They say it cannot be done - 1000bhp Supercharged VXR8

[R8VXF]

So this is the build thread for me to get my VXR8 GTS to a daily useable 1000bhp using supercharging rather than twin turboing. Why? Because I want to This is a long term build thread due to current time constraints from commuting and having to fit my life into weekends. I also want to do as much as possible myself, only employing the help of garages/mechanics where I do not have the tools or facilities to complete certain items.

So let me start with the current situation. I have a 2014 Vauxhall VXR8 GTS with a supercharged small block Chevy LSA producing around 580bhp. Utilising a stock bottom end and the stock blower, this is good for around 800bhp. To get to the 4 figure mark, I will be swapping out the stock roots 1.9l blower for a Whipple twin-screw 2.9l blower. Along the way I will be porting, changing cam and associated pieces, headers and exhaust etc. I will systematically work through the air flow path from front to back and will retune as appropriate.

I have a baseline dyno figure from late last year that shows as putting 478.1hp to the ground, and this was taken at Surrey Rolling Road on 19th December. The main purpose of this was to use Charlie's wideband O2 sensor to check that the fuelling was behaving as commanded by the stock tune. As you can see from the attached pictures, the AFR gets rather rich at the top end, but this is behaving exactly as expected and as commanded by the fuelling, so nothing seems to be amiss in the engine department. Good times.



Since that dyno session, I have adjusted the commanded AFR to be flat throughout the entire rev range, which should free up a few horses, along with raising the boost pressure entry point into power enrichment mode, which should save a bit of fuel!

I am now currently awaiting delivery of a Lingenfelter Performance cold air induction kit which should remove any restriction that the stock air box is introducing. http://www.lingenfelter.com/PROD.html?Product_Code...

According to some testing on an equivalent Roto-fab CAI kit on a ZL1 Camaro (same engine), this alone accounted for an extra 30rwhp! (Farcebook link: https://www.facebook.com/media/set/?set=a.10151547...

Partial list of mods to be done:

• Valve springs
• Injectors
• Cam
• Fuel pump booster
• Headers
• Whipple the st out of it

Edited by R8VXF on Wednesday 17th February 20:02

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xeric said:

Who said it can't be done?

Quite a few people are adamant that 800bhp for a valley blower is the useable limit.

RenesisEvo said:

R8VXF said:

Since that dyno session, I have adjusted the commanded AFR to be flat throughout the entire rev range, which should free up a few horses, along with raising the boost pressure entry point into power enrichment mode, which should save a bit of fuel!

This isn't something I know a lot about, so feel free to tell me I'm wrong. I thought the reason why the AFR drops, i.e why the ECU chucks more fuel in than necessary, at higher engine speeds/loads (presumably the trace is at WOT) is to cool the combustion chamber, to prevent pre-ignition (knocking/detonation) causing uncontrolled combustion, which leads to big pressure fluctuations that can break pistons and blocks. So by holding stoichiometric right to the top of the rev range, yes you save fuel but you might also risk knocking - unless you're managing cylinder temperatures in another way, or I've missed something?

The mixture doesn't need to be that rich. 12 is perfectly fine at current levels, when boost increases I will richen it up a bit though.

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PhillipM said:

SonicShadow said:

That's about a 17% drivetrain loss, not that unreasonable really.

I'd say it is at that power level. I'd expect it on something with much lower power that looses a lot from fixed losses.

TR6060 gearbox through a 9.5 inch diff. 15-20% loss is standard through this transmission. 576bhp is the factory rating, 476 is the rated figure at SRR through the wheels. I will take 800 to the wheels as the figure for 1000 at the fly.

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eliot said:

Good luck - but I dont think it will happen with your proposed approach.
Stop wasting money on cold air intakes and spend some more time researching and amassing a decent budget. Things like LSX block should be on your list - or just call peter knight for an ouline budget idea.

Edited by eliot on Tuesday 16th February 21:02

Shame you know nothing.

@S800VXR - Yes, I speak to J quite a bit and know what he has spent. No-one has tried my current approach, so should be fun

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PhillipM said:

I don't loose that much power through an old transaxle with a massive 5.85:1 diff, high angle CV joints and Mud Terrain tyres....

You didn't loose anything.

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Max_Torque said:

Are we talking a "real"(stabilised engine dyno) 1000bhp or a "i got a 1000 brake number on my chassis rolls print out" 1000 bhp? Big difference!

800 to the wheels should be about right Max. As measured at SRR. If you pay to take the engine out and get it tested, jobsagoodun

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PhillipM said:

Be some bloody warm components and tyres if they converting 100bhp into heat....

Yup, that is why the diff has its own oil cooler.

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castex said:

He's right though. My wife and her mother are both in accordance that it cannot be done.

Bugger. I better trust them and give up everything. Including life.

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castex said:

R8VXF said:

Bugger. I better trust them and give up everything. Including life.

I tend to take their collective input with a pinch of salt, chum. Good luck with everything.

I have many kilos of block salt here if you need any at any time

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AER said:

R8VXF said:

Max_Torque said:

Are we talking a "real"(stabilised engine dyno) 1000bhp or a "i got a 1000 brake number on my chassis rolls print out" 1000 bhp? Big difference!

800 to the wheels should be about right Max. As measured at SRR. If you pay to take the engine out and get it tested, jobsagoodun

Why don't you just pluck a four-figure number out of the air now? It'd save you a lot of money and be just as credible.

Alternatively, sit down and do the calcs on VE, compressor power, gross power requirements, BSAC, BMEP, Pmax etc and convince the engineers amongst us that you know how engines work, rather than just throwing money at the problem and magicking a dubious number at the very end of the process.

Okay, will do. Gimme some time to work the numbers. This is just my pie in the sky goal that I hop to beat. I am constantly learning and adjusting. I am just gonna prove some aholes wrong

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PHCorvette said:

whatever you do, do not stroker kit the engine.

Dammit, was just watching an LSA stroked to 7l!

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PHCorvette said:

just wont put it to the road on those 1920s style thin rubbers they run on!

Yup, gonna need 300 at least. Might even go up to 355. Widebody GTS anyone....

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227bhp said:

R8VXF said:

VXR8 GTS to a daily useable 1000bhp using supercharging rather than twin turboing.

A daily useable 1000bhp? And you're going to do all this without taking the engine out?

These kind of jobs are better done first then written about after to save any possibility of egg on face situations.....

I'm sure it will need to come out at some point.

And I won't be embarrassed it doesn't happen, this is just me setting my goals.

[R8VXF]

To be honest, the thread title was clickbait

Please can we keep any more talk about what happened out of here and just concentrate on the build. Yes, there are no "pictures of shiny bits" yet, of course not. I am still spec'ing it all out. Also mentioned previously was this is a long term project that will go through certain stages and will take about 2 years to complete, maybe shorter, maybe longer, depending on my day job (currently 3 hours commuting each day )

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SonicShadow said:

Shakermaker said:

I think if you wanted Clickbait you should have gone more along the lines of "OMG! check out this 1000bhp car build! You won't BELIEVE number 8!!"

Get 1000bhp from your V8 with this one weird trick! Engine tuners hate him!

You do raise a good point. Think I need to work on my clickbait titles a bit more

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chuntington101 said:

Any reason for going with a whipe as opposed to say vortec YSI or Procharger F-1A? Both of these blowers should easily get you to your 1000bhp goal. I'm not sure if many have pushed the Whipple that high on reasonable comp. ratios and with normal fuel.

I like the way PD blowers deliver their power. There are plenty of examples of Whipples running 1000+bhp, shouldn't really be too hard

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LSA is 9.1:1, maybe looking into ported LS9 heads that would drop it to 9:1. This is an engine built to take boost don't forget. Under piston oil jets, lower comp ratio and just generally better than the LS3 that everyone else has played with.

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By everyone else I generally meant the heat pumped 112's etc Ringram has posted a link to a screwed 1000bhp LSA already, it is just working out what firewall clearance is needed for each type of screw and not sure the KB rear entry would fit. The whipple front entry is a different matter, and a more efficient airflow path.

Will check that GTO out :cheers:

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Rods/pistons etc are already factored in to the equation. One of the Whipple packs comes with the injectors and pump booster, but yeah new fuel pump is also on the cards. For this build, I am not going the turbo route. That is the one thing that is certain

I have a rough budget in mind which is acceptable to me. You also reminded me I need to speak to Goldy about the Camaro bonnet vents

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liam1986 said:

thanks Arnie. Ethyl, that's what the guy calls his car. totally un driveable but really cool!

I think you can safely claim your £5 this year