Guest [email protected] Posted March 9, 2011 Share Posted March 9, 2011 Hi guys, New to the forum, so go easy on me I'm not actually a Supra owner, but instead have a Lexus IS300 (2JZ-GE). I've just purchased a supercharger kit for the car from over in the USA. The previous owner of the kit dyno'd it at 305rwhp on 91 octane (from the stock 185rwhp). Unfortunately he wont sell me his spark plugs and he's not sure what ones his tuner installed. I've been asking around and a few people have mentioned looking into the Supra TT spark plugs. I'm not sure how many steps cooler they are than the GE plugs and whether they'd be suitable for the 120hp boost. So I thought I'd ask the experts Oh and no thread is worth sh*t without pics, so here's a pic of my baby: http://i2.sqi.sh/s_1/6wF/s_l_is004.jpg http://i2.sqi.sh/s_1/6wF/s_l_is001.jpg Quote Link to comment Share on other sites More sharing options...
steve spedd Posted March 9, 2011 Share Posted March 9, 2011 Nice looking motor mate. Have a look here this might help: http://www.mkivsupra.net/vbb/showthread.php?41927-FAQ-Spark-plugs Quote Link to comment Share on other sites More sharing options...
Guest [email protected] Posted March 9, 2011 Share Posted March 9, 2011 Cheers for the link mate. So it looks like I might be best off going with some stock TT plugs as I'm certainly not going to be pushing 1bar with a supercharger. Next question is, do I need to play it safe and go with copper BCPR6EP-11's or go straight for IK20's? Factoring in that I'm going to be running with the tune set up on the previous owners car for a while. But he was running 91octane and I'll be running 97/99 (so slightly less chance of dett?) Quote Link to comment Share on other sites More sharing options...
Scott Posted March 9, 2011 Share Posted March 9, 2011 Cheers for the link mate. So it looks like I might be best off going with some stock TT plugs as I'm certainly not going to be pushing 1bar with a supercharger. Next question is, do I need to play it safe and go with copper BCPR6EP-11's or go straight for IK20's? Factoring in that I'm going to be running with the tune set up on the previous owners car for a while. But he was running 91octane and I'll be running 97/99 (so slightly less chance of dett?) Unfortunately 91octane in the US is far better than our 97/99 octane. I think it's down to the RON or something like that. Basically they can easily run higher boost on stock fuel than what we can. The octane figure is only part of what helps against DET. Are you changing the headgasket or anything? It may be a good idea to get in touch with barneybrendan on this very forum. He has added a supercharger to his N/A, not sure on the HG specs or anything like that so it will be best to speak to him with regards to what boost he has found is safe to run and what fuel to use. Also, be aware that a US RWHP is generally the equivilant of a UK FWHP dependant on what dyno they were run on. Very small horses in the US Quote Link to comment Share on other sites More sharing options...
Guest [email protected] Posted March 9, 2011 Share Posted March 9, 2011 Interesting about the fuel. So I'll definitely need to run on 99 and maybe with octane booster (if there's any stuff that actually works?) - and probably with copper plugs to be safe too? I'm sticking with stock internals for the mo as I don't rag on the car (family transportation) and its pretty low mileage. Also most of the USA guys who are running turbo's are boosting to about 360-380rwhp with stock internals and obviously the extra stress of boost kicking in rather than linear S/C power. I believe the car was dyno'd on a Dynapack where it reported just over the stock rwhp before the S/C and 305rwhp after. So fingers crossed, it should be fairly accurate (especially given L.A vs UK weather). Quote Link to comment Share on other sites More sharing options...
Scott Posted March 9, 2011 Share Posted March 9, 2011 Interesting about the fuel. So I'll definitely need to run on 99 and maybe with octane booster (if there's any stuff that actually works?) - and probably with copper plugs to be safe too? I'm sticking with stock internals for the mo as I don't rag on the car (family transportation) and its pretty low mileage. Also most of the USA guys who are running turbo's are boosting to about 360-380rwhp with stock internals and obviously the extra stress of boost kicking in rather than linear S/C power. I believe the car was dyno'd on a Dynapack where it reported just over the stock rwhp before the S/C and 305rwhp after. So fingers crossed, it should be fairly accurate (especially given L.A vs UK weather). I wouldn't really bother with octane booster, Vpower will be fine for the most part. I also don't think you will need to go as far as forging the engine, I would definitely consider a thicker headgasket though. The trouble all stems down to the compression ratio, more compression = more chance of det. Thickening the headgasket by a mm or so increases the capacity meaning more air/fuel without any increase in end compression ergo you can turn the boost up a little more. I think the N/A-T engines on here run safely up to around 0.6bar of boost, if they want to run higher boost levels they tend to fit a thicker headgasket and turn the boost up accordingly. You might be right with the RWHP of the car, the stock figure certainly seems accurate. I wouldn't be surprised to see around 400hp from an N/A-T so there is no reason it wouldn't be the case with an N/A-SC. Be careful with the headgasket though. Hopefully some of the N/A-T guys will be along to fill in the gaps. I've only picked up what I know from various threads on here, not actual hands on experience. Quote Link to comment Share on other sites More sharing options...
Guest [email protected] Posted March 9, 2011 Share Posted March 9, 2011 Yeah sounds like I'll probably be right on the borderline then as I think my S/C pulley is 9PSI (iirc 0.6bar?). I'll heed your advice though and consider changing the HG - just a shame I didn't do it earlier as I only just had new cams installed :/ Quote Link to comment Share on other sites More sharing options...
barneybrendan Posted March 9, 2011 Share Posted March 9, 2011 (edited) i havnt changed my head gasket and im running about 7 psi on the na engine.If you are worrid about det thhen just install methonal injection to cool temps down. ref plugs i have equivilant tt ones. Edited March 9, 2011 by barneybrendan (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest [email protected] Posted March 9, 2011 Share Posted March 9, 2011 i havnt changed my head gasket and im running about 7 psi on the na engine.If you are worrid about det thhen just install methonal injection to cool temps down. Cheers mate. What sparks you running? Quote Link to comment Share on other sites More sharing options...
garethr Posted March 9, 2011 Share Posted March 9, 2011 I assume you've already found the MyIs, Club NA-T, and Club Lexus forums? Quote Link to comment Share on other sites More sharing options...
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