View Poll Results: Do you have an undertray (below engine)
No undertray fitted, no worries
95
59.01%
Got an undertray, wouldn't run without
66
40.99%
Voters: 161. You may not vote on this poll
Who runs their car without an undertray?
08 September 2010, 09:25 PM
#31
whats the idea of the underfloor ones on the my05 sti, do these aid downforce or just protect it, Just I noticed them when I got under to change the oil. Don't think I would take any off though they help protect from stonechips and dirt getting in the engine bay as well. Only takes a few clips when doing the service so not a real problem at all.
09 September 2010, 12:36 PM
#32
whats the idea of the underfloor ones on the my05 sti, do these aid downforce or just protect it, Just I noticed them when I got under to change the oil. Don't think I would take any off though they help protect from stonechips and dirt getting in the engine bay as well. Only takes a few clips when doing the service so not a real problem at all.
If Litchfield, creators of the T25 say TMIC's don't work as well without it then combined, they're both healthy reasons to keep it on IMHO.
Let's be fair - it's not like you're constantly taking it off anyway, and when you do, it's a 2 minute job, so why bin it?
Last edited by MrNoisy; 09 September 2010 at 12:38 PM.
09 September 2010, 08:47 PM
#33
+1. If it prevents rubbish from getting into the engine from under the car then in my eyes that's a good enough reason to start with.
If Litchfield, creators of the T25 say TMIC's don't work as well without it then combined, they're both healthy reasons to keep it on IMHO.
Let's be fair - it's not like you're constantly taking it off anyway, and when you do, it's a 2 minute job, so why bin it?
If Litchfield, creators of the T25 say TMIC's don't work as well without it then combined, they're both healthy reasons to keep it on IMHO.
Let's be fair - it's not like you're constantly taking it off anyway, and when you do, it's a 2 minute job, so why bin it?
I'd rather leave it in place as I'm sure Subaru would no go to the trouble and cost if it was not required, but may look at either a sump guard or a sheet aluminium replacement.
Anyone fancy having a go at making one?
10 September 2010, 10:37 AM
#34
I run heat wrapped headers on mine and run the undertray, never had any issues with melting.
Down to common sense really, if it looks too close it will melt unless something is done to stop it, biggest issue I had was with the headers being so close to loom running under the radiator, soon cured with common sense used.
Down to common sense really, if it looks too close it will melt unless something is done to stop it, biggest issue I had was with the headers being so close to loom running under the radiator, soon cured with common sense used.
10 September 2010, 10:43 AM
#35
Everything has an OEM design purpose which will to a greater or lesser extent affect the car depending on how you use it. 
I never had one on my classic and all its good. The classic engine bay is that drafty anyway I doubt an undertray would achieve anything.
Makes more sense on the slippery newage, but on the basis that lots of people put crap copy splitters and other moulded crap on their cars which are untested for aero or cooling purposes, it's never going to be a major problem to run without.
I never had one on my classic and all its good. The classic engine bay is that drafty anyway I doubt an undertray would achieve anything. Makes more sense on the slippery newage, but on the basis that lots of people put crap copy splitters and other moulded crap on their cars which are untested for aero or cooling purposes, it's never going to be a major problem to run without.
10 September 2010, 12:56 PM
#36
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I'm running without an undertray but only because I removed the subframe and haven't yet figured out the best way to re-attach the tray.
I noticed that without the tray, there's nothing to stop water and dirt splashing up onto the O2 sensor so my car doesn't go in the rain until the tray is back on.
I noticed that without the tray, there's nothing to stop water and dirt splashing up onto the O2 sensor so my car doesn't go in the rain until the tray is back on.
10 September 2010, 01:32 PM
#37
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not had one on mine for 4 years or so, never had problems.
as far as how it affects cooling, mmm, not seen any wind tunnel testing to prove either way, which will be the only way to tell.
as far as how it affects cooling, mmm, not seen any wind tunnel testing to prove either way, which will be the only way to tell.
11 September 2010, 02:52 PM
#39
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Update to my vote of undertray in place.. I went through a flood last night, no option but to press on (very slowly I might add) and I came out the other side with a scraping sound. Stopped in a lay by and had a look under the car, turns out part of the under tray was hanging off. Think its the one protecting the gearbox and front diff, not sure though. However some guys helped me take it off and ive got half an undertray system now.
13 September 2010, 04:19 PM
#40
Dont like the idea of running without an undertray but know a lot of people who go without. I'm sure it must help with undercar aerodynamics, and like has already been said will stop stones and c**p getting thrown up into the engine bay so I'm keeping mine on 
29 October 2010, 07:38 PM
#53
29 October 2010, 07:52 PM
#56
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You can just about see the lip of mine in this picture
Genuine Sti sump guard. Basically a huge piece of aluminium.
Equal lenghth and wrapped headers, no problems
Genuine Sti sump guard. Basically a huge piece of aluminium.
Equal lenghth and wrapped headers, no problems
