Noz Posted December 20, 2011 Share Posted December 20, 2011 Am interested in the modifications required to run more boost with stock compression 10.1:1 and Stock head gasket. More a point of chat rather than my next target or my next purchase. What would be required to run higher boost to reduce det, I'm assuming better ECU management would be advised? Maybe water/meth. Would lighter internals put less stress on the engine to do this? I've tried searching forums and doesn't seem to be any higher CR values with 400+. I'd be interested in if a stock GE could hit 500hp on stock HG. Maybe new ARP bolts would help/? Just throwing some ideas on how someone would do this WITHOUT dropping compression (pistons would be the easy way out). Quote Link to comment Share on other sites More sharing options...
caseys Posted December 20, 2011 Share Posted December 20, 2011 Shouldn't this be in the tech section really? Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 Your probably right mate. Quote Link to comment Share on other sites More sharing options...
Scott Posted December 20, 2011 Share Posted December 20, 2011 Club N/A-T should have this covered I would have thought? Basically all you need to know is what fails at those levels and then replace it. If it's the rings, get better rings. If it's the pistons, get better pistons etc etc. The only thing I'm not sure of is if the stock compression is just a touch too much. I have heard of high CR single installs before, I doubt they are quite on a par with stock N/A compression though. There is no reason you can't have a high CR turbo engine, but I'm not sure on what the actual limitations of the CR is. Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 I've had a look on clubna-t and because it's funded by XSpower all advise gives is anything over 9psi use a 1.3mm HG and drop compression to 9.2:1. That claimed it doesn't make any difference to drivability but would be good to try and run a stock NA compression with higher than usual boost reliably. What compression were the singles running? Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2011 Share Posted December 20, 2011 The stock N/A lump is O.K. to 1.1, with a good water/meth system you could go a little more. Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 1.1.... bar? Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2011 Share Posted December 20, 2011 (edited) Yes, my supercharger will be pumping @ 1 bar sometime soon. Edited December 20, 2011 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted December 20, 2011 Share Posted December 20, 2011 I've had a look on clubna-t and because it's funded by XSpower all advise gives is anything over 9psi use a 1.3mm HG and drop compression to 9.2:1. That claimed it doesn't make any difference to drivability but would be good to try and run a stock NA compression with higher than usual boost reliably. What compression were the singles running? I honestly can't remember. There is a project thread titled high CR single build, or something of that ilk. I think it might be Terminator but I could be wrong. HTH Quote Link to comment Share on other sites More sharing options...
johnny g Posted December 20, 2011 Share Posted December 20, 2011 Yea, was Terminator. Lee P is also running high compression. If you want to run a high compression turbo engine, then knock control is key, and high resolution, fine control fuelling. Syvecs. Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2011 Share Posted December 20, 2011 With suitable engine management, it will be the dynamic compression and charge temp that are the limiting factors. There is a link in my garage to a calculator that predicts the dynamic figures, below are the results for my build with stock N/A cams @ inlet +1o exhaust -3o. 4.50” = 11.9 psi (0.82 bar) = dynamic compression 15.8:1 - 664 cfm (18,802 lpm) @ ambient temp - engine 6,800rpm s/c 10,245rpm 4.40" = 12.5 psi (0.86 bar) = dynamic compression 16.2:1 - 679 cfm (19,227 lpm) @ ambient temp - engine 6,800rpm s/c 10,478rpm 4.25" = 13.5 psi (0.93 bar) = dynamic compression 16.8:1 - 703 cfm (19,907 lpm) @ ambient temp - engine 6,800rpm s/c 10,848rpm 4.00” = 15.3 psi (1.05 bar) = dynamic compression 17.9:1 - 747 cfm (21,152 lpm) @ ambient temp - engine 6,800rpm s/c 11,526rpm 3.80” = 16.9 psi (1.16 bar) = dynamic compression 18.8:1 - 786 cfm (22,257 lpm) @ ambient temp - engine 6,800rpm s/c 12,132rpm Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 I assume your going to be running water/meth then at such high compression with 1bar. Are you using standard head bolts? Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2011 Share Posted December 20, 2011 (edited) I have an Aquamist 2C system which will be controlled by the AEM, one jet before supercharger and 3 jets after charge cooler, the water/meth is not essential until over 1 bar ish, my 4.2" pulley should deliver around 0.95 bar but with the cooler charge from the w/m, it will be possible to advance the ignition and gain power. The lump is stock, it's cheaper to swap an engine than tinker with it. Edited December 20, 2011 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
JamieP Posted December 20, 2011 Share Posted December 20, 2011 Some of the high comp single supra's mentioned above are 9:1 CR, KDW and Amir have both made itro of a 1000whp on pump fuel with high comp engines. With a good ecu i can imagine a stock compression GE engine could be pushed fair way, good thing you have on your side is the fact they can be bought for next to nothing if all goes wrong. Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2011 Share Posted December 20, 2011 (edited) That's my philosophy, push a stock N/A lump as far as it's happy, if it does go bang, it's only £100 and a weekends tinkering. The 500 club doesn't come cheaper than that. Edited December 20, 2011 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 20, 2011 Share Posted December 20, 2011 The N/A doesn't have piston oil squirters, (unless it's one of my custom N/A blocks...), so crown temps will be a whole lot higher than a TT. A stock TT has oil gallery pistons, which makes a cast piston live a lot better on a supercharged engine. I would drop the CR with forged pistons, or with a custom head gasket if you want more boost, safely, on pump fuel. If you just want occasional usage race fuel and a different map will release LOADS more power, safely, at higher boost levels. It'll cost a packet on fuel though. Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 That's my philosophy, push a stock N/A lump as far as it's happy, if it does go bang, it's only £100 and a weekends tinkering. The 500 club doesn't come cheaper than that. So your locating a injector before the charger to reduce the heat in the charger as well as take advantage of the det properties from the meth, and 3 after to cool the combustion chamber? Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 The N/A doesn't have piston oil squirters, (unless it's one of my custom N/A blocks...), so crown temps will be a whole lot higher than a TT. A stock TT has oil gallery pistons, which makes a cast piston live a lot better on a supercharged engine. I would drop the CR with forged pistons, or with a custom head gasket if you want more boost, safely, on pump fuel. If you just want occasional usage race fuel and a different map will release LOADS more power, safely, at higher boost levels. It'll cost a packet on fuel though. I think for my appication chris the best way forward would be a 1.3mm gaskett, some bigger injectors and job done. Would be interesting how much extra I could gain with water/meth. I'd love to see an NA with higher CR pistons, there are 11.?:1 knocking around with boost, that would be awesome. Would generate some serious heat on those pistons though. Quote Link to comment Share on other sites More sharing options...
David P Posted December 20, 2011 Share Posted December 20, 2011 Here's a snap of the locations, there is full report in my build thread. Quote Link to comment Share on other sites More sharing options...
Morpheus Posted December 20, 2011 Share Posted December 20, 2011 (edited) Am interested in the modifications required to run more boost with stock compression 10.1:1 and Stock head gasket. More a point of chat rather than my next target or my next purchase. What would be required to run higher boost to reduce det, I'm assuming better ECU management would be advised? Maybe water/meth. Would lighter internals put less stress on the engine to do this? I've tried searching forums and doesn't seem to be any higher CR values with 400+. I'd be interested in if a stock GE could hit 500hp on stock HG. Maybe new ARP bolts would help/? Just throwing some ideas on how someone would do this WITHOUT dropping compression (pistons would be the easy way out). Your question is more a matter of chemistry than engine strength as no engine can be built strong enough to survive bad detonation. Higher octane fuel and some combustion chamber cleaning up would go a long way, as would ceramic coating of same, after the head work. As for a bone stock longblock, (block plus head/s), like you say, meth injection etc. are your only options above the quoted 9psi. I looked into this myself last year but sold the car before NA/T'ing it. Obviously, better intake cooling will help too, like a really big intercooler. Also, you have to consider safety if you're seriously risking engine failure, as it won't necessarily blow up on a dyno. It's as likely on a motorway. Edited December 20, 2011 by Morpheus (see edit history) Quote Link to comment Share on other sites More sharing options...
Noz Posted December 20, 2011 Author Share Posted December 20, 2011 A proper long hard beating isn't what I'd like to build for. I'd like the power there but not constant abuse so I'm hoping with water/meth I can get to where I want to go before I'd need a new gearbox. Don't see many people using water/meth on here, maybe it won't make as much difference as I hope. Quote Link to comment Share on other sites More sharing options...
Ricardod Posted December 20, 2011 Share Posted December 20, 2011 There are a few guys on clubna-t running over 16psi with e85 stock ge block. Keep in mind, the higher the octane the less detonation. Quote Link to comment Share on other sites More sharing options...
Style Posted September 24, 2014 Share Posted September 24, 2014 I'm gonna bump this as it's something I'm curious about. My car is due to get mapped soon after going NA-T and is still at stock 10:1 compression. I've uprated the fuel system and running full standalone AEM EMS. Full specs in my build thread but basically everything is there to support 550hp with full boost, timing and fuel control. With a good map could I see 1bar of boost on an unopened engine you reckon? If not, what would be the thing that limits this? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 24, 2014 Share Posted September 24, 2014 That's a lot of compression for a turbo engine on modern junk fuel. You need knock monitoring and to mask the cooling system to see worst case temp scenarios on the dyno. The ecu needs knock fold back. It needs aggressive temp fold back. Ideally it needs the compression dropping though. Get clever and it'll bite you. Add in the fact the engine is almost certainly tired and you can see why you need to be very very conservative with the boost and mapping. I would say 550 BHP for more than a few moments is asking for trouble on stock N/A pistons. Quote Link to comment Share on other sites More sharing options...
SupraP-Z Posted September 24, 2014 Share Posted September 24, 2014 Interesting thread this, it seems that the stock compression can only take you so far unless you mess with other substances, which would probably get quite costly. To go further - at which point the compression needs to be dropped via the pistons or headgasket. If you are going down the piston route, then you're essentially turning it into a TT especially if you do the CW oil squirter mod. So if compression was dropped via headgasket, what kind of power is safely achievable if all supporting mods are there on a stock block NA? Actually Chris just answered that...under 550bhp. How about vice versa, if TT pistons were put in with new piston rings, but without the CW oil squirter mod? Quote Link to comment Share on other sites More sharing options...
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