After having sold my JDM twin-scroll, which was the best subaru i have ever owned for a Flat

i need more power from my 265bhp STI Type UK

i am looking for power all the way to the red and i want more power/torque then the JDM i had

which i am aiming for 380+/360+

Below is a list of mods which i have either brought or its on waiting list. pelase feel free to give me any advice. i need them

Current List :

TD05 18G or MD321 H (is it worth to pay the extra for a MD321 H)
Walbro Pump
PFR7Bs
APS 3.5'' turbo back
Cold air induction ? (do i need it? i do love the sound)

now the most important i dont want any boost surge!! as i have been told by loads that the above turbos might give me boost surge.

also been told that MD321 will need to shim some of the gearbox out due to its too close to the box?

is there other bits i need? i am not looking for over 400BHP i am looking for power and driveability

already got Suspension mods and brakes. and Exedy Racing clutch

Many thanks
kevin

 

 

18G Will be perfect for the job, great torque delivery and IMO best for upto 400bhp... The 3.5" Turbo back isn't really necessary, a decent 3" with an open mouth decat is good enough.
Injectors, FPR, Headers,Apexi PFC Re-map, and maybe an AVC-R would be the other things I would add. Also even though the STI tmic is sufficient for up to 400, a front mount may be an idea if you want more power in the future..

 

R4lly,

I'm curious, how did you find the 18G compared to the MD321H ? Which did you find gave the better spool up, response, & top end ?


Kevin,

There is one small redundant lug on the side of the bell housing that needs cutting back. It's a 5 min' job.

Neither the 18G, or MD321 series turbo's are very prone to boost surge. Maybe people were referring to the 20G.

An STi UK should have Pink injectors, which with the Walbro should be fine for the power you're aiming for.

Agree with R4LLY about the exhaust, 3" is fine, and a good exhaust manifold, such as the 3 bolt design works very well.

I think an Ecutek remap would be a good option for the mapping.


Mark.

 

Mark he has not used the MD321H, he runs an 18G on built 2ltr sti engine running 1.7/8 bar boost. iirc rally's car made 407 bhp and 367lb/ft are power engineerings rollers.

Banny

 

I personally dont think you could compare those 2 turbos.. the 18g will see a genuine 360 tops whilst the 321H should see 400 comfortably.

I cant comment on surge from the 321 as i do not have one yet but a 20g will surge like crazy if not setup properly. Even then suge will result if youre trying to push too much boost below 4k rpm.

Ive personally never heard of any surge issues from an 18g myself.

Id like to see an 321T on a 2ltr myself and see how it performs

 

407bhp from an 18g????

 

Frayz, terryb runs a MD321T on his built 2ltr and made 455bhp, you can get more info on his thread in projects. Here is a link to rally's graph for the 18G.

https://www.scoobynet.com/general-te...ight=banny+sti

Banny

 

Rubbish! My 20g on my 2.1 doesn't surge and i pull full boost of 1.6 bar at 3000rpm. Yes they can surge if the inlet pipe is too large but setup properly early boost will not make it surge. I refer you to my post on 22b: 22B Bulletin Board: 18G

 

Somebody must of been reading my mind
This is what I'm aiming for on my V6 STi TypeR...

I've gone for the MD321H, and currently in the process of fitting everything back on.As soon as it's finished/mapped I'll feedback with comments on the performance.

Full list engine wise:

Tubular manifold (3bolt)
MD321H
FMIC
IK
550cc injectors
PFC
3" turbo back


Fitting the MD321 on the car is quite straight forward and the lug that need trimming is v.obvious once the stock turbo is out. Nothing a grinder/good file can't manage

I'll be writting a mini project, when finished too, so that will make it clearer. Just a taste though of the new turbo test fitted (picture quality not the best but you get the idea):

 

Stuart,

You can't compare a 20G on your 2.1lt, to a 2.0lt, because the bigger engine is what is stopping the surge, that and restricting the intake pipe.

Mark.

 

[quote=Lateral Performance;6700242]R4lly,



I'm curious, how did you find the 18G compared to the MD321H ? Which did you find gave the better spool up, response, & top end ?


quote]


Mark,
As banny stated I haven't tried the MD321H yet, for driveability my experience with the 18g has been excellent, I had not really known much about the MD when I had upgraded my parts, but from what I gathered it was a better turbo for over 400bhp, wheras the 18G provided was better for mid range torque and spool-up; Which is what I wanted......

 

As banny said this is running at high boost levels of about 1.7/8 bar....
I'm not sure but I don't believe any one has tried running this kind of boost before on an 18G, which could be why not many people get close to 400 with the 18G.....

 

thanks guys

so how much boost i need to get 380 on a MD321?

 

Around 1.3-1.4bar will be more than enough with supporting mods.