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280Zone

Wish me luck...at the dyno..

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280Zone    2147483647

Long story shortened, had 1st V8 car loved it, traded for a "better" V8 Z ended up not being "better" but worse. Bought another engine that was "better" but ended up not better. Third transmission, after trying to find a true automatic. Now have totally rebuilt turbo 350 trans and a brand new Year One crate engine with 400 "dyno" horsepower. If this doesn't give me 350 Hp to the rear wheels lots of parts are going up for sale! Do or die this Friday!

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John Scott    0

Just an idea, but go to any 1/4 mile track, take your

(trap speed X .00426) X (trap speed X .00426) x (trap speed X .00426) X weight. It will be approximate of a typical dynojet..weather conditions, altitude make big differences...The good thing is you also have an actual measurement with the car rolling down the road, not a controlled dynocell.

I'm guessing low 300s, 325 for a number. Dyno'd on the stand is worlds apart from living in a Z engine compartment, exhaust compromises, heat, airflow.

Good luck and hope you get more than you hoped for.

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jack46    2

There are many good drag calculators on line given et, mph, weight etc. I suggest if you want an estimate of what performance to expect go to one of the following

 

http://www.stealth316.com/2-calc-hp-et-mph.htm

 

http://www.wallaceracing.com/et-hp-mph.php

 

http://www.dsm.org/tools/calchp.htm

 

http://robrobinette.com/et.htm

 

 

Good luck with the dyno

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Savage42    21

Oh, then there is something seriously off. Did you run the A/F ratio sniffer on the exhaust? I'd assume you have something off with ignition, mixture or cam timing? Definitely down 100 HP!! Hope you figure it out!! (the parking brake was off, right) ;)

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Tony D    143

I've see that before. A 383 dynoed at 244 to the rear wheels, it took another year or so playing with G-Tech and WBO2 to get everything dialed in and making 300+ to the rears.It's more than bolting it all together, unfortunately. Torque is probably pretty good, but to get anywhere near that HP, you will need to do some fine tuning.Disapointing, I know, but it's the way it is...

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280Zone    2147483647

The engine is a vortec 350 with these specs;

Compression ratio: 9.5:1

* Vacuum produced: 12hg @ 800RPM

* Recommended fuel: 92 octane

* Max recommended RPM- 6000

* Block: Seasoned 4-bolt iron

* Crankshaft: Nodular iron

* Pistons: Hypereutectic

* Connecting rods: Powdered metal

* Camshaft- Hydraulic roller

* Valve lift:.520"

* Duration @ .050" (int/exh): 218deg/228deg

* Rocker arms: Stamped steel 1.6:1 ratio

* Cylinder heads: Ported Vortec

* Valves: Stainless steel 2.02 int/1.60 exh

* Valve springs: Heavy duty

* Bore x Stroke: 4.030" x 3.48"

* Intake manifold: Dual-plane aluminum

 

with a Holley 770 street avenger, MSD 6al ingition, HEI Distributor, Sanderson cast iron headers/manifolds, electric fan and water pump.

 

Ran the tail pipe sniffer and had a target of 13 Air/Fuel. Swapped out the jets a couple of time to get it consistant through the whole run.

 

Sending dyno results to YearOne to see if they can shed any light on the subject.

236HP_thumb.jpg

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rucus01    10
The engine is a vortec 350 with these specs;

Compression ratio: 9.5:1

* Vacuum produced: 12hg @ 800RPM

* Recommended fuel: 92 octane

* Max recommended RPM- 6000

* Block: Seasoned 4-bolt iron

* Crankshaft: Nodular iron

* Pistons: Hypereutectic

* Connecting rods: Powdered metal

* Camshaft- Hydraulic roller

* Valve lift:.520"

* Duration @ .050" (int/exh): 218deg/228deg

* Rocker arms: Stamped steel 1.6:1 ratio

* Cylinder heads: Ported Vortec

* Valves: Stainless steel 2.02 int/1.60 exh

* Valve springs: Heavy duty

* Bore x Stroke: 4.030" x 3.48"

* Intake manifold: Dual-plane aluminum

 

with a Holley 770 street avenger, MSD 6al ingition, HEI Distributor, Sanderson cast iron headers/manifolds, electric fan and water pump.

 

Ran the tail pipe sniffer and had a target of 13 Air/Fuel. Swapped out the jets a couple of time to get it consistant through the whole run.

 

Sending dyno results to YearOne to see if they can shed any light on the subject.

 

 

 

I would check the timing and make sure its following the a good curve. You could have too much or not enough timing. Find out from year one what it should be when its all in. Also check your manifold temperature and see if its too hot. Check your exahust manifold for any leaks. You mention that you are using a cast Iron manifold, its possible it isnt sufficent for that combo. What size and what kind of exahust do you have on the car past the manifold ? That cam has a decent amount of overlap and if you arent extracting properly your mixture will be dirty and you HP will be way down.

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280Zone    2147483647

My exhaust is different than what year one uses for dyno testing, they used long tube headers I have Sanderson cast iron block hugger "headers" manifolds. The intake manifold temps were just over 100 (I am in Phoenix and our daytime temps are running in the high 90's). Water temp in the engine runs about 160 degrees. I can't quite figure that out either since I run a stock Z car radiator, no thermostat only a restrictor plate because of the electric water pump. I admit my exhaust after the manifolds sucks cause the shop didn't listen to what I want and gave me what they wanted. Going to the track this Friday to see what numbers it runs then will probably run a lager straight pipe with no mufflers next time to compare. Still waiting for Year one to respond...

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grumpyvette    677

have you taken a exhaust back pressure reading at full throttle?

did you degree the cam in or only install it per the dot-to-dot marks?

what was your total ignition advance at 3000rpm?

what was the true F/A ratio?

what was the vacuum reading on the intake at full throttle?

go any pictures of the spark plugs?

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rucus01    10
My exhaust is different than what year one uses for dyno testing, they used long tube headers I have Sanderson cast iron block hugger "headers" manifolds. The intake manifold temps were just over 100 (I am in Phoenix and our daytime temps are running in the high 90's). Water temp in the engine runs about 160 degrees. I can't quite figure that out either since I run a stock Z car radiator, no thermostat only a restrictor plate because of the electric water pump. I admit my exhaust after the manifolds sucks cause the shop didn't listen to what I want and gave me what they wanted. Going to the track this Friday to see what numbers it runs then will probably run a lager straight pipe with no mufflers next time to compare. Still waiting for Year one to respond...

 

 

If you do the SAE correction for those conditions it shows you should of made 371 at the crank. Poor exahust and a tune that is a bit off, and I can see you dropping to 300 fairly easy, which is about what you made. Do the things we mentioned and tighten up your tune and you should be able to hit 270-280 at the wheels under the same conditions. I would check the things that you did on the motor for problems (exahuast leak,plugs,plugwires,are the secondaries on the carb opening?)

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dr_hunt    350
Year One crate engine advertised as a 400+ hp engine. Dyno results I end up with 236 at the wheels. Seems I lost 100HP in shipping.

 

You all missed it. It's called density air boys. Hot dry phoenix air sucks, bet your at 5000ft +++ loosing 20% of your advertised HP to start with so your at about 320HP max right out of the box at the flywheel. Throw in the drivetrain losses of another 20% and your at about 260HP at the wheels if it's all properly tuned.

 

Nope, your spot on there dude, get it tuned drive it to sez/dni and see what happens :shock:

 

It takes alot of motor to run at altitude.

Edited by dr_hunt

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