Gator Bait

I've see this come up in a few threads and thought it deserved it's own thread to be hashed out and opinions shared.

I'm of the camp that way too much is almost enough. But I use my car as a play toy and I'm a lazy driver. I'll play through the gears but short shift after the 3-4. I rarely go beyond 3/4 throttle. So of my 430whp I likely only use 300 90% of the time. And ya...I want about another 100 whp. Why? Because underwear is cheap, why not? That 10% of the time I wanna be stupid is the whole reason for the car existing

What say you?

mrmustang

That depends on the use.

Daily Driver
Street driven only
Track driven only
Or
A combination of both


Bill S.

V8droptop

Cars are complete packages. Too much power, not enough tire, not enough brake, is a bad combination. I think the limit to the chassis is how much tire you can get under there, followed by how much power before the chassis flexes/twists under heavy launching. On v8 cars with less power, 315s are pretty common, and I'd not seen anyone try that yet without it looking silly. One guy did it on his MSM, looks funny, but it worked.

Are you concerned with drag racing, or just hitting the gas from a highway roll? Different things entirely.

Gator Bait

I'm not a drag racer...some roll on playing on occasion might occur, otherwise it's just a street and occasional track day (road course) toy. I'm happy with the grip I get out of my 225/45/15 RA1's. I was even considering some more street oriented tires but have backed away from that idea. IMO...it's not can the tire take the summed wot HP, it's can the driver control the skinny pedal to keep the tires in traction. Managing the pwr delivery is part of the fun. ...with in reason... And reason is highly subjective. ...as is this thread.

tbone heller

Mine has very good driving manners until it starts to see some boost. This is when stuff starts to get CRAZY. That being said, Mr Miyagi has a 12psi pulley, methanol injection kit, SN95 computer, & a new dyno tune coming in the future, if I ever finish my home addition. Some parts are half installed, & others are sitting on the shelf. There is not enough time to work on both.

V8droptop

The blown 5.0 sounds like a blast. I'd love to get a turbo 5.3 in something, down the line. Cheap way to 500hp.

225s would take all the fun out of it for me. You are right, though, those tires will make you a better driver. 275+ tires would let you focus more on driving the course, though. I just don't see how 225s and 500hp would be a great mix, I assume you can break the rear loose at highway speeds easily. If I ever get around to getting the 11" avons, I'll report on how that works out. It sounds like a blast.

Gator Bait

In first I can light them up in some situations and they'll light (long chirp, not burn out) the 1-2 shift up decentl during a wot/redline shift. After that it's all hook. I'm talking straight lines of course. Direction changes are a different story for obvious reasons. I can wag the back end pretty well on corner exit in 3rd and I've felt some squirm in 4th. But again, I'm not one to jam my foot on the skinny pedal. ...maybe I drive wimpy...

V8droptop

I dunno, I could beat up on the 225 rs-3's pretty easily with just 300hp and a turbo. I'm not driving the LS swap yet, so theoretical only, but I can't imagine its going to get any better with more torque, more hp, and more weight over the front axle.

Have you considered 275 tires at all? Most are track-only dot tires, that I know of, unfortunately.

Gator Bait

In my head I relate turbo cars to two-stroke motorcycles... the power comes on harder needing more traction. Where a NA car is more like a 4 stroke with more tractable power delivery. ...but that's just in my head, correct or not. I've never been a snapped open throttle guy so there's that too. I'm just not that aggressive.

As far as wider tires, I'm unwilling to cut my fenders at this point and need some rain safety so I'm staying with the RA1's. ..it's a street car..

charchri4

Only use 300hp 90% of the time??? You do realize there is roughly a million Miatas out there functioning just fine with less than 150hp right? LOL how far removed we are from the crowd arguing about the ND only having 155 HP when it could have had 170!

But to toss my .02 in I'm right with droptop on this one. The car is a complete package and any part of it out of balance takes much away from the experience. Performance is just one piece of the puzzle. Appearance, reliability, comfort, exhaust note and many others go in to the package.

To me as long as the car stays in balance both physically and in terms of reliability and comfort and is pleasing to the eye then I apply my usual rule. 10 lbs per hp is fun, 8 lbs per hp is OMG that's fun, and at 6 lbs per hp, well lets just say you will never want a mistress....

Gator Bait

I know I always go back to motorcycles...because its what I relate most to..

I listened to the voices that told be to take my ZX10R off the track and buy a track prepped SV650 (the Miata of motorcycles). Was it a great bike that taught me to carry more corner speed to keep my times down? Of course. But it wouldn't float the front wheel the entire distance of the front straight placing it back down just in time to lean into turn 1 all while your gut is in your boots and heart in your throat. I like HP. I like my toys on the edge (or beyond) of too much of it. I want to work at controlling it. It may not be the fastest way around a track but holy 6 pound 8 ounce baby Jesus, I love it! Balance be damned. So long as the power delivery is tractable I want it all!!

As for those oem pwr'd Miatas. I appreciate their merits. But I've never owned one for all the reason above. I wanted this car for it's excess and sleeper quality. People just don't see it coming. ...but they sure as hell see it going!!

Sunshine Guy

There has justifiably been a lot of talk about tires being a major limiting factor for useable horsepower. The solution commonly suggested is stickier, and/or wider. Stickier is a proven commodity; it increases the coefficient of traction which means more grip on the ground. However, wider may not offer all the benefit it intuitively should.

I've done a fair amount of reading where some people who know a whole lot more about tires than me claim that going from reasonably wide tires to very wide tires in the same heights doesn't necessarily...or flat doesn't... "put more rubber on the ground."

The concept they tout is, a given amount of weight per square inch on a tire can only compress so much air, and therefore can only "flatten" the bottom of the tire so much to create the actual contact patch. If you go to a wider tire with the same tire pressure, you will still have the same square inches of contact patch, it will just be wider and shorter versus narrower and longer.

One can argue whether a long, narrow contact patch is more or less effective than a wider, shorter one. I don't know. But the idea that more rubber on the ground only comes with increasing the contact patch, and only so many square inches of contact patch can be generated with X pounds of weight compressing it...well, that just makes sense to me. In this theory, comparing realistic wide to wider tires, the only way to increase actual square inches of contact patch area is to reduce tire pressure.

To extend that thought process a bit, if contact patches either narrower/longer or wider/shorter in fact put the same amount of contact patch on the ground but one generated more straight line traction, then might it not logically follow that whichever was best for straight line traction would be worse for cornering traction? The contact patches are opposite shapes, so it would seem reasonable that if a shape provided more traction in one direction than the other shape, the inverse would be true in a lateral direction.

I don't know the answers, but good tire science certainly has a place in our traction hungry community.

V8droptop

I'll open by saying, I'm not a professional racer. Nor am I a hobby racer, competitor, or even terribly good a track driver. I do pay attention to my instructors and those who know more than me, however! I also stayed at a holiday inn express one night.

You're thought process is sound, but your missing one key element, that is weight transfer. That, and the fact that stickier compound tires typically run lower tire pressure. Also, the fact that sidewall strength/deflection is going to be different between these types of tires.

But, aside from that, your theory is sound, now think about it in your head, and put it in motion. The car, afterall, is a dynamic (moving) problem. When you accelerate in your corolla, perhaps not much happens for weight transfer, a bit more weight goes to the rear wheels, but not a ton. When I accelerate in my Mazda 3, a bit more goes to the rear due to a bit more acceleration, taking weight off the front where my power is, which = in fwd. In the MX-5, now with much more power/acceleration, the rear tire patches take on a lot more load, and the fronts take less, so your patches get bigger in the rear, smaller in the front. Add this to cornering and braking, the opposite happens. This is actually why cornering+braking+throttle lift in a RWD car is so catastrophic. In braking, your front tires have most of the weight/tire patch. The rear tires are light, and letting off the throttle goes into engine braking causing the rear tires to break traction, and if your turning, your inside wheel also has less tire patch, so the rear/inside wheel have small patches and the front outside wheel has the most patch. Think about it in your head, and mimic turning this way, you can see why the car will want to spin.

Like this:
Tire Contact Patch

Now, on wide vs narrow contact patch. If you have more narrow tires, the contact patch is theoretically the same overall area. Lets say a 225 tire vs a 275 tire, same brand, diamater, sidewall stiffness, etc etc. The difference is going to be sidewall deflection. The wider tire's contact patch is more wide than long, meaning that the side of the tire has to deflect less to make this shape. The far more narrow tire is going to have a long, skinny contact patch. This means that looking at it from the side, the tires isn't going to be as much a perfect circle as a circle with a bit squished at the bottom.

This rolls into slip angle and heat. The deflection of the sidewall like mentioned above=work=heat, in a nutshell. Then, there is slip angle. This will be your homework assignment! I've included a photo of a view of a tire in cornering. Research slip angle and find out why wider is better (Nissan was right!) No argument, high performance cars use wide tires for a reason, now to understand why!

http://lh4.ggpht.com/_Ii1ukGkfijY/Sq...jpg?imgmax=800

Sunshine Guy

Here's one gentleman that would seem to agree with you:

Gator Bait

I was originally thinking rear mounted turbo, but I'm more leaning towards a procharger type SC now. Who knows if I'll even do it though....

mrmustang

Yup, perfect example of jackasses on the street.


You want to race, take it to the track.

You want to act like that on the street, pack a body bag, as it is not a matter of if, but a matter of when your luck will run out.



Bill S.

Sunshine Guy

I agree. I hesitated to post the video because of both language and behavior. But I knew the car itself would be of significant interest to the community; I haven't seen another like it.

mrmustang

Perhaps because it, and it's owner are no more

Gator Bait

There are a couple that post on Youtube. There's the one posted and one is 'minivette' that runs around DFW. He's running a mid turbo set up (in front of the rear axle). It was built/tuned by the same shop that does my tuning. He's also putting down more HP than the one posted. I talked to them about doing a rear set up for me, but after talking through my goals pushed my towards an SC. Actually they encouraged me to stay NA. ...and are likely right about it 'being enough'. Any more would only be good for this type of roll racing and Cars and Coffee bragging rights.

There are starting to be alternatives for the hwy street races with groups hosting 'roll races' on closed courses (usually runways). These attract exotics and street cars running well in excess of 1000HP. 800 HP vettes are common place here. We are living in good times for HP addicts.

Sunshine Guy

That's the thing...the levels of NA power available these days push the envelope of what you used to be able to get reliably from a bolt-on supercharger or turbo without significantly upgrading the engine internally. If you plan to increase boost to where you need to strengthen engine internals and upgrade heads, cam, etc., you have to ask yourself if the same money/effort could meet your goals NA, especially if your new rotating assembly enables increased displacement.

V8droptop

Likely scenario, considering how the back end was acting in the video. That's playing with fire, right there..

Gator, I think N/A is a good way to go, personally. It can keep things more reliable and simple, and most of your goals can be met with an all motor build. Just increase displacement, increase top end flow, etc.

charchri4

Yeah but there the whole cars and coffee supercharged V8 Miata thing too...

V8droptop

If what your after is the bling factor, there is always 600-700hp NA builds with carbon fiber covers, billet mounts, and one of these sitting on top, or a row of ITBs.

http://www.marcellamanifolds.net/
Marcella Manifolds - images
https://www.google.com/search?q=marc...G&ved=0CDMQsAQ

This guys stuff always makes my jaw drop. You see him on various forums if you search, from hondas to pro v8 drag cars.

I'm going to be super happy with how my engine looks under the hood, but no doubt, a supercharger/turbo has a certain wow factor.

Here's another jaw dropper of an engine.
lsx 440

charchri4

Hey that is cool! There is a guy on protouring that is building a highrise manifold that looks like a fun project. I didn't consider the looks of the thing because that is usually pretty far off my radar but that would be cool.

No my thought was just being able to say, in the most casual way possible like you were answering what time of day it is, I had a 650 hp supercharged V8 not doing anything when the head gasket went on the stock engine so I thought I would see if it fits...

Gator Bait

see...you get it! Caveat is I want those 650 ponies to not ruin the car at the same time. Of course 'ruin' must be defined by the driver. ;

I got out for a drive yesterday. It was 70* and sunny (Ya..TEXAS!!!). Most of my drive I was in 3rd and 4th between 4k and 6k rpm. I never really paid attention before but all this talk about cams and rpm ranges and amount of hp actually being used had me curious. According to my dyno graph, I'm using 300-400 hp and over 400 ft/lbs when out for a spirited drive. Zero traction issues with my well cooked RA1's though I did drop the pressure down as ya'll recommended (28 cold which got me to 36 hot). No real point other than