Well I know I'm going to sound like an as-!! Oh well!!!! don't care!! But you know if you have to ask a question like this you have no business driving a high HP car!!!You know the Brain is suppose to be connected to your foot!!!! Most all times you see a high HP car all smashed up or even a more mild one also, it was done when someone was driving and just trying to be something they are not! Most all people will tell you YEA I can do it but most others can not!! WRONG!! People in really fast cars don't ask how to handle their car! They don't go for just HP either, they will look at the whole car and then suit the car to them, not suit them selves to a given car!!! Think about all this, it may save your life or someone else's! But then again you won't be able to act like Joe Racer on Friday nights with a so called lesser car!!

 

I am using Toyo Proxys rubber

 

As the saying goes, there's no replacement for displacement. However, I'm pretty sure that line of thinking was formulated at the drag strip. Don't get me wrong; I'm not saying a bit of excess power is altogether a bad thing. But, IMOE whenever a vehicle is traction limited it's a good call to build for a torque curve which won't just blow the given tires off of the car everytime you mash down on the loud pedal. For those who put a premium on carving up the road, excessive wheelspin is NOT your friend (particularly on street tires), as having to lift all the time to save one's own neck gets old in a hurry and it ain't the fast way 'round.

FWIW I've done a fair amount of both drag and road racing, so I do have an appreciation for both. My own priorities having shifted even moreso towards the latter type of performance, not too long ago I aborted doing a 496 build in favor of another hi-po 427. The more modeling was done the more apparent it became that the more gradually building torque and higher RPM power profiles of the 427 in question just far better suit my particular purposes.

Bottom line, whatever your purposes, IMHO you'll be happier in the long run if you strive to match your engine up with how near to achieving them your tires (the best affordable) will allow you to get. My $.02


TSW

 

I'm going to answer your post again, and highlight what I honed in on the first time and the second time.

I own a 2009 Z06, as mentioned before, and I think it has too much power to be enjoyed in this use case. I would NEVER let an inexperienced person drive the car, for "cutting loose" on twisty roads, I tend to stay a gear higher than peak just to keep the wheel torque down. Things can happen pretty fast on a public twisty road: animals, stalled cars, gravel, road, lost vehicle fluids, bicyclists, etc. Particularly road debris would have me concerned with driving the car at its full potential on the street.

Yes. The first six months of driving the car I nearly lost it a number of times, both on and off the track. With a big cube motor like a 565, this is going to be an even more prevalent scenario. As an amateur racer, I prefer to take a bottom up approach (so you're less likely to end up bottom up) rather than a top-down approach. What I mean is - you find your limits by going too slow and working your way up, rather than by going ***** to the wall and trying to slow down.

After using this experience for years, I've noticed that:
1. I am not as fast as the ***** to the wall guys.
2. I've wrecked fewer cars, blown fewer motors, and go through less tires and women.

Even with my approach at tackling vehicular and personal limits (never exceed your skill), I've gotten into some hairy situations as I mentioned before. The biggest problem with approaching a high power car is to retrain your INSTINCTS. No matter how careful and cautious you are puttering down the road at your cruise in, how are you going to react when someone sweeps into your lane? What if you get irritated at a slow mother--- and do a quick downshift and try to floor it past them: and forget your surface check and hit gravel?

That's what you need to be careful about, and I've found after having driven a 500 hp car for 5 years the following:
1) 500 hp is a pretty reasonable limit, as mentioned by gordonm. There's very few street tires that can hold it straight, and coming out of corners in first gear you have to be VERY judicial.
2) It's not as fun as you'd think. I think for a twisty road, a Porsche Boxster S would be more fun than the Z06. Doesn't necessarily mean it's faster, it's less stressful to drive hard and probably more rewarding.
3) 500hp is VERY hard to plant in a RWD car in low gears. I autocross. I could loop the car easily if I sneezed with my foot on the throttle on corner exit.

As for tires, that kind of power will put you at the level where I'd be wanting to run multiple wheel/tire combos so I can have a nice summer compound (Michelin Pilot Sport Cups, Kumho Ecsta XS, Nitto NT05s (listed in decreasing dry traction capability)) and then a nice all season tire, like Goodyear F1 GSD3s, Nitto Invo and others. The dry tires will perform poorly on a wet road, vice versa for wet on dry.

One thing you'll probably find by iterating your motor as such is that not only is there more power, but the personality of the motor will change. It could very well be that the first motor you build is a torque monster that just lights the tires off all the time, and the second seems pretty reasonable until you hit the cam's sweet spot and then watch out! (spin)

My Z06 has more torque down low than the car it replaced (an 02 Corvette), but doesn't "wake up" until 4500 RPM. I've had it get wonky going straight and hitting said "sweet spot".

Hope that helps.

 

TORQUE is the word you should be looking for - horsepower is merely a 'bi-product' of torque. Far better off with a 'lo-po' big cube engine than a 'hi-po' small cube engine - big cube engine will always have a far wider and gentler torque curve so will be less reliant on gearshifting at any particular point - manual gearbox will give you far better control of the power - auto-box/torque converter has too much of a 'flywheel' effect. Also with big cube engine axle ratio and gearbox ratios are far less important than with a smaller lower torque engine. My 3.08 rear-end with 27.2" high tyres and c/r M21 'digs-in' off the line with minimal wheelspin and then 'comes alive' in first gear at 40 mph yet will clear 70 mph before shifting in to second if you want

 

Head on collision while overtaking another car. Nothing indicates exessive power had anything to do with it. This kind of thing happens every day with all kinds of cars.

 

My old buddy that worked for years at a performance engine shop told me it was always better to build big and de-tune, then work your way into a hotter tune, than to build something that was near it's max at desired power.
I'm sure I can detune a 565 to 650hp, which will be closer to about 550 at my altitude, then pick up the program once I get used to that power...if I ever decide to change.
My experiences have always been that I always want more, whatever it is.

 

I'm guessing with your 'handle' you have an interest in L88's - my rationale when having my engine built-up was to have an engine that equated to the supposed power figures of an L88 but in a 'package' that was totally streetable with manners and economy similar to that of stock L36 engine - well I think that I have achieved that aim (although the 'new' engine won't 'lug down' in top gear to below 1000 rpm or pull in top from 15 mph! like the L36, and I do need to use 'super unleaded') - the other thing I considered was that if the L88 package could be driven through a stock big block drive train without breaking anything then that figure (550 hp) should be a benchmark figure. Its still 50% more nett hp and torgue over what a L36 puts out!

 

The other configuration I'm considering is a big bore, short stroke mill. The 565 is ready to put together and I have another ride to put it into, but I came across a bowtie block at 4.625 bore, will hone out at about 4.627, has .903 bushed lifter bores. I got it for a song because the owner didn't want to go any bigger, he's running high compression and spray and was a bit scared of going bigger. If I can find a strong 3.766 stroke crank, I can use an Eagle 6.635" rod with a 1.270" pin height piston for a 507. There are a few 4.625" shelf pistons, but most would need to have a dome milled to get compression down to 11:1 or so.
That's where the L88Plus came from
I blame Jim for that one, he's always raving about how much fun a higher revving mill is, making power up in the range where you can use it rather than having a tow truck engine with massive bottom end torque.
I wonder if a 6223 forging could handle 7000 with today's lighter pistons and rods? They're plentiful and will balance easily. My calculations put a modern piston/rod combo at about 5 ounces less per cylinder than an L88 was...

 

A properly prepped OEM forged/tuftrided 427 crank (3.76") will easily handle 7000 RPM, but make sure it's re-nitrided if you have any work done to one or you'll loose the surface hardening. Have one I'm putting in the 7200 RPM (limited), ~550 HP, pump gas 427 makeover for my shark. IMCO you should always stud the mains if you're going to rev it that high. FWIW, 6.385" rods with 3.76" crank yields a nice ~1.7:1 rod/stroke ratio. Yep, have a set of H-beams that length also.

For what you're looking to build, I'd just deal directly with JE and have them make you a set of 4032 forgings for your specific application. That way, not only will you save some $$ (vs buying thru someone else), you can also get the domes (blended), ring and compression heights right where you decide. I'm going with the expansion groove, but skipping the gas ports.

Something you'll need to start watching when revving a BB is valvetrain weight and component stiffness. Don't skimp on these bits! Smaller valve stems and titanium retainers are a good call, at a minimum, along with quality rockers and pushrods. And, don't under spring! Suggest a 4/7 swap, but in any event I'd go with a steel cam core with iron gear. Remember, the valvetrain won't care how big are the cylinder bores, rather how high you rev.

Thought I'd share some of how I'm going about my own L88'ish build, in case it's worth $.02

 

"Nearly all men can stand adversity, but if you want to test a man's character, give him power." - Abraham Lincoln

It's all about discipline.

Also, be careful de-tuning as you don't want to end up with all the bad street manners and none of the power. It's not just cheaper than redoing it but more likely to lead to a better result when approaching a build "holistically."

 

Why not just put some MT ET Street radials on it and be safe? You can now get them in 18" diameter if that is the look you are going for and they will hook up plenty good... I mean you are not gonna hook from a dead stop and dumping the clutch but.....they hook pretty damn good from a roll.... Your suspension will have a LOT to do with how it hooks.... IF you are running a road race style suspension with a super tight front end, its not going to hook.... But a stock front suspension/modded rear suspension C3 will hook pretty good...

I can flat hammer mine from a 20 mph roll and it dead hooks if the tires are warm and the street surface is good.... This is with 670lbs of tq at the crank... BUT my car is an auto and only has 3.36 gears....both of those soften the hit to the tires....AND my suspension is setup more for street cruising and drag racing....not corner carving..

Only problem with running the MT ET Streets is they wear out fast....and they are not great in the rain.

 

Only reason I would put a short stroke in it was if I was wanting to shift at 8500+ RPM all the time and cross the line up past that. A 4.25-4.375 stroke will rev 7500+ anytime you want to. Put good heads on it and let it go. You can adjust cam for manners. Even with a *small cam* they will make power. Mine still sounds wussy and will lug around under 2000 rpm in 5th gear with 3.07's.

Alan's 496 is running a 230'ish HR and cruises fine and makes stupid power into the 6000 rpm range. Keeping milder gears like he has and letting it *work* would be a lot of fun in a street car. Just think of his combo with another 70+ cubes, better heads and just a hair more cam. Talk about fun from a 30 mph roll!

JIM

 

If wheel spin with big time HP is the main concern...
Traction Control is the answer. We run a traction control system on our X275 Drag Radial car. It's a 518" BBC on one huge kit (550-600 HP)Try to hookthat up on 275's!
Traction control is a must with that combo. there is some excellent stuff out there that really works. 4's in the 1/8th @ 149 MPH 1.19 60ft.
PM me and I'll give you more info if interested.

 

Yeah thats what I'm wanting....

I see me and you building me a 555, maybe those 3Xtras you tested and a decent sized solid roller.....and I would LOVE to do the Holley XFI injection...... Basically your motor and FI system....MAYBE a tad less cam just so I easily idle it every where with the AC on....... 850hp should be just enough....Ofcourse I will keep my 3.36s(if Mike's Super 10 bolt stays together...LOL) and have a killer 200R4 in it....

High 9s with AC that I could drive every day......Sounds like a plan...

Did I mention drag radials...? LOL Gotta keep that big power under control.....

 

I'd suspect the OP isn't the only one who'd like to know more...

 

...get some good insurance and update your will, LOL

 

Someone mentioned something that happened to me about the car going "wonky" at certain RPM. I was in second gear and slowly getting hard on it finally it was to the floor and was picking up speed nicely. About 5000RPM the rear tires broke loose and I could feel that greasy snaking feel of the rear moving around. Almost spilled my coffee

 

Just watch Tokyo Drift a few times. LOTS of RPM...keep 'em burning and hang on! Wanna actually accelerate? Just back out a little.

JIM

 

I do hope those without sufficient skills realize they shouldn't attempt that approach at home.