388 replies to this topic

[smiley]

I asume you are aware there is an LS4 throttle body (80mm) available for us, versus the lsj oem 68mm.

 

[1cobrav8]

I asume you are aware there is an LS4 throttle body (80mm) available for us, versus the lsj oem 68mm.  

It's already fitted 👍🏼

[Nev]

18 PSI to make 508 BHP ? That sounds pretty amazing, what's your CC, about 2400 CC?

 

[1cobrav8]

89mm bore 94.6mm stroke 2354cc. Yer I wasn't expecting these results, original target was 450bhp

[Exmantaa]

Why the new piston design? Even bigger bore, or???

[Nev]

I would imagine a lower SCR to about 8.5:1 or perhaps 8.25:1 would be helpful, as it would allow a good deal more ignition advance at high RPM (at the expense of poor torque at very low RPM).

 

At the moment, assuming he has 9.0:1 static compression ratio (SCR), then with 18 PSI of boost (and assuming no leak/pumping losses on a perfect Vocky engine) the dynamic compression ratio (DCR) will be a smidge over 14:1 - which is really very high indeed.

 

Calc graph is here if you are interested: https://d90a4646-a-6...&attredirects=0

 

Edited by Nev, 18 August 2016 - 05:46 AM.

[1cobrav8]

I wouldn't want to lower the compression ratio, if anything I want to higher it and use more methanol. The methanol is what allows me to run higher compression and higher ignition figures. Currently running 24deg at wot 1.3bar with no knock. 

 

For example if I run one of my boosted hayabusa motors the conventional way, ie turbo,intercooler and super unleaded fuel I would set the compression ratio to 9-9.5:1. If i then ran the same engine configuration on methanol I would set the compression ratio to 11:1. 

[1cobrav8]

Why the new piston design? Even bigger bore, or???

 

Current thoughts if i can make it work is...

 

-LE5 98mm crank with adapter 6-1 trigger wheel

-Carrillo Rods

-Custom LE5 89mm pistons to suit my Darton sleeves set to 9.2-9.5:1 compression ratio

-Possibly next Stg of cams but not sure on this yet as I like the way my car drives at present, if I do put this new set up together I may drive it first on my original cams and then swap them to see the direct comparisson. 

-A pre supercharger methanol jet is to be added, this will be added soon though on the current setup. 

-Need to also consider additional breathers at this point

 

This would give me 2440cc, almost 100cc more and the added benefit of the more well know Carrillo rods! Should allow for the same power at a lower rpm. I wouldn't rev the new setup past 7300-7400 rpm though due to piston speeds. 

[NickB787]

Personal opinion of someone who started this Harrop business, don't chase the numbers it will never end and you will just end up spending stupid amount of money, just enjoy it As Arno said Bye

[1cobrav8]

Personal opinion of someone who started this Harrop business, don't chase the numbers it will never end and you will just end up spending stupid amount of money, just enjoy it As Arno said Bye

I agree and can see your side of things but its all part of the enjoyment for me. Pushing boundaries and learning limits and is all part of the fun. It also shows others who are running less power what there components can take etc. 

 

I don't want to go to much more but the car still lacks the shove in the back that I want in both 3rd and 4th. The additional torque from the new setup if it happens should certainly give me this. 

[tibby]

Next project: a V8 turbo'd hayabusa twinengine vx220. HELL YEAH!!!

[ChrisS1]

Crazy stuff. Keep it up

[Rosssco]

 

I don't want to go to much more but the car still lacks the shove in the back that I want in both 3rd and 4th. The additional torque from the new setup if it happens should certainly give me this. 

 

 

Maybe look at gearbox options in that case? Perhaps a close-ratio M32 gearbox would give you the required in-gear shove rather than searching for further engine torque output?  

[1cobrav8]

 

 

I don't want to go to much more but the car still lacks the shove in the back that I want in both 3rd and 4th. The additional torque from the new setup if it happens should certainly give me this. 

 

 

Maybe look at gearbox options in that case? Perhaps a close-ratio M32 gearbox would give you the required in-gear shove rather than searching for further engine torque output?  

 

its certainly something to consider, id eventually like a sequential box though which is why I haven't done to much with it yet. Is the M32 the 6 speed box?......isn't that supposed to be quite weak? 

[Rosssco]

M32 is 6 speed yep, variety of ratios available, including some pretty short FD's.

 

Its pretty strong enough for your requirements, but I think there are bearing upgrades available as there are some deficiencies I understand. Others will be able to advise better.

[The Batman]

Probably be worth you fitting a turbo f23 gearbox

[Andrew aka Stuwy]

500 BHP - Not enough shove

[tibby]

F23= stronger than M32 M32 fails http://www.astraowne...ailed-Post-here

[smiley]

500 BHP - Not enough shove

 

Let's indeed see that in some perspective.

 

Lamborghini Aventador LP700-4 700 bhp/690 nm @ 1575 kg = 444 bhp per 1000kg

 

Bugatti Veyron 1001bhp/1250nm @ 1880 kg = 532 bhp per 1000kg VX220 1cobrav8 Edition 509 bhp/498 nm @ 930 kg = 547 bhp per 1000kg

Edited by smiley, 18 August 2016 - 12:30 PM.

[techieboy]

And no question which looks and sounds better.