[steve]

So I finally had my Spotts built 488 dyno tuned. Tell me what you think and what you need to know. I have swapped the rear to 3:55 before the pull. What do you think I might see at the track with just radial tires and some good driving….

[soupman]

Is that torque value correct? It appears to be double the horsepower, I never seen a spread that far apart between horsepower and torque, but could be….

[Scott Stoneburg]

Holy cow torque monster!!!! It made 420hp and 880 lb/ft of torque?

[JLMounce]

Are you sure you posted the correct dynograph? The hp and torque numbers at the reported rpm leads me to believe this is a diesel application, not a 488 poncho.

If this dyno is of your 488, it’s probably highly suspect.

Also to know what type of number you might run we’d need to know vehicle weight as well.

[Goatracer1]

Someone has to explain the figures to me. How can you have half the HP figure at a higher rpm than the torque value? Also what are the mph figures?

[Stan Weiss]

Originally Posted by Goatracer1

Someone has to explain the figures to me. How can you have half the HP figure at a higher rpm than the torque value? Also what are the mph figures?

887.0 Torque @ 2271 RPM is 383.5 HP

429.6 HP @ 2980 RPM is 757.5 Torque

Also it has correct the output to SAE J1349 where as most engine dynos use SAE J607

Stan

[Dragncar]

Not familiar with chassis dyno numbers.
Someone want to break this down that knows more about these things ?
385 HP engines don't have 757 lbs torque.
What would the flywheel HP and TQ be ?

[Joe's Garage]

Non-believable numbers for a gasoline engine.

[steve]

Sorry you don’t believe the numbers. I’m driving the car now. It is a torque monster. It was done on a “Mustang Dynamometer” it’s a 3300lb 81 firebird. I have the build sheet from Spotts to prove it. The engine was not cheap….

[steve25]

How is the reported torque at the crank (1223 ) over 330 foot pounds higher then at the rear wheels when the rear wheel torque is being multiplied by the rear gears?

I am assuming that this motor is NA

[steve]

I’ve posted this Dyno to get reactions from people who have more experience with the process. I’ve never had a car dyno tested before so I have nothing to compare it to. The shop is reputable. The mechanic is a BOP guy who races big cars. He has done quality work on several of my vehicles.

[steve25]

You’re stating that you just had your car tested on this chassis dyno, yet unless I am reading the sheet wrong this print out / test is from 2022.
I don’t think this is your test!

[ta man]

Looks more like a diesel truck engine dyno graph..I'm not buying this..is it April 1st?

[steve]

Ha. No that’s not the case. I just seems like it was done a short while ago to me. I’m on the 9th year of the build. I went back into receipts and that dyno pull was done when I still had the 3:08 rear in it.

[steve]

I have the car and the engine in my garage as I write this. The dyno sheet is real. I’ve been on PY a long time and no reason to lie. It’s not me you are questioning it’s the guy who did the dyno….maybe he made a mistake. We did have a short conversation about the numbers though so there was no error about who’s dyno it was. Or maybe you question Paul. Does anyone here know Paul Spotts ? Local tp the PY “Ames Performace” area like myself.

[steve]

Cost me 1300

[steve]

Took me a while to get it tuned with the Holley terminator EFI. Paid for two dyno pulls from different guys actually. In the end my friend Mike had the best tune solution. He is a wizard. He resides on this forum. I’m still learning the software….tuning is still beyond me.

[scott70]

🍺🍸🥂

[steve25]

Yup, something stinks here!

I don’t care if you had tested a NA 588 cid motor, your not making 590 crankshaft hp at less then 3000 rpm, it’s pure bs or a mistake!

[steve]

I’ll ask the mechanic to explain it and let you know what he says.