ultimately cubic inch has only a partial bearing on it, let me stick you with a 4.56 gear in a stock l98 vs a 3.54 in a lb9 5 speed, who wins?

ya ya more cubes everyone knows, you hit the nail with a bigger hammer, who cares in the real world? Being able to launch my car, and then actually have power up high, i suppose my logic was a bit off but traction is way more important to me, so yea if i could (i haven't done the math to figure if this works) lose 30 ft lbs at launching/coming out turns rpms to gain hp at a higher rpms, i'd do that all day. A reliably launching/cornering car is worth it to me. and as far as losing power cause of smaller cubes, gear it to match the new power, if you do it right you have the same or more rear wheel power, less flywheel power, a lower top speed but probably a more attainable top speed(120mph vs 145mph, is that actually a usefull difference 99.9% of the time?)and better launchability and acceleration as well. you only have so much traction my friends.

If you have a powerband that has a high peak power rpm vs a torque rich midrange, you can gear more efficiently, if i have a 4 inch bore with less stroke, i have effectively increased the ability of my cam/intake/heads, so we're saying the same thing the difference is a 327 is cheaper then a stealth ram for me.

i'm not defending 305's either, although it's been shown plenty can be done with them, they are definatly not worth the effort for an effective/cheap street racer, the reason for a 327 is i can use 350 heads effectively to make the kind of powercurve i want which would be closer to a rotories but over a shorter rpm range. Now, all that said, i know i still have alot to learn, so if you think i'm wrong, please show why you think so, there may be some reason the tpi is just not suited for a smaller engine but i'm still wrapping my head around it. I'm here to learn by the way, consider the above me explaining my point of view, please be respectable if you have something to add to the above, i've worked hard to learn as much as possible about going fast, i'm just trying to learn and share.

 

305 is not a practical starting point for a race car moter PERIOD

 

no it isn't but i understand how difficult it seems to do anything else when you have an l03, i mean those guys are really cursed, even bolt ons require serious work to the supporting systems to be effective, you practically rebuild the driveline in those cars before you break 13's. Now that said, there are planty of fast 305's, and if someone WANTS to build a headache, well it's their money and more power to them to find their own path.

Now what happened to this race guys??? alot of people want to see this civic get stomped!!

 

you are at least right with the powerband being setup different for different applications. don't look at it though as using stroke of the motor to adjust that. the differences you get from stroke for where the powerband is would be very minor. the stroke does not limit how high you can rev for any kind of street application. sure if you wanted to hit 15krpms stroke might play a little more of a game there (think F1 cars) but then again you would need so much work done to the to be able to make the rest of the engine rev up that high wouldn't make it worthwhile.
going from lets say a 350 to a 327 with a stock tpi intake might allow you to rev a little higher up just due to the engine not being choked down by the intake as quick. ie lets say intake can only flow 300cfm (throwing an umber out there) if all else is setup the same a 350 will start to flow that cfm at alower rpm then a 327 would. even then though with a stock tpi intake you are still going to have it limited early due to the long length of the runners being tuned for a lower rpm. and still even then the 350 should put out more useable power. going with a 327 is a broken bandaid fix for the wrong problem. its kinda like if you put dink OEM heads, stock tpi intake, and a peanut OEM lg4 cam from a 305 on a 383 realizing it doesn't rev for crap or make much power and thinking 383's suck and going with a smaller motor to rev higher. it's not the problem of the 383, it's that your expecting it to drink through a straw when it needs a firehose.
the best idea if you want to move the rpm range up in the rpm range is to get a larger cam with more duration and lift, get heads with larger freer flowing ports. this helps with all motors to make more power and more often then not will move fat part of the rpm range up higher. also with that usually as long as you are staying with the same class of head, cam, and what not just going to a larger size usually they are fairly close in price. so again it's not really size, stroke, displacement or anything that gives your powerband. it's cam, heads, intake manifold, and even exhaust play more of a part in it.


one other thing having power up higher in the rpm range means harder to launch not easier. all that means is you have to rev up higher which gives the rotating assembly more intertia to shock the tires loose when you get off the clutch which will start to spin the tires. if the tires don't spin at that point the motor rpms will usually drop out of your powerband and you get a nice littel bog. to keep it in the fat without bogging or spinning takes a lot more work and effort.

also having more power to come out of the turn is always good. it allows you to get up to accelerating quicker. just means you have to have a little mroe skill to not give too much power. more power is always better unless you don't know how to handle it.

also with gearing it doesn't effect the hosepower output from engine to wheels. torque yes but not horsepower since the same amount of work is being done. torque goes up after gearing but rpm on the output go lower so it all evens out with the horsepower.

 

hp is a relative number though and all the driver feels is torque, period. i can demonstrate this to you wth your own car if you like, though i suspect you allready know what i'm saying. I have seen before though, cases where power was Decreased, and corner exit/launching speeds were Increased because of it, why? because the driver didn't have to hold the throttle as far closed coming out of the turn/hole, meaning the straightaway was being used more effectively. What i'm talking about here is tuning a car on the fine edge to work with limited tires. i suppose i should have mentioned that! hahaha yes that's a key aspect i missed, is that i use stock size tires!

I see exactly where you are coming from and what your are saying, it makes good sense and it is the typical point of view of us gear monkey's. What i'm getting at though, is efficiency of power usage and also efficiency of traction usage, i know for a fact that as my power has increased this saeson, my 60 ft's have become more and more erratic, and typically higher. i cut 2.0-2.2's at best but i can't really launch at more then 20 percent throttle, this is no acceptable! What else is unacceptable is that after i just had to feather it out of the hole (meaning i HAD power there i couldn't use because of traction limitations!!) i reach a measly 4500 rpms, and fall flat on my face power wise, so my power is in a useless place i only hit in 1st gear, and I have to basically avoid using it due to traction loss. does that make more sense? yea great i can win races in school zones all day long.

now i'm just waiting for a person to say, get better tires. great idea cept i WANT to use stock sizes since i have the gta wheels and eagle gsc's, a decent tire anyways. I want a car that makes GREAT use of a little power.

Thanks for the input rx7speed you are completely correct, i just don't want more torque, just better placed and used torque. By the way perhaps part of why this all got muddled up is because i said i wanted to use tpi, perhaps i should have said MPFI, though tpi is the only mass produced mpfi system that i can call pretty hahah..
I enjoyed your reply, i hope this discussion is more usefull then the original thread.

 

understandable with torque and horsepower and driver only feels torque. I can easily attest to that as well. 3000rpms in first vs 3000rpms in 5th. both have teh same horsepower at the wheels but first by far has more feeling cause more torque is at the wheels

as far as exit and cornering. being in your powerband of course is key. trying to keep the car at 1500rpms instead of downshifting to bring the car into the powerband is a nono. but having a car that has too much power at the time is better then not enough. granted you have to hold the throttle closed more sure but 300ft/lbs of torque at 50% throttle vs 300lbs/ft of torque at 75% throttle still gets the same amount of torque to the ground the only difference is the one that is only using 50% is going to take more skill to drive and has more room to play with as he is comming out of the straight and when full throttle hits will have way more power then car b already using 75% of the throttle. if I'm missing what your saying please correct me. either way if both are setup the same and have the same powerband just one has more power, more power is always better there. well at least more power is always better if you can drive with it and handle it. that line between doing it right and giving too much gets much smaller the more power you make.

sorry to say but erratic 60' times are more by driver then by more power. I'm not trying to be mean or rude with that one there. only other case would be a very touchy car to climate. with this it shouldn't matter if you are driving a 800hp car on spare tires or a little RWD 80hp celica on slicks you should be able to get the same 60's consistent at least. With the 60's going up though that is another story. that could be caused by same thing being driver either lack of skill or lack of skill at least with that setup. And if you have driven the car quite a bit with the old setup and then started to change things that second very well could be also just being that it now changes how, where and what you do when you launch. where the power boost has come also can cause problems. high rpm peaky cars are a f'in pain in the ( | ) to launch. So if when making your car stronger if it moved your powerband up in the rpm range i could understand that also. look about the s2000 regarding that one. just as fast as a stock l98 if not faster with a good driver but it's uncommon to find them launched well. with the lack of power in the lower rpm range you have to rev them up that much higher to get them into the powerband. that just means your engine stores up taht much more rotating energy. let off the clutch and it hits those tires like a sack of bricks and they want to spin, only catch though is now since a lot of that was intertia from the motor rotating hitting those tires it doesn't last and the rpms drop real quick since the motor can't back up that initial jolt and your out of your powerband leading a bog, but you rev it up just a little higher now you just keep those tires spinning whcih same thing you don't go anywhere. to get a good launch on a high rpm peaky car takes some finesse of the clutch and throttle. letting off the clutch just slow enough to prevent the bog and yet keeping on just enough throttle to prevent them from spinning. drive a car like that one day. if you have any rx7, s2000, or something like that in your area that you can test drive you might want to try it, just hope you can drive stick. if nothing else it would be some good fun. you can very well go faster through the whole 1/4 with the higher rpm car as most generally do. it's just some more skill and touch that will get you there. and please don't take it as me ripping on you I'm not. when driving my rx7 I will easily admit I suck . so far out of all the years I've owned that car (longer then I've been a member of this site) I have only had maybe 4-5 launches I have been real proud of. the rest of them while some might be decent or what not have never been as good as they could of been. this is also under the too much is better then not enough. my rx7 doesn't have enough low end power. it makes launching difficult. it's not that it has too much high rpm power.

with having more power on tap and what your talking about with efficiency. if you can only use 20% of the throttle at launch or the tires go smoke then you need to do some suspension/tire work. I understand you want to keep stock tires and that's fine but don't reduce your power output just so now you can launch at 75% throttle. this goes back to that too much is better then not enough. that is what that throttle is for. you can always give it less throttle but you can never give it 110% throttle. trust me I've tried

I'm at work so trying to mix between this and handle my calls. that and as I'm on the call I think of something else but can't edit it till after I'm done and might not edit that well so please excuse me if this is a jumbled mess. but I'm off to ongoing training for some changes so I will be back in a few. been nice talking to you

 

Rokit, I've got to agree with RX-7 on this one, more power is never slower. More power w/o control can be slower, and can be dangerous as well. Now, peaky high rpm power is defintely harder to launch. My SVT Contour was dead below 4500rpm, and had pretty limited traction. Launch required about 4500-5000rpm, and serious clutch/throttle work. Done right it was awesome, done wrong and you'd blow of the tires, or bog way out. TPI is the opposite kind of tough to launch, it'll make so much torque at such a low rpm, especially with the 700R4's extremely steep first gear, it'll easily shread the tires. Defintely requires finesse.

 

I work at the sears in oakbrook and I was there for the race. You guys would have to see the race to believe it. I tried to keep up but they were both too fast for me. At the light on cermak, they started. All4u had the launch and somehow grabbed right away. I didn't and spun the tires. Dalton was only maybe a car length or so behind. I got to about 45 or so and Dalton started to pull on all4u. From what I could see, Dalton inched out a head and I could see that he was about a half a car ahead. I started to lose sight but then all4u pulled ahead like a bat out of hell and left Dalton behind. I would say that by the end of the 3/4 mile drag to St. Charles, All4u had to be a least 5 maybe 6 cars ahead. I couldn't keep up but there isn't anything done to my car and it is got alot of miles and in need of a tune up. I did notice that all4u does have some kind of **** on his rear bumper that isn't stock. I don't know what it does but it is outside the car and how could he turn it off and on if he is in the car? What does it do exactly? I do understand what dalton meant when he said that all all4u has nitrous because he does pull hard after 90 or so but not hard as if he had nitrous. It honestly was a good race but all4u won by at least 5 cars. It was cool. Just thought people would like to know the result.

 

that **** on the back bumper is most likely for the fuel pump.

 

fuel pump or electrical kill switch?

 

fuel AND electrical, thats an emergency safety switch incase the car catches fire or crashes at a dragstrip, the people working there can hit it to kill fuel/electrical.

I agree more power is USUALLY not slower, however if there is the same amount of traction between two cars, and one has significantly more low end torque, which one will be the most consistant? Now, what if the car with less torque down low, had more horsepower up high then the frist car but still a reasonable amount of torque down low, and was geared/powered so that it had less wheel torque then the first car in first gear, but more rear wheel torque in the other gears? Across ten passes the more hp oriented motor will launch easier(still hard mind you just more within the limits of the tires) and pull harder after it shifts, with correct gearing it WILL have more power just in a better place after the launch where 330 ft lbs can be too much of a good thing.


So in the end what i'm saying is you shouldn't run more torque then you can support tire wise, and having your torque flatter and extending to a higher rpm so that you can gear to make up for a weaker bottom end and maximize your acceleration is better for racing then our stock setup. if i only have x amount of traction i'd rather have a flat and long torque curve.

I take no offence at the driver comments, we all start somewhere, i'm admittedly a novice drag racer, been on the scene for a long time, know alot but i don't have much seat time yet.

Also i might be speaking too soon, my limited slip is not err,, limiting much of anything these days, it'll still burn both rears but i feel it let one go from time to time, my shocks and struts are nonexistant along with my sway bar bushings, the springs and sway's feel good still but there's alot of wear on my suspension at this point, the suspension in my project car is in MUCH better shape and i hope to add lca's and sfc's to that car this winter. it will be runnign the same engine from my current car though.

 

You should run as much torque as possible, and run enough tire to handle it. Thats the fastest way down the drag strip. Most drag cars can adjust suspension, converter/clutch, and gear ratios to control the torque of whatever combo motor they run. I can't see building a motor to suit traction needs of a specific car. Higher rpm, peaky power delivery, type motors are defintely more difficult to launch. There is a 3 or 4 rotary powered car that runs at our local drag strip, standard transmission, and revs to ridiculous high revs. (12,000rpm plus, no power below 8000rpm) That guy has to leave with so much rpm, its pretty tough to get the car to leave just right every time, if at all. I'm sure he'd love to have some bottom end. I think most people find the power of the low-end on a TPI motor to be an asset when applied correctly.

 

Darn it, yes the switch is a cut off switch for the electrical. Rockit is way to smart for me and yes I won. It wasn't 6 lengths though, it was more like three or four. My car spun the tires shifting to second and kicked a little sideways. I lost some time on that but still won. Go Firechickens! Oh, and yes I was all motor. No nitrous at this time but maybe this winter I'll hook up two 20 lbs. bottles to a two stage system so I can take CRX's! I think I could take them without juice. Anyway it was a good race.

 

So when are You gonna get that race taped against Dalton's turbo Civic??? We're all still waitin man!

 

guys i see your point of view, and agree to be honest, coming as close as i have to losing after a spinning start, i'm a bit,, touchy about tpi's torque. i guess we'll see where i'm at after i get a suspension with some mods to it behind the l98.