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 Post subject: Power gains
PostPosted: Sun Jul 30, 2017 9:32 am 
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Clubman

Joined: Sat Apr 29, 2017 8:54 am
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Hi guys.
What sort of power gain is expected by doing simple mods such as 3inch downpipe decat, with a 3inch bore blitz nur spec exhaust from decat pipe backand k&n induction kit and running boost at the max stock level of 16-17 psi
Thanks in advance for replys fellas
Regards Baz


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 Post subject: Re: Power gains
PostPosted: Sun Jul 30, 2017 1:12 pm 
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Group B
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Joined: Sat Sep 02, 2006 3:13 pm
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Location: Bournemouth
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From my experience, the gains from a huge, loud exhaust and decat aren't huge, in fact when I forced to re-fit a cat it seemed a bit more torquey.
Induction kit will probably lose you power as it will be sucking up warm engine bay air rather than cold outside air. The head and inlet were designed by yamaha, and are tuned to give a good spead of power. Out of interest, we had a standard 205 on a dyno with a bit of time to spare, so the guy decided to show us how much we'd gain with an induction kit The pipe was detached from the air filter box and left ope, this gave another 6BHP over standard. We then removed the paper air filter element, reconnected the pipe and tried again - still 6BHP up. This was all with the bonet up so cold air going in either way. The upshot is that for optimum power gain, fit a good quality low restriction air filter element in the standard airbox.

Winding up boost is the quick and easy way to good power gains, but isn't without it's price as it puts extra strains on the engine. The standard 185 engine has a paper head gasket, and these are prone to going once boost is above standard. Just bear in mind that sooner or later you will probably need to fit a steel head gasket, a fairly costly job if you pay a garage to do it. (the 205 steel head gasket is actually cheaper than a 185 paper one, but the mating faces need to be much cleaner and flatter, often needing a head skim)

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 Post subject: Re: Power gains
PostPosted: Sun Jul 30, 2017 1:24 pm 
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Clubman

Joined: Sat Apr 29, 2017 8:54 am
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Yeah I rebuilt the engine a few years back and used the Toyota steel head gasket (it's a 205) so removal of the cat and blitz exhaust is not really worth doing then?

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 Post subject: Re: Power gains
PostPosted: Sun Jul 30, 2017 1:30 pm 
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Clubman

Joined: Sat Apr 29, 2017 8:54 am
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I read this morning on another forum that gains can be as much as 60 hp more which I thought was a bit much but would have thought it was worth a bit in particular the cat removal.
I know the 205 cat is a high flow cat but the size does restrict the flow somewhat and the 3 inch bore must help it breathe easier


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 Post subject: Re: Power gains
PostPosted: Sun Jul 30, 2017 1:59 pm 
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Clubman

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Also nibbles I have just piped in the boos gauge into a different vac pipe on your a dive as it was piped into the map sensor line so thanks for that it may or may not have had an effect but best safe than sorry

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 Post subject: Re: Power gains
PostPosted: Sun Jul 30, 2017 2:01 pm 
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Clubman

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Bloody spell check should have read boost and advice in last post

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 12:03 am 
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Location: Bournemouth
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Does that forum also claim 10BHP increase from the club sticker ?

I've never tried different exhausts on a dyno, but when driving I've never noticed big changes.
Inlets we did try as it was quick and easy, and the claims for 'induction kits' were shown to be false.

Not sure why I thought yours was a cs. The common failing on a 205 from raising boost is broken ringland on a piston. The 205 engineered out the failings on the 185 and earlier to run a higher boost as standard. This brings it closer to the ultimate limits of the pistons. I've heard of plenty of 205's with ringland failure running 1.1 - 1.2 bar boost. Also heard of many that have run for years without. Maybe it has something to do with weight of foot.

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 10:29 am 
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Clubman

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Been there and done that ringland on number two goosed and a full rebuild ensued
1.1bar is about 16psi which is what the Toyota manual says the turbo should be seeing max on test (anything from 14-16 psi is within limits)
When mine screwed up and lost number 2 it was running about 20 psi on a reconned turbo I had mine reconned at Turbo technics

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 10:32 am 
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I'm almost certain that the turbo on the UK motor had a steel shaft in it as opposed to the jdm ceramic shaft

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 1:21 pm 
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WRC
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Location: Austria
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Hi,

the maximum on a oem engine.....the CT20 is able to do
0.25kg/sec this is enought for ~360HP at 1,25bar with oem cams

i would advise not to run more the 1,1bar (16psi) on oem ecu,
the gen3 3S-GTE have low clearance pistons and they can break
above that level (EGT to high -> clearance not enough -> ringland death )

if you want power then the ceramic tourbine wheel is what you need (low mass high response), in fact after 20years (!)
they can break, so if you want a safer turbo then the steel one is the way to go

greetz

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Last edited by Sunny on Thu Aug 03, 2017 9:45 pm, edited 1 time in total.

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 1:44 pm 
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Clubman

Joined: Sat Apr 29, 2017 8:54 am
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Don't follow?
Are you saying that the maximum power you can get with an oem internals set up is 260 bhp

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 7:59 pm 
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Club Staff
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Joined: Wed Jul 13, 2005 12:14 am
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Location: Camberley, Surrey
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If you want to be sure that a standard engine will last as long as possible then standardish power is the only way to go. Many have run ~300hp for a long time on standard engines but remember that started 10+ years ago and the engines are all more tired now than they were. Plenty of failures now happening on only mildly tuned engines.

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 Post subject: Re: Power gains
PostPosted: Wed Aug 02, 2017 8:54 pm 
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Clubman

Joined: Sat Apr 29, 2017 8:54 am
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Sirius wrote:
If you want to be sure that a standard engine will last as long as possible then standardish power is the only way to go. Many have run ~300hp for a long time on standard engines but remember that started 10+ years ago and the engines are all more tired now than they were. Plenty of failures now happening on only mildly tuned engines.
Yeah I see what you mean but mine has been with me since new late 1995, and the engine is about 12000 mile into a full rebuild from the sump up crank, rods, pistons head skimmed and valves renewed all with Toyota genuine parts
So it's as new really and should be upto a push on power

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 Post subject: Re: Power gains
PostPosted: Thu Aug 03, 2017 12:09 am 
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I take it you fitted standard pistons rather than forged ?
Was the block rebored to a larger size, or just a light hone and standard size ?

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 Post subject: Re: Power gains
PostPosted: Thu Aug 03, 2017 11:39 am 
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Clubman

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Yeah it was standard as the lead time for forged pistons etc was to long
It was rebored to the next size up

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