litchfield twin scroll turbo
27 January 2010, 06:26 PM
#155
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Had a few logistical problems with my servicing .. and delays due to the late arrival of the turbo .. but all things being equal Iain should be mapping my 420 2.0ltr derivative tomorrow afternoon ......
27 January 2010, 06:35 PM
#156
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Carl Davey, specialist Subaru Impreza parts supply
Hence I am staying with the 58mm induction pipe .. albeit the upgraded Samco one from Iain.
Not sure it helps fully 'cos I am not technical .. but hope it does a bit
27 January 2010, 06:45 PM
#157
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Don't forget that the fannymould spacers don't just raise the fannymould so you can get a bigger inlet pipe in.... they also reduce the amount of heat transferred from the engine to the fannymould and the charge air within.
27 January 2010, 06:45 PM
#158
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I communicated with both Iain and Simon on this and we concluded that there was probably a marginal improvement on spool up, but the 76 mm inlet is a pig to fit and you need to add cylinder head spacers like these to get it to fit.
Carl Davey, specialist Subaru Impreza parts supply
Hence I am staying with the 58mm induction pipe .. albeit the upgraded Samco one from Iain.
Not sure it helps fully 'cos I am not technical .. but hope it does a bit
Carl Davey, specialist Subaru Impreza parts supply
Hence I am staying with the 58mm induction pipe .. albeit the upgraded Samco one from Iain.
Not sure it helps fully 'cos I am not technical .. but hope it does a bit
As for the spacers if you are running a TMIC, those aren't going to work as the TMIC won't be able to mount properly with a 10mm spacer like that. I would have to say you would have to go FMIC to use those. There is a company in the US that makes those as well. Here is a link to theirs: https://www.grimmspeed.com/catalog/p...products_id=54
Last edited by Kayen; 27 January 2010 at 06:46 PM.
27 January 2010, 07:56 PM
#160
Apologies if Iv missed out some info somewhere but what engine work are you guys doing/done, to go with the bigger turbos? I imagine upto approx 400bhp you wont need anything doing on a JDM 2.0 litre engine, but on the bigger 450bhp turbos???
27 January 2010, 08:25 PM
#163
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I have a previous graph with my current near standard spec - MY05 JDM STi, with 3" Turbo back decatted Milltek exhaust, K&N Panel filter and re-map showing 334bhp and 318lbs. For some reason this is probably a little lower (especially on the torque) than other 05 JDM STi's out there ... but it is still representative of other similar spec'd cars.
And yes, I've asked Iain to get a graph from his local RR when he maps on Friday so I will post up what comes of that as they will are the same type of rollers as the previous one. Of course there will be variations 'cos of temps, air pressure, m/c setup and all the rest of it, but it should be an interesting comparison none the less.
My spec on Sat will be the same as above except that I am adding a catted centre section to the exhaust to help with MOTs and to quieten it down a bit (decatted twin scrolls can be pretty noisy with a Milltek). I also now have a 'snorkotomy' (ie the air intake resonator box in the inner wing has been taken out), a 3 port solenoid is being added and a Walbro 255 fuel pump is being added too (probably unnecessarily, but that was my choice), the turbo inlet pipe is being changed to a smoother one direct from the standard airbox (am staying with the std 58mm diameter), I'm upgrading the injectors to Iain's own 800cc ones and I'm going for the 'midrange' 420bhp turbo with the heatshield to reduce temperatures affecting the top mount (which I am also staying with).
Iain advised me that whilst this turbo derivative has a lower top end power than the 450 version it still has very good midrange performance, and more importantly to me as I do quite a bit of motorway driving and am frequently accelerating in 5th and 6th, it is much better able to cope with accelerating from 2-2.5k revs than the 450+ version.
Oh .. and I am having a remap obviously - and, as the JDM has the facility for gear specific mapping , Iain is going to do that too, but we're stopping short of launch control as I don't do any standing starts and don't want it breaking.
Hope that helps as I think this would be a typical, or similar, upgrade for many others 'out there'
27 January 2010, 10:36 PM
#167
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That is one of the reasons why I went for the 420 instead of 450 .. although Iain thought there was still some headroom .... I suspect I'll still need a new clutch before long though as have 55k on the clock ..
27 January 2010, 11:28 PM
#171
Just a deltadash plot for now.
I've not driven it yet, so my reaction is purely based on figures - but for a twin-entry, hitting 1.5bar at 4000rpm seems a bit poor to me. Hopefully there'll be a good explanation and something that can get tweaked!
An MD555 would probably have produced more torque, and hit full boost lower down, for less money. But, as I say, not driven it yet, and Iain not had a chance to comment so I might be jumping the gun.
I've not driven it yet, so my reaction is purely based on figures - but for a twin-entry, hitting 1.5bar at 4000rpm seems a bit poor to me. Hopefully there'll be a good explanation and something that can get tweaked!
An MD555 would probably have produced more torque, and hit full boost lower down, for less money. But, as I say, not driven it yet, and Iain not had a chance to comment so I might be jumping the gun.
27 January 2010, 11:50 PM
#172
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Is this a 58mm or 76mm inlet? I am no tuner but it seems decently choppy up top. Hopefully Iain can help explain or get things sorted out. I agree your torque seems decently low especially on a 2.5L. I am sure it will still be plenty of fun.
I wonder what kind of graph you would get if you did a road log and used Airboy's Spreadsheet to graph it out.
I wonder what kind of graph you would get if you did a road log and used Airboy's Spreadsheet to graph it out.
28 January 2010, 12:01 AM
#174
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Could the 76mm inlet be a cause of slower spool, but it should give you better top end. Also I don't know the extent of your build, but you don't have any TGV's in your Intake Manifold?
Are you picking it up tomorrow morning?
Are you picking it up tomorrow morning?
28 January 2010, 01:05 AM
#178
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The JDM STI Manifold doesn't have TGV's, just wondering how your build was done. People going to a 76mm Inlet (3in) here in the States people do TGV deletes on their 2.5L, otherwise it won't help to have the larger inlet.
I hope T20 Driver's tune turns out well for him, can't wait to see a 2.0L tune.
28 January 2010, 01:16 AM
#179
28 January 2010, 01:19 AM
#180
Just to add to this - this is the first example of this turbo to be tried so there may well be teething problems, and any problems may not be related to the turbo of course. I will be speaking with Len at S4U, Iain and Simon tomorrow to see what's up. I know they will all work with me to get the best result from my build
Last edited by TimH; 28 January 2010 at 01:45 AM.