Axle Posted November 10, 2008 Share Posted November 10, 2008 Appologies if this has been posted before (I couldnt find the answers through the search function), but i was curious to hear from those in the knowledge what kind of power figures a Stock Supra TT engine could take before it was pushing it to its complete limits. I have seen differing opinions ranging from 500 BHP to 800 BHP? Also at the limit of the engine, what is its weak point so to speak? Which would be the advised mods to pursue to extend the reliabilty of ones engine beyond the limitations of the stock in the upper BHP band? Quote Link to comment Share on other sites More sharing options...
paul mac Posted November 10, 2008 Share Posted November 10, 2008 i have read many times and i dont know whether its just urban myth or not that the Supra engine was designed as a 500hp motor and once you get inside one its quite easy to see why people think this, the crank and bearings are a good size, the con rods are beefy and there are no cutting edge aspects in the engine (ally block for example) just tried and tested tough as old boots engineering and i think this is the reason the 2JZ GTE holds together so well. I think if you maintain the engine properly the stock bottom end will hold up to 500 - 600hp very well, going past this will accelerate the engines demise (or need for a rebuild) a lot quicker, weak points of the 2JZ are just the same as any other engine, adequate maintenance (or lack of it) i would say probably kills more engines than anything else and age is another thing we cant get away from, how long will a 16 year old engine hold together running double the power it left the factory with however well its maintained, if your worrying about reliability its probably time for a re-build Quote Link to comment Share on other sites More sharing options...
Luxluc Posted November 10, 2008 Share Posted November 10, 2008 i have read many times and i dont know whether its just urban myth or not that the Supra engine was designed as a 500hp motor and once you get inside one its quite easy to see why people think this, the crank and bearings are a good size, the con rods are beefy and there are no cutting edge aspects in the engine (ally block for example) just tried and tested tough as old boots engineering and i think this is the reason the 2JZ GTE holds together so well. I think if you maintain the engine properly the stock bottom end will hold up to 500 - 600hp very well, going past this will accelerate the engines demise (or need for a rebuild) a lot quicker, weak points of the 2JZ are just the same as any other engine, adequate maintenance (or lack of it) i would say probably kills more engines than anything else and age is another thing we cant get away from, how long will a 16 year old engine hold together running double the power it left the factory with however well its maintained, if your worrying about reliability its probably time for a re-build Good comment Quote Link to comment Share on other sites More sharing options...
Axle Posted November 10, 2008 Author Share Posted November 10, 2008 if your worrying about reliability its probably time for a re-build My current engine doesn need it tbh. Im just planning ahead for a possible single route i may take. How much are rebuilds generally? - And does the engine ever run as smoothly after they are done? Quote Link to comment Share on other sites More sharing options...
toyotasupra1980 Posted November 10, 2008 Share Posted November 10, 2008 500 - 800bhp would be awsome to have and play around with and i do believe the supra is designed for the high power level's, but to be honest for me i am happy with just 400bhp which is allot of power for the roads in the uk and still keeps the reliability of the engine. Quote Link to comment Share on other sites More sharing options...
bolarbag Posted November 10, 2008 Share Posted November 10, 2008 My current engine doesn need it tbh. Im just planning ahead for a possible single route i may take. How much are rebuilds generally? - And does the engine ever run as smoothly after they are done? 7000 for engine and head alone, using all high end parts - staying at almost stock CR and assuming your engine is in good condition already i.e no block scoring, no heavy out of tolerance bores, its not worth imho, not unless your loaded - but then why drive a sup in the first place? Really 550bhp is enough for out roads, if you do decide to invest the 10k going single, just keep buying up 2nd hand engines - I calculate you would be able to afford at least 7to make it worth your while;) Quote Link to comment Share on other sites More sharing options...
Axle Posted November 16, 2008 Author Share Posted November 16, 2008 Just a thought - would adding water injection not significantly increase the longevity of the stock engine? Quote Link to comment Share on other sites More sharing options...
bignum Posted November 16, 2008 Share Posted November 16, 2008 Yes, helps keep charge temps down and limit knock. Quote Link to comment Share on other sites More sharing options...
Axle Posted November 16, 2008 Author Share Posted November 16, 2008 (edited) Cheers Bignum. So unless you suffer with engine knock, is water injection pointless? Or just more of a safety net? Edited November 16, 2008 by Axle (see edit history) Quote Link to comment Share on other sites More sharing options...
bignum Posted November 16, 2008 Share Posted November 16, 2008 Imo w/i is the best thing to add on any turbo motor, i only use it as a safety feature, some guys map for it. Quote Link to comment Share on other sites More sharing options...
paul mac Posted November 16, 2008 Share Posted November 16, 2008 Imo w/i is the best thing to add on any turbo motor, i only use it as a safety feature, some guys map for it. I really struggle with this "safety" concept of water/methanol injection, if an engine is set up correctly on a dyno it is "safe" by definition and will not blow itself to pieces due to too much advance or running dangerously lean to extract the most possible HP, so what is the water/meth injection actually doing other than impressing your mates down the pub. I understand the dangers of a water/meth system malfunction but there is more than enough off the shelf kit to mitigate this risk. The first large scale use of this system was on the WW2 Focke-Wulf 190D and the German engineers were certainly not playing safe and cranked the power up on this bad boy by about 450 hp, i know this doesn't relate to much to a Supra but it demonstrates the potential on an internal combustion engine. IMO to fit it as a "safety" feature implys poor mapping or no confidence in the mapper. Quote Link to comment Share on other sites More sharing options...
Branners Posted November 16, 2008 Share Posted November 16, 2008 you cant really mitigate for the loss of a water injection pump though, when it goes it just goes and det eats an engine before you actually realise its happened. I think the Aquamist pumps of old scared the willies out of people. They failed far too often as they needed to be completely away from road spray, and most engine bays couldnt do that. So the pumps got wet and failed. You can have a warning light on the water injection so you know when the pump is running, but in the melee or a high speed run would you be watching that LED close enough? I think thats why people dont map for WI, they hold it as a safety measure so if the pump does go pop and they dont notice then its not the end of the engine. Its not like a good fmic or uprated fuel system, those tend to either work or not work. Water injection can stop working but you wont even know until its too late. Quote Link to comment Share on other sites More sharing options...
JamieP Posted November 16, 2008 Share Posted November 16, 2008 They seem to hold 600bhp well, few cars in the club at that level on stock engines now, hopefully mine will be up there in a couple of weeks, if you want to feel what 550bhp on a T67 feels like you are welcome to come round for a ride in mine. Quote Link to comment Share on other sites More sharing options...
dude Posted November 16, 2008 Share Posted November 16, 2008 Only ever had problems when i got det, then the iridium plugs fell apart and bye bye valves etc, even at 2.5 bar of boost and over 8000 rpm it stayed pretty reliable, motor was relatively stock but with ARP bolts and i did make sure all the rods and pistons were the same weight:) Quote Link to comment Share on other sites More sharing options...
paul mac Posted November 16, 2008 Share Posted November 16, 2008 you cant really mitigate for the loss of a water injection pump though have to disagree with this Branners have a look here http://www.coolingmist.com/pagedisplay.aspx?feature_key=safety and this is just one manufacturer, all these safety features can be linked to any aftermarket ecu (be it standalone or piggyback) so the instant a problem is detected the ecu switchs to a safe map, i dont want to spiral this thread away from the original question so wont mention this topic again Quote Link to comment Share on other sites More sharing options...
Terminator Posted November 16, 2008 Share Posted November 16, 2008 If you want low down stock type idle with a single I would not go over 264 cams. Quote Link to comment Share on other sites More sharing options...
Axle Posted November 17, 2008 Author Share Posted November 17, 2008 Interesting debate on the Water injection side of things. I dont think it matters if the thread was to take the direction of better understanding of the effects of Water injection, as its all within trying to obtain the most from the Stock Supra engine, so is related as such. Can someone please calrify what issues would arise from keeping stock cams (UK) and gunning for a near 560-600 BHP? As the general concensus appears to be to ditch stock cams? JP- Thanks for the offer. May have to take you up on it sometime. Although your car wont feel as fast with me it in.. Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 17, 2008 Share Posted November 17, 2008 I believe Homer achieved around that on stock cams. It chokes up in the higher rev ranges somewhat but I don't think you'll be too disappointed -Ian Quote Link to comment Share on other sites More sharing options...
Axle Posted November 17, 2008 Author Share Posted November 17, 2008 Thanks Ian. Quote Link to comment Share on other sites More sharing options...
Terminator Posted November 17, 2008 Share Posted November 17, 2008 I was chatting to a drag racer last week, who uses water injection for race cars. He is dead against WI on road cars. The main reason being the disciple required to keep the system in tip top working condition. He sees pumps as consumables and uses two pumps a season each one only doing about 40 runs on the strip. Quote Link to comment Share on other sites More sharing options...
JamieP Posted November 17, 2008 Share Posted November 17, 2008 Mine and Homers both achieved around 550bhp on stock cams, good for spool but 550 is about there limit on a mid size turbo i think. TBH its bloody fast at that power, im thinking i really dont need any more power but i have the extra parts now so im gonna go for it. Quote Link to comment Share on other sites More sharing options...
b_have Posted November 17, 2008 Share Posted November 17, 2008 I've run water injection for years (and map with it on) Ryan could not get near any knock on the dyno and always see super cool AIT's. Running the Power FC with knock alarm (all warning lights flash at any hint of det). Been running over 600bhp for over a year now (7 track days this year), stock bottom end. Quote Link to comment Share on other sites More sharing options...
bignum Posted November 17, 2008 Share Posted November 17, 2008 All bpu supra`s should have w/i fitted, especially j-specs and it sounds good down the pub, Quote Link to comment Share on other sites More sharing options...
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