i just put a tach in today to replace my factory waaaaay off one. and was thinking to myself and asked, "self, what is a safe redline to set this to? stick to the same as what the stock tach says?" anyone have any input?

 

Anything over stock red-line and you're most likely losing power

 

ok so the safe place to put it is at the factory 5? my caro only has whats on my sig

 

With the headers and modded TB, I'd say you'd be ok to ~5500 because of the extra air-flow, but I don't know alot. My auto shifts at an indicated 6000 at WOT...heh.

 

anything over 5 losing power is bullcrap! depends on your intake & exhaust and also your cam and valvetrain. of course, running on a stockish cam won't yield you any power at these rpms... you also want to be sure your valvetrain is upgraded, at least the springs i'd say.

just my 0.02, i'm still pondering myself about where to set redline after my lt1 cam swap and some other work on intake & exhaust. let's hear some other thoughts on this, i'm curious how much is safe for the L03 bottom end actually!

 

I would worry more about the valve train (springs mainly) as opposed to the bottom end. Worry about the bottom end when your are running slicks and lots of hp. I ran my 305 just above 6k, that is if the stock tach was correct. What the new tach reading higher or lower?

I think that the redline should be determined by where you lose power according to a dyno. Another thought is that you need to look at each gear change individually, and shift when you are going to get the most out of the power band for the next gear. In other words, you may want to hold out longer in 3rd to put you closer to the power band in 4th, but opposite for 1st to 2nd.

You may optimize 1/4 mile time by looking at a speed vs gear vs rpm table in a spreadsheet.

 

good thinking there graebz28! just one more thing, if you set redline you can either set a very specific and exact rpm for redline, or if running on a dyno, rpm will also be accurate. so if tach is off probably won't matter?

what do you guys recommend upgrade-wise for valvetrain? i got comp cams 981 valve springs (370 lb/in rate) and the GMPP timing gear & chain set to throw in so far, as recommended in the LT1 cam digest thread.

anyway, how do you actually set the shift points?
also, wouldn't be rear gearing involved in this decision?

 

i also am worrying about the limit of the bottom end. i would naturally upgrade the valvetrain. so not worried about that but how high can you take it?


i am thinking about building this motor combo peak power at 6.1k
i wanna make my car a road race/street car and swap to t56. this sounds like a good combo
http://www.popularhotrodding.com/eng...cks/index.html


as far as my tach reads... in which the 91s are really bad about i have read.. at idle the car reads around 3k new tach reads 500. stock 6k new tach reads around 3k. stock hitting the dash, my sunpro is anywhere around 3.8 to 5ish

 

At 6100 for peak power, I would think it would be a good idea to go through the bottom end and balance the crank, etc. Taking the stock bottom end to 5500 isn’t very hard on it as long as you keep the engine running smooth, not detonating, and well maintained. With the current mods, I’d say it would be a practical choice as well.

 

i pull up to 6500 and have no problems, i will say my power peaks at about 5600-5800

 

I didn't mean you couldn't do it without problems, but I don't think it's a good idea with these bottom ends to do it on a continous basis. I'd rather go through it and know it should instead of hoping it does.

 

i got my shift light on at 5k, i normaly shift at 5400-5600 if im running it.....like i said, i have taken it to 6500 plenty of times, but as said in other posts its a good running motor, well maintained, with top notch oil in it

yellow line is 4500, with a 5000 red on a TBI

yellow is 5000 with a 5500 red on a TPI

atleast thats what the factory tachs say


but with the same bottom end, stands to reason that the TBI can do what the TPI can, just is it in its power range.......stock the TBI would be best not over 5300 prob, but far from stock 5500-5800 seems to be ok, anything over is just to make more noise LOL, still pulls but not as hard.....i do know that mine lay rubber going into 2nd its best with it goes ot of 1st at 5600-5700k

i got my set up to light at 5k, i been thinking of moving it up tp 5600 since that seems to be best for me

here is a link to an older vid, light turning on at 4600, and shifting at 5600...it was taken when my trans was slipping so you dont get to here the nice bark going into 2nd......there is another video i got with that on it... waiting to get it back on the road and see what this new trans does....its built even badder that the old one so BTW when the TV cable brakes inside the trans it sure can cause a good trans to go south

http://myspacetv.com/index.cfm?fusea...deoid=28487107

 

I've pulled 305 engines to 6,700 rpm and the current 350 TPI to 6K. Really depends on what you are dealing with. An engine with good heads, a nice cam, free flowing intake, and exhaust will rev to the moon. As long as the valvetrain is good and the lower end is in good shape a stock bottem end small block will turn 6K. If you stud the mains, use good rod bolts, 60 psi oil pressure spring, take care of windage, and balance the rotating assembly your small block will hold 6,800 rpm easily.

I would keep a stock head, stock cam 305 TBI under 5K. The torque is already non-existant at 5,000, much less any higher. Why stress the lower-end if you are only going to go slower. Add some performance enhancing parts and it will breathe up top, but until then, keep the RPMs low. My stock TBI 350 in my van liked 4,600 rpm @ WOT as the upshift points. I've found similar response from the F/B-car TBIs.

 

you know, i got thinking about it, its been so long since i drove mine (its back on the road next week ) i cant remember if it was 5200-5400 or 5500-5700 that it pull the hardest into gears

i know i turn it up to 6500 at times, but its not that often, as we most agree it starts to slow it down that high, like i said thats just to make noise

Im going to have to play with it at the track on the fun runs and see what rpm shifting at gives the best time and post it up

man i wish i could just get out in it and go down the road and remind myself of the best RPM to shift at

 

now i know thats what would be best, doing mods to the bottom. but the situation im in is this. i just got a new tranny can hold up to 450 in therory. i already had this motor replaced. it has about 110k miles on it. no leaks nothing. i use syntec in it last oil change. every other time i use catrol on a regular basis. i take good care of this car. i would rather not pull my motor AGAIN. untill i build one on the side. a BAD one. i just want a little more for now but will give me pleanty of power for the twistys and some playing on the street. this is a upper engine package and i would like to keep it that way. to top out the challange, i wanna play with using my tbi with this setup somehow. thats why i want to figure this out. how much can this motor take? the mag had a low? com engine and a flat tappet. i have a roller cam and 9.3:1? so i wanna know what i should step up to? this is the whole reason for this post. wow lots of typing but i think i got my point?

 

im building 336 stroker (give or take a few depending on the overbore)

but anyway im going with a 454 TBI unit, a good but cheap aftermarket heads, that im going to work on making better, a good TBI intake from edelbrock or what not, 1500-6500RPM roller cam, gear driven timing, high flow oil pump with a high press spring, deep oil pan..... and whatever else looks good on a 305 donner block

there is alot more you can do thats just what im going with

 

Whats the best shift point for a stocker? I have the AM monster tach and light...

 

No, you tell us what the best shift point for your specific car is.

Do you mean the 918 beehive springs. Those are awesome. I'll eventually throw some on my e-tec to free up the top end. Save your money and get a good true roller timing chain. I got a summit racing one. Those GMs ones are waaaay over priced.

 

stock, i would say 4800 prob.........dont know, mine has been far from stock for a long time...... but try it somewhere around 4800

 

Funny that you say that, I just set it to 4800 today as it seems to be the best point. Thanks

 

You might surprise yourself, 4,600 rpm MAY even be better on a mostly stock car. I usually rev 10% over peak HP rpm. Stock TBI is 175 HP @ 4,200 RPM IIRC. That means 10% over is 4,620. Any more and you are just making noise.

 

Ill try that as soon as I get a chance. Thanks

 

would one of you guys care to explain how to SET a shift points on our transmission? i'm not too familiar with ATs yet i guess. thanks in advance

[offtopic]
are you talking about the comp cams 26981-16 beehives? nope, i got the standard ones, 981-16.. 63$ vs. 155$
anyone using the 981 and got any comments or suggestions?
oh and which chain exactely are you using graebz? i already got the gmpp one, but just for future reference..
[/offtopic]

 

The governor does the shifting in the th700r4. Here is a good link.

http://www.dragracingonline.com/tech...vi_9-bm-1.html

 

you cant without doing trans work, (the governer) the shift points we are talking about are the shift light on an aftermarket tach

 

mine auto shifts at 4200 and i have a 305 tbi how can i make it go high when i have it in OD

 

I have mage my tbi hit 6k but that was for a little fun but as alot of people have said "just because it can go that high doesn't mean you should". I have made 2.8's hit 7200 but I wasn't making any power, though my old Rx7 could rev to 10k and make power all the way to about 9.5k but that was only to make a point to who ever was next to me (damn I miss that car).