GolfGTIforum.co.uk
Model specific boards => Golf mk2 => Topic started by: paultownsend on 11 November 2008, 01:04
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iv a reasonable spec engine in my 91 8v gti
40/35 'big valve' head
newman 268- looking to change
matched inlet/exhaust manifolds
2.0 agg tall block
'hotgolf' lightened fly
milltek manifold back system
this spec made at midland vw with only ignition timing adjustment-
134hp@5712rpm
144.6 lbf.ft@4515
i only wanted an indication of output and jody there did a good job and health check. its certainly not as optimistic as stealths figures! but both figures seem relative
the engine pulls really well down low (2k), and the first 4 gears will pull into the red easily. this is something i really dont want to loose.
i know the newman 268 is a little 'tame' but wonder if i change cam, (272, 276) il loose that drivability lower down. i really want to make nearest to that 150bhp as iv spent enough on the engine already, and its a real good, strong engine, and i need an excuse not to put an abf in there (so dont suggest it!) - cam suggestions please :smiley:
now, tsr are now distributing a milltek 4 branch for the tall block conversion now, and are promised to fit a treat. im very interested as my head should be flowing a fair bit now, esp at higher revs. it has a flexy on it, so shouldn't crack, and as long as i shield the bay, are there any disadvantages. or more to the point, what are the advantages. will this flow better than my reasonably ported std cast manifold. its alot of money at the moment, but i can justify it to finish the car off properly. and should it be complimented with a new cam?
Paul
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You can gas flow your original manifold and gain nearly as much as a tubular manifold.
A tubular manifold though would be better for exhaust scavenging though and assist gas flow from your cylinder head, provided it has been made and dimensioned properly.
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when i went to pick up my milltek exhaust from the factory, as i live close, they had an r8 on their dyno they were doing a production header, cats, and full system for.
when you see it with your own eyes its amazing. i just do not doubt their quality. and they have sold thousands for golf's through tsr.they are also the same as the tsr ones, just an inch taller to fit the taller block.
my manifold was said to of been ported, but i just dont see how it could flow like a 4 branch. my head just seems to flow so much more, it just pulls real hard to the red, it never did that before!
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Recently had an ABF (sssssshhhhh) on the rollers - only thing different was a tubular manifold and no cat.
It scored 173bhp.
You've got the potential for improved flow through the head, with your porting and big valves - a well-designed 4 branch will realise that improvement.
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tubular manifold will help, would like to see your rr printout but guessing you need more fuel as well
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You can never throw too much money at good engine, go for it!
Tom
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how would u go abt improving fueling on the digi 8v??
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il try see if theres a scanner at work for the printout
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Interesting thread this, as I am looking to do near as makes no difference the same mods to my 8v :afro:
I probably would run a wilder cam
276 and adjustable vernier :cool:
They are some good figures! :)
What work has been done to your inlet manifold?
With regards to increasing fuelling, I don't know for sure but maybe try-
http://www.bahnbrenner.com/vw_audi/products/459/3_5_Bar_Fuel_Pressure_Regulator ?
:)
Also, have you considered running megasquirt?
I'd love to use it, but I think I'd struggle to understand it at the moment :(
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just shoveing a higher pressure fuel reg in there is sub optimal, did that on TC's car just to see what diffrence it made, it's still in there and it goes fine up top, that was a 4 bar reg instead of a 3 but on the cold start it runs awful so you should really tweek the fuel map as well
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just shoveing a higher pressure fuel reg in there is sub optimal, did that on TC's car just to see what diffrence it made, it's still in there and it goes fine up top, that was a 4 bar reg instead of a 3 but on the cold start it runs awful so you should really tweek the fuel map as well
Fair enough!
Didn't really know for sure if it would be an improvement, just thought I'd suggest it for something to look into :)
What does a high pressure fuel reg do for bhp/torque if anything at all?
:)
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i was looking at a new fpr, from a porsche 944 i think. but yeah surely if its 4 bar, its 4 bar all the time. and it only needs it at over 4.5k revs. so would be overfueling below surely?
markS- im not sure if 276 will be a bit too much for a road car, and loose that low down power. id love someone who has one to comment
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I'm TC (as well as DH).
The 4 bar reg DOES seem to have made a difference especially over 4,500RPM, but then I'm running a 2E bottom end, with a flowed and mildly breathed on crossflow 8V head, G60 injectors on digi2 with a lambda and a crap map. On the first session on the rollers the car was leaning out over 4,500RPM. This was probably due to the map not being able to keep up with the cam and the flow across the head (the map's for a counterflow).
Since then we've slapped the 4.0bar reg into it, just to see what the effect would be (it was five-finger discounted out of an over-priced scrapyard). The car is now keener at higher revs, so probably producing more top end power, which we like.
As my car is a trailer queen/track slag/garage whore, when it's being driven it tends to spend *quite* a lot of it's time over 4,500RPM which is why I don't mind the car running like a bag of nails when it's cold and idling.
Quote DannyP on the first time passengering with me on track 'you like revs WAY too much for an 8V, you so shoulda gone for an ABF in here'.
Bed made, lie in etc.
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What maps are everyone running?
Are people using aftermarket ecus?
markS- im not sure if 276 will be a bit too much for a road car, and loose that low down power. id love someone who has one to comment
A fair point, hopefully someone will be able to comment :)
I imagine it is still driveable as it is not a race cam
Also, with an adjustable vernier, could you not tweak it so that the power band shifts down the rev range a bit?
Hopefully someone can clear it up for us :)
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i have 276 in my daily/weekend car and its ok, bit lumpyin the cold when its on auto choke but nothing u cant handle, once its warmed up it goes like stink, mines a 2e bottom end, big valve head, 276 cam, full stainless exhaust system manifold back
mine leans out way to much in higher revs though, so im looking at improving fueling myself
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was looking at takeing the tweeked chip out of DH's car and giveing it a hole load more fuel at the top end, the chip was desinged for tweeked counter flow engines not the crossflow thats in there so it was a bit lame up top till the fuel pressure went up, looked into it for a while found out how to give it more fuel but the ignition map is much harder to alter so DH bought megasquirt
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hi all,
Well i have finally been able to take my car for its first blast today,
im running a piper 276, ported polished head, 2.0ltr agg block, stainless 4 branch.
so far she seems great, tickover is almost perfect even from cold. and even good power from low down, but from 3 - 5.5 its awsome! havent really taken her past that yet,
as yet i havent had a chance to put a timing light on her, but as she is ticking over so well would i have much to gain?! having mot tomorrow so will check the co level, and will be fitting a new blue temp sensor ready for a r/r session at some point.
i must admit i was expecting a little more from it, but its ealy days with alot of tweaking ahead!
cheers
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plasticfantastic, what manifold did you use? and clearence issues?
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i used one from these off fleabay
http://shop.ebay.co.uk/merchant/tuning-center-kassel_W0QQ_dmdZ1QQ_ipgZ50QQ_sopZ12 (http://shop.ebay.co.uk/merchant/tuning-center-kassel_W0QQ_dmdZ1QQ_ipgZ50QQ_sopZ12)
they dont have one listed at the mo, but cost me 150pound delivered! well happy at that money.
no clearance issues at all, even on the 2ltr block, but i did raise my front mount by about 5mm.
did need to grind the inlet manifold a little, and definatley wouldnt fit it with the head in the car, take it off and do it on the bench!
sounds awsome, actually quite quiet, i made a custom centre section from 65mm tube and reduced it down to 45 to match the standard 8v rear boxes, but im now wondering if these may be restricting my engine especially top end?!
cheers
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thats the trade off with the exhaust. the oe vag system i had on mine was absolutely silent.loved it. but REALLY reigned in the top end. trying to find a compromise :)
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but im now wondering if these may be restricting my engine especially top end?!
As the gas flows away from the engine it cools, slows and becomes more dense, thus you shouldn't actually need as large a pipe towards the back..... but that wouldn't look very cool now, would it?
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but im now wondering if these may be restricting my engine especially top end?!
As the gas flows away from the engine it cools, slows and becomes more dense, thus you shouldn't actually need as large a pipe towards the back..... but that wouldn't look very cool now, would it?
well if its not likely to be the cause of my problem then i'll probably leave her as she is,
i like the standard look! and she is nice and quiet(ish).
so now she is running, whats my next step?! just feels like she should have a little more power?!
cheers
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i like the milltek because the tailpipes are removable. so they have neen removed. 2 pea shootes for me! i absolutely hate people who have the connotation that mk2 gti = chav
thats why i didnt want the jetex. 2 bazookas! (my other thread)
back to the original question. so we think the manifold will be a good idea. especially with the big valve head. but back to the cam. is there any point of moving the powerband higher in the rev range, as this would need more fueling, which is another cost option. think il be looking at somethinh like a 272'. has just a little more lift and duration, nothinh silly