bikecarbfred
|
| posted on 31/8/20 at 10:31 PM |
|
|
Rolling Road worries - Don't want to go
I've done about 100 miles on rebuilt engine on bike carbs, with race cams, ported inlet, lightened flywheel, 1.4 to 1.6L conversion using
different rods n pistons. Shallow sump with shortened oil pick up and racing baffle plate. so its kinda of tuned alot for a n/a
I have gone to round 4000 rpm on 2nd gear. I am using a default tuning map with megajolt.
It runs spot on. I'm using a KS3 Phormula knock sensor and everything seems fine up the 4000 rpm I have taken it.
My question is; Can I tune it using a KS3 knock sensor and some sort fo timing light?
I have always wondered how do they hear for knock on the rolling road when it is very noise?
I was at a rolling road once and it seems to me they were tuning it to AFR , so they kept advancing it and keeping an eye on AFR.
Maybe from thier experience they are able to know from AFR when to stop advancing.
There is no way anyone can hear for pinging. It is so loud in there lol
No wonder DIY tuned engines pop on rolling road.
I think it would be safer for me to use a knock sensor. Atleast you can avoid damage.
|
|
|
|
|
mcerd1
|
| posted on 31/8/20 at 10:44 PM |
|
|
whats the compression ratio of you engine now ?
(static or dynamic)
and what fuel are you running it on ?
unless you've gone crazy knock shouldn't be that big a problem for an NA engine....
[Edited on 31/8/2020 by mcerd1]
-
|
|
|
bikecarbfred
|
| posted on 31/8/20 at 10:51 PM |
|
|
11.5
v-ron 99 top stuff
|
|
|
mcerd1
|
| posted on 31/8/20 at 10:54 PM |
|
|
I assume that's static CR ?
Have you calculatd the dynamic CR?
Dynamic CR allows for the valve timing - so is more reivant to how it'll behave (long duration cams mean the valves are still open for quite a
bit of the piston stroke)
[Edited on 31/8/2020 by mcerd1]
-
|
|
|
coyoteboy
|
| posted on 31/8/20 at 10:54 PM |
|
|
If anywhere is safer for tuning it is the rolling road, where you can easily monitor AFR, knock and look for the associated torque dips from knock.
Regardless, in both places any decent tuner will be listening for knock either either electronically or via old school det cans.
And you shouldn't be tuning by advancing as far as possible until knock, as peak torque occurs before knock generally.
Having road tuned a highly strung 2 litre turbo, I'd much rather have had the controlled environment of an RR but wanted to learn the process
myself.
|
|
|
bikecarbfred
|
| posted on 31/8/20 at 11:03 PM |
|
|
quote:
Originally posted by coyoteboy
If anywhere is safer for tuning it is the rolling road, where you can easily monitor AFR, knock and look for the associated torque dips from knock.
Regardless, in both places any decent tuner will be listening for knock either either electronically or via old school det cans.
And you shouldn't be tuning by advancing as far as possible until knock, as peak torque occurs before knock generally.
Having road tuned a highly strung 2 litre turbo, I'd much rather have had the controlled environment of an RR but wanted to learn the process
myself.
Thanks for replying so quick. No one stands close enough on rolling roads to listen for pinging. thier all stand at monitor measuing AFR.
I have such an accurate AFR unit and also a a very sensitive accurate knock sensor. So AFR would not be a problem at all.
hmm suppose the only thing can't simulator is load. wonder how much load those rollers put on a cars wheels.
quote:
Originally posted by mcerd1
I assume that's static CR ?
Have you calculatd the dynamic CR?
Dynamic CR allows for the valve timing - so is more reivant to how it'll behave (long duration cams mean the valves are still open for quite a
bit of the piston stroke)
[Edited on 31/8/2020 by mcerd1]
Yeah, thats static 11.5.
Using road cams opens it up another 1mm. Did not go for race cams for obvious reasons.
|
|
|
mcerd1
|
| posted on 31/8/20 at 11:09 PM |
|
|
How did you calculate that 11.5 CR / did you measure the volume of the combustion chambers?
Do you know you can timings?
I just trying to get an idea of how close to knock you might be (in theory) and how confident you can be with those figures - you might find
it's actually fine on 97 petrol 
[Edited on 31/8/2020 by mcerd1]
-
|
|
|
coyoteboy
|
| posted on 31/8/20 at 11:17 PM |
|
|
quote:
Originally posted by bikecarbfred
Thanks for replying so quick. No one stands close enough on rolling roads to listen for pinging. thier all stand at monitor measuing AFR.
I have such an accurate AFR unit and also a a very sensitive accurate knock sensor. So AFR would not be a problem at all.
hmm suppose the only thing can't simulator is load. wonder how much load those rollers put on a cars wheels..
They're not listening by ear, they're watching for knock feedback from either your ECU or a bolt on knock sensor.
On the road you absolutely cannot replicate the loads the same way a rolling road can. You cannot tune steady state, only dynamically as you pass
through cells, and that means any tune incorrectly incorporates both static and dynamic effects into a static map and leaves you botching the solution
when the dynamic effects change at lower rates of RPM increase and high load scenarios.
Do you think OEMs and pro tuners are all wasting their time buying hundreds of thousands of pounds worth of engine and chassis dyno because they
can't hear knock by ear? 😊
|
|
|
bikecarbfred
|
| posted on 31/8/20 at 11:33 PM |
|
|
quote:
Originally posted by coyoteboy
quote:
Originally posted by bikecarbfred
Thanks for replying so quick. No one stands close enough on rolling roads to listen for pinging. thier all stand at monitor measuing AFR.
I have such an accurate AFR unit and also a a very sensitive accurate knock sensor. So AFR would not be a problem at all.
hmm suppose the only thing can't simulator is load. wonder how much load those rollers put on a cars wheels..
They're not listening by ear, they're watching for knock feedback from either your ECU or a bolt on knock sensor.
On the road you absolutely cannot replicate the loads the same way a rolling road can. You cannot tune steady state, only dynamically as you pass
through cells, and that means any tune incorrectly incorporates both static and dynamic effects into a static map and leaves you botching the solution
when the dynamic effects change at lower rates of RPM increase and high load scenarios.
Do you think OEMs and pro tuners are all wasting their time buying hundreds of thousands of pounds worth of engine and chassis dyno because they
can't hear knock by ear? 😊
got it! I understand. I suppose it is important they do trig up a lead from knock sensor point. I was not questioning the worth of RR. I was just
wondering if there is any other way. Like an old school way of tuning... Every tuner at the rolling road might not be as good as one n other. That is
something money cannot buy.
quote:
Originally posted by mcerd1
How did you calculate that 11.5 CR / did you measure the volume of the combustion chambers?
Do you know you can timings?
I just trying to get an idea of how close to knock you might be (in theory) and how confident you can be with those figures - you might find
it's actually fine on 97 petrol
[Edited on 31/8/2020 by mcerd1]
for an old car i was surprised to see on on petrol flap, to see, 98 or 99 ron.
i know the CR is 11.5 because my set up is the same at a OEM POLO 6N2 which VW state 11.5CR
The only different is the camshaft. shrick mild- road 264 camshaft, think original is 288. 10mm lift as opposed to 8.5mm
|
|
|
coyoteboy
|
| posted on 1/9/20 at 03:46 AM |
|
|
Oh absolutely experience and skill is a huge part of it and not all will do it well. Or with the right tools. That's why it's best to go
by recommendation. My point was just that fundamentally it's better on the dyno rather than the road. But sure you *can * do it on the road if
you have a capable driver and can do the tuning yourself from the passenger seat, but it's really hard to find safe ways of doing it and I
personally spent more in fuel doing it than I would have spent on a professional. But I like learning and was prepared to risk engine damage to learn
the process.
|
|
|
snapper
|
| posted on 1/9/20 at 06:02 AM |
|
|
Northampton motorsport attach a knock sensor and have ear defenders with speakers in to hear the knock
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
bi22le
|
| posted on 1/9/20 at 08:16 PM |
|
|
I can't recall ATSpeed attaching a knock sensor to my car when I recently had a RR remap with them, that does not mean they didn't do it
though.
They did pick up knock though. They moaned at me for filling the car with 95RON. We drained it all out and put some 99RON in. I did wonder at the time
what was going on, the car did not sound happy, he then stopped and asked what fuel was in it.
This was evident when they were doing lower RPM cruising stuff IIRC. The rollers created drag and demand for motorway cruising and they mapped to
that.
They were very thorough, mapping different loads and TPS with the complete rev range. It took ages and would be impossible on the road.
A very expensive day but I think worth it for a once in a car engine's life.
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
|
|
|
Oddified
|
| posted on 1/9/20 at 10:34 PM |
|
|
As said, it's not easy doing it yourself but it can be done. A good wideband afr, knock and data logging tps/map/rpm etc, and even careful use
of the handbrake/left foot braking to load the engine can be useful!. Listen to the engine, if it doesn't sound/feel right it probably
isn't right.
Even a good rolling road session will seldom get the cold starting/warm up maps correct so being comfortable tweaking those is well worth the effort
any way even if you get the main mapping done on a rolling road/dyno.
Ian
|
|
|
pewe
|
| posted on 2/9/20 at 08:54 AM |
|
|
That's what i really like about this site.
Huge amounts of acquired knowledge generously shared without any back-biting or acrimony.
Keep it up lads,
Cheers, Pewe 
|
|
|
ttalps2000
|
| posted on 2/9/20 at 12:30 PM |
|
|
get it on the rollers and do it properlly! Tried road tuning before, dont bother!
if you want experience, then go to Northampton Motorsport. Not the cheapest you will find a rolling road for, but compared to the previous company i
used, you get what you pay for!! Troy is a top tuner and transformed my car on itb's
|
|
|
sdh2903
|
| posted on 2/9/20 at 12:55 PM |
|
|
quote:
Originally posted by bi22le
I can't recall ATSpeed attaching a knock sensor to my car when I recently had a RR remap with them, that does not mean they didn't do it
though.
They did pick up knock though. They moaned at me for filling the car with 95RON. We drained it all out and put some 99RON in. I did wonder at the time
what was going on, the car did not sound happy, he then stopped and asked what fuel was in it.
This was evident when they were doing lower RPM cruising stuff IIRC. The rollers created drag and demand for motorway cruising and they mapped to
that.
They were very thorough, mapping different loads and TPS with the complete rev range. It took ages and would be impossible on the road.
A very expensive day but I think worth it for a once in a car engine's life.
Problem with that is your committed to 99ron now. What happens if your out on a blat and can't get super? OK if its a track only car where your
taking all your fuel with you.
|
|
|
bikecarbfred
|
| posted on 2/9/20 at 02:21 PM |
|
|
quote:
Originally posted by bi22le
I can't recall ATSpeed attaching a knock sensor to my car when I recently had a RR remap with them, that does not mean they didn't do it
though.
They did pick up knock though. They moaned at me for filling the car with 95RON. We drained it all out and put some 99RON in. I did wonder at the time
what was going on, the car did not sound happy, he then stopped and asked what fuel was in it.
This was evident when they were doing lower RPM cruising stuff IIRC. The rollers created drag and demand for motorway cruising and they mapped to
that.
They were very thorough, mapping different loads and TPS with the complete rev range. It took ages and would be impossible on the road.
A very expensive day but I think worth it for a once in a car engine's life.
There you go. This was my point all along.
They did not plug a lead in. GOT KNOCK
and blamed 95 ron. (Edited swear word out) everywhere. Who can you trust? lol
[Edited on 2/9/20 by bikecarbfred]
|
|
|
rusty nuts
|
| posted on 2/9/20 at 03:50 PM |
|
|
A compression ratio of 11.5 would probably caused problems with 101 octane fuel when that was available ?
|
|
|
mcerd1
|
| posted on 2/9/20 at 04:05 PM |
|
|
quote:
Originally posted by bikecarbfred
There you go. This was my point all along.
They did not plug a lead in. GOT KNOCK
and blamed 95 ron. (Edited swear word out) everywhere. Who can you trust? lol
I doubt not plugging in the sensor caused the knock - thats only going to come from bad air/fuel, bad timing or too much compression for the type
of fuel your burning
the first 2 of those issues are best sorted out on a dyno
unless your engine is extremely fragile I doubt finding a little bit of knock during tuning is going to do any real damage in the short term -
remember that back in the old days knock sensors didn't exist, but folk could still tune engines on a dyno...
and tuning it on the road just means you've got less control 
but if your engine is effectively the same as an OE one as you say (that presumably ran on 95 RON - for which most car makers allow pretty big
margins) - how worried do you really need to be ?
Also when I google that engine code I find a much more reasonable 10.4:1 CR for the stock engine ?
have you tried to calculate the dynamic CR yet?
(if not try these)
https://uempistons.com/p-27-compression-ratio-calculator.html
https://uempistons.com/p-28-effective-compression-ratio-calculator.html
when comparing to the US results (lots more published about this over the pond) our 95 RON is approx. the same as US 90 R+M/2 (97RON = 92 R+M/2 )
everything I've read says 97 is plenty for Dynamic CR's around 8.0:1 - 8.5:1 (assuming alloy heads, 0.5 less with old iron ones like
mine)
this is why it would be good if you had measurements for your specific engines combustion chamber volume, compressed gasket volume, deck height, rod
length, stroke and the timing for the inlet valve closing - then you could be much more certain of how close you are to knocking in reality...
you can do the same calcs with stock figures but as soon as you skim the head, deck the block, fit a different gasket, change the pistons, rods, cams
etc.... you've changed it and the stock CR is no longer relevant to your engine (assuming it was ever an accurate figure in the first place)
using my own engine as an example:
I've got 42mm CC chambers in the head (measured with my DIY setup, but probably within ±1 or 2 cc)
with:
93mm pistons (3.661" )
76.95mm stroke (3.03" )
93.5mm gasket bore (3.681" )
128.5mm long rods (exactly 5.06" )
inlet valve closes at 63°
a stock gasket is about 0.040" thick (~1.0mm) which would give mine a static CR of 11.671:1 and a dynamic of 9.402  a bit OTT for an old
iron lump
changing to the 0.075" gasket gives me a 10.49:1 static ratio with a dynamic of 8.472 still a tough on the high side for 95 given the know
behaviour of my type of engine (but it might be ok - i'll find out on the rollers )
[Edited on 2/9/2020 by mcerd1]
-
|
|
|
bikecarbfred
|
| posted on 2/9/20 at 10:24 PM |
|
|
sorry i forgot to mention it would be a gti 6n2 equivilant engine which is 11.5CR
better do some homework on dynamic CR
|
|
|
bikecarbfred
|
| posted on 3/11/20 at 12:43 AM |
|
|
anyone know any rolling road near sheffield, doncaster who would work with megajolt?
|
|
|
Duncan Grier
|
| posted on 3/11/20 at 08:20 AM |
|
|
I would try Chris @efi-parts in Runcorn. Can't say enough good things about him and well known and respected.
https://efi-parts.co.uk/rolling-road/
|
|
|
40inches
|
| posted on 3/11/20 at 09:59 AM |
|
|
quote:
Originally posted by bikecarbfred
anyone know any rolling road near sheffield, doncaster who would work with megajolt?
Try Kits and Classics in Chesterfield. He mapped my Megasquirt and found knock without a sensor fitted.
http://www.kitsandclassics.co.uk/
|
|
|
bi22le
|
| posted on 3/11/20 at 12:25 PM |
|
|
quote:
Originally posted by bikecarbfred
quote:
Originally posted by bi22le
I can't recall ATSpeed attaching a knock sensor to my car when I recently had a RR remap with them, that does not mean they didn't do it
though.
They did pick up knock though. They moaned at me for filling the car with 95RON. We drained it all out and put some 99RON in. I did wonder at the time
what was going on, the car did not sound happy, he then stopped and asked what fuel was in it.
This was evident when they were doing lower RPM cruising stuff IIRC. The rollers created drag and demand for motorway cruising and they mapped to
that.
They were very thorough, mapping different loads and TPS with the complete rev range. It took ages and would be impossible on the road.
A very expensive day but I think worth it for a once in a car engine's life.
There you go. This was my point all along.
They did not plug a lead in. GOT KNOCK
and blamed 95 ron. (Edited swear word out) everywhere. Who can you trust? lol
[Edited on 2/9/20 by bikecarbfred]
I don't think they blamed 95 at all, ATSpeed are one of the best tuners in the country. It's a jap import engine running 11:1 and knocking
happened under load conditions. These engines were designed to run higher octane then 95 and this has a highish CR so it was no real surprise. I use
it for track only so don't mind 99 Ron. If I get caught out and have to use 95 on the road, I will do.
Going back to OP, having an established tuner check over the engine and spend the day mapping it gives me great piece of mind. If you can tune it
safely and within its limits then do so.
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
|
|
|
perksy
|
| posted on 3/11/20 at 11:28 PM |
|
|
quote:
Originally posted by ttalps2000
get it on the rollers and do it properlly! Tried road tuning before, dont bother!
if you want experience, then go to Northampton Motorsport. Not the cheapest you will find a rolling road for, but compared to the previous company i
used, you get what you pay for!! Troy is a top tuner and transformed my car on itb's
Agreed
Troy finished mine off on the road with his laptop on his knees and then the bonnet starting to lift off 
|
|
|
.jpg)
