Advise on Race Fuel & Timing!!

[Sprog]

Hi Guys (n Gals)
This is kindof a normally aspirated question too actually

I drive a Stage 2 MK4 Anniversary AUQ, I ussually mascerade as a Leon Cupra, but decided I'd just be honest this time
I was at the last vs. rolling road day

uk-mkivs is REALLY lacking technical knowlege nowadays and I really need some help re: Race Fuel


Right, I'm looking at running some race fuel (just on occassion - it aint cheap LOL)

The car is currently mapped for V-Power, but basically I'm just wondering what is the highest Octane a 1.8T can adapt to and how much you can take advantage of it by manually adjusting ignition timing, and what sort of values you would run for different octanes etc.

I'm full on AUQ stage 2, FMIC etc - so basically at the limit of the turbo - so I'm hoping to make a touch more power from higher ron and timing enhancements - I can adjust the timing using customsettings.exe but have never done anything like this before!!

I'm looking at Sunoco 260GT (105 Octane with 3.5% Oxygen) I think the 109 Octane would be pushing it LOL

Has anyone done this before, what sort of gains should I expect?

Any help would be much appreciated. Thanks in advance.

 

[DPJ]

I think you'd manage some reasonable gains on 105 Octane Fuel.

You need to advance the timing and log CFs bit by bit.

You'd achieve the same results with the right octane booster........... I'd try that before splashing out on the fuel.

 

[Wilko]

I've used vp109 a few times, but to be honnest even when you think your tank is dry, you probably still have 3-4 litres in it.
This means that unless you are prepared to chuck a whole can in at once, it'll get watered down by the pump fuel you still have in the tank.
It will give you great gains if you have the cash to put enough of it in.
7-10% power improvement. You can't get as much with any octane booster, but you can get near.

 

[Sprog]

Thanks DPJ, Wilko (lol I put a post on the seat forum and you reply!)
I've used Miller CVT before for a RR day and it only gave me 3 ponies (although that was on differnt conditions on different rolling roads so it could have done nothing, even negative effect to be fair). but i didn't adjust the timing at all.

Is there a drain plug on the tank? Is it possible to drop the fuel out? My mates Integra has one - just wondered if golf did.

Sorry, what are CFs? Are you talking about knock?
Is this a vag-com measuring block?

Any idea what amount is a good start re: timing advance. and when should I start to back the timing up after detecting too much knock (lol and how much is too much).
Doesn't ECU retard timing if it detects knock anyway? Can't I just set it forward and let the ECU retard it for me?

Thanks very much indeed for all the help.

 

[ibizacupra]

block 020 is CF timing pull, and you dont want to see more than 6's ideally across the board.
upping timing with unitsettings or lemmiwinks etc a couple of degrees at a time, and logging will be a guide.
log block 031 also to see what afr you are running also.. you may be able to get some more fueling in there with the additional timing


why do you want to do this? just for dyno run or 1/4 mile?

 

[Sprog]

Thanks very much for the help everyone.
I'll go out and do some logging. I'll be using customsettings.exe for the adjustments.
Curious to know what I'm running at the moment, always on V-Power - I hope to get a small gain just by adjusting for this.

Race Fuel will be for both dyno and 1/4 (rare - because it's v. expensive and it's a daily driver) - although I wouldn't expect to see much over the 1/4. it's really for the peak bhp figure I guess. Would be nice to see 250 on a K03s (although I'm not sure how feasible that is)

On a slightly different subject.
I'm on standard internals at the moment - last RR day, I pulled about 320lbft, 237 bhp.

With these potential gains from timing etc. Would I expect to see an increase in peak torque aswell (3100 rpm) or mainly just top end, hence peak BHP figure? and are these gains going to be safe on the stock internals?

Again, thanks for your time.

 

[ibizacupra]

sorry you said k03s, and also said 320lbft and 237bhp?

where was this dyno'd

i must go there and get myself a 700bhp power figure..
k03s and those numbers are not real in my experience.

post your airflow logs when you do your runs.. be interesting to compare what you get vs what power others get from airflows..

 

[phil_m]

320Nm i would think..

 

[Sprog]

uLOL yeah I know! I was surprised as you!
I pulled 270 at JBS's road immediately after my stage 2. But then I was losing power top end with an intermitent flat spot, JBS couldn't find the problem, so after some research I swapped for an N75K (from an S2 I think) - I remember when I did the research, it's faster at trimming than F, J etc. So seemed like a good choice - and it was definately better regarding the drop it power at 6k! Far more infrequent. A side affect was a noticable increase in torque.

JBS Dyno Sheet (sorry - they are scans - quite big)
w_w_w.themakoshark.com/Stuff/DynoChartJBS2008-07-11.jpg

At scn vs. uk-mkivs rolling road day - I got this.
w_w_w.themakoshark.com/Stuff/DynoChartAwesomeGTI2008-11-01.jpg

a bit of a spike, but it was consistently over 300.

Now if this is wrong or skewed in some way, cool, I'm not delusional but you can see it is NOT NM, it is definately lbft.

I don't actually have an airflow graph from after I fitted the N75K, but I've got boost? (I'm doing 22-23psi at 3k) IIRC

I'll log Airflow when I do my runs tomorrow.

Thanks guys

 

[Sprog]

Sorry about the links - I don't have 15 posts and it wouldn't let me post links.

 

[m0rk]

uLOL yeah I know! I was surprised as you!
I pulled 270 at JBS's road immediately after my stage 2. But then I was losing power top end with an intermitent flat spot, JBS couldn't find the problem, so after some research I swapped for an N75K (from an S2 I think) - I remember when I did the research, it's faster at trimming than F, J etc. So seemed like a good choice - and it was definately better regarding the drop it power at 6k! Far more infrequent. A side affect was a noticable increase in torque.

JBS Dyno Sheet (sorry - they are scans - quite big)
w_w_w.themakoshark.com/Stuff/DynoChartJBS2008-07-11.jpg

At scn vs. uk-mkivs rolling road day - I got this.
w_w_w.themakoshark.com/Stuff/DynoChartAwesomeGTI2008-11-01.jpg

a bit of a spike, but it was consistently over 300.

Now if this is wrong or skewed in some way, cool, I'm not delusional but you can see it is NOT NM, it is definately lbft.

I don't actually have an airflow graph from after I fitted the N75K, but I've got boost? (I'm doing 22-23psi at 3k) IIRC

I'll log Airflow when I do my runs tomorrow.

Thanks guys

How did your peak torque shift 1000rpm lower at awesome than at etch-a-sketch?

 

[Sprog]

Etch-a-sketch hahaha.

The only thing which changed between the runs was I that for the awesome run, I was using Millers CVT, so 104 octane (allegedly - but with no timing advance) and the N75K.
Like I said, when I put the N75K on, there was a big change in torque! but also the JBS run immediately after the stage 2 remap. Myself and my friend commented on how the car appeared to get quicker on the way home (which is feasible I guess because of the ECU adjusting).

What were other people's results like at the scn vs. uk-mkivs RR day? I can't remember anyone commenting on the readings from the RR being dodgy!? I mean circa 240 is fairly acceptable for a K03s, its just the torque curve lower down the RPM range where the difference is. It's still 'typical k03s' i.e. pretty weak top-end.

 

[ibizacupra]

i would hate to know what boost spike you must be getting for torque figure like that.
K03s

hard to believe for sure

as m0rk says there is 1000rpm difference in where peak torque is delivered on the 2 dyno's

welcome to dyno lottery

everyones a winner & loser @ the same time.


post your airflow and logs up when you can. make for an interesting read

 

[Sprog]

"You'd hate to know?"

I hate dynos. They are so unreliable FFS - to the point where there is actually no point.

Just about to give car a wash then I'll go out for some logging. I'll do a 4th gear airmass run (along with some timing tweeks hopefully) - just waiting for my mate to turn up with some Millers CVL Turbo ha ha.

 

[Sprog]

Right, finally managed to get out and do some logging.

Just on V-Power, managed to adjust the timing up to +3.0 degrees with it every now and again touching 6. Guess I should drop it back a touch more to 2.25.
Gonna be interesting to see how far I can push with some CVL Turbo Octane booster in.

Also, here is a log of my air mass.

	Group A:	'003			
		Idle speed	Air mass in	Throt Angle	Ignit Angle
	TIME	700-820 rpm	2.0-4.5 g/s	0.2-4.0%	0-12 BTDC
Marker	STAMP	 /min	 g/s	%	 °ATDC
	0	880	13.89	51	9
	0.54	960	14.64	54.1	12.8
	1.11	1040	15.83	56.9	12
	1.71	1120	18.31	62.4	12.8
	2.22	1160	19.81	65.9	13.5
	2.72	1240	20.42	70.2	13.5
	3.33	1320	22.64	75.3	14.3
	3.83	1400	24.31	79.2	15
	4.33	1480	26.5	83.9	15.8
	4.95	1600	28.5	90.2	15
	5.56	1680	31.47	96.1	15
	6.22	1800	35.36	100	9.8
	6.75	1920	39.28	100	14.3
	7.25	2040	44.33	100	9
	7.76	2160	51.67	100	8.3
	8.36	2320	62	100	12.8
	8.86	2480	74.72	100	12.8
	9.36	2640	85.64	100	12
	9.97	2880	107.03	100	7.5
	10.47	3080	118.31	100	7.5
	10.98	3280	126.56	100	8.3
	11.59	3560	136.11	100	7.5
	12.24	3800	146.31	100	7.5
	12.78	4040	151.67	100	7.5
	13.29	4240	160.86	100	7.5
	13.89	4480	164.92	100	7.5
	14.4	4640	165.78	100	8.3
	14.99	4840	169.11	100	9
	15.5	5000	170.47	100	12.8
	16	5160	171.83	100	11.3
	16.5	5320	174.75	100	15
	17.01	5440	175.94	100	13.5
	17.64	5640	177.89	100	14.3
	18.28	5760	178.75	100	16.5
	18.83	5920	177.89	99.6	17.3
	19.44	6080	177.61	99.6	15.8
	20.03	6200	178.75	100	15.8
	20.63	6320	180.39	99.6	18
	21.15	6440	179.83	100	15.8
	21.75	6520	180.56	100	15
	22.36	6640	181.81	99.6	14.3
	22.95	6720	174.97	100	18
	23.45	6800	169.22	100	24

 

[ibizacupra]

thats good airflow for k03s, holding up well at the high rpms..

The boost log would show how much its pushing to get the torque firgure. thats the scarey bit from my perspective (rods) if your torque is so high

 

[Sprog]

I'll try and get round to doing some more logging tonight, try some octane booster and see how far I can push it. I'll do a boost log too if I get time (going on holiday tomorrow). But last time I did one, I was peaking 22-23psi IIRC at 3k

Bit of topic, but something I've always wondered - I've been told the stock rods etc. are rated to 300 (340 if you talk to APR lol). Now they are saying bhp, but would torque also put similar stresses on the parts? I'm guessing not, because the bhp is equivalent to the high torque at high rpm, where mine is down lol at 3k.
I've been running this setup since last october and had no problems - but the last thing I want to do is throw a rod.

 

[ibizacupra]

300lbft torque is in the region of bending... but its not boost alone which can do this, the greater stress is detonation and the forces it would apply to the rod..

Its high boost for a k03s but not as high as I have seen a couple.
sustained boost and onset from your log will reveal the delivery.

the dyno plots had 1000rpm difference in delivered peak torque so your road logs would help confirm which is the nearest of the two.

try logging block 002,115,120 during one of your 3rd/4th gear pulls.

you will be able to plot torque directly against boost and airflow then,.

 

[Sprog]

My copy of VAG-COM is serial cable. So the sample rate is totally cr_p!
Can only get decent results by measuring one block at a time.
Will doing them separately give anything useful?

This might be a stupid question, and I'm assuming the answer is yes, but advancing the timing, or running race fuel will be putting more stress on the rods - potentially pushing them past their 'limit'?

The N75 K valve only really increased torque down the bottom of the range (but smoothed out the entire curve) and didn't really affect the peak horsepower figure up top. Maybe I should swap back to N75 F if I'm on race fuel

 

[ibizacupra]

more power more torque more stress on everything... detonation is what would most likely break something if the Cf's went unchecked