Twinscroll Turbo choice. SC46 billet or LM450 billet?
 

Ok, there is a about a £500 price difference, the SC series being the cheaper.

Scooby Clinic's are 'true' twin scroll, Litchfields LM are 'twin entry'.

My car...

2003/4 STI Spec C blobeye
Performance mods....
miltek sports cat system
panel filter change
3 port solenoid
Mapped on 97 ron to 353 by Bob Rawle.

I would like to just bolt on a turbo to start with maybe just changing to 740cc injectors.


Any opinions, thoughts and experiences with either or both turbos mentioned above to help me make the correct decision.

What will my standard Spec C internals safely take without having to worry about them. i.e pistons, conrods and crankshaft.

considering LM 420 or 450
SC 42 or 46

Cheers
Andrew :)

Tyron[cannon fodder] has a LM series billet turbo on his spec-c and the performance is fantastic with lag being almost zero and bhp just over 400 it makes for a brilliant road.
I would give the thumbs up to the LM series turbo any day,can't comment on the SC series twin scroll sorry.
PM user name HOOKIE,he has just broke a twin scrolled SC46 blob eye so should be able to comment on the turbo:thumb:

If LM450 is same as MDX321T(both using same turbine,just LM using own twinscroll exhaust housing),my choice will be MDX321T twin scroll or LM450,both will make 450bhp on V-power/T99

On our one MDX321T Billet made 490bhp on V-power and 20% methanol,but think will make more,best is ask here Shaun which is running LM and he knows about the LM almost everything




Jura

I'm currently running an SC42 T/S on a JDM Blobeye. With a FMIC and the usual fuelling upgrades (pump and injectors) the car is running 435bhp at just under a bar and half of boost. This is with twenty percent methanol though. The car feels excellent on the road and there is negligible lag. Infact I can't notice any increase in lag over the previous standard set up.
As to what you can safely run? How long's a piece of string. I would have no qualms about upping the boost to 1.6/1.7 bar but need some knock control as I'm on standard management. I know of others who have run up to two bar on standard engines and not had failure, I guess it depends if you want approach the tuning aspect with reckless abandon!

Thanks Ryan, it certainly does make for a very fast road car. :D

Turbo choice all comes down to how you want your car to perform, the LM400 being the 'baby' of the range you might think it'd run out of puff but far from it. It pulls well all the way through the rev range and where the VF36 struggles it just keeps on virtually all the way to the red line.

Have a look at the spec on my car in my garage, I'm running a forged engine, APS FMIC and CAIK, 650cc injectors and a Simtek and during its final mapping when Bob gave it the full fat map even he was impressed by how well the LM400 spooled and how quick the car was.

Are you on the search for a very quick car or for pub boasting rights? :D

Also you are more than welcome to have a try of my car if it helps you, I'm organising a run around the Brecon Beacons if you want a side by side comparison.

Sorry forgot to say I've not put mine on a dyno yet but Bob estimated around 425/420 and I'd not argue that for one second.

thanks for all the responses. I've spent plenty of time reading up on Shauns JDM Hawkeye project and spent last night and this morning trawling through the last 70 pages on the Scooby Clinic 'Billet' thread which catalogues the last 12 months of there turbo development. I must admit SC are putting on a big marketing plan, though from graphs and things i've read i'm not yet convinced of the performance figures for the SC. Torque comes in slow and late compared to Shauns LM graphs. Headline figures are also low with the SC , users relying on Meth to 'boost' performance, which is something i'm just not interested in.

Do you get what you pay for? the SC turbos seem like a good bang for the buck as i could have one mapped on with injector replacement for about 2k all in. The LM option if done properly could amount to a grand more.

I will contact Hookie and see how his SC46 is performing.

Thanks for the invite Tyron, I'll pick this up in the local forum section :)

god damned double posts!!

I have just had an LM420 fitted, PE 800cc injectors, and a Simtek.

Will be mapped on Tuesday!

You lucky lucky boy. Get a graph up next week if you can. Who's doing your map?

Simon JGM is mapping this one.

:nono:

Assuming you only running VPower or 99, if that turbo on your car makes anywhere near 425bhp, I'll run down the local high street with my cock hanging out. :p

The housing won't flow anywhere near enough for that bhp.

Get it on a dyno..... otherwise STFU! :lol1: :D

well well well, i never thought i would ever hear Shaun say a bad word about the LM turbos... or is that a dig at the mapper??

apac,
Whatever you decide to do I would go with the bigger turbo. As in the 450bhp sized variant.

The slightly more lag with say the Billet LM450 over the Billet LM400, is imo, negliable for the increase in bhp & torque.

Don't forget the LM's & MDX's are made from the highest quality Ni-Resist iron (most are not!), and come Zircotec Ceramic coated.

There is no reason (all things being equal) that you should get any problems with your standard engine at this level for road use.

Hi mate I bought Hookies turbo; it will be going on my car soon, I will let you know how it does. He told me it was running 425bhp at 1.4 bar on standard ecu.

What!?!?..... I'm not saying a bad word about the LM or a mapper. :lol1:

It's a "forget arse/delta dash dyno figures" and get a proper dyno figure. I also know what the exhaust housing will flow on the LM400, as does Iain and as does Turbo Dynamics. ;) These exhaust housings on the LM400 are flat knacker at just over 400bhp..... this is why the lag is so low as the housing is small.

I'm not interested in having a car that's a dyno queen, constantly chasing that next 1bhp improvement and if I had I'd have gone for a much higher output turbo as the engine and ancillary parts are more than capable of running more power.

I prefer on the road performance and not chasing the next 'big improvement', when the car is mapped next (after the Alcatek firmware updates) then I'll ask Bob if we can do some Delatdash runs in order to satisfy your mocking; perhaps some constructive criticism rather than the proverbial might have been in order rather than trying to belittle me?

If it isn't 425bhp then I really couldn't care as I like how the car is on the road, Bob's guess was off his backside dyno as we'd run out of time and he had to get off.

Cool:) i suppose the general conscensus for both the LM and SC is to go the whole hog and get the larger. The SC46 has been well tested and proved and i have seen many comments including your comparison tests that the 450 is best choice. "If you're gonna get wet, might as well go swimming"...:luxhello:

Shaun, from memory, with standard airbox and Tmic did you make 400 on the LM450?
and what was the delivery aznd top end like with the restrained turbo.

If I knew you would react like that to my tongue in cheek comments, I wouldn't have posted in that way. I thought you knew my posting style by now.

I apologise if you took exception.

If you're going to stick with the OEM TMIC and induction/inlet.... don't bother with anything more than the LM400.

Not sure what you mean with "delivery".

due to funds i will be forced to upgrade in stages. Turbo and injectors first. Forgive the the expression, What i'm trying to find out is how will the 450 generally perform with the above restrictions in place.

and its lambing season down here, welshmen get a little uptight at this time of the year;)

It will perform absolutely fine mate.... it just won't be able to flow the air which is fine.

With regards to your last comment.... no comment. I don't want to upset anyone else! :cry:

Tbho Shaun unless you have been in Tyron's car then STFU yourself;)
I have personally driven the car and many many other subaru's with various power level's and I would say it does tip the 400bhp mark.

so iirc, did you make 400 with the OEM intake? on the 450 that is.

and I'll take the flak on the comment, welshman to welshman

Prodriverules,
STFU me. Nah. ;)

Apac,
The oem intake pipe (to turbo) was changed when the LM400 went on iirc. The oem one was split at the end.

I'm not surprised mate:lol1:

oh yeah i forgot trhe plastic split. Thanks also for replying to my questions in your project thread.:thumb:

No problem, I probably took it slightly the wrong way as I'm suffering from an advanced case of man influenza and I've been ratty and foul tempered all day. :cuckoo:

Andrew, have a try of mine as I think the LM400 makes for a really good road car plus if you're going to track it at the likes of Llandow or Castle Combe then it makes for a great point to point car.

The LM400 will lose out at the top end as it obviously can shift enough air due to it's smaller housing but it's all a trade off between spool and power as I see it.

This thread has got me thinking now about whipping my LM400 off and seeing what Turbo Dynamics can do with it in terms of uprating it :brickwall, as when the Simtek comes off the car will be off the road anyway. :Suspiciou :idea:

As for lambing season with this bloody cold that's about all I could catch at the moment, theyr'e slippery and lively little things. :eek: :lol1:

Thanks Ryan. ;)