Is it possible to get a twin scroll to single scroll up pipe for a MY03 STi to allow me to run a MD321t turbo. I can sort the DP thats not a problem.

If its not available off the shelf and I got one made up are there any down sides to leaving the twin scroll headers in place and having a single scroll up pipe.

I hope that makes sense

 

There is one listed on ebay:

Impreza stainless steel up pipe on eBay, also Exhaust Components, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 09-Jun-09 20:45:00 BST)

Banny

 

Thanks for that I have sent him an e-mail.

Any one else?

 

Why do you want to run a single scroll turbo when you can get a twin scroll hybrid that can do the same job?
Go check out http://www.litimports.co.uk/shop/con...product=LIE024 for their 400bhp package

Tony

 

Perhaps because the MD321T's are so well and trully proven and they are readily available.

 

I am currently running a VF37 which Bob Rawle has maxed out @363bhp I was planning this route but the price of the turbo on its own is £1610 and its only goint to gain me around 35-45bhp whereas a MD321t for a similar price will be good for around 85+bhp + more torque and is a proven unit not a comprimise hybrid!!

What I dont want to do is spend (another) sh*t load of money on a built stroker engine & twin scroll hybrid to still find it runs out of steam at the top end.

 

i thought twin scrolls were a better option over the single scroll? i am sure rcm, lateral must do a biger twinscroll you coul dbolt straight on, and if it were more money i am sure it would work out similar by the time you have bought the dp and up pipe etc and would you not need to change the hearders to? to match to the single scroll turbo or am i just tripping and got that wrong

 

I do prefer the power delivery of a twin scroll but they just run out of puff at high revs. The frustrating thing for me is 8 weeks ago I converted (at considerable cost) to twin scroll and thought that would be fine with a map until my engine started playing up and now ive got to have the motor rebuilt I may as well go the whole hog and do the turbo aswell.

My idea was to change the up pipe and have a new flange welded on the (8 week old) downpipe. I just need to know if there are any drawbacks to doing this.

I have tried a couple of places for a bolt on TS turbos but powerstation, lateral, turbo technics, universal turbos but no real sucess. Powerstation & Turbo Dynamics who supplied my original VF37 have quoted £1195+vat to shoe horn a garrett GT3071R core into my VF37 but as I said above its still not an ideal situation hence wanting to swap back to single scroll.

 

I run a single scroll turbo on a Spec C, so have a twin to single scroll up-pipe. Speak to Tracktive Solutions as they supplied mine.

 

Great Thanks for that ill call them at lunch. Out of interest what turbo are you running? What power?

Thanks
Brad

 

My VF36 never ran out of puff at the top end
Anyway, this part you should read again

Designed as a bolt on replacement for the JDM Twinscroll cars these new turbos will support power from 380bhp to over 500bhp

Tony

 

Yeah, but where are they? He wants one now. The VF36 does run out of puff at the top end, but I'd still take a 400bhp(be that Litchfield or Hybrid VF) TS setup over a 450bhp single scroll setup, every and any day of the week!!

 

Surely though when you start putting a hybrid on you loose the whole beauty of a TS setup as there is always a trade off between spool up/top end and if you start compromising the spool you may as well take the extra BHP from a MD321 or other single scroll setup?

 

would or is it much work to go the other way from a single scroll on a p1 to a twin scroll?

other than the twinscroll turbo itself what else would be needed?

regards

 

i think it is the way it dilivers the power and how responsive they are sort of compensates for the loss of the top end power, from what i have read etc a twinscroll has an instant powerband with less lag over a single scroll so i could only assume that the lag on a larger single scroll would be more noticable comapred to a slighlty smaller twinscroll and rather then having to wait for the power to build up on the 321 say the twinscroll would be sitting there waiting to go so in turn makes it feel faster and more on the button

just my opinion from articles, post etc i have never driven a twinscroll so have no rela hands on experiance but i am sure tony will be along to expalin

 

Twin scroll Oil sump, twin scroll headers, Twinscroll up pipe, twin scroll down pipe twin scroll turbo.
About £3K's worth including mapping

 

The only time I ever noticed the VF turbo being lathargic at the top end of the rev range was with a standard panel filter in, she struggled to push much after 6.5k rpm, changed that to an STI panel filter and (on a private road of course ) she still pulled like a train at 155mph
I just must have had a good un

Tony

 

Tony..... believe me, the VF is WEAK at the top end. It is just because you have not driven anything that actually does pull well at the top end.

Monkeyboy,
It's an AET drop-in turbo that gives me over 485bhp at the HUBS on VPower! But then this is on a Cosworth 2.5L, High Compression Tracktive Solutions built engine.

 

No, the turbo is still relatively small, my brothers is a hybrid twin scroll on his Spec C. It was making 1.6 bar at 2800(had to be reigned in), plus being more efficient up top than the VF36(pulls harder).

 

It does run out of puff at the top end, the natural change up point is around 7Krpm. Running Octane booster or a splash of E85 allows you to run more timing up top and that makes a huge difference, but the turbo is all out of puff otherwise.

 

This is the road dyno graph I got when Bob rawle mapped the car back in march. Its not deadfull but you can feel the urge dying out really quickly on the road towards the top of the rev range.

 

OP, aren't you missing something here?

What about the SC46 TWIN SCROLL turbo. A direct drop in, and should make at least 420-440bhp on V-Power - i.e. a similar output to a 321T! But with it still being TS, it will (should?!) spool even better than the SS 321T!


Win-win-win - as you also won't have to also fanny around with a replacement TS-to-SS converting uppipe and SS downpipe!

 

O...M...G!

Only just noticed the date!

Thread resurrection fail!