They say it cannot be done - 1000bhp Supercharged VXR8

[PH XKR]

lets remember this is a single cam, single phased timing, pushrod with 2 valves per cylinder. OK the O/Ps car is supercharged but the comment about 108% or higher efficiency is some good bloody going on an N/A LS

[PhillipM]

PH XKR said:

How, just how can you have more than 100% volume efficiency unless the VE is miscalculated on an N/A? BTW good luck getting 100% VE

An S2000 has well over 100% VE for about 4-5krpm....bearing in mind we're replying to someone who thinks 70% VE is a good going - maybe for an old VW aircooled motor....or a side valve hedge strimmer.

[PH XKR]

did you read the 2nd post? Its based on an LS block with 2 valves per cylinder, a single phased cam and that's about it. The OP has a charger so can get the over 100% VE but 80 to 90% on an LS isn't shabby

[AER]

80-90% on an L-series V8 really is pretty shabby given that a stock L76/L98 will be around the 100% VE at peak torque. An LS2 in standard trim will be just over 100% at peak torque. Peak power VE's are all down on these numbers though.

The amount of grief and ball-ache put in to getting homologation power figures to be accurate, repeatable and good enough for the marketing department to be happy with makes my eyebrow-raising muscle very sensitive to garage dynamometer numbers - even engine dyno data is hard work to make reliable. Not impossible, but it takes a lot of attention to detail.

[Alias218]

Max_Torque said:

Alias218 said:

Gaining >100% VE on an NA application is categorically impossible

Have you revealed this amazing discovery of yours to any engine developers? ;-)


(hint, and F1 engine peaks at around 125% manifold VE, and decent NA road car (think bmw S54 or honda F20C) hits around 110% VE!)

I stood to be corrected and I have been. I was under the impression from what I remember from Uni that this wasn't possible, however it would seem I was wrong.

Every day's a school day.

[anonymous-user]

Max_Torque said:

Because we have a standard fpor accuracy which is considered to be verifiable. You say "most of the numbers quoted by the automotive industry aren't totally accurate" so by that token, which is likely to be the most accurate:

1) £10M facility, which is inspected and certified by an independent 3rd party, and where every bit of equipment and every process is fully standardised and traceable

or

2) A man in a shed with a dyno. (who incidentally, makes his living by creating "powerful" engines. Now i'm not saying you engine builder is fiddling the numbers, but you can VERIFY that he isn't..........


I've been designing, developing, and calibrating engines for 25 years, and AER for even longer than that (sorry ;-) and our "bulls*it" radar is finely tuned. Physics can't be beaten, and as an actual expert (you know, one who earns their living from the trade in question) the balance of probability is that a 6l s/c engine at 12psi and <7000rpm can't make a genuine 1000bhp.

I don't disagree that it's unlikely he will get 1000hp from his 6.2L engine using a supercharger but if you do some research, it's entirely possible with turbos. Several people in our own community have achieved 1000hp or more using 7.0L versions using either LS7 or LSX blocks combined with twin turbos. GM PP market the LSX b-15 6.2L block as built for 1000hp / 15psi boost.

As to your earlier point about manufacturer claims, I take it you haven't read about VW and their involvement in the emissions scandal? Claiming something that's proven not to be true?

[anonymous-user]

PH XKR said:

He's on his 12th powerful engine so after 80k I'm sure he knows when he's being lied to

Quite so, although including my original LS1, I'm actually on my 4th iteration (2 blown up). Nonetheless, I've tried various combinations of capacity, stroke, cam profile, heads etc. What I've learned is you are best sticking to OE as possible and you can only push so far whilst maintaining drivability and reliability.

Whatever the true HP of my engine (waiting for MAX_TORQUE to provide an Internet certificate), I do know it won't flow any more air with the current blower and a bigger one would start to break things. That's why I would use turbos to go to the next level. However, then it would be pretty much undeliverable.

[AER]

wormus said:

As to your earlier point about manufacturer claims, I take it you haven't read about VW and their involvement in the emissions scandal? Claiming something that's proven not to be true?

Nothing was really proven in the VW emissions scandal per se. It was an admission that tipped things into the current situation. The cars were actually capable of meeting the emissions standard which is different from claiming something that was not physically possible.

[AW111]

Alias218 said:

I stood to be corrected and I have been. I was under the impression from what I remember from Uni that this wasn't possible, however it would seem I was wrong.

Every day's a school day.

Achieving >100% VE is done by tuning the intake (and exhaust) system so that the pressure waves reflecting off the airbox / plenum arrive back at the intake valve to force a bit more mixture in. The inertia of the moving charge in the intake runner also helps.

• This is a gross simplification: others here have a far deeper knowledge than me

[PH XKR]

Modern ls are a lot better but stock tunes are often not at 100% even at peak torque. This can be seen by fairly significant gains by tune alone, all parts kept stock

[DanielSan]

HappyMidget said:

Some nice parts are on order that should move me closer to the goal

Excellent.

I'll be honest, I'm not particularly bothered what number you get on a dyno, I just like seeing people do cool st to cars that are already pretty damp awesome

[chuntington101]

Alias218 said:

AER said:

chuntington101 said:

AER said:

chuntington101 said:

Stick some boost on top of it and why would it not make the number SEM state?

...because 12psi isn't even double the intake pressure and boosting with a supercharger takes a shïtload of crankshaft power. There's only two reasons for starters...

Talking about psi as a judgement for bhp is a bit silly though! You have no idea what heads or comp. ratio that motor is making. It could be making 600bhp NA! Stick 12psi (or 0.8 bar) and that would take you upto around 1050 bhp. Take a 100bhp off (not sure about the maths on this) and you have your 940bhp. It really depends on how stout the engine under the supercharger is.

Not silly at all. Your NA 600hp assumption at 6800rpm would need a VE of around 108%. That's one monster intake system for an NA V8, if indeed it is actually possible. As soon as you take it off and put a supercharger on top, you can kiss goodbye to most of that intake tuning.

Gaining >100% VE on an NA application is categorically impossible. VE is the volume of air you can get into a given swept volume using atmospheric pressure as the reference - at atmospheric pressure (as you would find in an NA application) the volume of air you can squeeze into a given swept volume can at most be equal to that swept volume i.e. 100% VE. Greater than 100% is only possible on FI application because the turbo/supercharger is stuffing more air into the swept volume than the swept volume itself (greater air charge density).

70% VE on an NA application is bloody good going. 108% VE NA is hocus pocus.

Inertial supercharging, IMHO, blurs the line between NA and FI and doesn't represent a true NA engine as the intake charge is still being forced, albeit without a secondary pump to facilitate this.

Edit: not that you need telling this given your provenance!

Edited by Alias218 on Wednesday 25th May 20:04

Edited by Alias218 on Wednesday 25th May 20:17

So am I daft or not for thinking that a 6.3ltr LS engine can hit 600bhp NA at these rpm? This will NOT be stock and will probably be running at least 10:1 comp ratio (SME sells the Pistons for this). The heads will be much better flowing than stock also.

And then what power could this engine make with 13psi boost?

[chuntington101]

Max_Torque said:

chuntington101 said:

Max_Torque said:

Factory s/c LS9s run 11psi, and make a genuine ~620bhp

1000bhp is roughly 60% greater output...........

Through a stock (restrictive) intake and exhaust system and stock heads. Also this could be running more comp. ratio and a better matched cam. Not to mention the stock tune! Bolt on mods and a retune can make significant power gains well they have in the ZR1s anyway.

I'm not saying 930bhp is correct but how much do the experts on here think it would be making?....

er, i think you'll find AER and I are the experts on here, what with having been designing high performance automotive powertrains for the last 25 years each!!

I never said you both weren't experts! I love reading your posts and I am very glad this forum has people like you guys to share the wealth of knowledge that you have! However I did ask you to guesstimate a realistic power output! And like the best experts you skirted around the edges

[anonymous-user]

chuntington101 said:

So am I daft or not for thinking that a 6.3ltr LS engine can hit 600bhp NA at these rpm? This will NOT be stock and will probably be running at least 10:1 comp ratio (SME sells the Pistons for this). The heads will be much better flowing than stock also.

And then what power could this engine make with 13psi boost?

No, you'll need about 7.4L and 11:1 CR for 600hp NA. Stock CR is about 10:1 by the way so you are way off the mark. If you want 600hp. Get a bolt on supercharger.

[Havoc856]

White elephant producing a supercharged 1000+HP on an engine dyno in the corner of the room....

https://www.youtube.com/watch?v=TcI-yzbrJi4

Maybe the OP should listen to those in the thread who seem to have significant knowledge (Max_Torque etc - genuinely interesting to read their posts) regarding this sort of stuff.... instead of responding in a Ronin-esque style.

Wish you all the best though with your endeavour...

[anonymous-user]

Havoc856 said:

White elephant producing a supercharged 1000+HP on an engine dyno in the corner of the room....

https://www.youtube.com/watch?v=TcI-yzbrJi4

Maybe the OP should listen to those in the thread who seem to have significant knowledge (Max_Torque etc - genuinely interesting to read their posts) regarding this sort of stuff.... instead of responding in a Ronin-esque style.

Wish you all the best though with your endeavour...

As useful as it is to be a generic powertrain expert, there are plenty of people with first hand experience who can offer the best advice for this particular generation of engine. We've spent lots of our own collective funds to find out what works and what doesn't.

I don't think a supercharged LSA will ever make 1000hp on a PD blower without breaking. Use a centri or turbos then yes, I'd agree but if 1000hp is your goal, don't start with an LSA.

[AER]

Havoc856 said:

White elephant producing a supercharged 1000+HP on an engine dyno in the corner of the room....

https://www.youtube.com/watch?v=TcI-yzbrJi4

The figures quoted in the video are reasonably possible, especially running E85 Firstly, it's a 7.0L engine and running 15 psi boost, but delivery ratio (VE relative to manifold pressure) is still sub 100% with some reasonable assumptions on BSAC/BSFC.

[HappyMidget]

Sam knows it can be done http://www.streetmachine.com.au/features/1512/feat...

[chuntington101]

wormus said:

chuntington101 said:

So am I daft or not for thinking that a 6.3ltr LS engine can hit 600bhp NA at these rpm? This will NOT be stock and will probably be running at least 10:1 comp ratio (SME sells the Pistons for this). The heads will be much better flowing than stock also.

And then what power could this engine make with 13psi boost?

No, you'll need about 7.4L and 11:1 CR for 600hp NA. Stock CR is about 10:1 by the way so you are way off the mark. If you want 600hp. Get a bolt on supercharger.

Really? That's strange then because GM offer a 525bhp version of the LS3 that looks just to have a hotter can in there!

http://m.chevrolet.com/performance/crate-engines/l...

Not quite sure why you would need 7.4 Ltr to make 600bhp! GM even offer their 454 that will make near 650bhp.

[anonymous-user]

525 hp isn't 600! Look at the LS7, 7L, 500hp in stock tune. To be honest, the best option for power per £ is the LSA which will make 700hp with a simple cam change and a remap.