V8-Z ALL INCLUSIVE QUESTION

[Kevin Shasteen]

Originally posted by ellobo97:

 

I just installed the 3.9 rear end, with 69 corvette heads double hump heads with 64cc chambers and I believe 2.02 exhaust and 1.9 and a Comp 270 cam.

 

Sorry Ellobo; I too have been away from the ol'puter for awhile. Just ran your #'s & I'll tell you how I got there; kind of interesting...almost like an investigator as I had to look through some of my old books to help come up w/some 'real worl' figures.

 

These are the Knowns:

 

1) 350V8/alluminum intake

2) 270 Comp Cam

a) 224 Duration @ .050 w/.468 Lift on

1.5"1 Rocker Arms & 110Degree LSA

3) "69" Vintage Corvette Dbl.Hmp. Heads

4) 3.9 Differential gears

5) 225/50/15's....this equals 23.85 diameter

6) 700r4 trans....1:1 ratio in 3rd gear

 

Unknowns:

1) Your actual Comp.Ratio

2) Using cast or forged crank/pistons?

3) I'm guressing your car weighs @ 2700lbs; I ran my numbers w/your car @ 2900 w/you in it & a full tank of gas.

 

My Research:

 

I) "Standard Catologue of American Cars"

Lists the 69Vette's engine at:

a) 300hp @ 4800rpm

10.25:1 Compression Ratio

 

II) "Chevy V8 Interchange Manual"

 

a) 69Vette's camshaft had

1) 224 Duration @ .050

2) .460 Lift but didnt mention the Lobe

Displacement Angle (Overlap).

Double Hump Heads are

1) 492 Castings

2) or 186 Castings

 

Now Knowing all that: factor in a Hotrod article I found whereby they put together an engine allmost identical to your set up: Factory Block, Cast Pistons, Cast Crank w/dual plane intake, iron heads & a camshaft similiar to the Comp 270 cam.

Their dyno run brought their maximum HP/Torque to 338Hp @ 5500rpm's & 390ft.lbs. @ 3500rpm's.

I dont think their cylinder heads had as low CC's as yours do, therefor, your HP/Torque is probably a little higher.

 

With this in mind, your car should perform:

 

1) 345hp @ 5800rpms

2) 395ft.lbs. torque @ 3900rpm's

3) ET = 11.78 @ 105mph

 

*To confirm this: simply find an open road w/out any traffic & run your car upto 105mh & notice your rpms.(I'm not responsible for any traffic tickets nor any injuries

[Kevin Shasteen]

Originally posted by kc6wfs:

 

I have a 2000 vortec 2.02/1.60 valves and 10.1 compression. 330hp so they say.

I'm running 14/60/235 tires and they grip very well.

 

What do your numbers tell you?

330HP 2200lb I think, I'll weigh it at the track. 700R4 trans normal gearing, 3:54 rear end, 14/60/245 (not sure on inches round).

 

Thanks.

Dave Booth

 

Without knowing how you came to your supposed HP rating the numbers will only reflect what "variable" is applied:

 

If you're engine is pumping the 330hp range:

a) Tires = 245/60/14's...26.5 Diameter

3.545 rear gears

c) 1:1 gear ratio in 3rd

d) 2200lbs car(?); Unless you have undergone extensive weight reduction your car should weigh around 2700 w/out you in it. I ran my numbers @ 2900lbs w/you & a full tank of gas; correct me if I'm wrong.

 

This should yield you:

 

1) 330hp

2) 2900lbs

3) 3.545 rear w/26.5 tire diameter

4) ET = (Depending on what rpm's at the trap)

a) 122mph if RPM's are at 5500

111mph if RPM's are at 5000

5) Deriving your ET from your weight & alleged 330hp came up w/12.02 @ 113mph.

 

*To confirm your mph/rpm's simply run your car upto the above rpm's & notice your mph. (I'm not responsible for traffic tickets nor any injuries)

 

**If I knew what the 700r4's overdrive gear was I could tell you what your RPM's should be @ a given mph & vic-versa; but I dont remember the 700's 4th gear numbers; sorry.

anyone else??

 

 

 

[This message has been edited by Kevin Shasteen (edited January 23, 2001).]

[Guest Dean570z]

Kevin:

You must be an engineer or engineering student to enjoy all this calculation stuff. Here is another data point, not much different than Dave Booth's or RickB's data.

 

76 280z

350 bored 0.040 over. Keith Black Pistons running 9.5 CR. Iron heads, ported (not polished). Comp Cam valve train including rollers and roller rockers. Factory Alum intake with Holley carb. HEI dist with custom advance. Rams Horn exhaust (beats block hugger headers, but not true headers).

 

Trans is 700R4 with B&M Strip Kit and 3000 rpm stall converter

 

Tires: 225/60 x 14 Nitto's. Super soft compound, will be sorry to see these wear out.

 

Stock R200 Open rear end.

 

When I finished putting this engine together I had access to an engine dyno and and it cranked out just short of 400 horsepower (back in 93). I don't remember much else, such as torque or rpm's, just the disappointment of not reaching the magical 400 hp goal.

 

In early 94, ran a 12.00 quarter mile near Long Beach, Calif, I think speeds were in the 115 mph range. I could get wheelspin in the first 3 gears. As someone else mentioned, light foot on the start, then mash it down. Accelerator pump is set up for this kind of reaction.

 

Current status: Needs the 700R4 replaced, it broke big time during one of it's commute. Engine/trans has over 60,000 miles now, was very reliable till trans gave out, 20 mpg on the highway.

 

Hope this helps you.

 

Dean Byers

570z (built in 93, daily commuter till 98)

Quartz Hill, Calif

[Guest Anonymous]

This is a reply to Kevin. Thanks for all that info. That is really great. I have a lock up torque converter in my tranny as well if that really matters. I was always wondering what HP I have. so around 330. That's cool. I'll get to the drags as soon as they open and see if I can really do that time. Thanks for all the info. I really don't know what type of piston's I have in it. They are stock, and they are the dished top, not flat top. I would think they are cast. I guess I should have found that out when I pulled my heads. Oh well. I'm in the process of looking for a t56 and installing it into my car. I just don't car for the auto thing. thanks again for all the info guys

 

sean

 

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"I feel the need, the need for speed!!"

[Guest Anonymous]

I just saw that you were wondering about my idle. Right now I have it set right around 900 in park and 700 in drive. The new came gives it a good lobe. I like it

 

sean

[Guest Anonymous]

Kevin,

 

your really good with numbers there, one more question. If I put TPI in, what is that going to do to my overall numbers? Thanks for the info.

 

Sean

 

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"I feel the need, the need for speed!!"

[Guest EPS]

Keven,

 

First thing! go auto trans or you will have huge hook up problems which translate into slower et's. Auto trans can be built for great performance and the 10% additional parasitic drag in nothing when you consider much better hook up and lack of gear shifting loss time. But get it built with all the "right stuff" by someone who really knows how.

[Kevin Shasteen]

Originally posted by Dean570z:

 

You must be an engineer or engineering student to enjoy all this calculation stuff.

 

76 280z 350 bored 0.040 over. Keith Black Pistons running 9.5 CR. Iron heads, ported not polished. Comp Cam, rollers & roller rockers, Factory Alum intake, Holley carb: Trans is 700R4/B&M Strip Kit & 3000rpm stall.

Tires: 225/60 x 14 Nitto's. Stock R200 rear.

 

Dean570Z,

 

Thanks Dean for the compliment: I assure you I am no Egghead: I have been interested in musclecars for sometime & have bought along the way any performance book I thought might help. My formulas I've merely obtained from those books. Some books are totally dedicated to this subject-but dont limit yourself to just one; obtain as many as you can...if that is your interest....go for it!

 

Now back to your vehicle: you said your dyno run put your eng's HP @ 400; remember, that figure represents flywheel power. Put the restriction of Weight/Gears of your car &the Human Factor of shifting and you will find a usual 15/20% loss of power: In other words, your engines ability to perform by itself on a dyno -vs- your eng's ability to move your car (Power-vs-Performance).

 

Having said that, here's what I came up with.

 

Knowns:

1) 76 280Z w/24.6 Tire Diameter

2) 350 w/.030 overbore = 355.12 cu.in.

3) 9.5:1 Comp Ratio

4) Roller Cam

5) Factory Allum.Intake

6) 700r4 w/3000 Stall Cvtr.

7) Holley Carb

8) R200 Rear

 

UNKNOWNS:

1)Actual Rear Gears? Assumed 3.545

2)What cfm Carb..wont effect#'s except VE/Volumetric Efficiency

3)Which Factory Allum.Intak..assum Dual Plane

4)What are your Cam's Spec's

 

Proven Performance:

You ran 1/4 in "94" & obtained 12.00 @ 115mph

 

Theoretical #'s Ran & the Results are:

A) 344 HP (Rear Wheel Power not Flywheel HP)

1) Derived from your 1/4 time & Speed

11.8 ET's

1)Assuming 2900lbs w/you in it

2) ET's derived from your weight & HP

C) 2898 theoretical weight confirmed from calculating your theoretical hp & mph @ 1/4.

D) 5568 RPM's @ the 1/4 mile traps

1) RPM's derived from MPH, Gears & Tires

 

HOPE THIS HELPS:

[Kevin Shasteen]

Originally posted by EPS:

 

 

First thing! go auto trans or you will have huge hook up problems which translate into slower et's

 

Thanks EPS for your comment: I have a 2004r in my 70 Cutlass/Rallaye 350 which replaced the th350 in an attempt to get mpg (Fat Chance). I enjoy the auto trans when in Dallas Rush Hour but much prefer to grind the gears.

 

My brother has a Mitsubishi 3000 VR4 & shifting into 6spd & watching the rpm's fall us just toooo coooool!

 

IMO, My Humble opinion, I really prefer to shift gears. I know my Z is @ 600/800lbs lighter than my Cutlass; but hey I'm a glutton for punishment. I like the control of shifting & 6spds to boot!

 

Gotta Go....SuperBowl Party....GO COWBOYS: Wait, Da'Boiz didnt make it this year did they(?), oh well, Go Ravens/Giants!!

[Kevin Shasteen]

Originally posted by ellobo97:

 

If I put TPI in, what is that going to do to my overall numbers?

 

Hey Sean; I could only guess at that one. I'ld say your engine would run slightly more efficient & your wouldnt have to worry about driving your car from sea level to Mile High Denver Co as the FI makes those Atmospheric adjustments automatically. The drawbacks are you have to spend more diagnostic time when something fails as w/FI you now have multiple sensors & the computers to boot.

 

You also asked earlier about the lock up converter in your trans & if that made a difference. I found my 700r4 book from Turbohydramatic & they claimed that the 700's cvtr has the ability to double the eng's torque in 1st & reverse. by @ 2.0:1

 

As speed increases the stator will revolve freely on its shaft, until then your 1st gear ratio of 3.06:1 is multiplied 2.0:1 for an overall 6.12:1...no wonder the 700r4 pulls so hard in 1st gear!

 

I dont have any books on Converters in general; I know the job of the Converter is to multiply torque-but to what degree the other Cvtrs work is unknown to me; I just know what my book says about the 700's Cvtr.

 

700's Gear Ratio's are:

 

1st @ 3.06:1

2nd @ 1.63:1

3rd @ 1.00:1 (Direct Drive)

4th @ .70:1 (Overdrive)

 

Original T-56...........2nd T-56

1st @ 3.36:1............1st @ 2.97:1

2nd @ 2.07:1............2nd @ 2.07:1

3rd @ 1.35:1............3rd @ 1.43:1

4th @ 1.00:1............4th @ 1.00:1

5th @ .80:1............5th @ .80:1

6yh @ .62:1............6th @ .62:1

Final Drive @ 2.73......Final Drive @ 3.23

 

*Final Drives were for the Camaro/Firebirds

 

 

[This message has been edited by Kevin Shasteen (edited January 30, 2001).]

[Guest Anonymous]

Thanks for the info. Now the quest for the t56 begins.

 

sean

 

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"I feel the need, the need for speed!!"

"Don't hate the player, hate the game!"