250 shot on hyperutectic pistons????
#21
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Originally Posted by ws6sojuiced01
On my car stock everything other than exhaust and lid and fuel pump hit 530 RWTQ At 4000 rpm on a 150shot are you saying thats my limit do to tq spike?
but then if i proggressive controle it the TQ spike will be slim to none?
but then if i proggressive controle it the TQ spike will be slim to none?
well..the limit of a stock bottom LS1 is not an entirely known quantity. Most rod and ring land failures seem to happen very quick with tq over 750 rwtq. I still dont even know if thats due to actual stress from cylinder pressure or the fact that the hit was so large at low rpm it cuased detonation at that point due to too much timing or not enough octane to prevent detonation.
So your 530 rwtq is not too excessive. I am not sure when you are activating the kit or how long it takes for full TQ to hit after activation but those are all considerations into setting up your dual stage or progressive. Take a look at thei dual stage I did waaay back. Dont even look at the HP lines. All I care about is the TQ line. Notice how the first hit comes on and TQ rises rapidly to a peak of about 625 rwtq at ~4300 rpm...then notice how quickly it tapers off as rpm climbs. HAd I not hit it with t second stage that TQ line would have continued to fall off rapidly. Thats the nature of nitrous since its a constant flow. It probably would have fallen off to around 460 rwtq by 6300 rpm if you guestimate. Not alot of power...especially for subjecting the bottom end to ~625 rwtq down in the lower rpm.
SO now look at the area where obviously the second stage comes on at approx 5000 rpm. Just before that point the TQ was falling drasticaly so we hit it with another small shot... Its about a 100+ rwtq jump at that point. The HP line climbs greatly and platues. The TQ is held longer out in the rpm.
Now look at the tq line of the second stage...note how it also begins to fall off with rpm and note the angle. Now try to imagine that line if you took it the other direction towards the lower rpm...make a mental plot. If I had hit both stages at 3800 rpm you can clearly see how high that TQ would have been in the lower rpms to achive the same overall HP. Probably 750 rwtq. Obviosly and ideal TQ line would be flat all the way across and just move the entire thing up or down. 500 rwtq all the way from 3000 to 6500...awesome. 600 rwtq from 3000 to 6500...excellent. That makes tuneing VERY easy since the are no clylinder pressure spikes. Because its the spikes that limit your tuning. You need to pull enough timing and run enough octane to control detonation at those big TQ peaks. The tune to cover those TQ peaks may not be the best tune for the rest of the power curve...because as you have seen TQ drops off drastically with rpm. If the TQ is flat....it makes detonation much easier to control. Anyways heres the old graph. Take a look and ponder the TQ lines. Please note that TQ is a direct measure of cylinder pressure. Its not the whole story...but its a very valuable indicator of the cylinder pressure.
#22
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BTW...the NX/FJO controllers in rpm mode will allow for a near perfect TQ curve. Especially now that they have the "true curve" mode. This is why I promote them so much. I personally think they should be included with nitrous kits as standard equipment these days.
#25
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Originally Posted by 383LQ4SS
BTW...I will be hitting a stock motor, cam only setup with in excess of 250 soon enough. Maybe more. We will see how long it lasts.
Al is there any progressives that can handle 3-stages? Yes I now it would be easier to just go with one or two stages. But, this is a test bed/car and likely will have two dry stages and a direct port. I have it now where I can run any one kit or a combo of hits. Maybe just a progressive on the DP.
Robert
#29
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Originally Posted by spanktu
383&robert,
the dry setups actually have less torque through the RPM range than a same HP
wet shot correct?
the dry setups actually have less torque through the RPM range than a same HP
wet shot correct?
Robert
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robert,
you could use a first small stage off the throttle switch then just let the controller take care of the other two.
but it probably would not be that beneficial to your setup now because it sounds like
you have all the bugs worked out on the hit
you could use a first small stage off the throttle switch then just let the controller take care of the other two.
but it probably would not be that beneficial to your setup now because it sounds like
you have all the bugs worked out on the hit
#33
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Sure you could. I just used ws that I already had. Some of the new progressives have great features, but likely will take some test/tune to find optimum results. Whereas, my experiance with ws, I know where/what/why/when, so tuning is a breeze. With that said, I am looking to add a progresive to a DP as one stage.
Robert
Robert