanks for the info

How much is it to go to a 2.5L out of Intrest..?

I will create a list if Turbo options..and I think this will be a good place to start.

I have the f10 m5..4.4 twin turbo..if there is Lag.. it must be at idle..lol

Thanks..will try Alan - what sort of rough costs are involved in going to a 2.1? Is it £1000's

Here is the dyno that came with the car..


https://cimg7.ibsrv.net/gimg/www.sco...368ee84440.jpg

A decent remap will see that set up spoiling earlier.
Yes you can fit a ts to a uk car,will need exhaust manifold and up pipe to match.

Plus the TS sump, dipstick, turbo and downpipe, potentially from downpipe back too depending on whats already there.

Aye,down pipe and a sump too,easy conversion tho.

Have you been out in a genuine 550bhp car?

The reason I ask is that's the difference between going rotated and staying stock position.

There are plenty of stock position turbos that will get you close to 500hp and to be perfectly honest are plenty quick enough for most people.

One of the best cars I have owned was a JDM widetrack with a stock position turbo that made just over 500bhp. Going rotated is lots of work and to do it properly is fooking expensive.


If I were in your shoes I'd look at the SC46 Billet from scooby clinic. Will get you up where you need to be and will be a hoot to drive.

If I had my time again I'd have kept the JDM and that's coming from someone that's been down the slippery slope of rotated turbos and north of 600bhp.

Hi,

not not been a scooby that fast...have in my f10 m5 though..

Just had a chat with ScoobyClinic.. SC46 is the one, however they have said running 450bhp on standard internals maybe a push...is possible, however depends on how it is driven,,

Also spoke to Alan, going to a 2,1 makes sence..but at a cost of £6K...i would really have to love the scooby..and being a 3rd car..think i will be opting for working with the engine i have.. lol

Also was told standard ECU is good..unless i am looking to mod the car further..lilke removing the maf headers etc...

Here are the Turbos i have found:

The 1st one being the cheapset

http://www.forcedperformance.net/fp-...ru-wrxsti.html

http://shop.scoobyclinic.com/index.p...product_id=907

http://lateralperformance.co.uk/prod...6054edf812d2c4

https://drivenperformance.co.nz/prod...-scroll-turbo/

https://www.exoticspeed.com/products...lly-wastegated

https://www.turbodynamics.co.uk/shop...65b20811ac6943

http://www.streetracersgd.co.uk/inde...ternally-gated

Ahh...that's interesting...I found all the single scroll turbos...wondering if i should look at twin scroll.

How much would a manifold and up pipe set me back

Remember that if you go twin scroll you will lose the subaru burble and it will sound like a revvy honda weed-whacker

I would not be wasting cash on a twin scroll setup as it’s not that good. I bought Dazdavies old gt35 for my car and on a rotated setup I was making 2.3bar at 3300rpm. I don’t think Daz made that on his front mount set up? It’s not the size of the turbo what cause lag it’s the bits that go with it that make it spoil nice .

why not just run your engine to 450bhp and if it breaks get it rebuilt then?