Regarding the differences between the LM450 Billet and MD321T Billet.... I doubt you'll ever find that information publicly. They both use the same exhaust housings and are made by the same turbo supplier - Turbo Dynamics. There will probably be come differences in the compressor wheel, but they're essentionally the same turbo.

Personally I would stick with the OEM ECU and go big MAF, but it will be down to knowledge of your mapper as to whether they can get the best out of that set-up. The easy solution for some mappers is to fit a different ECU.... but imo it's not needed for the kind of power level the LM450 or MD321T provide.

 

The handling differences are the track, diff set-up, castor, hubs & aero that I'm aware of. DBW is EU & US nothing to do with JDM until MY08>

 

Torsen rear diff, not a good move IMHO.

Torsen diffs work well in the front.

 

The front diff on MY03 Spec C is shuretrack, not torsen, both are helical type diffs, but there might be a difference. I will get a car very soon, and will do some tests. For me this upgrade is just the forced, cheapest and the fastest way to get a car back on a road again, it's not the perfomance mod. Will see, what I have got.

Shaun, could you tell me where I can buy the same as yours 80mm intake pipe with the K&N filter element fitted? I see your suppliers/servicemen had to do some custom work to fit it , may be these guys will do the same work for me? I will be pleased to get the same intake as yours . Will pay immediately, hope they could ship it out overseas to Russia Now I have the HKS green mushroom itake kit, it's standart MAF pipe diameter. Do you have any opinion about it, is it good (if I would use it if I go aftermarket ecu way)?

Does there any difference in driving feel, running OE ecu and aftermarket ecu on MAP (motec, syvecs, hydra, autronic etc). OE ecu produces much more calculations and corrections/compensations, MAF got inertia (it is a much slower than MAP on reaction sensor) , so the reaction on pressing the accelerator pedal should be different.
Motec may have some issues with the cold start, idle control, and the main issue is detonation control, OE ECU knock control is much better. It's clear why so, motec is made for sports, OE is for public road use. What way to go on the modded car is hard to decide for me now.

 

You can buy the induction kit I have used from http://www.rogerclarkmotorsport.co.uk/ You need to email them and ask for the 80mm induction kit (it's not listed on the website).

The only custom work required was to cut the silicon elbow. If you still have the OEM inlet pipe and elbow, you won't need to do this.

The green HKS filter won't fit the RCM kit, which comes with a K&N anyhow.

There is absolutely nothing wrong with a MAF set-up at this level, assuming your mapper actually knows what he is doing. My driveability is exactly the same as it was when the car was at 340bhp.

Normally an aftermarket ECU (MAP) is judged against an OEM ECU set-up for driveability... not the other way around. There is absolutely no reason for me to move away from the OEM ECU at the moment.

 

I've got the original STi pink silicone inlet turbo pipe from RA-R, S203, S204, and polished stainless steel ZeroSports elbow. After using the Sti pipe for a year, I found this
http://sti.jp/e/news/notice/20111020.html
Now don't know what to do. remove the inlet manifold and check everything or ever take it off the car. It's was very expensive for such a product! I have ordered it directly from Japan and was proud to get an original STi part, and look now what I've got )

I did not find 80mm induction kit at rogerclark's site, that's why I have asked you about it. Now I will send them a request on it.

 

this is my car, I have to move the front registration numberplate somewhere after installing the Bllitz fmic. to do like on the Evo on side? No. Have no Idea. Have to just take it off sometimes
May be ever not install the fmic and go OE tmic way? The summer is hot here, +30C for a couple of months guaranteed.

 

Don't worry about shifting the number plate..... only the **** amongst us thinks it's going to make any difference in the real world!

For the type of turbo you're fitting.... you should use a FMIC to get the potential of what the turbo can deliver safely.

 

Works brilliantly in a Integrale! - on the road, at least. (Open front; VC centre; Torsen rear).

 

I see many people here use the fuel press regulator on their 450bhp setups, why? Is there really need to upgrade the stock one on such a power level? It's easier to get the bigger size injector and hold the stock fuel pressure, by the way bosch motorsports 1000CC size injectors got better atomization than any others, here is an opinion.

 

I was still stock at well over 500bhp on my previous SPEC C.

Some tuners prefer to use them as part of whatever set-up is being used.

 

Shaun, could you give me the direct link to your previous Spec C project thread? I opened all the threads you have started and still didn't recognize the one I am looking for.

 

This was the previous "Project" thread, but not the initial ScoobyNet Project Articles..... they have been lost forever.

https://www.scoobynet.com/projects-4...oject-car.html

However, here are PDF copies of the text from the original articles, although not in the original format (no pictures).

 

Hi Shaun,i've watched all your progress through scoobynet till date,congratulations keep the good work up.I decided to ask you some questions as you seem to be the proper guy to ask them.I have a stock 2003 impreza sti jdm except that the previous owner(a very genius one indeeed) has removed the stock induction and fitted a japspeed short ram intake,removed the twinscroll headers and put an unequal header(for the burble) and changed the Ecu to a V7 (AF481) due to the original ecu failed.I Already have bought a tomei equal twinscroll header as i couldnt find the original subaru twinscroll header for sale and also bought a full decat 3 inch milltek exhaust, however i havent fitted them yet as the clutch was feeling a bit 'used up', so i decided to buy an Exedy Stage 1 organic clutch kit which has arrived today.I have already begin dissasembling the engine ancilleries and have already removed the intercooler and the full exhaust.Now im trying to remove the lower bellhousing bolts/nuts which im finding a bit difficult due to accessability as i dont have a lift jack so i decided to remove the engine and do the clutch change the 'right way'.Lets put this aside,as you know the jdm sti comes with the vf37 which has very good spool and low torque but lacks the top end(its out of power at about 6000rpm-6200rpm.With the help of an uprated actuator , a 3 port boost selenoid it can give a bit more but now im confused on what to do,im thinking if i should change the turbo to a lm450 while i will have the engine out or if i should stick with the vf37 at the moment and have the 3 port boost selenoid+uprated actuator installed(as you can see i havent experienced yet the full power that the vf37 can give as it was completely stock and was not giving its maximum potential due to the unequal header being fitted).My car is not an everyday car but i like to keep it

 

similiar in drivability/usage as an everyday car,however sometimes i like to attend some drag races and maybe attend 2 times a year at pergusa track(Sicily),hope you can help,many thanks

 

You're always going to be limited by your turbo in reality.

IMO if you think you need/want more power, it would be a toss up between the LM400 and LM450. If you want absolute minimal lag and don't want a FMIC, go for the LM400. If you're up for spending a bit more money on ancillaries and don't mind losing a small amount lowdown... go for the LM450.

I'm very happy with the LM450 and just wished (in some respects) I had gone straight for that in the beginning. For a 450bhp turbo on a 2ltr engine, it is surprisingly driveable.

The powerbands and comaprisons shown on this thread informs you of that very clearly.

 

I decided to buy the Motec m800 pnp ecu with the optional knock correction module onboard, it comes as advanced pack (launch control, anti lag, flat shift, cam control, traction control, pit stop line speed limiter), the total price is 2 times more than the syvecs, but the mapper I trust doesn't know what syvecs is and he has a lot of experience with the motec. I see that many of the UK tuners still prefer motec but have an easy way to get the syvecs and get I mapped it right due there are many experienced mappers in the UK. So, is there any noticable difference in motec and syvecs? I hope I don't pay twice just for the brand. And I have to follow what my mapper is used to work with.

Why I decided to buy motec? Rogerclarks still did not answer any of my requests about 3 inch MAF tube Nobody likes Russians But I am a good Russian, not that angry as most others

One more quastion, about the boost levels. To get the safe maximum of MD321T Billet, I have to push 1,8bar in the middle and 1,6bar at the top of rpm, right? I will be running FMIC, so what is the desireable boost level on such a turbo? my engine internals are still stock..

 

My mapper will engage only Launch control and flat shift, he says you don't need anti lag, It's just for rallying, is he right? What you can say about the anti-lag using during some sprints and public roads ?

 

I see i know what you mean,however i dont think its worth it approx 2200 british pound for approx 30bhp at the top end for the lm400.My tuner told me that its even not worth spending that money for the lm450(Approx 3000 British pound) as ok it will gain about 75bhp at tops with similar spool but its still not worth.He reckons the way forward is a built engine(2.1-2.33-2.5) and a big turbo gt35 type and your looking at approx the same spool as the lm450 but with 600bhp.Im still undecided on what to do however im not looking to have a year wage spend on it and i prefer the look of the stock tmic than the gross piping of the fmic.So if i change the turbo it will be definatly the lm450 one as i dont find the lm400 worth at all,with my tuner saying that with the uprated forge actuator and 3 port boost selenoid he can push the vf37 to about 375bhp for just 230 british pound(10% of the cost of the lm400).

If i decide to keep the vf37 do you think its necessary to change the turbo and intercooler inlet pipes to sfs or they are not needed for such turbo?And also do you know of any used Lm450 turbo for sale?as that would really help the costs.Many thanks

 

On a std JDM Sti I have yet to see proven figures of anything above approx 360bhp with the std Vf36 let alone a VF3. (norm IMO seems to be 335 to 350 bhp). By "proven" I dont mean road dyno but a well used, known dyno. So the LM400 will give an additional 50 bhp over a Vf36/7. But its not just about top end bhp figure but when & how long is torque (and bhp) available from/for etc and driveability.

 

I did a mapping on my Spec C VF36 stock turbo, the best we could get was 346bhp. 375bhp is out these turbos world, imho. Even on LM400, you have to push it 1.4bar of boost to get that 375bhp.

 

Semion,
In my opinion you have bought an ECU that you don't really need for street use! With the right supporting mods and informed mapper, you could of stuck with the OEM ECU.

I'm currently running 1.8bar peak and 1.6 at the redline.... this is on a stock JDM newage engine.

Anti-Lag is for competition and absolutely no point for road use.

I would agree with you about the VF36/37 - normally these will give around 340bhp. However a LM400 will normally provide you with 390+. Mine had been one of many that has made 400bhp.... and that was at 1.3bar! It's not all about boost all of the time (pardon the pun), as timing has alot to do with it as well.

 

this is on a stock JDM newage APi engine.

 

Who said modding was cheap, but of course you bring up a valid point. However where do you draw the line, as a built engine with a rotated GT35 and all ancillaries, will set you back four times the price (£12k+ easy) of a LM450 set-up.

I've been down the 500-600bhp route and believe me...... it's not straight forward and costs serious money to do it properly.

I would agree though, that in many ways the LM450 makes more sense over the LM400, which is what I alluded to in a previous post.

You don't have to change inlet pipes for a LM450, let alone a OEM VF.

 

 

Shaun, is there any difference in "driving feel" between cars running speed density and OE MAF? my mapper says there is, whole different car, especially the accelerator pedal feel. Of course he is intersted, because he selling me that motec . Last ecutek mapping went wrong, I stuck with the car jerking around 2000-2500rpm, I've changed all the sensors under the hood, disassembled the transmission (there was an opinion because of DCCD failure) but with no success. Now my car runs fine on VF53 excluding that jerk around 2000-2500 rpm, when the turbo starts to spool up. On OE map runs ok! There are no mappers where I live, mapper is far away from me for 3700km from Moscow, and has a very limited of time to work with my car, we tried to remap 2 times with no success. We have to collect 3-5 cars at least to make him arrive, so to get a proper mapper is a problem here. My move to motec is a chance to make a success mapping in one day, because it is programmable "live", no need to repeat the upload cycles, so there will be much more time to pay attention to all the details in the map.

I am really thinking to visit UK myself on a car to get, for an end, the proper mapping. 6500km on a spec c is overkill, I couldn't hold on even for 400kms on the highway, it is not a mercedes.

 

Is it possible that the vf37 has less top end than the vf34?As here in Malta there are about a dozen running the vf34 in excess of 370bhp on stock turbo just with a forge actuator.As we are on the subject if i decide to uprate the actuator to a forge one,what is the most suitable spring to get it with is it the blue or red?

Shaun so you're saying that the sfs (intercooler part) inlet pipe and sfs turbo inlet (non restrictive)will not give a thing on a vf37?As i've seen the spec c one is bigger than the jdm on which essentially is the same turbo.So how about the spec c one fitted to a jdm then?And also while i have the engine out is there any other small but effective mods/servicing i can make to the engine besides changing the plugs and check the timing belt?thanks

 

No difference at all at this level.... unless your mapper can't map correctly!

You won't get MOTEC mapped in one day with cold start in my opinion, at the very least. This is one of the great things about using the OEM ECU you don't need to worry about this stuff. Plus with the OEM ECU you can buy something called EasyECU (see further back in this thread, but it's supplied by EcuTEK), where you can log the car, send the log files to your mapper (who could be in the UK) and he can then send you an altered map for you to reprogram your ECU with. I'm not suggesting for a minute this is how you initial get your car mapped, but at least if you have niggles once away from your mapper, things can probably be sorted remotely.

 

I'm not sure on the size of the VF37 exhaust housing to that of the VF34 housing, but this could certainly be an issue. However, we all know that dyno results can greatly vary.

Regarding spring for the Forge.... not sure.

The inlet hose on all the JDM's (STI and SPEC C) were the same size from MY05>. It was only the early SPEC C's that had the bigger inlet pipe, over and above the MY03-MY04 STI's. In my opinion you have far better things to spend you money on, if you're not looking at changing the turbo yet..... look at the inlet pipe if and when you do.

I would check the compression, but that would be about it.

 

OK then,i had already checked the compression before and if i recall correctly it was 140 on all cylinders.So then you're saying that only the early spec c had the bigger inlet than the jdm's,but what about mine at its a MY03 jdm.Maybe Subaru discovered that the smaller inlet is better then for such turbo.