Bob Rawle

One of the things you guys over look is that megarom was not developed asa a cable throttle Race Rom, it was done by Steve Done back in 2004 as a result of some conversations that went on when he owned a GC8 that had been fully converted to twin scroll, ecu, looms the lot. I had just imported my twin scroll car the year before. So it was more of a "big boys toy" at the time.

Its been picked up and used fairly extensively over the last three years or so but is what it is. Its a great piece of work and you can easily get to 500 bhp with the right mods.

I know that the map flag requests have not been unheard but in terms of being a priority then its not near the top of the list.

I agree it can be awkward determining which map is in use, especially when dual fuel is being used and boost etc maps remain the same, I always sense check by logging ignition advance against rpm and engine load, there is normally such a big difference between a meth map and a pump fuel map its clear. But for the driver a good memory helps.

All te cable throttle map switch roms are like this they were really developed to be used with the PSi 3 or EcuTek data monitors from which you could do everyone that Tim has mentioned in terms of map switch and parameter adjustment on the fly. Anyone who has the EcuTek version can still do this if they have a map switch rom in their ecu.

I have one ... but I have Race Rom :-)

bob

johnfelstead

The early PSI3 data monitors dont offer map switching information, so the later version can give you a display of the map selected even on MegaROM?

It would be useful if EcuTek could work with Tim to get a product on the market to replace the now defunct PSI3.

Bob Rawle

The EcuTek version does though, appreciating that EcuTek are considered to be the main men but they didn't write the coms protocol for the oem ecu's. I guess they are looking at what gets them value add in their business in the same way any other company does and prioritising accordingly.

cheers

bob

johnfelstead

No doubt. I'll keep my eye out for the EcuTek version of the PSI3 then, would be handy to have i think.

Bob Rawle

It would be very useful for you John as it allows tweaking of all the main parameters on the fly, fueling, ign, cam timing, boost levels, wastegate solenoid duty etc. You can also monitor 28 different parameters on seven screens of four per screen as well.

Just thinking that if JTI got hold of one and sort of reverse engineered it a bit that would help the Toucan version development. Not talking about a copy job here but certainly the unit would provide some insights.

I have a PSi 3 on the shelf that interfaces with a Motec M800 ecu as well and does the same sort of job. Dan might appreciate that methinks.

cheers

bob

johnfelstead

Sounds good, If i manage to fin one then Tim can use my car to look into this, he doesnt live too far from me.

See you in the morning!

JTinnovations

iTrader: (2)

I've had a look at the Romraider code, which should give me some clues as to the protocol, but as much info on what the Psi3 did/does wouldn't go amiss...and I'll keep an eye out for a second hand one (think there was one a week ago but pretty sure it sold quickly).

Bob Rawle

Getting back to the graphs, Shaun can you put up the afr plots to go with the others ?

You shouldn't be seeing any ignition pull back using meth, if you are then it probably needs a tad taking out, a reduction of less than one degree could be enough to stop it flinching like that.

Just finished with John

cheers

bob

johnfelstead

Back home now, midrange is nuts!

Got the car on SRR tomorrow, should be interesting.

Thanks again Bob, it took some time with all the changes due to the 4BAR, but the results are fantastic! Proper torque.

Shaun

AFR graph put up on the previous post.

The car did not show any ignition correction or knock when the car was mapped on the road / dyno with Richard. I know as I was reading all the logs with Richard.

Richard has sent me another map with some ignition taken out over that rpm range in question, but I will reset the ECU and log some runs prior to swapping the map out, as the ECU is progressively putting ignition back in and I'll take a bet that an ecu reset will see no correction on the road.

Bob Rawle

Thanks Shaun, looks typical for a road mapped car run on a dyno, V Power afr looks a tad rich but on the road will be ok.

Regarding the ignition I was just observing that the ign map probably could do with a tiny bit more head room as its not normal (for me) to see the SRR dyno causing a meth mapped car to pull it down. But as you say on the road you should be fine and its not as if the car is going to get the "JF" treatment (lol)

Could also be the the SRR dyno loads the car a bit harder than Richards, great results there though in any case.

cheers

bob

Bob Rawle

Interesting, I did not double post, the bbs had a bit of a flid and spat out two the same. It normally would not allow two posts that close together, second post now deleted

bob

Shaun

Re-visit to Surrey Rolling Road

Now before you start to laugh please humour me. I went back to Surrey Rolling Road today.

Perhaps it was the doormant "Dyno Queen" in me. Perhaps it was fact that I couldn't quite live with the 479.1bhp. Perhaps it was all Bob's fault.

I'd spoke to Richard post the last dyno run, forwarded the graphs and the ECU logs. After I had explained to him that the ECU was putting the ignition back in on the road and the fact we never saw any corrected ignition on the road or dyno (his dyno) when mapping, he didn't think anything was untoward. I did say I was going to take it back to see if we could run without the ignition correction and whether it would make any difference to the figures. To try something else he then sent me an amended map with just under a degree less ignition over the 6-7k band.

The plan was to perform an ECU reset and try the existing map again. If it pulled ignition I would then load the adjusted map. If I had any problems Richard would be on the end of the phone so he could (if needed) send me another map..... this is the beauty of having EasyECU and a mapper willing to adjust anything on the fly and send new roms to me via email.

I turned up at SRR and I performed an ECU reset.

1st proper run was 479.1bhp lol - no ignition correction or knock
2nd run was 479.5bhp double lol - no ignition correction or knock
3rd run was 495bhp - I got excited at this point, but the car was coming out of the rollers.
4th run was 479.9bhp - still no correction or knock and it simply wasn't worth carrying on

Now I could have used and promoted the 495bhp run...... you would never had known, but this is about factual information and no one gains anything by bull****ting.

I never loaded the adjusted map as it wasn't needed.

Whilst the peak figures have stayed where they were previously, the car has picked up some bhp / torque in top part of the mid-range (just over 10bhp). The spool was also better slightly as it was a tad cooler today.

If anything it shows that this set-up is giving absolute repeatable figures. Trust me..... that isn't the case with some of the dyno figures you see.

Also this isn't a "Let's play the dyno game and see what we can get out of it and then we'll wind it back a touch" map. It's the same map for the dyno as the road and will be used on track as and when.

So I think I can probably say I've got the best out of the set-up I currently have, which considering it's on the OEM ECU and engine..... is pretty excellent!

What do you think I should do next? Get a different (bigger) LM turbo from Litchfield Imports / Turbo Dynamics?

johnfelstead

Good stuff Shaun. Stop fannying about and drive the thing now, if you are going to change anything, spend some money on tyres as your current ones are rock hard!

ScoobyDoo69

iTrader: (17)

Hang on... a big lengthy post and no graph?

Hammer man

iTrader: (25)

Brakes, so you can stop with all this power

Shaun

John,
You'll PYSL about that one.....

I stopped at the services on the way back and just thought I'd have a quick look at my tyres. I thought to myself "these tyres need changing as they're pretty hard, but I have at least another 2yrs worth of tread left on them!".

ScoobyDoo69,
Would you like me to post the bull**** one for 495bhp or the other three runs which were basically the same as last weeks! Now that would be a waste of bandwidth.

Cliff,
I have upgraded brakes already. I just need an upgraded brain to use it all properly.

ScoobyDoo69

iTrader: (17)

What I'd like to see, if at all possible, Shaun, is maybe a dash mounted camera looking at the speedo/revs with a few pulls so we can get an idea of how well it pulls from low down, going through the gears etc.

Most the videos on Youtube are from American owners claiming 500WHP or so and the speedo doesn't seem to move so fast Would be nice to see a comparison

Shaun

ScoobyDoo69,
Unless I get to somewhere like Bruntingthorpe (or any other kind of facility where I can do this), you'll forgive me for not posting up videos of acceleration runs like this. It's certainly something I can probably look into sorting out though, as it would be interesting to not only do that for you guys, but to also look at how the car performs over a 30-100mph run etc. Perhaps I can look at entering next years MLR Marham event.

ScoobyDoo69

iTrader: (17)

A Speedo cam and empty road is the same as being at Bruntingthorpe though isn't it ?

Shaun

Discussion on LM450 vs LM450 Billet - peak figures and what it all means
Perhaps I get too **** for my own good at times, but since so many people always seem to concentrate on peak figures, I thought it may be good to discuss two turbo's in the same range and talk about the apparent difference between them.

Many of you will know that MelTypeR's MY06 SPEC C and myself are running very similar overall specifications. OEM late 2ltr engines, same FMIC, etc etc. I'm fairly certain that the MY06 JDM STI and SPEC C engines are exactly the same (same heads and cams etc), but I can't be 100% sure on that. I'm sure supernerd John can verify that one.

Obviously we can't assume that two set-ups will give the same results, even if they are both identical..... nothing in life is that comparable when it comes to this kind of thing. So there may be an element of that, which can impact any comparison between two cars. But that aside.....

The single biggest difference is that fact that Mel has the non billet LM450 and I have the Billet LM450.

Let's compare as close as we can with apples and apples graphs (so these are both on the same dyno and both on VPower only):

MelTypeR's LM450 @ 461bhp/425ftlb


Shaun's Billet LM450 @ 442bhp/440ftlb


Now some people may immediately compare peak BHP figures and think, "hold on.... Mel's is making 20bhp more - that's the better set-up". You really need to look closer than that!

You need to ALWAYS look at the area under the curve and see where each set-up is making it's power across the WHOLE of the rev range.

Let's compare the figures at various rpm points instead:

RPM----------------MelTypeR----------------Shaun
2500---------------72bhp/156ftlb-----------72bhp/168ftlb
3000---------------102bhp/180ftlb----------12bhp/192ftlb
3500---------------150bhp/225ftlb----------168bhp/252ftlb
4000---------------261bhp/342ftlb----------312bhp/411ftlb
4500---------------363bhp/424ftlb----------378bhp/440ftlb
5000---------------396bhp/417ftlb----------396bhp/411ftlb
5500---------------432bhp/414ftlb----------420bhp/397ftlb
6000---------------461bhp/399ftlb----------432bhp/378ftlb
6500---------------456bhp/372ftlb----------440bhp/355ftlb
7000---------------447bhp/336ftlb----------439bhp/330ftlb
7500---------------432bhp/300ftlb----------420bhp/294ftlb

This makes it more interesting.

Up to 5000rpm mine pulls ahead at every point with both BHP and more importantly torque. You look at 4k there is 70ftlb of torque difference between mine and Mel's. Then from 5500rpm onwards it starts to go the other way and Mel's set-up pulls ahead at every point.

You couldn't get more "swings and roundabouts" than that one! But it really does show a difference that can be substantiated with the differences in the wheels used in both the Billet and non Billet LM's. Let me explain.....

Power is ultimately derived (forced induction) by the amount of effecient (cool) air you can get in and get out of the engine (with appropriate fueling and ignition as a given). Look at a desk fan and the bigger the blades, the more powerful the fan is and the more air you can feel it shifting. Similar principal for a turbo.

Let's for argument's sake suggest that the non-billet LM450 has a compressor (inlet) measurement from the blade tip to the core (spindle that the blades attach to) of 100mm and overall diameter from tip to tip is 210mm.

Let's for argument's sake suggest that the billet LM450 has a compressor (inlet) measurement from the blade tip to the core (spindle that the blades attach to) of 100mm (still the same) and overall diameter from tip to tip is 205mm.

Where's the 5mm gone? It's the reduction of the spindle diameter needed, as Billet is stronger and doesn't need as much support for strength. This all means though, that whilst the blade length is the same you're losing efficiency towards the extremities of the blades to shift as much air. The efficiency of the blades are towards the edges, not at the shaft. This then explains why the non Billet achieves higher flow at the top end, then the Billet does (in this form of example).

Now whilst the numbers used here are for example, I know that the Billet core I'm using does indeed have the same blade length as the non Billet, but it has less of a diameter on the shaft area. The idea behind this was to make the core as light as possible (mine is around 33% lighter than the non Billet version - not all non Billet to Billet versions are this much lighter from other manufacturers) without making a massive impact on the outright flow potential, but ensure that the mid-range was increased and the response (which can't be shown on a dyno graph) was much improved. This type of comparison above shows that really nicely.

So it really comes down to what you want.

For a road car it is absolutely priority (in my opinion) to maximise low down and mid-range power/torque (especially torque). This makes for a very quick road car and is always a rev range that you use all the time. The fact that my set-up (in comparison to Mel's) loses some from 5.5k onwards is not of major importance to me.... I make less use of that area on the road than I do with the 2-5.5k.

Based on how mapping has gone, we're fairly certain that we have reached the optimum efficiency (boost profile wise) of the Billet LM450. If we wanted more power, we would need to alter the specification of the core. This is something that we have already discussed and it was going to be looked at, to see what other changes would effect the overall performance. We (I) still may do this in the future with Litchfields and Turbo Dynamics, but I suspect if we start extending the blade length, we will start to lose some power/torque/response lowdown.

Another possible way forward is to change the core material from Billet to something else. This was certainly being discussed late last year, so that maybe the way forward with future tests. The idea is to use another type of material which is even lighter, so will allow us to extend the blade length to increase the flow, but potentially keep everything else the same up to this 5.5k band.

Turbo development keeps going on, so don't think this is it with regards to possibilities.

As a final comparison, Tim Hardisty posted a graph (from SRR) some time ago of his then, 2ltr with the VF36/37 twinscroll on.

People who have had this type of standard set-up know only too well and great they are lowdown / midrange.

Let's look at a similar comparison at RPM points.

Tim's VF set-up 344bhp/380ftlb


Ignore the shape of the graph from 5k onwards..... we're interested in the low to mid-range comparison here (this is the VF36/37 strongest point!).

RPM----------------Tim-----------------------Shaun
2500---------------60bhp/130ftlb------------72bhp/168ftlb
3000---------------90bhp/165ftlb------------112bhp/192ftlb
3500---------------150bhp/230ftlb-----------168bhp/252ftlb
4000---------------285bhp/375ftlb-----------312bhp/411ftlb
4500---------------325bhp/375ftlb-----------378bhp/440ftlb
5000---------------345bhp/360ftlb-----------396bhp/411ftlb

Yet again, it just shows how awesome this Billet LM450 is. It just nails the VF36/37 all the way through the inital RPM onwards.

Of course you start to add Meth into the mix and the game get's even more exciting!

The fact that you can now buy a turbo that gives so much more power / torque EVERYWHERE is an amazing achievement in my opinion. The standard VF36/37 set-up has always been the ultimate OEM Subaru road standard. This LM just nails it from the go and to suggest that this size (LM450) is not suited to a 2ltr, is quite frankly a statement that does not make sense anymore.

I used this strapline with my previous SPEC C, but it really is so on the money with this turbo set-up.... "You really can have your cake and eat it!!".

Please please please don't compare just peak figures when you're looking at comparisons. I hope this highlights that there is more to a set-up than peak figures!!!

Mel - I hope this has given you some more food for thought, when you decide what you're going to be doing with your potential LM450 upgrade to the Billet version.

johnfelstead

The engines are the same, bar the change to a roller bearing core on the VF36 turbo compared to the sleave bearing cored VF37 and the Spec C has the external oil/air cooler rather than the oil/water heat exchanger.

The JDM STi was the base homologation car, with the Spec C being an ammendment to the docs, no changes in engine spec are listed other than those above.

I couldn't agree more with your last statement.

TimH

iTrader: (11)

Not sure it's relevant since mine's a 2.5, but here's a comparison of your LM450, Shaun, and mine running the LM480 (VPower).

RPM----------------Tim LM480-----------------Shaun
2500---------------80bhp/160ftlb-----------72bhp/168ftlb
3000--------------120bhp/210ftlb-----------112bhp/192ftlb
3500--------------180bhp/270ftlb-----------168bhp/252ftlb
4000--------------330bhp/430ftlb-----------312bhp/411ftlb
4500--------------420bhp/490ftlb-----------378bhp/465ftlb
5000--------------440bhp/460ftlb-----------396bhp/411ftlb
5500--------------470bhp/450ftlb
6000--------------490bhp/430ftlb

johnfelstead

You guys either cant read graphs or cant do maths properly.

Power = (torque x rpm)/5252

So if you have 465ftlb @ 4500rpm you have 398BHP, not 378BHP.

Looking at your graph shaun, i think it's a case of you cant read, as i doubt you'd do the maths

Lets agree that you have 378BHP @ 4500rpm, so actually have 441ftlb, not 465ftlb.

Maybe you should take another look at your graphs and figures as you are miles off the real figures you are getting. To make life easier if your eyes can't cope with looking at two graph lines, just use the torque figure and calculate your power, that is after all what the dyno is doing.

Shaun

Apologies to you and everyone else.... I have corrected that at 4.5k! When I wrote that line I was (for whatever reason) thinking of the peak torque I had attained with the Meth map for some reason.

Sorry and apologies for the confusion at that one rpm point.

Shaun

I thought as much John but thanks for the sanity check.

Of course you know about the last point more than most, but that's another story on another thread.

Shaun

In my honest opinion that makes my figures for a boggo 2ltr lowdown look even more impressive in some ways.

johnfelstead

Shaun

TimH

iTrader: (11)

Well, at least mine's bigger than yours