HSV Dyno day Oct SRR

HSV Dyno day Oct SRR

Author
Discussion

stigmundfreud

22,454 posts

209 months

Monday 20th October 2014
quotequote all
just some more arm chair expert idea... check the gravity of the fuel before wasting time on the kr sensor as it could be water ingress either at pump source (highly unlikely) or the car has a leak, quick easy check test.

M11 MFP

687 posts

192 months

Monday 20th October 2014
quotequote all
Wyld Stallyn said:
Meanwhile on a more sensible note:

If I got 377..2 RWHP

How do I Work out the Fly BHP? confused
Well 405 fw (known) = 321.8 rw in my case, which with a 20hp standing charge makes the ratio 1.196.

So try (1.2 x rwhp)+20

= 472.64 simples.

ringram

14,700 posts

247 months

Monday 20th October 2014
quotequote all
wormus said:
I don't understand how that can be true when it depends on so many factors: fuel, IATs, compression ratio/boost? Low boost is fine on a stock, supercharged engine and you get less heat and excellent drivability.
Great a nice question smile

Basically most BHP theory is based on WOT operation not "throttled" engine operation. In that instance compression, boost, temperatures etc mean that spark timing must be reduced from optimal in order to avoid knock. You still get power, its just not as much as you would get if you could advance timing and not get knock.

Low boost reduces heat, lowers effective compression and allows MORE timing getting you closer to MBT.

Think of it this way, can you increase compression to infinity? Can you reduce octance to 0? Can you increase temperature to infinity?
The answer is of course no. So at what point can you change these things and still let the ECU and OEM build an engine that can achieve MBT without knock?

Well thats pretty much how the stock engine is designed. Its designed to run MBT without knock. Because thats its most efficient point.

So now you add forced induction without changing anything else. You have increased effective compression maybe 50% (more pressure in cylinder) you raise heat maybe 50*C and do you think you can run the same optimal timing as OEM? No of course not. You are now knock limited & timing must reduce to avoid knock and maintain power as best as possible.

You can add timing and gain power, but you will get knock. So you cant. So what do you do? You do what you can to keep timing high as possible to retain power. You run high octane, you run intercoolers, you drop engine temps, you run cams to reduce compression temps, you coat headers, you inject meth and nos etc. You do what you can to reduce the factors which affect your ability to run MBT.

Xpuffin

9,209 posts

204 months

Monday 20th October 2014
quotequote all
Xpuffin said:
R8VXF said:
At what point has anyone said this is a scientific experiment? I think people are taking this far too seriously. I made this as a help for people to log their results next week at an event I probably will not even be at, so thought it might be a bit of fun to be able to let people log other results that they may have in their collection. If people do not like my methodology then feel free not to participate, but to those who have participated so far and going forwards, I would like to say thank you.
With respect, being new to this forum, you are unaware of exactly how many arguments the HSV Dyno days cause. I know, I started and hosted them untill the bickering about results got too much.
And as an ex moderator dealing with the justified complaints from the perf companies was also an issue.
Is all I'm saying.
See what I mean hehe

Wyld Stallyn

2,056 posts

127 months

Monday 20th October 2014
quotequote all
So given that I already got a CAI, Cam, lifters, headers etc and I got 'Many' FWHPs cool

What's the best bang for buck Power Up mod I could do next..? *


  • Budgetary Limitations Prohibit the Use of Forced Induction

ringram

14,700 posts

247 months

Monday 20th October 2014
quotequote all
monkfish1 said:
Which is what i said. Im glad you now see the "discrepancy".

I disagree that 95 octane fuel would give this result, though if it was exceptionally poor i guess its possible. But unlikely. I have done one or two FI engines in my time on which to base my advice.............
Ok, I guess thats what the logs will help with.

For the benefit of all, knock retard is not related to the actual timing that needs to be pulled to avoid knock. But related to the amplitude of the recorded knock. It ramps out over time.

Id be looking to see if there was sustained knock, or just a one off and at what area in the spark table. Sustained knock is clearly more serious. A one off less so. But -9* knock retard isnt out of the ordinary. OEM tunes Ive seen -7. In fact the guy (Bart) who blew his engine up with LPG (related or otherwise) was pulling 12 degree's on petrol! and knocking like buggery. Cue Tuner B apparently. Difference is that FI runs way less timing than NA under load so -9 is a much larger % and has a larger effect.

Mind you add in IAT adjustment for heat and unknown fuel and Id be tempted to do lots of logging. I only found out I had knock at 7000rpm at TR. Never went there since or before, so had no idea. Might just be a bad set of conditions. Occam's Razor suggests starting there to me. Also of course no point logging until its running the right fuel as the baseline is screwed.

jonnM

1,102 posts

138 months

Monday 20th October 2014
quotequote all
Wyld Stallyn said:
So given that I already got a CAI, Cam, lifters, headers etc and I got 'Many' FWHPs cool

What's the best bang for buck Power Up mod I could do next..? *


  • Budgetary Limitations Prohibit the Use of Forced Induction
Ported LS3 heads, stroker kit, bigger cam, 3" cat-back.....

Would probably cost the same as going FI yikes

Wyld Stallyn

2,056 posts

127 months

Monday 20th October 2014
quotequote all
jonnM said:
Wyld Stallyn said:
So given that I already got a CAI, Cam, lifters, headers etc and I got 'Many' FWHPs cool

What's the best bang for buck Power Up mod I could do next..? *


  • Budgetary Limitations Prohibit the Use of Forced Induction
Ported LS3 heads, stroker kit, bigger cam, 3" cat-back.....

Would probably cost the same as going FI yikes
OTR..?

stigmundfreud

22,454 posts

209 months

Monday 20th October 2014
quotequote all
every DD ends like this biggrin usually 10 pages up to the event, then a page on results, then 800 arguing about the results biggrin

remember that year the rollers were running really low figures (consistent across all the cars) people went mental instead of focussing on the comparable performance compared to the previous run!

jonnM

1,102 posts

138 months

Monday 20th October 2014
quotequote all
Wyld Stallyn said:
jonnM said:
Wyld Stallyn said:
So given that I already got a CAI, Cam, lifters, headers etc and I got 'Many' FWHPs cool

What's the best bang for buck Power Up mod I could do next..? *


  • Budgetary Limitations Prohibit the Use of Forced Induction
Ported LS3 heads, stroker kit, bigger cam, 3" cat-back.....

Would probably cost the same as going FI yikes
OTR..?
Are you still running the standard LS2 inlet manifold?

007 VXR

Original Poster:

64,187 posts

186 months

Monday 20th October 2014
quotequote all
stigmundfreud said:
every DD ends like this biggrin usually 10 pages up to the event, then a page on results, then 800 arguing about the results biggrin

remember that year the rollers were running really low figures (consistent across all the cars) people went mental instead of focussing on the comparable performance compared to the previous run!
hehe

Wyld Stallyn

2,056 posts

127 months

Monday 20th October 2014
quotequote all
jonnM said:
Are you still running the standard LS2 inlet manifold?
Guilty yes

monkfish1

10,874 posts

223 months

Monday 20th October 2014
quotequote all
Wyld Stallyn said:
OTR..?
What you have (intake) is plenty good enough. FAST Intake manifold would be next id suggest. But your gains are only going to get smaller from here.

Id be happy with what you have.

stigmundfreud

22,454 posts

209 months

Monday 20th October 2014
quotequote all
Wyld Stallyn said:
jonnM said:
Are you still running the standard LS2 inlet manifold?
Guilty yes
buy your next mod because it makes you feel good not because of what power increase you will get as you are now into diminishing returns. Your car over stock will feel massively different, if you did heads and intake it wont feel that much different

if you are on standard gearing you should do the diff, it will give you the best seat of the pants other than going FI but we don't wanna go there!

jonnM

1,102 posts

138 months

Monday 20th October 2014
quotequote all
monkfish1 said:
Wyld Stallyn said:
OTR..?
FAST Intake manifold would be next id suggest.
yes


ARAF

20,759 posts

222 months

Monday 20th October 2014
quotequote all
Wyld Stallyn said:
So given that I already got a CAI, Cam, lifters, headers etc and I got 'Many' FWHPs cool

What's the best bang for buck Power Up mod I could do next..? *


  • Budgetary Limitations Prohibit the Use of Forced Induction
NOS will give you the biggest bang for your buck. Not sure it's the best, but could be worth considering. scratchchin

Wyld Stallyn

2,056 posts

127 months

Monday 20th October 2014
quotequote all
stigmundfreud said:
buy your next mod because it makes you feel good not because of what power increase you will get as you are now into diminishing returns. Your car over stock will feel massively different, if you did heads and intake it wont feel that much different

if you are on standard gearing you should do the diff, it will give you the best seat of the pants other than going FI but we don't wanna go there!
Good Point Stiggy thumbup

My Next Mod will be Underseal (Peace of Mind = Feel Good?)

I well understand the Laws of diminishing returns eek

Just curious about what could give a little more power..?

007 VXR

Original Poster:

64,187 posts

186 months

Monday 20th October 2014
quotequote all
stigmundfreud said:
buy your next mod because it makes you feel good not because of what power increase you will get as you are now into diminishing returns. Your car over stock will feel massively different, if you did heads and intake it wont feel that much different

if you are on standard gearing you should do the diff, it will give you the best seat of the pants other than going FI but we don't wanna go there!
agree on returns biggrin

monkfish1

10,874 posts

223 months

Monday 20th October 2014
quotequote all
stigmundfreud said:
buy your next mod because it makes you feel good not because of what power increase you will get as you are now into diminishing returns. Your car over stock will feel massively different, if you did heads and intake it wont feel that much different

if you are on standard gearing you should do the diff, it will give you the best seat of the pants other than going FI but we don't wanna go there!
Good point stig. If you are still on the stock diff, that where id go next rather than power.

S800VXR

5,876 posts

199 months

Monday 20th October 2014
quotequote all
FI FTW!



Just to stir Richard! biggrin