ding, ding. round 2. 40ft is a guessimate.

i sit at idle. lights go down. floor it. i see the tach read about 1800-1900 rpms. i flip the power switch. taking into consideration my human reaction time, i'd say about 2000-2200.

either way, it's WELL below 3000 rpms. the magical do not hit it under mark. as i said in the other thread, whenever you want to meet me at bradenton and watch for yourself, i'll oblige.

 

SOOOOO...you really only have a "guestimate" of the actual rpm you are spraying...dont use a window switch...and are looking at a tach needle that LAGS big time...hit the activation switch during the launch after 1800-1900 rpms...but you are telling eveyone its just fine and dandy to spray a 175 shot at 2000 rpms??? Does that about sum it up?

Sounds like great actual real world FACTUAL DATA to work with there.

Yes..im being a smartass. But there is a reason why people that have been down this road before do things the way they do them.

If anyone is going to try to hit juice lower than 3000 rpm I would HIGHLY recomend a window switch. Set it at 3000 rpm. Make a pass. Set it at 2900 rpm...make a pass...etc,etc. As you begin to go lower in rpm..ask yourself if you would have no problem spraying double the HP at double the rpm. IOW...if you spray a 100 shot at 2000 rpm...would you be comfortable spraying a 200 shot at 4000 rpms? because thats about what it equates to. A 175 shot at 2000 rpms is gonna see similair cylinder pressure to a 350 shot at 4000 rpms etc.

 

like i said anytime you want to jump in the passenger seat, i'll oblige.

a window switch is only as good as the computer that built it. SSSOOOOOO you actually believe a window switch is accurate? i just love those wonderful little items. especially those one with that special if your rpms are within 200 rpms of activation when launching, you don't get activation. go ahead and set it for 3000 rpms, then launch at 2800 rpms. damn it, just lost that race. oh well, at least i'm safe.

so what if it does see the same cylinder pressures. if the motor can't handle the pressure, it won't matter at what rpms you hit it at. yes, it does put more strain on the rotating assembly. but even you can't say at what rpm is too low.

and just how much does a stock tach actually LAG? let's have some of that FACTUAL DATA on that. last i checked mine, it was off maybe 200 rpm at 6000 rpms at most according to the tach readout on the dynojet i use. 3000 rpms on the dash read 3000 rpms on the dynojet.

we'll go at this for about two days. all this trying to discredit me just like the last thread. it's nice being the moderator though. you can have the last word and lock it.

have you ever tried hitting the bottle below 3000 rpms yourself? apparantly not. you just go by what you're told don't you. i've hit it at 1500 rpms according to the tach in the 99TA i had. tires spun, so can't do that. back to 1800 rpms it was.

that's the difference between you and me. you only do what you've been told can be done. i test the waters and go against the grain. believe none of what you read and half of what you see.

 

ok time for some real world FACTUAL DATA. see the above car. it belonged to mike senia of Yank converters. they enlisted vinci high performance to test a whole slew of their converters. the motor was a complete stock short block except for cam. this means stock pistons, crank, and rods. the testing was done in 3RD GEAR at 0 MPH starts. they even did 150 n2o runs in 3RD GEAR. right now, Yank's site has been changed over and i can't find all those wonderful graphs they had up. i will though. he wanted his converters put to the limits. there was no care about the trans or motor. he had backups. tell you what. call up VHP and mike senia @ Yank about it.- motor never let go. never.

 

Nobody is trying to discredit anyone, period. The real problem is information for new guys. When you insinuate that no window sw is needed and coming off idle is fine, with a wet shot, you have to be certain the new guys understand the risks/reasoning behind it.

I have in fact sprayed more cars without window switches than with, however, I understand what I am doing, some new guys may not.
Example, an automatic with a dry hit, I have no problemo spraying outa the hole. Now, what that means to me is, powerbraking a bit to take rpms up, then on launch flooring it and by time the n2o is hitting the clys, rpms are up and out of danger. I have not hurt any engines this way.

Furthermore, if you are really serious about racing, the human factor needs to be eliminated wherever possible. Meaning, a person will never be consistant reaching over and flipping a switch, compared to electronics that will do an absolute evertime. This reasoning can be seen in the choice of transmissions in racing. The auto is prefered because it is consistant, whereas, the manual is much, much harder for the average guy to get right.

I have my ws set at exactly 3000rpms, a little lower is acceptable. But try a stick shift with a wet kit coming off idle. See what I mean, a new guy may not realize these things. I do give you kudos for allways stating, do at your own risk, type of thing.

About cly pressures at below 2500rpm, it's like doubling your shot, that's how high they become, and that was the point being made.

We have different opinions, maybe/maybe not, it a forum for information and that's what we all are doing yourself included.
Robert

 

Now these after market converters, correct me if I am wrong, flash to a higher rpm instantly when floored. If so, that takes you out of the danger zone?
Robert

 

they have stock converter dyno runs starting at 0 mph 3rd gear. not sure if they have it on the bottle. as that's what they were comparing all their converters against.

 

yeah right. that's why i've got this moderator coming into this post and saying this right here.

and this


i'm sure i really don't need to pull up the other thread. the day he's in my car and watches what i do, is the day he can tell people that i don't know what and when i'm doing something. i've never come in here telling people that he doesn't know what he does or how he does things. there's no need for his UNFACTUAL DATA comments about what and how i do things.

i'm ok with anyone's disagreeing about what i say. that's opinions. but, never tell me what i do and don't do.

 

i posted this in another thread. it's my timeslips from the 99TA i had. showing what happens ETwise the sooner you engage the nitrous. now, of course, this is with the factory LAGGING tach. maybe 3000 rpms was really 4000 rpms. the world may never know. oh and this car was completely stock from air filter to exhaust tips. well except for plugs, wires, and fuel filter.

http://stealthram.com/1999TransAm.html

 

what the heck are you talking about? The window switches I have used are pretty damn accurate. A thousand times more accurate than attempting to watch a stock tach at WOT and trying to guess your rpm, then flipping a switch.

I cant believe I have to explain some of this stuff to you. Its very difficult to estimate what might be too much nitrous at a very low rpm...espsecially taking into account that as you get lower in rpm the difference if 100-200 rpm can become CRUCIAL. If a 350 shot at 4000 rpm is similair in to a 175 at 2000...this can tell you a few things. Would you ever run a 350 shot at 4000 rpm on pump gas? Of course not..and timing should be reduced as well or the motor will not live long. The same would go for the 175 shot at 2000. If you were actually hitting it that low with an actual 175 shot...I would suspect you were getting detonation. But as I said I have my doubts its actually engaging that low.

Again...ill explain what lag means since from your description its apparent this concept escapes you. First...its DOES NOT mean tach ERROR...meaning that if you hold your engine steady at 3000 rpm according to the stock tach..then use an external device (such as dynojet) to measure actual engine rpm and then note the difference. From my experiance stock tachs are usally pretty accurate in that area. What lag IS....hook up an MSD tach...floor the motor and watch that MSD sweep very quickly in comparison to the stock tach. The stock tach LAGS behind actual engine rpm greatly. The faster the acceleration the worse the lag. Lag would be worst in first gear. On a mildly quick car this could be as much as 500 rpm or easliy more with a stalled car. On my car when I floor the car unloaded the difference between my MSD tach and stock is HUGE. 3000 rpm or more. Accelrating in first gear the tach lags probably 2000 rpm or more. So the only way to ensure accurate activation is my using a good window switch such as the MSD unit. As Robert said it remoes the "human factors"

Your arguement on whats safe and perfectly ok is riddled with innacuracies that are obvious. I cant let that fly here. Sorry.


I have hit the nitrous below 3000 rpm way back when I had no window switch. However I cant say exactly how low I ever hit it because with the laggy tach and human error that would be involved ...its really hard to say.
As far as doing what Im told...lol..hardly. I try to do what logic dictates and experiance has shown me to do. As I said...there are MUCH better ways to get down the track faster than to spray a 175 shot at 2000 rpms.

Thats fine and dandy if you want to go against the grain....but atleast have a logical point of veiw and try to appear like you know what your talking about. And IMO your method for saying that spraying a 175 shot at 2000 rpms is A-OK is less than sound. I honestly do not believe you are spraying a 175 shot at 1500-2000 rpm.

 

wheres the factual data???? And what does 0 mph have to do with engine rpm? If its a stalled car then its going to probably be fairly high. And if its a stock stall...at what rpm did they spray it. I dont see any data??? If you pull up a Yank graph clearly showing nitrous engagement at a VERY low rpm that would be nice.


The biggest tell tale sign that you are well beyond the 1800-2000 rpm you claim you are is that you say you are approx 40 feet out from the line before juice is engaged. There is no way...even on the stock stalled car you are at 1800 rpm at that point. Bottom line is...YOU HAVE NO IDEA what rpm you are on engagement. Want to prove your claims that a 175 shot is safe at 1800 rpms? Put in a window switch and set it to 1800 rpms and spray your 175 shot by mashing the pedal off the line. DO that about 5 times in a row on the stock stalled car and then i will be a believer.

 

... never sprayed a car in my life, but, it's coming in early October so I'm trying to learn the do's and don'ts of spraying. This is good information and so far you guys have kept things 'among men' ... great constructive criticism.


\
It would be good if it stays that way and if some more data were posted because I'm learning a lot from everyone here about nitrous usage.

Thanks for all the info ... would be nice to hear from other experienced folks who've sprayed a lot over the years. At the dragstip, soon, I want to stand my car straight up ... but not BLOW it up. Keep the flow of knowledge coming.

 

i guess you missed that one sentance i put in there saying Yank has changed their site around and i can't find their dyno graphs didn't you? read before typing. i'll get the info. 0 mph means the car is sitting at idle. about what 700-800 rpms. now stop and reread this sentance. the car is locked in 3rd GEAR at 0 MPH. i talked with joe vinci last night about the yank car. they couldn't engage the nitrous from standstill as it would blow the tires off the dyno. now, the actual rpm it was engaged at i can't tell as yank has changed their site around and i cannot at this time locate the graphs on their site. you talk about all the stress nitrous puts on a motor (and i don't disagree with you on that), here's a car that had at leat 50 runs in 3rd gear starting at 0 mph with a stock shortblock. the motor never once came apart from all the dynoing. you think hitting nitrous in 1st gear at 2000 rpms is hard on the motor. i can only imagaine what the motor in the yank car went through with all the testing. until i can locate the dyno graphs off yank's site, you are more than welcome to call mike senia @ Yank or roger vinci @ vinci high performance and ask for yourself.


if i'm having to guess my rpms, i'd say i'm guessing the distance as well. unless there are length markers on the track you go to. how's this i'm about 1-2 car lengths. so, if a car is 15ft long, that's somewhere between 15-30 feet. is that better for you?

bring me a window switch and have a seat. i'll meet you at bradenton if you want. what i love about this website is it that unless some computer is telling you what's going on, it just can't be happening. human input just doesn't cut it around here. only thing left to do is have robots drive the cars. take all the human error out.

was just over at macedo motorsports the other day. the a/f ratio was off by almost a full point because the wideband o2 took a crap. but hey, it has to be right. it's a computer. man, how did this world survived without computers is beyond me.

 

maybe. has a computer ever been wrong? for the most part, i'll agree with you. it will make the runs more consistent.

you ever read the mag article where they took a stock 350 motor and put it on an engine dyno. they did a pill it until you kill it article. motor, again, stock shortblock. that means original 1976 cast pistons, crank and rods. they did put new heads, bearings, rings, head gaskets and cam in. i'll have to find it to make sure what gas they used. they did a NA pull, then 125 nitrous pull. another NA pull then 225 nitrous. then NA and 325 nitrous pull. then NA (made most NA power this pull) then 425 nitrous pull. they didn't get to do this run. they were purging into the motor before every run. when they purged it took out two pistons. of course, they did the runs at 3000 rpms.

so, you're saying my stock tach, because of lag, can be 1000 rpms off? man that's alot. i guess when i told you that my stock tach was only off by about 200 rpms at 6000 rpms read off the dynojet was during a run. so, does a stock tach 'catch up'?

well, if the stock tach is is off as much as you say it is, then those that don't have an aftermarket tach needs some kind of starting point. so, what are we that use the stock tach hitting the nitrous at if we see 3000 rpms on the dash? not everone will use a window switch. i do see a need for them on manual cars. just not autos. unless you just want to remove the human error and not spray through shifts (another thread on that one day). your arguement on what's not safe is riddled with just as much innacuracy. you have even said that yourself. you can't tell us what's the lowest point. but insist we don't do it. of course for the new guy just entering into the world of nitrous, i agree with stating for cautiousness.

yes there are better ways. but, it's not what the orignal poster was asking.


see here we go with the attack of credibility. i just don't know how much more logical it can get. i do what i do. but hey, i don't have all these computers to back me up. after all. computers can't do something worng. or be innacurate. that's why microsoft has constant patches and updates. computers do what humans tell them to do. so, if the human at the window switch factory screws up in the programming functions, you're screwed. but hey, i set my window switch to 3000 rpms and i still blew up my motor.

computers are too fallible. while safety items are nice to have and can save your motor, i just prefer the good old fashioned human control. while not CONSISTENT, alot less things go wrong. i do have a FPSS, who wants it? still sitting in my tool box. i'd rather be off a couple hundred rpms, or a .1-.2 off in ET than have electronics failures and cost me the race.

[/quote]And IMO your method for saying that spraying a 175 shot at 2000 rpms is A-OK is less than sound. I honestly do not believe you are spraying a 175 shot at 1500-2000 rpm.[/QUOTE]

apparantly it is A-OK as i'm not the only one doing it. as evidence of two others in this thread saying they do it. why don't you go bother them about? haven't seen you say anything to them. seems like you are singling me out. so, until you spread some of the criticizm around, back off.

 

tell you what, i'm going to man out. just like the other thread, too much chest beating between us. so, you have the last say. after all, you're the moderator. you know more than i do. have done more than i have. and you must know something that i don't because you are a moderator.

 

If the others here that say they spray at a very low rpm are using a window switch to activate it at that point then its likely they are. But they also dont come in this forum and constantly say that spraying at 2000 rpm is fine and dandy.

And Im not really trying to attack your credibitly as much as show you where you may be missing a few things. otherwise I would not type the lenghty replies.

As far as the stock tach and it being off for you by only 200 rpm....first,,,the tach lage relative to acceleration. SO it biggest lag point will be at peak Tq. It may catch up slightly in the upper rpm ranges. But I want to ask...what method were you using to see that the tach was off only 200 rpm at 6000 rpm? Where you watching the dynojet rpm as you watched the stock tach as you did a WOT run? Seems like that would be pretty difficult under rapid accelration. Eyeballing two tachs during a dyno run seems tough. Its hard enough for me to eyeball the stock tach and the Autometer tach and they are side by side.


As far as the Yank car....having 50 runs in thirds from a stop all motor is no huge stress on the shortblock. Now if your saying they sprayed it all 50 runs off idle with a 150 shot in third gear from a stop...that would be impresssive. I would like to see the graphs.

As for Mecedos wideband...it was off...so what. What would you use to tune if you had no wideband? Are you going to be reading your plugs and making adjustments from that? There is a reason why widebands and electronic devices have taken the performance world by storm that last ten years or so. It has a direct relationship to all these extremely high HP cars that run around on the street now reliably and safely. It has also promoted the incredibly quick ETs we are seeing. Technology is a great thing in the racing world.

 

i know i said i was going to man out. but, i see this is being more civilized at this point. so, i'll continue.


no window switch post #5
no window switch post #8
not sure if he's using a window switch post # 16
now tell me you're not singling me out. i see no response from you to these guys telling them the same things you keep telling me. they aren't spraying that low, etc...


it just comes off that way when you type. while using the factory tach, may not be the most accurate, i can't see it being 500-1000 rpms off.

when i dyno, i'll run it up until it taps the rev limiter, then let off. i know crazy right. it guarantees i'm at the rpm limit doesn't it. i've watched the dynojet tach when doing this. then i've watched my dash tach. only way i could watch both tachs is if i had fish eyes. or someone with outward crossed eyes.

not all 50+ runs. once yank gets the graphs linked on their site again, if they do, you can view them all you want. point being is they did do 3rd gear n2o runs i want to say no higher than 15 mph starts due to tires breaking loose. i'm trying t ofind out if they did any locked runs as well.

point being is electronics screw up. not saying that stuff doesn't work. just isn't the all reliable. i use the o2 readings off my scanner to tune and look at what the computer sees as well. i, as well as vinci, have done enough testing to determine that 890-910 equates to about 13.0:1 a/f ratio wideband. let's not get into the cons and pros of narrowband and wideband differences here.

and technology is a great thing. if i didn't think so, i'd have the edelbrock/MSD intake and timing controller on this thing already. i'm not against using any electronics. on my 86TA i bought a NOS progressive controller. i sepnt $315.00 and gained nothing. reason why is i wasn't losing traction to begin with. so, the help wasn't needed.

i'm more than willing to meet up with you and do some datalogging. just to see how far off the tach really is in comparison. if i'm not hitting it at 2000 rpms, i'll be the first to post it. until i datalog it, i'll believe my tach. i'm really not here to argue and throw mud either. i like to learn. i don't think i would've ever went to 200 motor rating if i hadn't read on this board people doing 250.

 

 

i feel that way some days as well.

 

Too bad MRR23 doesn't have HPT or Edit and a w.o.t. switch. This thread could have been about half the length.