Right but the problem is you have no data to extract a more informed comment. By data I mean AFR vs Torque/Power at engine speed. The dyno dynamics unit you said the car was tested on should have given this information. So you are just going on the feedback of the tester. What is "spot on" fuelling? Why was the first run "dangerously lean" , yet measured "137bhp" and subsequent runs where up to 127 bhp peak. If the fuel curve is "spot on" now, why do you need to change the fuel pump? How come standard and "remapped" ECU made no difference to peak number back to back on the same dyno and did this apply to the entire power and torque curve? I would expect the standard ECU with G60 injectors fitted will run richer of a back to back test as there is no closed loop on a UK Digifant 2. How much richer would have to be determined by the dyno fuel mixture trace, which you do not have. Still we are limited by 1.8 PB spark tables. Without data recordings from all 3 dyno's it is very difficult to separate and analyse the real issue, if any. Reality is does this car run just as any other overbored/stroked 1.8 or 2E converted engine with a PB head and uprated cam - all optimised of course. I hope we are not just chasing numbers.
..not chasing numbers that cant be achieved Eddie..the tester is also unsure of the underlying issue as to why the spec will not hit the numbers......for instance same engine built by TSR with a 276 versus my 272 hit 154bhp on their maha and same engine with 272 hit between 145-150 depending on conditions ....this is on standard ecu and injectors too @ 3bar with ignition timing @ 8btdc Wildly swinging the cam made very little difference to curve and peak only differed by 2bhp....pretty much peaked at 5600 then plateaued to 6k and then dropped wildly every time.....this is what has confused the operator to the point where having swapped many things to rule out he told me he had come across only once before where a TSR built kr unit with wild cams would not go above 150bhp....cams et al were swapped to solve to no avail....eventually turned out to be fuel pump and turns in consistent 170bhp now before going i was convinced cam timing was all that was needed after the remap etc and now i think have i been led up the garden path by some/all/or none
Hi Tim... For a start, swinging the cam wildly is'nt helping...you need a baseline setting measured to see where the cam setting is is...you could be advancing it from an already advanced position. .Retarding it from an already retarded position..advancing or retarding from a neutral position..etc etc. You need to get the engine to a true tdc position. .Dial gauge reading off the piston through a plug hole. Then measure the lift at tdc on the inlet and exhaust at that point. The best power spread will come from the inlet having between 0-20 thou more lift on the inlet than the exhaust...whatever that figure is. The other point is...with a 272 degree cam, power will indeed drop off over around 5,500, and there's no surprise in it dropping like a stone after 6k...so no power is going to be found up there. Set the cam as above so yr not chasing that problem at least, and don't expect power past the above suggestion...then just sort yr fueling issue out.
Yes. That may be so but you need to compare the graphs from these cars in order to understand what is going. The peak numbers are a sample point of a graph and there will be reasons when this will be so. It may have differed by "2bhp" because you would have needed to match ECU cal to new air-charge. Digi2 = big compromise. So 127bhp @ 5600rpm and 127bhp @ 6000rpm tells me that the engine at those points had 119lbft and 111lbft respectively. The torque would quickly drop off from there >90lbft and thus the reason for the power measurement ( dropping off like a stone). The character of the engine at those points suggests it achieved peak torque of ~130lbft at 4-4.5K rpm on that day . I am assuming the torque plot before 5.6-6K rpm and this is not really good enough. This type of information is what I would need to match with 8v typical profiles and corresponding in car acceleration studies, on what we experience here. The cam timing should have been optimised at the first place that remapped the ECU TBH.
........becoming a little clearer after sleeping on it and as said the peak power seems right and i thought the cam timing was sorted..i can whip the rocker and look at that again myself. Just the rest of it makes little sense to me when 2 different ecus gave the same results etc....would a dodgy fuel pump cause these symptoms??...i had a calibrated gauge on fuel rail over the weekend and this corresponded to the gauge on the regulator so seems good.....i just dont know what step to take next to prevent unnecessary time/money/confusion thanks guys..appreciate your inputs
What AFR does the car deliver at the moment at WOT and at what fuel pressure? i.e. @ full chat your fuel pressure should maintain 3bar on a good pump. As you did not get a trace from TSR, you said you have a dyno dynamics plot. If so one of the pages should have AFR vs bhp/TQ vs engine speed. This would be the same profile the car would have tested at TSR on the baseline ( G60 injectors, Mapped ECU, old VAF etc). Let me know what that is by posting here or by pm.
So just to reiterate then Jason if you could....TDC Cyl 1=lobes down/valves open. Cyl 4 =lobes pointing up equally then rock so the inlet is 20thou more lift on 4 ???
Timo: No.1 both lobes down (overlap) . Both valves just open. Mark TDC on crank. Rotate crank till one valve just closes. Zero a dial gauge on the bucket. Turn crank back to TDC, not the clock reading. Do other one same. This is the lift on overlap.
More or less Tim yeah... Jon has summed it up really... but you need to measure it as above with a dial gauge. I set the engine to a true tdc, then as Jon said mount a dial gauge up with a pointer on the inlet bucket and zero it... turn the engine back so the lift comes off until it stops reading...it'll prob split at around 0.060-0.065 thou, so look for it to stop reading around there. Note whatever the figure is and move the dial gauge over to the exhaust bucket and do it all again... remember to turn the engine the other way this time... note the reading. If the inlet is between 0 & 20 thou more leave it there... 10-15 thou would be ideal... so you can adjust the vernier so the exhaust reads more or less... depending what it needs to achieve the above... then start from scratch and check it all again.
think i have that Jason and Jon thanks...so i am measuring on cylinder one pulley end with lobes on overlap(pointing down @ 5oclock and 7oclock)and setting inlet 20thou more lift than exhaust (bucket lower=valve open more=more lift)?? I shall touch up the lathe guys at work for use of a dial guage then just the potential fueling issue to sort
Right Eddie i have had a rummage and cant find the dyno-dynamics printout but i distinctly remember him commenting "fueling is spot on everywhere"..Reworx ..a jap turbo car tuners in Portsmouth TSR dont monitor AFRs as such but CO2 through rev range........."was as little as 0.6 at high revs when should have been 5or6"????...i assume this is % and i remember he set co to 2% at idle and adjusted each time the cam was moved......fuel pressure is 2.2bar at idle now spiking at 2.8ish .....set to achieve "a nice curve"....which peaks @ 5600 ish and straight lines to 6100 and then drops sharply Sorry i cant be any more precise than that but i was so deflated at the time i didnt even want a printout to remind me Thanks
You got it. If yr changing settings then set it to 10-15 thou more... if it happens to be currently 0-9 or 14-20 leave it there unless you dont mind fiddling. Blimmey... if it is 0.6% im surprised you've not melted a piston unless you dont drive under load much. Yes you need to be looking at around 5% c/o... unless thats a lambda reading... in which case its very rich.
I could only assume but the the power reading at those points say very little about the rest of the curve or if torque was actually maintained as expected. PM sent.
Thanks Jason...i shall have a play with that......the running lean leads me to believe it is indeed a fueling problem as Tom @ TSR is convinced and it has begun breaking down since the stealth and the later dyno-dynamics run where i was informed the fueling was spot on....i have no reason to disbelieve anyone. just hoping its sods law but dont wanna put a new pump on to no avail
SO....just a little update fellas it would seem the above might be true as i have now changed the main fuel pump and binned the uncertain adjustable FPR and replaced with a cleaned and tested bosch 3.0bar standard jobbie.........and i can say that the "bum dyno" is showing more power...it definately goes harder @ WOT and doesnt trail off til its through 6000rpm Back to Tom @ TSR on the 18th for verification and fine tune the cam and see what we got
An update guys...... Not a good day on the rollers again! New fuel pump did make a difference but no more top end power, Cam scuffed and followers about to collapse ...kent cam 17k miles Cue Newman 276 and new followers Still no more top end power Exhaust off to check for obstructions etc Remove G60 injectors and Stealth chip and replace with standard digi items Still no more top end power it just seems that no matter what Tom did it is reluctant to go past 128bhp peak......the power/torque curve is really good.....levels off @ 5.5k and drops off at 6.2k SO....now i have a custom chip and G60 injectors that may or may not have been a waste of 300......i cant complain with the figures achieved there though as it was a marked improvement.....for some reason it wont hit those figures again! With worn kent cam, G60 injectors and custom chip...128bhp peak after much fettling With Newman 276 and digi injectors and chip...128bhp peak after much fettling NOW....do i put the G60s back in with the Stealth chip and go back to Vince for comparison or try and make it work with the digis???? It seems no matter what Tom @ TSR tried nothing really changed power wise...and he did put a lot of effort in and was late leaving too which i am grateful for but the fact remains i have a hole in my pocket and no different with changed hardware and software although it responds much quicker now and at 80mph 4k in 5th i can bury the loud pedal and it pins you back in the seat and f"s off at a fair lick Rob @ TSR suggested i measure the stroke to confirm it is a 2ltr ...i did this roughly with a length of dowel yesterday and it appears to be around the 92mm mark suggesting it is a 2ltr Just very confused now with a very bruised wallet Thanks for listening
Got any AFR plots? If you've got enough fuel in there, it's the ignition mapping that will deliver the power increases. Any idea how much advance you're running at 4000-6000 rpm? Did the guys at TSR move the timing around much?
Plenty of fuel in there Mike........after fuel pump change we were at 10% @WOT at high revs.....got it down eventually Timing wise he set it @ 8btdc @2500rpm.....i have no idea what this equates to higher up although i do remember him saying he would check the advance curve at high rpms but this was towards the end of the day/tether
Based on your comments the peak numbers may not have improved, but the response to torque has, based on the different brand of cam and the tuning, limited only by the ECU cal. Like Mike I would be interested in viewing the plots for WOT torque/power/AFR/CO for: Kent Cam+G60 injectors + matching ECU calibration. The above with factory ECU and injectors. Newman Cam + OE ECU and Injectors. Newman Cam + G60 injectors and calibration. All of the above would have been generated at TSR. What you have to remember is you already went elsewhere, told the vehicle had improved, based on "custom" fuel mixture tuning, and then retested on a modern dyno back to back with a STD ECU, only to be told, as reported by yourself, that this was not the case.
