GVK, i have been thinking about this isn't the slight carboning up of the head essential to get the best from it, or is that just old tuners bull? give it a month or two to coke up a little and i bet the bottom end torque comes back a bit. I remember a Dave Walker tale about exactly that happening. A customer bringing the car back and saying it was sh1t, but it got progressively better over the next few months.
14.31 before the quaife went in [/QUOTE] You dont count! 1.8 16v flowed head and quaife, thats it! Oh sorry, hijack of thread ended.....
I've not heard this before...I had my head mirror polished on the ex. ports and the comb. chambers to prevent carbon build up at the machinists recommendation. He builds Honda heads and the occasional VW one (which is why I chose him - if you can improve an F20C/B18C-R V-TEC head, you're a genius IMO!). I still think that the cylinder head is the problem. There's no other variable in the engine that fits the problem so well. That graph just shows EXACTLY what happens when you lose port velocity - power and torque follow a similar curve as before, yet are less, pretty much right through the revs (then surprise, surprise there's more top end, but still not enough!). I remember looking at the pics and the p&p job looked 2nd to none, however, it's impossible to tell from photos if the intake runners have been over-enlarged, whether or not the machinist is skilled. I don't care what anyone says, all that you should do to the inlets on a road-spec VW 16v head is remove the casting flashing and mildly reshape the flow path - they don't need enlarging unless you want more than say 7.8k, they're already probably too big anyway. I say find a standard head, put it on and see what happens, if only for a comparison. Whats a bet there'll be the same BHP and more torque right through...
Wouldnt it be easier/cheaper to test this by putting standard KR cams back in with the moded head and then compare it to the RR print outs with the standard head?
Well,that's what I'm going to do anyway. The car had great torque with the twin exhaust cams and the flowed head, so can't see the head being the problem Apart from the lost mid-range trying to drive in traffic is a nightmare, below 40mph the car's jittering about Whole car shakes at idle while waiting @ junctions, sorry not for me. Schricks will be for sale, PM if interested Edited by: G_V_K
re: the coking up thing. bill blydenstein says it takes about 2,000 miles of coking up before his heads make what they say on the tin. my mates got a b+ head on his 8v astra and did concurrent rolling road tests, at the same rolling road.
just for clarity, its a 2.0 8v, irmscher inlet manifold, filter and exhaust. blue line is with the b+ head after 500 miles, red line is the b+ head after 5000 miles.
matt d and ians cars go well with the shricks, must be something that needs changing on yours gary to make it the same as theirs,,, it is strange though
The flowed head seems to have made a good difference. How much does it cost to have one done, or how much could I expect to pay for a decent second hand one?
gvk i wouldnt sell them, keep with them and do as prof says get some milege on the head and see if things improve. Try talking to TSR about improving the torque output? They must have changed something your not aware of.
Well I had an interesting day yesterday Vince maps my DTA EMS for my throttle bodies and finds that my engine refuses to give me anymore power than it had on K-Jet . Even zeroing the cam timing and then playing with the vernier made hardly any difference so maybe putting a vernier pulley on Gary's car wont help him either . I was there all day and poor Vince's ears were ringing, he also says he wont be taking on any more mapping work with cars like mine but i'm ok as he's happy to work on mine now he's started . At the moment we can only point the blame at my Magnex exhaust which i've been told by a few people is not really the sort of thing i want on an engine like mine . The only other thing is the engine has only done about 900 miles but it's a genuine VW jobbie so i dont think that's really making much of a difference. On a more positive note though it does feel better on the road than it ever did before so i'm not to p1ssed off (yet ). Just need to look at my options for getting a better exhaust but that can wait for the time being.
Oops so where are the graphs and what not then Matt Perhaps the throttle bodies would work a *bit* better to smooth out a seriously tuned RACE 16v with ultra lumpy cams...
Ive some pics of my heads and the last one I did for a customer here on throttle bodies if someone can host them. Does your man have a flowbench, as I test all my heads on flowbench and would like to know what his are compared to mine. Steven
Gary, i've only just had chance to look at your figures and i can see why you're not happy so what's the difference between yours and Ians now? Inlet manifold, exhaust and the fact he has a newish metering head? I'm not so sure about the vernier belt pulley now after my experience yesterday.
Gary Get some miles on the head......they are transformed once they have carbon on them....AmD's advice years ago. Get a 50mm inlet......4 branch mated to either a Sebring or Remus 2.5 inch system.........should greatly improve things Have you changed your injectors ?? or done flow rate tests ?? Ian
I went to a good 2.5" system from a crap 2.25" with the ITB's and gained just under 15BHP and WAY more torque after a remap - definately give it a go!
