Jump to content
HybridZ

Well, I dyno'd the z today


Guest Anonymous

Recommended Posts

Guest Anonymous

It's got a 355, about 9.5:1 with TRW flattops, mildly ported dart sportsman II's, Team G intake, HP 830 carb, the long Hooker conversion headers, and a small solid roller cam-235 degrees @ .050 and .550 lift. It made 297 hp at the wheels. I was a little disappointed, but this was through a full length exhaust system with the air filter still in place. The car runs 11.70's on slicks.

Link to comment
Share on other sites

Screw the dyno #'s, your car runs 11.7's!! What tranny are you running?

If auto what stall converter? What size slicks? My car made 275rwhp when it was way rich and am hoping for around 290 to the wheels now that it is tuned. My goal was 11.9's . Anyway, nice #'s and lets see some pics of the z!

Link to comment
Share on other sites

You're only making 297HP at the wheels and you run 11.7s... Dude you should be MUCH happier. The 1/4 times are what you need to focus on... Trust me on this. Another 100hp won't get you that much further down in your times...

 

Mike

Link to comment
Share on other sites

11.7!! I don't know how much money you have in your ride, but to help to put that into perspective;

 

Vette-$54K/13.1 qtr. mile

Viper GTS-$88K/12.6

Ferrari 360-$176K/13.2

Porsche 911TT-$118K/12.3

 

I think that we hear all the time about 8,9,10 second cars and we get a little jaded. I for one, am thrilled to be able to pull up along side a $100K car in my 33 yr. old Z that I built in my garage and know that I could smoke'em if it came to it.

Link to comment
Share on other sites

I don't feel so bad now as I dynoed 270 rwhp last week and was truly bummed. I to have a 71 with a sbc 355 roller cam motor. I only turn mid 12's as I have never turned better than 2.10 for 60 ft. time.

 

Mike

Link to comment
Share on other sites

:D you're crazy man! be happy that is what you have at the rear wheels. With an automatic trans. you can have up to a 40% hp loss through the drive train. you could be running 375+ at the flywheel! And those e.t.s are great wish i had an 11. second ride.

 

40% loss?! Umm no. Maybe with a 5K+ stall but not with anything you'd run on the street.

 

Hrm, I don't feel so bad though as I saw 300RWHP without the secondaries opening up on my car. 383SBC with aluminum heads etc. through shorty headers and full exhaust. Cannot wait to go EFI with it...

Link to comment
Share on other sites

No dyno tuning this past weekend as the shop was preparing for races or so I was told. They are going to have another special soon..3 pulls 30 bucks. So I guess I will wait.

 

This time I will only dyno if the A/F is up and running, I want to know what to tune or tweek and that is the only real way to figure it out.

 

By the way has anyone put those Nordskog fuel A/F gauges in your car with a bung welded in your header and an o2 sensor installed? My Buddy swears by it and said to put my money (around 100 bucks) into that and screw the dyno for tuning.

 

By the way he is a certified Mechanic, maybe he's on to something.

 

Mike

Link to comment
Share on other sites

Guest Your Car is Slow

Narrowband 02 sensors arent very accurate...they cannot read anything accurately outside of stoich (14.7:1)....a narrowband 02 sensor cant understand the difference between 14.8:1 and 20:1...it just realizes the voltage coming from the sensor wire is higher(or lower) than what it should be for a stoich reading.

 

Now a wideband 02 sensor is a different matter alltogether (this is what they use for dyno sniffers). The element is significantly more expensive and it requires a controller to maintain a proper temperature to the element to get the most accurate reading possible. There are numerous routes to go to get a wideband 02 sensor. The most popular being the FJO wideband kit (what I had on my bike)...or you can make your own (Ill see if I can find the page detailing how to make the controller) and purchase your own wideband sensor (about 200 bucks).

 

This IMO is the only accurate way to tune your car for max performance. Narrowband 02 sensors can help...but certainly not accomplish what you seem to be wanting to do.

Link to comment
Share on other sites

Guest Anonymous
I don't feel so bad now as I dynoed 270 rwhp last week and was truly bummed. I to have a 71 with a sbc 355 roller cam motor. I only turn mid 12's as I have never turned better than 2.10 for 60 ft. time.

 

Mike

 

That's exactly what I have-a '71 with a 355 roller motor. I'm a little baffled by your 60 ft times. Mine ran high 1.8's/low 1.9's with street tires. The low 1.7's I'm getting are on slicks, but they aren't traction limited, the tires aren't spinning. More torque would result in better 60 ft times. My suspension is stock, except that the worn out springs have those spring helper things stuck in them to keep the ride height decent. The car was that way when I got it, and I haven't changed it (yet). Everything else about the suspension is stock. I can't figure out why your only getting 2.1's-maybe it's in the gearing or converter? I'm running 3.54's, soon to change to 4.10's. The car had 3.90's, but the previous owner punished those with another motor so badly that they eventually developed a ton of slack. So, I put in a 3.54 differential I was able to get my hands on cheap. The car immediately slowed down 2 tenths. The same guy I got it from has a 4.10 differential he's going to sell me when he gets done using it. It ought to really pick the car up. Another thing-my rwhp numbers may be off. My converter is a JW, and when the guy who bought it new got it, JW recommended that he not use it with less than a 4.10 gear. So, seeing that I'm using it with 3.54's, I could see how it could really eat some hp up on a dyno. I know that a chassis dyno ought to measure hp at the wheels regardless of how much is lost getting there, but it gets it's rpm input to calculate hp from the engine. If a weird converter combination is eating a bunch of power and allowing lots of slippage, that might allow the motor to rev higher than normal for a given wheel speed, thus throwing the rpm part of the equation off. In turn, that would mess the hp calculation up. I don't know for sure, but I've heard things about chassis dynos not being very accurate with automatic transmission cars. Kinda makes me wonder in any case.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...