Power Curve Comparison

[Jamo]

Ah right - so because im new im not alowed to voice an opinion??
Obviously experience counts for nothing merely how long youve owned your car and how high your post count is.
Ill remember that in future Jamo - thanks for letting me know.

thanks again

Pete.

If you'd been there then your opinion would have counted, but you weren't you didn't know all the facts and accused people of being short changed out of their money.

In my book thats ignorance of the highest order as i spent allot of personally time organising the event.

[blown_vr6]

Jamo,

I dont have to drive 360 miles round trip to see that a car that has been run up in a low gear and a flash reading of torque could have been produced - i can look at the stats right in front of me.
You seem to be taking this personally - beleive me it is not and if you think its that then your reading into it more than you need to.
I have organised dyno days before on more than one occasion and i know how much effort goes into the organisational side of things but that doesnt get round why they did the runs in such a low gear?.
Whatever way you look at it you will not load a turbo car up at low engine speed in a low gear compared to low engine speed in a high gear - you might reach similar end results in terms of outright peak torque and power figures but the curves will not replicate what the car is capable of in a non artificial environment - ie the road and surely thats what want to know?.
Perhaps 'short changed' wasnt the correct phrase to use in hindsight but i would have gone away thinking 'what if' as im sure Andy is possibly thinking the same?.
Again - thats nothing for you to feel responsible for - you organised what alot of people thought was a great day and thats the main thing.

Pete.

[Rusty]

Alright chaps. Calm down. I'd appreciate it if this post was a subjective analysis of the results rather than a slagging match.

I was perfectly happy to trust the judgement of the dyno operator at the time and was very happy with my results. I have been to many rolling roads around the country with previous cars and can quite honestly say that I didn't feel short changed at all and was very pleased with the professionalism and courtesy shown by Weston and the dyno operator. Jamo put a lot of effort into organising this and did a great job of making sure that it ran well on the day, hence his reaction.

Back to the job in hand, the comparison of the graphs and explanations for the differences.

I did not mean to imply that the torque curves were completely different and do not think that I mentioned that anywhere. I was meerely commenting on the notable lag induced by the run being 2 gears lower. This interested me and obviously has intersted a few other s on here too!

The form and magnitude of the torque curves are similar, as is the shape of the power curve (unsuprisingly) so I am starting to believe the result a bit more, having initially greeted it with disbelief and scepticism. There were 3 runs in all, 251bhp, 254bhp and 259bhp. Consistent if nothing else.

My reason for showing the graph was that I was phooking chuffed with the results of 18 month's worth of graft, expendature and investigation and wanted to explain what differences my modifications and efforts had produced so that others may develop their own opinions on whether they might want to do the same. Some have cost nothing, others have cost a lot. Some people might be pleased to see what £1k gets you on a standard S2.

To post over 250bhp on a standard map is pretty decent IMHO and I'd like to see more in the future too before going for a bigger turbo or remap.

[Jamo]

The big thing Andy is at Western you cars will not suffer from heat soak hence why you and Nip were getting more BHP per run as the engine warmed up more.

Only Ross suffered heatsoak and i think thats because his filter is pointing to the cabin and not reversed back to the front of the engine where the fan was.

[Rusty]

The big fan hitting the top of the engine sorted that one, not to mention how cold it was in the dyno cell!

I'm sure it felt quicker on the drive home...

[S2central.net]

@Jamo - I think you've been a bit harsh here mate... Believe me I know much time and effort is required to organise and host that event at the rollers. Nobody is diss'ing you for that...

Peter was just expressing an opinion based on his experience - I see no reason why you had to respond in such a way.

FWIW - I am also confused why the roller operator did some cars in 3rd and some in 4th. Consistency is very important on the rollers. Just my opinion - I am very grateful for members/mods like you that go the extra mile for the forum and organise stuff like this, but these replies to Peter do not show you in your best light.

I don't imagine that you intended to cause offense - god knows I've ruffled some feathers in the past with a few posts I'd later wish I'd not sent - or at least delayed until I had found a better way of expressing myself.

Paul

[S2central.net]

And getting back to the topic in question... Quite an impressive gain for a zorst there

Looks to me like the original run was done in 4th or higher - you can actually see where heatsoak must have affected it on the previous run... And you can see that it created more boost earlier on the 1st runs. The recent runs in 3rd showed that max boost came in later - this will have helped keep IAT down.

All that aside - looks like ~10% gain with the zorst and that airbox mod... Be real interesting to see what an RS2 intercooler would give... and a PPP to go with it... Then add a remap or a homebrew to see what she does !

Out of interest - was there much difference in transmission losses on the two rollers ?

Paul

[Chris M]

You just cannot load the turbo up enough against such a short ratio - 5th yes but 3rd???

Pete.

Hope my turbo was fully loaded up and my dyno figures were correct as my Torque peaked at 415lbs/ft @ around 3500RPM on stock rods

[Mihnea]

Sorry Jamo, I beg to differ, my car's intake temps during both runs I've had and logged fully (I can post graphed data of all these runs) started at 26 degrees C and ended up at 55 on run 1 and 58 on run 2. On the street I'll probably only see 35 max in 4th gear on a similar type of run, BTDT and logged that.

Because of the higher load on the rollers and the poor cooling my timing cR@pped out to 7 degrees less than on the street (mainly at high revs, probably more like 4 degrees less in the midrange) and also my ECU triggered "EGT enrich mode" at 5500 RPM in both runs because EGTs reached 920 degrees C before the turbos (not at the turbine inlet though, a little bit closer to the heads than that).

On the street with decent fuel I haven't managed to trigger EGT enrich yet, all I've logged before has always been below 840 before the turbines, so loads more headroom for power with a leaner mixture but then higher chances of pinging and poor timing on crap fuel whenever I HAVE to use it, as these dyno runs done on Tesco 97.

So I wouldn't say that no one suffered from heatsoak. My FMIC is quite decent (7 degrees temp rise on a run from 60 to 155 mph, logged for proof) and I don't think my car was the worst one there for that matter.

Mihnea

The big thing Andy is at Western you cars will not suffer from heat soak hence why you and Nip were getting more BHP per run as the engine warmed up more.

Only Ross suffered heatsoak and i think thats because his filter is pointing to the cabin and not reversed back to the front of the engine where the fan was.

[slow2]

All that aside - looks like ~10% gain with the zorst and that airbox mod... Be real interesting to see what an RS2 intercooler would give... and a PPP to go with it... Then add a remap or a homebrew to see what she does !

I can answear that question paul, on my car i have a 70mm exhaust(cat removed for the day) RS2 intercooler, RS2 airbox and Homefry,

my results were:
274.8 bhp, 311ftlb torque,
Maximum Boost 1.4bar at 3370 rpm tailing off to 0.9bar at 7000rpm,
Maximun EGT 688c,
AFR 12.0 at 3370rpm, 11.4 at 4000rpm, 11.0 at 5000rpm, 10.9 at 6000rpm, 11.2 at 7ooo

Not a lot of extra hp for all the add on's and Homefry i thought i would of been closer to 290hp, any ideas anyone!

[Chris M]

A re-map might have been better to take full advantage of the other mods and maybe 7A exhaust cam too, thats what i did with my old S2

Cheers,
Chris

[slow2]

I think your probably right about the remap chris, just thought i would have a go at maxin a homefry set up before i do some serious power upgrades.

[kwlw]

I can answear that question paul, on my car i have a 70mm exhaust(cat removed for the day) RS2 intercooler, RS2 airbox and Homefry,

my results were:
274.8 bhp, 311ftlb torque,
Maximum Boost 1.4bar at 3370 rpm tailing off to 0.9bar at 7000rpm,
Maximun EGT 688c,
AFR 12.0 at 3370rpm, 11.4 at 4000rpm, 11.0 at 5000rpm, 10.9 at 6000rpm, 11.2 at 7ooo

Not a lot of extra hp for all the add on's and Homefry i thought i would of been closer to 290hp, any ideas anyone!

I would say nice figures for generic chip. Especially if the dyno was measuring real parameters, not the "writing story for customer".

I understand, that customer is usually more satisfied, when dyno adds let's say 20 additional horses (tuning is all about to have more).

If some guy claims, that he has 300hp with stock turbo, then his engine is running beyond safety limits. Like Mihnea said "Happy engine rebuilding" type of chip .

Sau
P.S. Any mods you give to engine are needed to be taken into account when mapping, don't expect miracles from generic chip. For example MTM stage1 chip is only 260hp.

[S2central.net]

mmmm must admit I would have expected more on slow2's car. I've dynoed my own homebrews at 280bhp on stock exhaust with CATs (original parts) and stock intercooler. I know others have similarly dynoed at 270-280bhp on that spec too.

Obviously these run on the slightly rich side for safety margin - important with any generic upgrade. Running leaner and with higher EGTs would give you more zip - looks to me you have planty of headroom for that.

Could be the dreaded heatsoak I guess... could you have suffered from that more than the others on the day ?

Seeing as you have the AFR & EGT gizmos, it might be worth you fitting an adjustable FPR to yours and try carefully reducing the pressure to make you run leaner at WOT. The reduced pressure at idle should be within adaptation limits on lambda control. Its worth a try I reckon - have you actually measured your fuel pressure ? Maybe it is on the high side - this is a good example of where a custom remap has a technical advantage in that it can be tweaked to get perfect fuelling despite variance in mechanical things like FPR's. Costs more of course, but that's life.

Out of interest - what fuel is the car running ?


Paul

[Rusty]

RS2 IC and a cold air feed might be the way forward. Been thinking about how to get a cold air feed to the air box with the standard inlet. Requires relocation of the crossmember pipe to provide clearance for a cold air feed. Might have a play if I can find a spare XM and IC to TB meatal / plastic pipe.

Then possibly a home polishing job on the inlet and especially exhaust ports when I do a head gasket and even an RS2 EM coupled to a Milltek DP & cat if I keep the car long enough to save up for all this stuff! 7A cam would be nice too...

It's official, this forum is VERY BAD for your bank balance!