RobSheffield Posted October 16, 2006 Share Posted October 16, 2006 We all see 3.4l stroker kits, and see the cars in action in the states on the strip, but will this modification do any good on the road (clearly with cams and a large turbo) Aid spool for example? lots of torque low down? Quote Link to comment Share on other sites More sharing options...
Robert Posted October 16, 2006 Share Posted October 16, 2006 What would a 3.4L engine be like with the stock turbos? stupid idea maybe but always wondered. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 16, 2006 Share Posted October 16, 2006 400 cc more has to be better, but at a huge price:) Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted October 16, 2006 Author Share Posted October 16, 2006 400 cc more has to be better, but at a huge price:) But does it Jamie? Or does it over/under square the bores perhaps? This is what i wanted to find out Quote Link to comment Share on other sites More sharing options...
Alex Posted October 16, 2006 Share Posted October 16, 2006 Yep...a 3.4 on the road will add drivability through torque. More air spools the turbo's up faster and obviously more air can be squeezed into a cylinder per cycle so more fuel can be burnt and more power produced. Having a 3.4 would be great for everyone...but few can justify the expense. Quote Link to comment Share on other sites More sharing options...
Alex Posted October 16, 2006 Share Posted October 16, 2006 The HKS (for example) kit uses lighter parts from stock so the rev limit isn't troubled by the extra length in the stroke. Infact the drag cars in the states run 9,500rpm with these strokers. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 16, 2006 Share Posted October 16, 2006 But does it Jamie? Or does it over/under square the bores perhaps? This is what i wanted to find out Its a longer stroke crank;) Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted October 16, 2006 Author Share Posted October 16, 2006 Its a longer stroke crank;) ~I know Jamie, the point being does that alter things? i knwo its lighter too, but is it less willing to rev because of the longer stroke? Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 16, 2006 Share Posted October 16, 2006 Under / over square is just a way of saying whether the stroke is longer than the bore is wide, or vice-versa. I can never remember which is which. I dont think the Supra is "square" to start with, is it? Quote Link to comment Share on other sites More sharing options...
Alex Posted October 16, 2006 Share Posted October 16, 2006 Weight = lower = more rev happy Quote Link to comment Share on other sites More sharing options...
Alex Posted October 16, 2006 Share Posted October 16, 2006 Under / over square is just a way of saying whether the stroke is longer than the bore is wide, or vice-versa. I can never remember which is which. I dont think the Supra is "square" to start with, is it? 86*86mm 3.4 = 87*94 Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 16, 2006 Share Posted October 16, 2006 Ah, right. So it is a square engine then. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 16, 2006 Share Posted October 16, 2006 On a side note talking of revs.... when greg checked his datalog he had been reving a stock engine to 11k on the strip. (came from thor with no rev limit installed) Quote Link to comment Share on other sites More sharing options...
Alex Posted October 16, 2006 Share Posted October 16, 2006 Really....well that's a first for the Supra world. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 16, 2006 Share Posted October 16, 2006 On a side note talking of revs.... when greg checked his datalog he had been reving a stock engine to 11k on the strip. (came from thor with no rev limit installed) whats been done to the head? Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted October 16, 2006 Author Share Posted October 16, 2006 so it starts off as a suare, and becomes over/under square (whichever!) is that a good thing Alex i know lower weight is good for revs, but does the longer stroke negate the effect? Its a question, i dont have any agendas, just wondering what real world road benefits are out there. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 16, 2006 Share Posted October 16, 2006 spool and torque Rob. A stroker will spool a turbo earlier and add more lowdown torque. It shouldnt be able to rev as highly as a square or short stroke engine like the 2.5TT soarer lump, but if money were no object I would take a stroker. The downsides are cost, and if you spin a bearing the lot could become junk, where with stock crank you can generally find a decent 2nd that is servicable. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 16, 2006 Share Posted October 16, 2006 whats been done to the head? Nothing i think... that was the old engine, the one he has now has 272's i think but not sure.. Quote Link to comment Share on other sites More sharing options...
Digsy Posted October 16, 2006 Share Posted October 16, 2006 so it starts off as a suare, and becomes over/under square (whichever!) is that a good thing Alex i know lower weight is good for revs, but does the longer stroke negate the effect? Its a question, i dont have any agendas, just wondering what real world road benefits are out there. Its probably more the case that the parts are lighter because the stroke is longer (and hence the rod is shorter). Yes, increasing the r/l ratio will increase piston acceleration at TDC and BDC, and hence inertia loading. If you can retro fit lighter pistons and rods then this will help bring the inertia loads back down. If someone gives me the Supra rod length and an estimate of rod and piston mass I can work it out. Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted October 16, 2006 Author Share Posted October 16, 2006 Fair enough, sounds like a lot of money for some risks and spool and torque Now i have heard the expert view at least i know....just had been bugging me why we dont see so many, despite the fact a few pro tuner cars over here do use forged pistons/rods seems odd that if the engine was in bits they wouldnt have stroked it Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted October 16, 2006 Share Posted October 16, 2006 Nothing i think... that was the old engine, the one he has now has 272's i think but not sure.. I really can't see the stock Valve springs taking 11k mate!! Quote Link to comment Share on other sites More sharing options...
gregsupra4 Posted October 16, 2006 Share Posted October 16, 2006 11k was the high point on the data log after the 2nd run at June's Jap show, this was down to the clutch slipping and me not watching the rev counter or shift light which I had set to 8000. The log also showed that almost eveything went haywire at 9240rpm and the AFRs went off the scale. As Dan was not part of the team at that time I had another tuner in the pits look at the rev setup and found that it was set to Fuel cut at 15000rpm and ignition cut at 15500rpm, it was then re-set to fuel cut at 8500 and ignition cut at 8500. We ran the rest of the Jap show without any problems apart from the clutch. The problem we thought was the engine at USC was in fact 7 of the 8 bolts holding the flywheel to the crank had sheared,we think this was done the day before when the half shaft snapped. By this time we had already pulled the old engine out and on inspection found that the internals were unaffected and were in fact in very good condition, so much so that if we had not already dropped in the new engine we would have continued to finish the season with that engine. As I had stated before the new engine was just a throwaway for the Jap show final and we wanted to see just what we could get out of a stock lump with some mods, we had already had 853rwhp at 700ft lbs out of the old engine and this was again stock apart from 2x1.6mm head gaskets and HKS 272 cams on both inlet and exhaust, we had very little time to get the car ready and done a couple of runs on our estate taking the revs to 9000rpm and all seemed well on the logs. However on the saturday at the Jap show final whilst setting up the launch control someting went tits up with the electrics and so we did not manage to do a run. After spending most of saturday evening and a good deal of Sunday morning the problem was tracked down to a broken AEM so with only 45mins to put the car back together throw in a new AEM drop in an untested map, get the car on the trailer and to the pod for midday was a bit of a rush. We made it just before midday and had no time to test anything before going out for our only qualifying run. The run was a disaster I went from 1st to 4th and by the time I went back to 2nd and up through the gears again I done the worst run of the season. So a lot of work and even more hassle and to top it all the new RPS carbon carbon clutch flywheel again parted company from the crank so for us a really bad sad end to this season, however we are going to give the car one last outing on the 29th of this month to try and see once again if we can push the stock internals past the limit. Quote Link to comment Share on other sites More sharing options...
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