I've always had excellent success with street tuning. Maybe some of us are better at sensing changes to our machines than others? o No: Not everyone's the same. I'd like to think I'm smarter than the average bear. Anyway, not to dwell on the butt dyno thing, I also mentioned that putting it on a real dyno would be the best way to tell what's going on. I also said that it's all parts of a puzzle, did anyone not overlook that part? Each thing done to test shows a larger picture: track, butt dyno, street tuning, real dyno, etc. Yes I know torque trails off as hp goes up, but you know there's other gears in your transmission right? Once you shift, where does the RPM go back down to? That's right. the torque band. Then it has to rev up again, then shift again, and boom, torque again. So where are you sitting the majority of your time when the engine is winding out in 2nd and then shifts into 3rd and goes a while in 3rd? It's certainly not your peak hp. Think about it fellas, c'mon. (THIS is also why the ST300 2 speed trans has another advantage over the 3 speed TH tranny's (in addition to the less parasitic loss). There's more to this than meets the eye guys. Think.) You're seeing peak hp a lot less often than you are your wide Buick 350 torque band. So what then do you suppose would cause a car to slow down during the latter half of the quarter? hmm? Ever notice how big blocks walk away from small blocks (as a rule) when hp ratings are the same? why is this i wonder.... What the real world dyno will show that the track will not (as is apparent by these responses) is where your power is sitting at any given RPM, and how it compares to the other setup. The track is a guessing game just as much as street tuning (in terms of where your power is, and both take more time vs a dyno to tune your car), with the main difference being a timer. I used to set up 1/4 mile sections of back road late at night decades ago when there wasn't as much traffic (more difficult to do today, I know), and have someone time me. Yes it's not the same, but it makes for a good 'make shift' track simulation. It helps. Then there's the testing at varying RPMs and in different gears, not just driving it normally. Everything is taken into consideration when street tuning, and I could get a hell of a lot more done that way than taking it to some track for a few runs a day. To get the full picture, you need to do all these things, otherwise you get only a partial picture, or most of the picture, which is often good enough for most people. The main point of the post wasn't the butt dyno, although that's what everyone seems to be focusing on. The main point was the loss of speed from 1/8 mile to 1/4 mile, and that it's not your peak HP that is affecting this! Larger runners from port work, sharp edges, huge secondaries = murder on your velocity and what does velocity make? Do I really have to spell it out... Sigh. I need to get away from this forum for a while. Ah well. It's all part of the process of learning, eh? Gary
A lot of dyno curves show a pretty good dip from 3000-4000 for various reasons, including the dyno process itself sometimes. It can be hard to tune out, single planes more so.
My rockers are quiet (TA roller) I know they will make a clacking sound if theres clearance, no clacking tho. The lifter chatter has been there for years, 2 different cams, 310 was the noisiest, 413 is quieter, I think I tried every brand of lifter back in the 90's, I took all the brands apart just to see WTH. Currently have the GM/Delphi lifter In all the times I've had this engine apart and reassembled, never found any evidence of an issue, oil flow is proper/good Wear patter is good on foot of lifter and lobe of cam, pushrods spin while running. Everything is behavingou:
Gary , have you ever built a car and ran it more than 3 times? Because now if I read it correctly you think a 300 2spd would be a better fit than a th350?. If so you put a 2spd in front of a 325hp street geared 3700lb car and let me know how that works out for you ha,...I find it comical that now mph loss has nothing to do with HP. Don't tell me your one of the guys that think if you hook you'll run more mph are you? Im not trying to pick a fight but it just seems you got lots of theories and not much experience, if im wrong tell us what cars you've built and ran
I can tell you this, where I live, there is nowhere you can street tune a car. Traffic is constant. Hooking a car at WOT, and then holding it wide open through all three gears is a whole other world from anything I can do on the street here.
I don't think you can expect a silent valve train with an aftermarket performance cam. A little noise is no big deal. A bit loose is better than too tight. I'd still like to see your fuel pressure and AFR at WOT from the 1/8 to 1/4.
Its probably easier to do when your working with a 300hp car, yea try running a true 500+hp car on an unprepped road sticky tires or not and all you'll be doing is drawing designs on the pavement
My Crower cams make no noise, but then there not rehashed Chevy lobes. Mark, how much lifter preload do you have?
What's the duration @ 050 numbers of this cam? If its 230 ish or bigger, it will need a minimum of a 4000 stall to ever get the car to work. That is, the converter will need to flash to at least 4000 rpm at the hit if the throttle, then have a fall back of no more than 1200 rpm. I can tell you if you shift @6000 rpm, then youd need a 4800 to 5000 stall minimum. Oh AND GEARS And no disrespect but the 275 drag radial will always be quicker than the bias tire. Run them on car in my sig. 1.25 60 ft all motor That's reality folks And yes I race
Yeah you got me all figured out. Why don't you address the points I made instead of trying to detract from the points by making petty accusations? While you're at it, you can apply some reading comprehension to it and maybe figure out what I actually said. You can start with basic counting. How many times does the car see peak HP? How long does the car stay within its torque curve? We'll take baby steps at first if need be. And remember folks who started it. I'll be back later to address this issue should it inflate into something larger. Gary
Of course you do Steve. HP = Torque X RPM/ 5252. BTW, I called my friend to ask him about the MPH gain from 1/8 to 1/4. He told me that a car that is perfectly dialed in for the track would pick up 20 MPH. If you pick up less than that, your top end power is lacking (for whatever reason). If you pick up more than that, your bottom end is lacking and you need improvement in the 1st 1/8 mile. That would seemingly apply to me since I pick up close to 23 MPH. I asked him about the 18 MPH you pick up, and he said that is close enough to be considered normal especially for a heavy street car. I don't claim to be an expert in any of this. I only hit the track once, MAYBE twice a year. I thought it was interesting though.
Larry, I'm kind of thinking along those lines also. Because I do have ridiculous torque the HP is pale in comparison. Thats why no 20+MPH gain. That said I have JW making a new converter to see if it can be improved. Wow did this post get derailed. Heres something else to think about. I know it's not a 350 Buick with a SP3 but my 408 BB Chevy with a torker SP loves huge carbs. I went from a modified 750DP to a BG modified 850 DP that flows 1015 now and it loves it. Has 50cc pumps front and rear and would still like more fuel off the line.
Your argument is irrelevant to the thread, seeing how no one is talking about any such thing. You seem to be twisting things around to pick a fight (for whatever reason, I dunno...maybe I said something that you disagreed with and/or pissed you off?). No one here that I've seen, be it the OP or myself, has talked about tuning a 500+ hp dragqueen specifically tuned for nothing but 1/4 mile numbers. It's certainly not real world driving, it's a super quick straight-line rush that you build up to spending countless hours and money on, only for it to be over in a few seconds. I bet your girlfriend/wife just loves that... I fear my wit is lost on the majority of the readers, but alas, I still try anyway. I try to get everyone to think outside of the box so to speak, especially when there are uncertainties that people are trying to figure out. Poo-poo'ing someone's idea is one thing, but outright insulting them is quite another, and is just downright rude. All I'm trying to do is help. I certainly didn't deserve the response you gave. I never said it had nothing to do with hp, only that it was about torque (in Mark's case, because we are, afterall, talking about his car, not some 500+ hp machine). If I'm wrong, I'm wrong. I'm not stupid, and I certainly know my fair share about cars and engines, particularly Buicks. And yes, I've built my share of them. Raced them too. I thought I spoke of this before? Maybe you haven't read all my posts. I've moved on past the racing idea and just enjoy a nice peppy street machine that lasts a good long time. Of course, this gets ridiculed too, but whatever. I wish you well and do not wish to further this petty dong measuring contest any further. I'm very confident that I am way more than adequate. The knowledge I share here is the result of decades of research and testing, most of which I recall from memory. Maybe I'm just getting too old for this. I spend waaaay too much time here, making suggestions, trying to help others, only for it to end up with **** like this. It's just not worth it. I thought this forum was getting better, but maybe it was just wishful thinking. Ah well. Everyone have a great weekend. I have other things to do and a life to live. Gary
On the TA rockers, I measured one turn of the adjuster to equal .050, so I have the lifters preloaded .025 ( 1/2 turn )
Are you sure they are still there? If you had .025" preload and the cam is going down it would not take long to lose that amount of preload. Remind me what valvesprings you have in it.
My cam card is in the car, but IIRC the 413 cam is 234/244 @ .050 Power range 3000 to 5800 2500 to 3000 stall recommended
TA 1130 springs When I put the SP3 on, I checked the lobes (looked at 'em) they looked good Checked 4 of the lifters, barely discernable light gray circular patter on foot of lifter, all normal.
