Toby 0 Posted October 23, 2003 Having had my car on the rollers I've been wondering about the flat spot that it has at 5000RPM and it seems that I'm not alone. There are at least 2 others in the UK with exactly the same problem as well as a few in the USA. We're all at a loss as to how to get over it - although there are various schools of thought... It could help if we were able to compare specs and plots of different G60's with/without the same flat spot. So if anyone who was there (and of course anyone else who wasn't with a plot of their G60) could post their specs and plots it would be appreciated. So here's the plot(s) that I got: your starter for ten... Cheers Toby Quote Share this post Link to post Share on other sites
Banana Man 0 Posted October 23, 2003 I was there but not in the G60, Before I took it off the road there was a flat spot between 5k to around 5.6k and after that it would pick up again I advanced the timing a degree or 2 on the ignition timing and it helped alot the flat spot was drastically reduced. It could also be a weak hall sender so I am told but didn't have a chance to try that one before I took it off the road. What chip are you running Toby?? As it seems alot of the sns stg5 chipped cars seem to have this problem as well!! Quote Share this post Link to post Share on other sites
dexter 0 Posted October 23, 2003 Thats weird, Im sure my 16v can do 130mph. It does 120 with ease. Cant understand why yours is 116? D Quote Share this post Link to post Share on other sites
dexter 0 Posted October 23, 2003 Anyone got a set of 16v results so I can compare? D Quote Share this post Link to post Share on other sites
Toby 0 Posted October 23, 2003 Spec: Jabbasport R1 charger & ind kit with cold feed through carbon canister hole, 68 mm pulley, SNS V-4 (UK), 3.5 FPR, p&p TB, no boost recirc, port matched head and manifolds, JE pistons (stnd size), stnd injectors and IC (FMIC coming soon...), Milltek exhaust - no cat. 6 degrees advance (as far as I can go before pinking), 450 @ CO pot, new: clean W6DPO's, knock & blue coolant temp sensors, HT leads dizzy cap, rotor arm etc... I've heard about the hall sender being a possibility too - but thats about it - and apparently it's a pig to do. I spoke to Vince @ Stealth and he thought it unlikely that the hall sender is faulty as that would probably show up as a much bigger problem (i.e. not running). Change one thing at a time and see I suppose... Quote Share this post Link to post Share on other sites
Sy_VW 0 Posted October 23, 2003 Toby I chatted to you at the Stealth RR day. I had the back G60 which was the first G60 on the rollers. I haven't got the plots on me at work today but will scan them in tomorrow and post them up into this thread. When I do you will see that my BHP/torque curve doesn't show any dipping in power as you are suffering. It made 195.4BHP. Its a difficult one to try and isolate why yours is doing that. FYI mine was chipped at AMD. Ill post the full spec tomorrow. Simon Quote Share this post Link to post Share on other sites
Dubcharged 0 Posted October 23, 2003 It would really help if stealth did a wideband A/F during the run, this would show if the problem is with the fuelling. At 5k rpm we have seen some cars running good boost levels to exhibit this flat due to the injectors going static. Its a tough one to sort out since it could be a variety of things. Best thing to do for now Toby is for us to meet up and wideband your car, if its map related then we should be able to fix it. :) Quote Share this post Link to post Share on other sites
Toby 0 Posted October 23, 2003 Cheers Dubcharged, Have sent you a PM. Quote Share this post Link to post Share on other sites
steveo29 0 Posted October 23, 2003 i too sufer the 5k flat....stg 4 jabba ,std cam,3.5 fpr,no cat...i have had it with std grey inj and sns chip and with reds with chip...both with 68/65mm...the best i could do was 375ohms on the c/o pot but its too rich bilal..cant you test one of these guys cars??as it sounds like we ALL have some engine fault ??? anyone know where to get the hall sender kit cheep?? Quote Share this post Link to post Share on other sites
Toby 0 Posted October 23, 2003 Just phoned the Stealer - £87 for the hall sender kit. Bit expensive as a "change and hope it fixes it"! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 23, 2003 Thats weird, Im sure my 16v can do 130mph. It does 120 with ease. Cant understand why yours is 116? D Rolling road power runs are measured using 4th gear. Kev Quote Share this post Link to post Share on other sites
steveo29 0 Posted October 23, 2003 toby..yeah its a bit steep for a maybe? can we all list what new and whats not on our engines mine.... new plugs(proper exp ones) ,leads,cap,arm lambda sensor fuel filter red inj bosch fpr new batt/alt cables..inc all earths all boost pipes checked for leaks /damage sns chip whats not new... c/o pot hall sender knock sensor PLEASE LIST WHATS NEW/OLD ON YOUR ENGINE lets get this sorted Quote Share this post Link to post Share on other sites
Supercharged 2 Posted October 23, 2003 I think the flat spots are to do with custom chips as mine didn't show any, just a constant rise in power up to 170BHP (standard car + powerflow cat-back now on 83k) I did get a very slight dip in Torque at around 4k but got up to 167 lb/ft Stealth Rollers = Proper Bo! Quote Share this post Link to post Share on other sites
steveo29 0 Posted October 23, 2003 ours werent custom chips...of the shelf as such Quote Share this post Link to post Share on other sites
funky 0 Posted October 23, 2003 not really any flat spots on my old graph this is with a jabba chip was down on bhp though very unhealthy charger funky Quote Share this post Link to post Share on other sites
Supercharged 2 Posted October 23, 2003 ours werent custom chips...of the shelf as such Yeah sorry, thats what I meant, the 'off the shelf' chips are the problem. I reckon a 'custom' chip might sort it out! - maybe you should try it with the original back in if you still have it? Quote Share this post Link to post Share on other sites
steveo29 0 Posted October 23, 2003 no sam from sns kept that :x Quote Share this post Link to post Share on other sites
G60 0 Posted October 23, 2003 not too sure why daz or any of the SNS guys haven't spoken up... all i've heard about lately is 5k flat spots. supposedly... its incredibly likely that it is the hall sender. has anyone here encountered a 5k flat spot that has recently replaced the hall sender? i doubt it. this tends to be a problem that gets blamed on the chip, or on the fuel system not being able to cope with upgrades after a chip/pulley/whatever has been done.. what it comes down to is that the chip (a strong chip, like SNS's) amplifies the problems that may already be present with your sensers. that includes o2, knock, pressure and coolant sensors, co pot and hall sender. (goes without saying that this is why you get your car running 100% before you fuck around with mods) i'm fairly confident that if you replace the hall sender (as long as the other seners are good) it will cure the problem. if you haven't replaced the hall sender before its worth doing even if it doesn't solve the infamous 5k flat spot. i wish i had my car together and on a dyno so i could see if i had this problem... i'm curious to see if the hall sender does the trick.......... Quote Share this post Link to post Share on other sites
exturbo2003 0 Posted October 23, 2003 my graphs from sunday Quote Share this post Link to post Share on other sites
beavis 0 Posted October 23, 2003 Here we are... 5k flatspots become apprent on cars with dodgy hall senders. We have set a few cars up with majour 5k flatspots. Adjusting the CO pot and timing failed to get rid of it, we then swapped the distributers over with new/proven ones and the problem was resolved. The SNS chips do highlight any weak senders on the car, it is a weird position for us as we have to explain to customers that they need to replace senders for the car to drive 100%. About 1 in 5 of the cars we chip suffer from the flat spot initally until the dizi/knock sensor is replaced. All G60 owners should be looking at, and the majority have replaced, knock sensor, CO potentiomter and possibly hall senders. All C's are knocking on being a decade old and age is taking its toll. As much as we like to think that VW are 100% reliable, these senders do become effectivly worn out and expired, most people dismiss them as they cannot be examined like a mechanical item for wear/play/cracks etc. All senders are avaliable form VAG or Bosch agants, Knock sensors £35, CO pots £47 and hall senders £60. Quote Share this post Link to post Share on other sites
beavis 0 Posted October 23, 2003 I'm sure i replyed to this the other day in another part of the forum and explained what is going on with the 5k spikes. Quote Share this post Link to post Share on other sites
exturbo2003 0 Posted October 23, 2003 I'm sure i replyed to this the other day in another part of the forum the other day, explained what is going on with the 5k spikes. give us a link then please matey Quote Share this post Link to post Share on other sites
Sy_VW 0 Posted October 24, 2003 As promised here are the plots from my G60 from the Stealth day. Spec from the top of my head: 68 pulley AMD Chip RSR Outlet Chargecooler Mocal oil cooler Carbon canister removed/cold air feed Stainless steel exhaust without cat I haven't replaced anything recently (touch wood) that would effect engine output. Happy to help if I can. Simon Quote Share this post Link to post Share on other sites
Dubcharged 0 Posted October 24, 2003 The SNS chips used in the cars at the stealth RR have been used in a number of G60's and most of them have produced a smooth power line with no flat at 5k. Some of them are on ths forum as well. The reason why our maps are particularly showing flats at 5k in some motors is due to the fact that we are able to be more aggressive in power extraction due to our No Lag response. Usually, tuners have to hold back on the power since the fuelling takes a moment to stabilise. Quote Share this post Link to post Share on other sites
