I was having a flashback to my rallycross mini days. Coming out of a hairpin (etc) and then flooring it in second produced a turbo like instant pull your arms out type acceleration. You would never guess this from the rr plots. Presumably a full race A series with split 45's , properly set up on to make best use of the pump jet circuit gives the necessary 'transient' result. None of my race Golfs have given a similar result, with twice the power. All rr plots we see/discuss are 'steady state'. Full throttle at 3000 to the redline. That's what I was trying to get across Obviously, I bow to Eddie's greater knowledge on this subject, these are just my observations for discussion. Jon
Fuelling aside gents, getting enough fuel for 200bhp from k-jet is perfectly achievable.. What ignition systems did the group A cars have?
I said exactly that back in post #11 of this thread. The worst of the std 16v heads I've tested to date recorded 104cfm (027 KR casting) with a best to date from an 051 ABF head @ 110cfm...both those peak flow figures and the strong mid range flow will support 200hp with the right spec...i.e enough cam, C.R, exhaust and inlet flow to get the job done. As many know, k jet doesn't tolerate wild cams and allow nice drivabilty...and if the mid range torque is ruined then the power at peak wont come...hp=torque x rpm...unless the rev range is pushed ever higher with ever wilder cams...further killing low and mid range.
Ah Jason. That is true about the k-jet. It is a mechanical device that is set up to be optimum in a limited window. Also Mike, Jason's flow testing on the 16v 051**373D cylinder head sort of makes your work a bit harder, if you are to keep things 'period'. However we are still focusing on maximum effort of the engine as a function of power, when the entire drive request to WOT should be considered i.e idle, part load, varying transients, cruise and so on. As a result the equation for power could be transposed in a manner modern ECUs tend to be calibrated to and in fact the main force developed by the engine - Torque I would prefer to say, torque is a function of engine filling and combustion strength. The rate at which this occurs gives that power number. Most aftermarket dynos I have used or rented tend to measure energy exerted by the retarders and back calculate wheel torque as a secondary measurement. The engine on the other hand generates torque at a rate. Speaking more generally and for the purpose of discussion, with a larger cam, assuming optimising of fuel and ignition timing, cam timing, CR, intake and exhaust settings are ideal, for a given engine with fixed CC@WOT, the maximum filling would shift higher and higher in the rev range, loose any plateau, become peaky and thus lead to a high bhp number. During lighter loads (cruise), large over lap periods would result in 'lumpy operation' or poor combustion and inconstant drive torque, unless the engine speed was fast enough to make less noticeable. Of course in the modern world to achieve maximum torque and maximum response to an engine torque is easier with the aid engine ECU tuning. This has given rise to the standard engine being tuned to the same level as the mechanical method of cams high compression alone. On K-Jet, though the WUR can be messed around to deliver OKish fuel control for a fixed window of operation (usually running lean after) and on a 16v, its antiquated ignition ECU settings leave lots to be desired. This is a pretty large limitation to realising the engine's maximum torque. After lots of effort, you could end up like trackcab16v with a pretty trick engine based on hardware. As Paul knows, there is significantly 'more' in such an engine if it were to be put on the cheapest of engine controls, not only from increasing the range for WOT torque but also by increasing the time to torque response anywhere else. Going by what I have seen over the years as part time tester and arranging large mass dyno days at at Garage Streamline, most VW 16v 2.0 NASP engines, including the std ones can develop a similar max average torque measurement 160lbft. The stock engine with OE manifold, stock cams and CR on 98RON between 4-5krpm with sharp torque roll off, the big modified ones with exhausts, ITBs, increased CR, big cams between 5-6krpm with slow roll off. All tuned to the 'optimum'. Admittedly, these are numbers and peak point references are specific to one dyno but the pattern can be repeated somewhere else, albeit with different numbers and peaks. That is the easy part! There is all the mapping or set up work that goes onto get the maximum response to a given throttle opening. My tuning philosophy has been to tune for maximum engine response and you will soon realise what limitations are in the the hardware and controls, when expectations are not meet. My point is this. '200bhp' ( a number chosen to create discussion) from an old fixed cammed VW engine with a pretty compromised head design, is pretty difficult to get to if the hardware is based on 139bhp components. Instead the emphasis should be on creating a quick responding engine, while still giving it that 'period' look.
lets no forget guys that the thread heading by sirguyda WAS 200 HP ON KJET. loads have people have hit this figure on standalone
another classic thread: http://www.clubgti.com/showthread.php?19222-About-time-too-GVK-head-cams-job!
just re-read that all again,nothing changes with 16v tuninglol,I never got to the bottom of my figures,was happy with the way it drove and left it at that,its been parked up since I done my bike test,7yrs but hope to bring it back to life in the new year but if the suns out its a case of Honda Blackbird or work on the mk1 and I can see it sitting there for a few more years
Eddies post #90 seems to hit the nail on the head ( sorry but mind blank can't think what WOT means, help ) lol Eddie can you start a engine requirement list ie 1. 2 ltr high compression block 2. Ported , polished 027 head 3. Shrick cams Is KR hydralic head going to be ok? Flywheel crank rods Pistons ? Wiegh balance lighten ? Is this blue printing ? So can we do a parts needed and work required lists to make it easy for me to work through lol Thanks guys Mike
Blue printing is using standard parts with the best tolerance for the job ie longest stroke a crank could be within the standard spec and so on
So my race car engine ( diesel crank and bored out) re2000 gti engineering and oettinger r2000 engines are all blueprinted
That's not blue printing in the true sense of the of the word on As the mk2 was never 2L in the UK So more modified using the OEM part bin and aftermarket parts Blue printing was used when you had to use a standard engine in a race series If a crank had a + or - 0.002" limit and the conrods and piston hight have the same Add that up and you have a small increase in stroke and compression All within the standard tolerance
As an example of a solid, budget kjet 16v motor with no fancy bits, the one in my track mk2 isn`t bad. std abf bottom end, ported 051 kr head (unknown origin), kr cams, ported/smoothed inlet with port matching, ported exhaust manifold, abf downpipe to 2.5" supersprint single box exhaust, 90 spec mk2 gtd airbox, lightened 02a flywheel wur mod and set up @ stealth. Made 186.1 bhp @ 6604 rpm & 152.9 lb ft @ 5858 rpm. In a sub 900kg mk2, on R tyres with decent brakes, basic suspension & geo, it is an entertaining and to others surprisingly effective package. For me that was the point at which the law of diminishing returns was about to ramp up significantly and itb`s with standalone were the next logical steps in the motor`s development. If your looking for a checklist to tick things off, add a wideband afr gauge, mine never made it onto the car, but was advised by a few people a lot wiser than me, to`get one on there if your sticking with kjet.` You`ve already got people with a wealth of 16v experience blessing you with their knowledge (not limited to, but including Eddie, Jason, Paul, Rob etc) and if you are methodical and take their advice on board you should end up with something exciting regardless of the numbers
Gt2 thanks for the sage advice Things seem to be going along nicely and we seem to have resurrected a bit of old Skool kjet valver interest My cup car is 890 kgs and handles well staying kjet but but pushed to the economical max My re2000 car is going to slowly get sorted and hopefully get the original 170 bhp from it Hope to get as much power and torque as possible on a sensible budget much like you've done Thanks again for your input GT2
