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The ECU considers just a bit more negative than -2000 to be unsafe and gets upset.

On present evidence, I suggest retuning if you can get -614 in the same RPM/load area repeatedly. If you just get -307 sporadically in different areas each time it is tested, I reckon that is the sweet spot.
 

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Indeed not - but given Thistle comments regarding safe limits I might be in the market for a custom tune as I have managed to record a peak Knock of -1522...

Will drop you a mail with the logs if that is alright.
 

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Holy cow! I've just uploaded the new RPM/Boost custom map Ben sent me and the car flies!

Just when I thought it couldn't get any more awesome... :clap:

Haven't datalogged yet, but using live knock monitoring, I think I saw "-8xx/0".

What does the /0 mean?
 

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Min/Max. If you see -800 consistently it might be worth taking a bit of timing out.

Ben now has my original version of this map that I still run, and a second version that Rich tried with 2 degrees timing retard.

Rich ran the same acceleration times with both versions, and saved nearly 1.4 seconds 0-120 mph on VBox compared to the previous 99 map.
 

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Discussion Starter · #27 ·
Holy cow! I've just uploaded the new RPM/Boost custom map Ben sent me and the car flies!

Just when I thought it couldn't get any more awesome... :clap:

Haven't datalogged yet, but using live knock monitoring, I think I saw "-8xx/0".

What does the /0 mean?

well its a base map dave, you need to send me your datalogs to check and i'll smooth timing and boost as required. But thanks for letting me know via the forum :p

highest/lowest


btw Rich GT's V box figures are suggesting dipping into 10's :)
 

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Stock US GTR on 91 octane is showing -1400 on knock, so I think we don't need to be aiming for 0. Joe is going to post his log on NAGTROC.
 

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well its a base map dave, you need to send me your datalogs to check and i'll smooth timing and boost as required. But thanks for letting me know via the forum :p

highest/lowest


btw Rich GT's V box figures are suggesting dipping into 10's :)
Hey I wasn't complaining! From what little I've seen the tune is devastatingly quick with very little knock for a base map.

Once it's custom tuned, we're going to the dyno! :cool:
 

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Aaarrrggghhh! I hate dynos. If they tell you it makes less power than before and is running too rich, yet you know it is faster on the road, don't be surprised.

If on the other hand it makes more power, Ben & I will happily take the credit.

Get a knock log on the dyno though, and compare to the road. This will explain any discrepancies.

Bottom line is I'd rather it did 0-120 in 10.5 on a V-box and high 10s at a grippy Pod and showed 500 BHP than I would see 11s at the Pod and 600 BHP ;)
 

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So a busy week or so, trying the new RPM based map and having it tweaked by GTC. So I have now been spending a bit of time crunching data from both the Racelogic Performance Box and from the Cobb AP.

So here's my graph for the day, ;) this taken from a full throttle run up through the gears.



So MPH along the bottom, left scale has Boost, AFR and Ignition Advance, on the right is Wastegate Duty. You can see the gear changes when the ignition briefly retards, and then the boost builds again until it's limited by the wastegate being at 99%.


A few question that the graph prompts to me that thistle might like to comment on?

1) What limits the boost in first gear? Surely it could be higher?

2) The effect is more marked as you go up the box, but why does the boost rise, then drop a bit, then rise again before tailing off with
the WG at 100%? Can we fill in the small dip?

3) Any chance of a RPM & Gear related map? That would presumably allow the WG to be ramped up to 99% earlier in 1st 4th & 5th?


More data and thoughts / questions to follow, but will save them for another post.


Rich
 

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Surely you're most likely to break things in 1st gear, hence having a smoother ramp up/lower boost is sensible?

I certainly found my new map caused the rears to lose traction very easily in the first 2 gears! :D

What were your measured 0-60mph and 0-100mph times?

Have you found how to measure the 1/4 mile using the Performance Box?

Couldn't find an empty enough stretch of, er, test track today... ;)
 

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Nice graphs and analysis Rich, you should be a mapper as you have more of the issues covered than many mappers do. Many just put bigger boost numbers on stock maps.

1) What limits the boost in first gear? Surely it could be higher?

Time, exhaust gas flow, (lack of) proper launch control to launch under proper load and boost. Wastegate duty although not 100% in first gear is not the cause as even with a much lower wastegate duty than 100% the wastegates are closed until there is a decent boost level.

2) The effect is more marked as you go up the box, but why does the boost rise, then drop a bit, then rise again before tailing off with
the WG at 100%? Can we fill in the small dip?

Consider the gear ratios are getting closer between each gear as you go up the box. This means you are using higher revs in higher gears, this means less boost. The lumpiness on gearchanges is due to changes in turbine speed to match the new engine speed, and ignition retard. It is unavoidable and minor. Much better than before the RPM based control we have now, and would be no better with an EBC.

3) Any chance of a RPM & Gear related map? That would presumably allow the WG to be ramped up to 99% earlier in 1st 4th & 5th?

Wouldn't make any difference in 1st as noted above, because it is never below 60%, wastegate is closed the whole time anyway. It goes up smoothly towards 100% as you go through the power band in the later gears. Boost is tapering all the time as revs increase though, that is no bad thing at all as it is keeping the turbo in its efficiency range, you're increasing ignition timing to compensate for RPM, and you are staying near peak power for much of the time which is what makes you fast.

Overall I'm really chuffed with this graph, it shows really good boost, AFR and ignition control considering you're flat foot shifting in R mode. It is virtually textbook of how you'd want it to be, well it would be if I wrote the textbook LOL.
 

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Ben/Thistle, any chance of a Stage 1 99Ron map being approved for use in the forseeable future?
 

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Difficult question, the stages are not of our design/choosing, and you can see my opinion in that Rich's and my car (both standard) are running stage 2 fuelling, more that stage 2 top end boost and less than stage 2 timing. I think Rich's map would be a good base for standard cars or Y-pipes/catbacks.
 

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The problem with data is that you can end up with so much of it that you can't see what is going on, that's why I like graphs. ;) I have crunched some of the older data into the same format, so that we can see where we have come from and what has improved.

So three graphs in the same format. Cobb Stage2, GTC Stage2 99Ron and a repeat of the latest GTC Stage2 99RON RPM Map.

I have added the Knock readout to the last 2 as Knock /100 to keep it on the LH scale. Remember that -307 is a single knock event, so shown as -3.7 I will make a couple of observations on each and leave it to thistle to add anything that he thinks is useful?



So the standard Cobb Stage 2 Map. WG duty flatlines at 75% boost rapidly tails off to 13PSI in the higher gears.



The GTC Stage 2 99Ron Map. Have to say I was over the moon with this map, enabled me to do the 11.05 sec run at Santa Pod.:thumbsup:

WG duty flatlines at a slightly higher 78%, boost is higher and holds better but still drops to 13PSI.

There are several Knock events, several of which are induced by the gear change spike.



Finally a repeat of the new GTC 99RON RPM based map, with the knock events included.

WG duty now able to be ramped, generally more boost and holds most of the time above 14PSI. Less advance than the Cobb Stage 2, Knock events significantly reduced.


Rich
 

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I feel like I passed the audit LOL, but thanks for showing the differences, you can really see the area under the boost curve which explains your reported faster V-box times.

Note there is no difference in 1st gear boost between the last two as it is a mechanical limitation and more duty cycle doesn't help as the wastegates are pretty much closed anyway.

Ignition timing is lower in the higher boost and airflow final map as it should be.

Perhaps you can cross post this latest bit on NAGTROC as I think they would find it interesting. It shows nicely the progress with knock and boost control.
 

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I feel like I passed the audit LOL, but thanks for showing the differences, you can really see the area under the boost curve which explains your reported faster V-box times.

Note there is no difference in 1st gear boost between the last two as it is a mechanical limitation and more duty cycle doesn't help as the wastegates are pretty much closed anyway.

Ignition timing is lower in the higher boost and airflow final map as it should be.

Perhaps you can cross post this latest bit on NAGTROC as I think they would find it interesting. It shows nicely the progress with knock and boost control.
what did you think of my last logs ?
 

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Superb, have replied to Ben. Final version with 0.01 difference in fuelling and 1 degree off the timing. Boost is perfect, just enough to max your injectors.
 
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