dr_jekyll Posted October 17, 2010 Share Posted October 17, 2010 400 from a 3.0L you are kidding, to get 400 from a staight 6 you would need a 3.6L with huge compression and revs for a start to get anywhere near! im just encourageing . o bet if you told an f1 team they had to use 3ltr straight 6 next season theyd find 700 hp Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 17, 2010 Share Posted October 17, 2010 I believe Chris Wilson's Zeus pushed 300bhp out of a 2l 4pot NA and he says the cams aren't *that* wild Regarding ITBs, maybe you should have a word with Paul Mac, he's been beavering away at ITBs on his car, probably save you a lot of time and money if he can give you some pointers. Are the high comp pistons nice and light? They'll need to be to support higher revs without fretting the conrod caps. Good call on the ignition system, you'll probably have to try and retrofit the coil on plug setup of the non VVTi TT, and junk the dizzy. Cam choice will be interesting to support higher revs - at least 264/264 to make use of up to 7000rpm, but depending on how you'll drive it, you might want 272 or even 280's. At least with no need for a dizzy you might be able to fit TT based cams. Quote Link to comment Share on other sites More sharing options...
Nic Posted October 17, 2010 Share Posted October 17, 2010 Tell you what mods, just delete the thread please, knew i shouldn't have started it If you're determined to do it Neil great, I for one am very interested in the project. It's not going to be cheap though, will you be doing the engine build yourself? Any pics of the throttle bodies you mentioned? Quote Link to comment Share on other sites More sharing options...
Nic Posted October 17, 2010 Share Posted October 17, 2010 Are the high comp pistons nice and light? They'll need to be to support higher revs without fretting the conrod caps. Just been having a read through the Mahle website, their pistons for the 2JZ-GTE seem very light at 319g. Anyone any ideas what a stock 2JZ-GE piston weighs? Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 17, 2010 Share Posted October 17, 2010 Just been having a read through the Mahle website, their pistons for the 2JZ-GTE seem very light at 319g. Anyone any ideas what a stock 2JZ-GE piston weighs? GTE stock pistons are 407g, id imagine ge are similar. Quote Link to comment Share on other sites More sharing options...
AlexM Posted October 17, 2010 Share Posted October 17, 2010 Good luck Neil, if you do go ahead with your plans please give detailed updates. Quote Link to comment Share on other sites More sharing options...
barneybrendan Posted October 17, 2010 Share Posted October 17, 2010 I for one will be watching this thread as its different.Its about time the na engine was played with in different types of builds.Good on you neil.We need pics though. Quote Link to comment Share on other sites More sharing options...
Rob_Mitchell Posted October 17, 2010 Share Posted October 17, 2010 good luck mate, fair play. hope it goes smoothly Quote Link to comment Share on other sites More sharing options...
HadeS Posted October 17, 2010 Share Posted October 17, 2010 N/A FTW Looking forward for some updates. Good luck dude. Quote Link to comment Share on other sites More sharing options...
David P Posted October 17, 2010 Share Posted October 17, 2010 Neil, Mine will be going on the rollers soon, that will give you a measure of what can be achieved without cam change and ITB's. Quote Link to comment Share on other sites More sharing options...
johnny g Posted October 17, 2010 Share Posted October 17, 2010 im just encourageing . o bet if you told an f1 team they had to use 3ltr straight 6 next season theyd find 700 hp They get 750 from 2.4... Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted October 17, 2010 Share Posted October 17, 2010 They get 750 from 2.4... precisley i was being conservative as they have v8s at the moment Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted October 18, 2010 Author Share Posted October 18, 2010 Throttle bodie pics. I have a couple of ideas to make them fit using an OE intake and a bit of cutting/ welding. Then next to the NA head, they are a wee bit wider but im sure i can bodge them on I am still on the lookout for more throttle bodies so i can have the pick of the lot but these seem fairly decent. Quote Link to comment Share on other sites More sharing options...
Schtuv Posted October 19, 2010 Share Posted October 19, 2010 Stupid question - how do ITBs increase the power and torque, compared to the default configuration? Is it just down to efficiency and being able to tune each cylinder. Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted October 19, 2010 Author Share Posted October 19, 2010 To get the best of them they need alot of supporting mods, lairy cams, high comp pistons and loads of revs, power will be high up so i'm looking to an 8.5-9k rev limit, they also help the car idle with the cams i will use. ITBs on their own wouldn't do much if anything to a standard car. I'm still learning about them and just jumped in and bought them but i am sure they will fit and work perfectly, if not i have my eyes on a set that are made for the 2JZ that i will have to get. Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 19, 2010 Share Posted October 19, 2010 Firstly, good for you for trying something completely different and going into it with your eyes open 100bhp per litre was the "holy grail" in NA road engine design for many a year. Its not that uncommon nowadays in performance engines, but its still a big ask if you are not starting from a clean sheet of paper. May I ask if you are planning any time on an engine dyno to develop this? Do you intend to use mainly off-the-shelf parts, or will you be fabricating your own exhaust manifold and intake system? I think Ian is probably right - you are going to have to up the rev limit considerably which will probably mean specialist cranktrain and valvetrain to keep mass down. As you mentioned in your first post I would think long and hard about increasing the capacity as mass and piston speed is going to be your enemy. The knife edged crank is a neat idea. Engines lose more power to crankcase windage that people realise. A word of warning though - removing material from the crank balance webs might upset the first-order balance and put a load more bending stress into what will become a very highly loaded crankshaft. Assuming you don't go for a stroker kit, do you plan to keep the stock crank? Is this going to be a "headline figure" 300bhp engine at all costs, or do you plan to make it usable as a road car? Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted October 19, 2010 Author Share Posted October 19, 2010 Doubt it will ever go on an engine Dyno TBH. Exhaust manifold will be one of Whifbitz new ones, intake is the tricky bit and yes i will be making it but will have to call on a friend to weld as i cant. The 300bhp is just a head line figure, not 100% sure i can get there in all honesty, it will be my road car, i will never track it but will do 1/4 mile events in it, i'm not too botherd about driveability, aslong as it idles and pulls high up the rev range then that will do me. I was going to use stock crank, but i keep looking at 3.4's but the price is just stupid high, i suppose i could just go with a 3.0 to start with and see how that goes then maybe in years to come try a 3.4. For now all i am concentrating on is the ITBs, working out runner lengths, design etc. I' not going to rush things and i'm looking to do it over a couple of years, once i get the ITBs mated to the head then its game on. Quote Link to comment Share on other sites More sharing options...
sdistc Posted October 19, 2010 Share Posted October 19, 2010 I'm not going to rehash all the usual negatives that have been said 100 times before - just wanted to say that I will be watching your developments with interest. Quote Link to comment Share on other sites More sharing options...
Rob_Mitchell Posted October 19, 2010 Share Posted October 19, 2010 i may have missed abit but is it not easyier to use the na lower runners and custom make that to fit the ITB's as the runners mate together with the head already. things like this make the club what it is, i love it when people go further with things. best of luck Quote Link to comment Share on other sites More sharing options...
David P Posted October 19, 2010 Share Posted October 19, 2010 (edited) I chose not to use ITB's, they look great and sound fantastic but to gain circa 10bhp top, would lose around 10ftlb bottom. Likewise with cams, to gain circa 20bhp top would lose around 20ftlb bottom. Good for the track, but for road use, it takes power from where you need it, and puts it where you don't often use it. Interested to see how it performs compared with my N/A build. Edited October 19, 2010 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted October 19, 2010 Author Share Posted October 19, 2010 i may have missed abit but is it not easyier to use the na lower runners and custom make that to fit the ITB's as the runners mate together with the head already. things like this make the club what it is, i love it when people go further with things. best of luck That is plan A, the easiest way i can see to do it, but not the prettiest lol. I chose not to use ITB's, they look great and sound fantastic but to gain circa 10bhp top, would lose around 10ftlb bottom. Likewise with cams, to gain circa 20bhp top would lose around 20ftlb bottom. Good for the track, but for road use, it takes power from where you need it, and puts it where you don't often use it. Interested to see how it performs compared with my N/A build. Yeah we are going for different approaches with our cars, i dont mind the torque loss for the gain in BHP, TBH i will be happy if i can get it running right and hoping the sound makes up for any losses i gain from fitting them. How long till yours is ready for the dyno matey? Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 19, 2010 Share Posted October 19, 2010 I have to admit I partially agree with David2009. Its perfectly possible to get the power you want without ITBs - they are not an integral part of the solution. I believe you have read my long monlogue on ITBs in the another thread. You can make an engine with a huge plenum and big lumpy cams with a single throttle body (provided it is not too restrictive) but its the ITBs that will give it the throttle response and idle stability that is a must-have for a road car. If you are 100% focussed on top end power then losing torque at the mid-bottom end doesn't sound like it will be a concern. You will probably have to keep stirring the box to avoid falling into a big torque dip though. I have done some rough hand calcs and I think you still have a choice to make over whether you tackle this by increasing the rev limit or upping capacity. If you stroke to 3.4litres with a not-very-ambitious 11.5 bar BMEP, then 300hp rolls in at just under 6900RPM - possibly within the range of the stock valvetrain (albeit with a drop-in camshaft). Plus you will get a billet crank which will hopefully be stronger then the stocker, and you get a fatter torque curve in with the bargain and will have to do less optimisation of the intake and echaust systems. However if you opt to keep the stock capacity, you will need to increase the rev limit to at least 7800RPM and ensure the engine can still breathe. This will mean new lighter pistons and rods and a new valvetrain, plus some intake and exhaust work to shift the tuning point to your new max power speed. I doubt that an off the shelf part will have the precise tune you need. If you want to keep within the stock engine speed you will need to increase BMEP to nearly 14bar to hit peak power at 6500RPM and that is, unfotunately beyond the realms of what is feasible for the home tuner. If I get a second I'll work out the NA Supra's BMEP curve to see what it manages in stock trim. Quote Link to comment Share on other sites More sharing options...
tooley Posted October 19, 2010 Share Posted October 19, 2010 will fuel wash be an issue with those throttle bodies......or will that nice speed six engine in the tvr for sale thread slot right in im just thinking outside of the norm here think how nice it would sound coming from the back of a supra Quote Link to comment Share on other sites More sharing options...
johnny g Posted October 19, 2010 Share Posted October 19, 2010 Or you could look for a 2GRSE engine from the Lexus. 315bhp in N/A form, with cats and a Lexus OEM tune. Gorgeous VVTi engine. Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 19, 2010 Share Posted October 19, 2010 Well I had a quick look and it turns out that the stock 2JZGE turns over a respectable 12.1bar BMEP at peak torque (4750RPM ish). The other good news is that we did a project here once that took a bog standard 2 litre four pot engine with a peak BMEP of 11.7bar at 4000 and turned it into something that achieved 13.5 at 8000 (121hp/litre - well in excess of what you want). I have put out some feelers to try to find out the level of work that this engine had done to give you an idea of what might be required. Quote Link to comment Share on other sites More sharing options...
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