Performance Headers, HOW MUCH!!!!
17 February 2007, 11:15 PM
#61
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Take driving lessons ...... you will then drive like I do - I do not need more than 215 BHP to cover ground as quickly as a 'kiddie' does with 600 BHP .... it's a plain simple fact of life.
17 February 2007, 11:18 PM
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17 February 2007, 11:24 PM
#69
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just trying to work out the best option's that will tie in with future mod's.it's hard to know in this scooby tuning game! but what i am starting to think is go the whole hog from word go.i have all ready changed the exhaust and had the car maped,but like every one on here we want more! looks like with my next round of mods i will be dumping my prodrive/tsl exhaust for a full de-cat 3" system,hence wasting the cash i have all ready spent on it plus the re-map.
17 February 2007, 11:27 PM
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It pains me to say it Pete but your are semi-right. The Kiddie bit doesn't make any difference it's training. Looking far ahead and reading the road well always making sure you are in the right gear at any one time to take advantage of any opportunities to make further progress. AAAAHHHH! That was hard!! 
17 February 2007, 11:31 PM
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have to agree with you there pete to a point,in most driving condition's on the public highway there's only so much speed you can carry before running into trafic,road-works etc.im sure it is hard to stretch the legs of a 500 horse power car but my god would'nt it be fun giving it a go!
17 February 2007, 11:39 PM
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............you remind me of my lady,she's a terible nag as well
18 February 2007, 07:59 AM
#78
I bought mine as part of a total package of upgrades with the furure also in mind, in my case then, a 2.2 stroker mod.
The ones I bought, £350 delivered, were the Gruppe S ones from the states, (hence the headers phrase sticking Pete).
Compared to the cast units they have a larger inside diameter and are smooth and constant inside. Gasket match of the header/manifold flange to head is really good compared to the cast stock unit (USA term there again!).
This, combined with several other mods gave a 407 bhp/370 lbft engine (certainly NOT all down to the headers change), but a good jump from 300 x 270.
Porting the cast units is a job of labour and is far from gasket matching.
I did my own before the Grouppe S came along and you need a long reach die grinder, air driven to 'blend' the inside diameters to approximate the indide diameters to match. Porting is a misleading term I think.
I am old enough to have 'ported' several manifolds on a number of cars over the years, and I'm sure there is a benefit when coupled to other complimentary mods.
Are tubular manifolds (wrapped of course) of benefit?
IMHO Yes (just look at the 40 years of tuning on Mini's and their LCBM mods)
Do they push the output of a turbocharged engine, Yes (imho) when used with mods to suit.
Never forget though on the Impreza you need a good ecu and a very good mapper to get the best form it ALL.
And before I get shot down:
Subaru have worked very hard to design a cost effective ecu with great mappers to ensure the car is as good as it is with cost effective engineering, and that includes the cast exaust system. We just butcher that work as we don't have to compromise to the same extent.
Lastly, don't forget the up-pipe!
Graham.
The ones I bought, £350 delivered, were the Gruppe S ones from the states, (hence the headers phrase sticking Pete).
Compared to the cast units they have a larger inside diameter and are smooth and constant inside. Gasket match of the header/manifold flange to head is really good compared to the cast stock unit (USA term there again!).
This, combined with several other mods gave a 407 bhp/370 lbft engine (certainly NOT all down to the headers change), but a good jump from 300 x 270.
Porting the cast units is a job of labour and is far from gasket matching.
I did my own before the Grouppe S came along and you need a long reach die grinder, air driven to 'blend' the inside diameters to approximate the indide diameters to match. Porting is a misleading term I think.
I am old enough to have 'ported' several manifolds on a number of cars over the years, and I'm sure there is a benefit when coupled to other complimentary mods.
Are tubular manifolds (wrapped of course) of benefit?
IMHO Yes (just look at the 40 years of tuning on Mini's and their LCBM mods)
Do they push the output of a turbocharged engine, Yes (imho) when used with mods to suit.
Never forget though on the Impreza you need a good ecu and a very good mapper to get the best form it ALL.
And before I get shot down:
Subaru have worked very hard to design a cost effective ecu with great mappers to ensure the car is as good as it is with cost effective engineering, and that includes the cast exaust system. We just butcher that work as we don't have to compromise to the same extent.
Lastly, don't forget the up-pipe!
Graham.
Last edited by 911; 18 February 2007 at 08:02 AM.
18 February 2007, 01:18 PM
#81
Yes, i can agree with you Pete.
As yet you have never offended me!! (please don't try!)
It is good to have a spark or two in threads just as long as the originator is ok, it is his after all.
Graham
As yet you have never offended me!! (please don't try!)
It is good to have a spark or two in threads just as long as the originator is ok, it is his after all.
Graham
19 February 2007, 02:44 PM
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19 February 2007, 04:08 PM
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If you care to look in a recent issue of Redline magazine (not something I actually read I hasten to add, but I'm reliably informed) you will have seen my car pictured at the ESC tunnel run III, very much on the street, and driven round that ordinary town of London.
Standard headers are fine at the 300hp level, but at 350hp the tubular variety can offer worthwhile gains. The standard headers are usually not very well matched to the heads at all. The ports on both are about the same size (both much smaller than the gasket hole diameter) but usually not properly aligned. There are some nasties that are best removed from the inside of the castings.
Paul
Standard headers are fine at the 300hp level, but at 350hp the tubular variety can offer worthwhile gains. The standard headers are usually not very well matched to the heads at all. The ports on both are about the same size (both much smaller than the gasket hole diameter) but usually not properly aligned. There are some nasties that are best removed from the inside of the castings.
Paul
Sorry, I didn't know they drove ordinary cars on ordinary streets in ordinary towns like the rest of us!! 
My 215 BHP STANDARD Impreza will equal (if not humiliate, due to my superior driving skills) most other Imprezas ... even if modded to 600 BHP - in the 'real World' !!
And thats the plain truth ............
My 215 BHP STANDARD Impreza will equal (if not humiliate, due to my superior driving skills) most other Imprezas ... even if modded to 600 BHP - in the 'real World' !!
And thats the plain truth ............
22 February 2007, 04:13 PM
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Look pete, stop posting irrelevant pictures and taking this off topic, you have had you say so leave the thread alone unless you have anything useful and 100% on topic to add!
Last edited by The Zohan; 22 February 2007 at 04:22 PM.
22 February 2007, 04:55 PM
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AMusing thread.
Going back to original post - good headers seem to be around the £350-£500 mark. I think hks headers at something stupid like £850! Ouch!!!
There are some cheap sh*te headers floating about, think they were branded megan, and these used to crack.
had Gruppe S which were good.
Seem to be alot of copy headers floating about copying the gt spec style
Going back to original post - good headers seem to be around the £350-£500 mark. I think hks headers at something stupid like £850! Ouch!!!
There are some cheap sh*te headers floating about, think they were branded megan, and these used to crack.
had Gruppe S which were good.
Seem to be alot of copy headers floating about copying the gt spec style
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