wr1970

Where is the break between high performace and mild? Street engines then race engines. Let see where this goes.Please be nice with your opinion.Respect others opinion.

GEARMAN69

awe.. I like this.. definition varies.. a mild stock looking big block can whip a hi perf small block that looks and sounds hot and eats its lunch sometimes. race I would define as octane needs and also basically if the cam is too big to hold an AC at idle well. Basically like the factory cars dropped AC on hot models Like W30 W31 or RA IV Poncho etc.. those are HP and Race

wr1970

So Gearman a 91 octane bbo that runs mid 11's in drive would be what?

droldsmorland

Streetable with streetable idle. Barely streetable barely idles.

GEARMAN69

Not enough info , what gear ratio ? is this a full weight vehicle with full interior

or a gutted out low geared race car that runs on pump gas. Thats is the other variable I didnt mention..


Octane and Idle quality but also gear ratio and general appearance or build of the body.. a gutted interior fiberglass paneled stickered up car with 4.10 gears and 91 octane BBO that lopes hard would be HP and Race but on pump gas.

Think of it as having 3 of the 4 deciding factors

High performance results can also be had by a mild performance engine with a mild gear and full weight and full interior. A few of my buds around here have mid 11 second N/A 64-67 GTO cars that are pump gas able full weight stock appearing bodies / interiors and only run a 3.23 gear but with a switch pitch th400 They are highly tuned and fine examples of "mild" high performance combos that are raced but could pass and are driven as just stockish street show cars

wr1970

Full interior carpet seats door panels no air 373 rear gear street legal. No power adders. Idles at 1,000 rpm. 91 octane fuel. All steel body with fiberglass scoop. At mid 11 seconds.

GEARMAN69

I would call it high performance street strip

marcar1993

We have the wrong reasons to argue street or strip.
A street car is a car that only can be driven daily, but is. Something that can sit in traffic and will not overheat. I know of 9 second cars that are daily driven pump gas cars with a/c.
I also know of 11 second cars that could not handle a traffic jam and need race fuel.

A street car is what you make of it. If you drive it on the street regularly and the vehicle takes it, it is a street car.
When you build it, you make the decision what you want to do with the car and design your build around YOUR expectations of a street car.

Some people do not want to deal with a street car with no a/c or low vacuum and an aggressive cam. Personally, my ideal street car has an aggressive cam, some gear, overdrive, and still retains a/c and a radio, and I can drive it on a highway on pump gas.

oldcutlass

I would think that it would be based on the percentage of increase in power and torque over stock. Whether its street driven or not is irrelevant to the differences.

wr1970

Marcar is can be drove in traffic.This car has power brakes. Many muscle cars had no air from the factory.Some had no power brakes. Radio optional. This car has a radio installed with all ***** and speaker non working.Might be fix able but not sure never had it checked out didn't really care.

wr1970

So where is the cut off from mild to high performance?

wr1970

Point is well taken. I think in the end maybe a poll should be taken to try and define the line of mild to high as not clear.JMHO

GEARMAN69

The cut off is where you stop arguing over a a pointless opinion that cannot be defined clearly LOL.

Mild should compare better to the word Radical as in Combination of parts or Behavior of said combination but the Performance will vary. For example my 455 is a mild combination over all but it is for race. It does run on 93 octane and 32 oz can of Torco though and has 3.08 gears. It lacks exhaust and a better radiator for street use though. Take the same drive train and swap to a 800 pound lighter 68 Firebird coupe with same 3.08 gear with the better radiator and A/C added and what doe that make it? a 11 second street car that I race. Switch to better flowing aluminum heads that also lowers my octane requirement to ditch the Torco and it goes faster. Still a street car and still 3.08's (or 3.23's)

Another comparison like my old mild 70-1/2 Trans Am 400 car, a sorta de-tune smooth idle pump gas version of the RA III engine I had but 9.3:1 instead off say 10.5 , Cast Pistons, Summit 214/224 cam , iron intake and heads , Qjet etc.. th350 3.55 gears ran up against a Hugger Orange and White 69 Z28 302 car on the street. Now that hot dog 69 Z is a full blown High Performance engine versus my Mild Pontiac for sure but when the light turns green he doesnt know what hit him. Blew his **** away. My car was a consistent mid 13 car in street trim in the mid 1990's best of 13.3@103

Another scenario

Built a fairly mild 406 SBC with only 1.94/1.5 valves , a hyd flat tappet cam, same Quadrajet I use now, HEi, TH350 , 4.10 gear. Under 6000 shifts, light truck, ran mid 11's but I did trailer it. It was a Race only set up as I wanted and I suppose it was High Performance but it was Mild compared to others race setup. Fast forward that 1998-2002 Build to today and now its a pump gas LS swap with AC running faster than I was then. I did try a sloppy poor working power **** plate on it once and it went 11.0 @121 with a 6.9 1/8th but a slower 60 foot than on motor.

Trailers Lives Matter

GEARMAN69

Driven to Track and Raced or Trailered to Track and Raced ?

wr1970

Gearman what i get out of your last post is this a mild performance car capable of say low 13 to 13 flat would be mild performance street car. That is if i read your post correctly.Would you say a high performance street car is 12 anything to what ever is high performance street car as long as it remains street able?Trailed and drove. The car has gone over hundred miles one way driven.

GEARMAN69

In today's world if we are going to rate it by its ET I would have to say a 13 second car better be mild since new cars do it with ease. High Performance Street car 12's or quicker seems fair as a break. An 11 second pump gas old school street car is still well respected by me in my world.

wr1970

Okay fair enough Gearman you and i have common ground on this discussion.I would like to hear more from others also. Not everyone runs a car at the track but may have a mild performance street car. They also may have a high performance car for the street. I think street car Tens is do able with right parts in a say 3750 lb car pump gas no power adders. I am talking old school street cars not new factory cars.

Inline

IMO time has driven past these ancients. This is US based forum, and mostly contains US based users, but outside of your country, drag-strips arent so big thing as it seems to be in your country. Im sorry btw if this goes a bit on OT side.. Also, i cant speak for anyone else, so this is just my opinion.

We define mild/ high-performance models more like from every-day use perspective. At todays traffic modern 140hp diesel with torque it carries is more than you can use; everything over is unnecessary. Big blocks are blasphemy. I, myself, find me occasionally trapetsing between BBO and SBO, even when properly done SBO has more than i could ever can use on traffic. At one point, todays word is efficiency. SBO fits more to this category, even in stock setup. And in the other hand; if you buy old us-made car with V8 here, youve already thrown most of common sense away. So whats fits your wallet and personal prefence? Both will get the job done, both will Fry the tires, and get you from point A to point B in exactly same time. Only bragging-rights differs.

End of OT. My vote when mirroring it to todays world were living: Mild performance: wont Fry the tires with locker. High performance: Fry the tires with locker.

GEARMAN69

Agreed WR1970

wr1970

Listen to the song Copper head road.{I still remember that rumbling sound.} Then you might get why here in the usa we love our old cars that burn the rubber off. Nice of you to post thanks.

76olds

I got the smell of whiskey burn'in down copper head road here.

So here's my take on performance IMO.

Ther are poor guys like myself who just uncork the exhaust, run headers/duals, add an intake, rear gears and knock some weight off with adding more aluminium parts.
To me that would be mild performance. 1 up from stock.

Going with a complete new engine build adding rear gears etc with higher compression would be a mid performance street driven car no track time. 2 up from stock and 1 up from mild performance.

Then the list goes on with high performance, dyno'd street/strip tire screamers - strictly race set up.

Eric

wr1970

76 olds i agree that there are levels to mild performance. So thanks for your opinion and post.

z11375ss

How would you classify my Cierra Diesel? I think this was THE worst car I EVER owned. This one isn't mine but is close enough. Yuck. The 516 on the window represents days and hours to run the quarter mile.

76olds

I'm considering taking my 76 down to Sparta Dragway near ST Thomas this summer on a Friday night.
I spoke with a friend and Friday nights are for test and tune, they also welcome first timers out to take a run.
If I get the bug then my 76 could get a major transformation under the hood.
Hopefully I'll do better than the 516 above !!

80 Rocket

My friend convinced me to bring my 80 Cutlass to the track in 2003 for the first time. I never been to a drag strip before. In 2016 I became Director of Race Operations of that same track........be careful, it's addicting.


ps- back then my 80 went 15.5 in the 1/4 mile first time out in 2003. Now it has went a best of 11.13, both engines being 355 cubes.

Mr Nick

Street engines drive themselves to the race track.

Race engines are towed to the race track.

76olds

I have heard its very addicting, I'm going to start rolling up our change just in case in need the extra power plant $$$.

Director would be a cool job to have, best seat in the house.

So far my wife is on board to let this fly so I'm half way to getting going with it.

I've pretty much got everything done on this 76 except the heart beating power plant haha, I knew it wasn't all for nothing.

Hope to be posting here later this summer with my wicket first timer times lol.

wr1970

My first pass at a track was on a dare in a 3/4 ton ford pickup? I was hooked after that.I think will have to check 17 sec pass. I have a picture of me holding up my time slip.LOL A guy has to have proof sometimes.LOL

80 Rocket

I still have my first time slip ever. I can barely read it but still have it.


To answer your question, I think the difference between mild and high performance is hp per cubic inch. If you make 400hp with 355 cubes you have 1.12hp per cubic inch (400hp/355cubes=1.12 hp per cubic inch).


Once you hit 1.2+ hp per cubic inch, you are in high performance territory. It actually takes some planning and know how to achieve this type of performance. This stage requires some porting as well as selecting proper headers and matching intake to maximize power. Even doing these things may not get you in this zone if camshaft selection or fuel management is off. Also, being here does not require race gas if you got a very good handle on things. When you are here in this zone, you have a well thought out build that has taken into consideration all variables and have properly matched all components to work together in unison.


I would classify .9-1.19 in the mild category. This is much easier to achieve with readily available shelf parts, and usually does not require as much planning and science behind it. Making 480hp with a 468" big block Olds could be done with a good machine shop in your corner utilizing stock heads with a good valve job (or aftermarket offerings in out of the box form), headers, shelf cam, and a compression ratio still friendly to pump gas. Getting on the high side of this will require some porting of the heads, though.


Anything less is in the stock power ballpark (the most powerful stock engines). There is nothing wrong with being in this zone. This is a great place to be when you are still learning, or are on a budget. Once you get out of this zone, durability really becomes an issue. Costs really start to escalate when you start to go past this zone as durability and cheap cannot be used in the same conversation.


Personally, I have the most fun in the stock type zone. I am helping a young man from this site right now with his build. He has a 76 350. We are reusing the stock bottom end (new bearings and rings). I am showing him how to properly disassemble the engine, clean and inspect parts, how to measure critical clearances, how to degree a cam, etc. However, because I would feel like I let this young man down, I am doing up a set of 7a heads to put on this thing. I upgraded the valves to 2"/1.62" and did a nice valve job with careful attention being paid to the throat diameter. On top of that, I spent a few hours grinding the short side radius as well as working the bowl with a carbide.


At the end of the day, the heads went from flowing 198cfm @ .500 lift to flowing 229cfm @ .500 on the intake side. The best part is the intake runners have only been slightly enlarged a few cc's with this type of work, thereby maintaining velocity and not killing any throttle response. The heads after .500 lift keep flowing the same (about 229-231cfm) so they are perfect for a cam in the .500-.530 lift range.


I wouldn't expect this build to make more than 320hp, and if it hits 320, it will be on the low side of mild per my definition. But, I would consider this a stock type build considering the stock components being used.

76olds

Thanks for starting this thread Neeley, I find it getting interesting.

Don posted some very good points with the ratio CUBES/HP.

I would think that most guys that get into the hobby think differently, I say this because I see so many intake/carb/exhaust changes at car shows.
Be it Olds, chev, dodge, ford, etc. The bolt on guys feel as thou just these upgrades are putting out mild performance, including myself actually.

When Don lands a post such as the above, it gets the wheels turning in my head and probably others who are reading this.

I suppose, true racers,engine guys will always have a different range of mild-high performance differences over your car guys that just think bolting on a few mods result in performance.

Great thread I enjoy reading this stuff as I educate myself a little more.

I can say that I'm no where in the performance category with the additions I've added to my Olds.

I know the Olds heads are the big downfall in performance, it was Classic Olds guys that informed me of this.
However I had already purchased most of the "Performance enhancing" parts prior to joining.

Cheers
Eric

wr1970

Don not only do i have the first time slip. I have all my log books and every time slip they are stored in shoe boxes. This helps them to stay good enough to read. You can spray a time slip the clear enamel this will make info darker. Don't drown it with spray. Good read Don on your post and i do agree with most.

Inline

I love them too, no doubt about it. But love and sense are two different things. Just gave my opinion about the topics question.

wr1970

We appreciate you making that opinion known. Who ever said the car guys that drive these muscle cars have any sense. LOL Cost isn't even or no drag strip isn't even the reason to own and drive these cars. It is a feeling you get driving one of these car.The sound of exhaust. Being able to work on them if the need arises. To know because of you this car is being used and appreciated for what it is. To see other people wave,honk the horn,come over and talk to you at a gas station. These are just a few reasons we love these cars. Have a good day inline and maybe someday you will own one of these type cars.

Troys Toy 70

I would agree with several of the points on this thread. It certainly depends on application.

I agree with Don's hpr/cubes the most. Although, I believe small blocks tend to reach the 1 to 1 mark quicker, so maybe there should be a sb and bb scale. I also think anything faster than 12.5-12.75 in the quarter for a 3,800lb car is the max for mild for a bb.

My generic definition is mild includes any engine mods that don't require major jumps in the drive train to keep up. I.e. if you jump the stall up by more than say 500 because you have to, to drive it.

80 Rocket

I am working on a better formula as we speak. This formula does not care about small block or big block.......it just cares about your powerband regardless of cubes. It's called BMEP (brake mean effective pressure). It standardizes the most basic build compared to an F1 engine. It is the ultimate equalizer. My airflow mentor/engine genius is going to give me his program that he made next Thursday. On top of standardizing a dyno session, it can really tell you how effective your powerband is.

80 Rocket

I would say if your bolt on performance stuff does not make more power than the factory made with factory stuff (the highest performance factory engines), you are still in "stock" land. It doesn't care about your feelings on the subject.


What your engine wants to really make power is pressure on the piston. If you don't up the compression, it will always disappoint you. Headers, intake, carb will not alleviate low pressure on the piston. What your 76 350 is asking for is some compression first and foremost. Every bolt on that follows will complement.

oldsmobiledave

I disagree. I tow my street car to the track because my local track shut down 5 years ago. It's 3.5 hours each way to the closest track and just not feasible to drive 7 hours round trip in the summer without a/c.

70cutty

That's completely irrelevant. You are towing it because you want to not cause the car can't be driven on the street.

wr1970

I trailer mine in hot weather not because the car is hot to drive with no air conditioning. It is because in the hot weather i can cool down in between rounds.When you race the windows are all rolled up and a helmet on. If you are fast enough you have to wear a jacket. You can not wear shorts. Let me tell you it gets damn hot with that jacket on and a full face helmet. I call it hotter than the hubs of hell. I am glad i am not fast enough to wear a full fire suit yet.

oldsmobiledave

The original statement was that race engines are towed to the track. Just because it was towed there doesn't make it a race engine. If the track was 10 miles from my house like it used to be I would gladly drive there.

My statement is not irrelevant but your opinion is simply that, your opinion and it is no more valid than mine.