gordyra r

i have a 2007 spec c ra r if i want too upgrade turbo and keep it twin scroll what turbos are available for say 440hp-450hp?

also can u bay potenxa re07 in uk? anyone

TonyBurns

iTrader: (3)

Have a word with Iain Litchfield, should resolve both your questions there

Tony

scoobytyson

Not sure there is any for that power, i thought the one powerstation sell is good for around 400bhp

Boyakasha

iTrader: (2)

That's what I think, you may find if you want that sort of power then you may need to go for an MD321 and swap your up pipe/down pipe etc.

stevebt

iTrader: (8)

ditch the twin scroll

MrRA

You can't buy the 18" RE070 in the UK. I've already been onto Bridgestone UK about it and how I thought they were potentially losing out on a nice niche market with that tyre.

I was told my comments were passed on to the Marketing Dept.

As far as the twin scroll goes, the HKS GT2385 will make that power, but will probably be too laggy on a 2ltr. They are best suited to a 2.2 stroked unit.

You could send your turbo off to Turbo Dynamics and the like in order to have a hybrid unit made.

stevebt

iTrader: (8)

I have already tried that option and the best option is "ditch the twin scroll"

scoobytyson

Thats the best bet

TimH

iTrader: (11)

Also interested in this....

What are the arguments for ditching the twin scroll? I love the twinscroll on mine as the power comes in so low down, with minimal lag, making around 350bhp. I would be loathe to give up the driveability for the sake of top end power, but maybe I'm missing the point?

rickya

iTrader: (18)

Horses for courses!
Im with you mate, for my purposes & driving uses the twin scroll is ideal.

MrRA

In my opinion there are no arguements for ditching a twin scroll. They are better low down and mid-range than single scroll units although they won't achieve the same peak power. Who cares though? Surely driveability counts more than anything?

Mikkel

I beg to differ. I test drove both a JDM STI with twin scroll and a 2.5ltr UK without and found the UK model to have the better power band and available quicker.

Obviously, didn't try the 2.0ltr UK as that was too old a car for me when testing at the time.

TimH

iTrader: (11)

Interesting debate this

Has anyone got RR dyno plots of:

UK MY05 2.0 STi
UK MY05 2.0 STi + PPP
UK MY05 2.0 STi + remap (e.g. Bob Rawle, Powerstation etc)
UK 2.5 STi
UK 2.5 STi + PPP
UK 2.5 STi + remap (e.g. Bob Rawle, Powerstation etc)
JDM 2.0 STi

all with no or "basic" mods (exhaust and filter)?

I've just added the dyno plot to my profile of my JDM 2.0 after its remap.

I know that this will not be an exact comparison, but it might be interesting?

my00scooby

iTrader: (1)

Any ideas what turbo would suit this model if a more modest 400bhp was being sought?

TonyBurns

iTrader: (3)

Yet the JDM car has more power, is quicker in gear and has better up take which is the advantage of the twin scroll turbo's, unfortunately a single scroll on the uk 2.5 wont be as good as the 2ltr twin scroll car, power comes in at about 13-1500 rpm on the jdm, its still about 2500 on the 2.5, try it in 6th gear next time, at 30mph, the 2.5 will still be struggling

Tony

TimH

iTrader: (11)

Not sure I agree about the 13-1500 rpm Tony? Unless the slighly higher state of tune of my remapped car has lost some of the low down power? I'd say more like 2000-2500rpm to be honest - although it will certainly pull in 6th at 30mph rather than stall!

Out of interest I drove a stock 300bhp '05 USDM 2.5STi earlier in the year and it felt really gutless compared to mine.

scoobytyson

I think its all to do with how u drive, i like to rev the car upto 7-8k and do a few 1/4 mile runs so the twin scroll was useless for me as they are out of puff at around 5.5k revs

TimH

iTrader: (11)

Boost is certainly tailing off from 5500rpm, with peak power at 6500 - but I know what you mean. If I was modifying my car further I would be trying to get more air flowing at higher rpm. Bob Rawle got 380bhp out of his JDM with the stock twinscroll (20bhp more than mine) and maintained 1.4bar to 7500 (IIRC) rpm by adding an RCM induction kit: I've not bothered since £150 plus a £300 remap is a lot of dosh for just 20bhp.

As an aside, there is a heap more torque to be had I think: I went on a RR day and found that my car was jumping off the rollers due to 380lbft of torque as a result of 1.7bar boost at 3600rpm , with correct fuelling I was told. But I subsequently found I had a split pipe to the boost control solenoid so the boost was not being controlled very well Even so, I think a map could deliberately allow higher boost at low rpm to get that torque...which is what, as a general rule, we actually need rather than out and out power (unless you're looking for top speed etc). Now the pipe is fixed, I definitely miss that surge of acceleration at 3500-ish rpm.

gussy

iTrader: (2)

Yes it is and gives you 398LLbs as well,as has been said in earlier posts its horses for courses it depends what you want to use the car for for me I prefer the low down push of the twinscroll plus you can rev to 8.000 gives me 1.6bar at 5.000 leveling to 1.4 solid Ideal plus with the turbo being a hybrid its midrange top end power has been opened up linked to the revy 2 ltr engine makes a good all round package

gussy

iTrader: (2)

Just had a quick check on that it gives 1.6 bar from 3.600 to 5.800 then tails down to 1.4 at 6.100 right through (straight line) to 8.000

bluenose172

iTrader: (2)

Hi Gussy,

So you have the Hybridised VF36/37 turbo? What were the figures?

stevebt

iTrader: (8)

I have a bit more lag on myturbo but If I want to show off I would just drop a gear The hit from acceleration on my turbo is in a different league to the hybrid twin scroll/ twin scroll turbo

ex-webby

Don't fit an induction kit to a twin scroll 2ltr, unless you want to either have to cap your boost profile or suffer from compressor surge. Either is not good and the standard airbox with uprated panel filter is easily up to the job.

Unfortunately, regarding turbos, you can not have everything. The more peak power you want (by getting a larger turbo), the more time the turbo takes to spool (all within reason).

You can't have your cake and eat it, with just a turbo change.

mervil

iTrader: (5)

Here's my Euro MY05 STi 2.0 with exhaust and K&N CAIK Not sure what the boost is doing tho

gussy

iTrader: (2)

Have to agree with Shaun????/Simon??? on this one it all depends what you use your car for if its fast B road work trackdays I would////and have gone for the hybrid it suit me perfectly.
Bluenose it gave 415/398 but that might change because I have plans in the pipeline this winter coming just need to get a budget on prices etc sorted

bluenose172

iTrader: (2)

If you ever change your Turbo, PM me a price!

gussy

iTrader: (2)

No problem

Davey P

iTrader: (1)

My twin scroll turbo makes 370 / 390 on my spec c, not bad IMO.

ex-webby

Faster spool is great, but I have found that spool is not always relative against actual power/torque produced.

My previous 2ltr twin scroll set-up used to reach full boost by 2800rpm (1.7bar) with a Hybrid, so slightly better than my previous standard twin scroll turbo.

My current Cosworth engine with the largest GT30 produces full boost of 1.7bar at about 3300rpm. On the face of it that does not sound so good, but this total set-up (regardless of what boost it makes at the same rpm points as my twin scroll) makes a shedload more power / torque EVERYWHERE (yes... that is even from 1400rpm on the dyno).

Remember to not just look at the spool rate in isolation.

Gussy,
You should know better than that.... it is Shaun here!

bluenose172

iTrader: (2)

DaveyP - Do you have a uprated boost solenoid and actuator?