Anyone Chassis Dyno'd their Stage II Car?

[Rob Raymer]

Chyke - my A/F was measured with the wideband O2 and F.A.S.T. system.

Cal, I wasn't trying to take anything away from your car. It's very impressive any way you look at it.
My only thing was, it seems like a lot of TR owners (you obviously being one), seem to think Dynojet numbers are worthless. When in fact, I think exactly the opposite. Are they sometimes wrong? Sure. But in most cases, they are very accurate. I forgot to mention earlier, but the newer Dynojets are capable of "loading" the rollers. I can enter a desired RPM, and have the dyno hold it there while I'm at full throttle. Until recently, about the only dyno's that could do that were Mustang brand dynos.
After I dynoed the car, I pretty much knew what it would run at the track (with traction). In fact, I said 135-137mph as soon as I saw the dyno numbers. Lucky guess?? Maybe.

Of course we'd all rather compare timeslips than dyno numbers. But explain to me a better (not to mention safer) way to tune a 137mph car than on a dyno? I was simply looking for some comparisons while waiting for track day.

It went a 10.36 off the trailer. I would hate to guess how many 1/4 mile runs I would have needed to run that, had I not tuned it on the dyno first.

One last thing....what was your mph and 60ft on that 10.03 run with the T70? Just curious.

Thanks,

 

[Rob Raymer]

Re: Much better to be a "Drag" Queen rather than a "Dyno" Queen!! LOL!

Originally posted by 86brick
No offense Rob, but if you want to see great dyno sheets and dyno #'s maybe you should check out this message

Why is everyone on here so against dyno sheets?? Maybe most of you just haven't used one properly. I mean, actually TUNED a car on a dyno.

I've got an LS1 Z28 with a T-88 and a 404ci stroker motor in it. And as soon as I'm done with it, I'll post my 8 second timeslip AND my dyno sheets! And you know what? I bet they'll even coincide with each other.

FWIW, I'll be a "Dyno" Queen over a "Drag" Queen any day. But that's just me....

 

[HighPSI]

I am not against using a dyno to tune it car. I used to do it quite often (used a Mustang dyno) before I started renting the track. I just haven't been that impressed with the Dynojet numbers I have seen. But then again, I had never seen a Dynojet that will load the chasis.
Earlier you asked if everyone was so secretive about their dyno numbers, and I tried to explain that most TR owners prefer to compare ET slips. The torque (or is it gearing/chasis?) of the TR allows it to run a pretty good ET at less mph (less hp?). I have seen many 11-12 second Buicks ET better than a Mustang or Camaro with the same mph.
The dyno has it's merits (it's definetly safer). But I can get a car tuned pretty well in just one trip to the track and we can work on the suspension at the same time.

The 10.02 I ran was at 134 with a 1.41 60'. This was with a small hydraulic cam, standard GN-1 heads and 3600+ pounds.

FWIW: I have built two Stage 2 engines with GN-1 heads and a 74 turbo in the last 2 months. Unfortunatly neither one was dynoed.

 

[VictoryTrans]

Cal, I see that you say a DynoJet isn't the most accurate. What would the most optimal place to get some numbers be? My dad mentioned wanting to get the car dyno'd after its out of the chassis shop, and if a DynoJet isnt any good, don't wanna waste any time. Thanks

 

[Chyke]

I asked about the measuring of your a/f for a good reason. I and several other tuners I know are chasing an issue with teh FAST a/f logging abilities. We have found that teh FAST WB reading is consistently lower that teh dyno's a/f meter by around two points. For example a a/f of 9.1 on teh FAST would be between 11 to 12 on teh dyno. Yet when we pull plugs etc, everthing indicates that the dyno is correct and not the FAST. This is just one of the reasons we do not run any systems in closed loop. We tune to the a/f on the dyno. Recently we have started using EGT sensors on all pulls on the chassis dyno and not just the engine dyno. I have discussed this with many tuners and the problem is most people don't like to discuss their tuning secrets. This is how they make their money. Have you noticed anything odd will tuning.

 

[TurboTR]

It's a conspiracy. <Shhh!> they're out there!



TurboTR

 

[JayC]

I have a dyno sheet up on Meankids. Feel free to have a look. That was a pretty conservative tuneup. About 22 PSI (Not the 14 PSI number everyone here local likes to toss around) and we run that car down around 11:1. 965 RWHP, 774 Ft#/TQ. Im confident we could have broken the 1000 horsepower mark if we would have leaned on it a little more but it was at a dyno day and the next closest car only made like 610 or so we didn't see the need.

 

[ALB231TB]

Rob you've got some very awesome cars. I don't have a turbo buick unit yet but I do have a 01 Z28. Not by choice of course (read 87 Olds thread I have in Junkyard parts to get the full story). Keep us posted on the dyno & time slips i'm always a avid reader of serious Power. How much power could be attained from a Stage II with pump gas 92-93 no octane boost?? just curious.

Have a good one

alb231TB

 

[Rob Raymer]

Originally posted by Chyke
We have found that teh FAST WB reading is consistently lower that teh dyno's a/f meter by around two points. For example a a/f of 9.1 on teh FAST would be between 11 to 12 on teh dyno. Yet when we pull plugs etc, everthing indicates that the dyno is correct and not the FAST
Have you noticed anything odd will tuning.

Actually, I noticed the exact same thing. On my FAST WB, my A/F was 10.25:1 on the dyno. But the Dynojet WB showed around 11.8-12.0:1. Know the age of the O2 on the dyno, I "assumed" the FAST WB would have been closer to correct.
I used an EGT on every dyno pull, as well as every pass at the track. When I pulled a plug on the dyno, it looked much leaner than the 10.25:1 we were seeing on the pull. And the EGT was showing about 1550 on the dyno.
On the track, the EGT was hovering around 1650 from about the 1/8mi to the 1000ft mark, and then would climb to 1700 by the 1/4. When we played the run back on the Datalog, it showed an A/F of 9.19:1 all the way through high gear.

Personally, I'd rather have faith in an EGT, than an O2 sensor. But that's me. Either way, anything more than 1750 on C16, and I'm adding more fuel to the tuning.

Anybody else dealing with the same issues??

Thanks.

 

[Chyke]

Did a pull today. Saw 1690 F on the egt. I have recently moved my O2 to the downpipe and the A/F read a little differenetly (varied from 10.0 to 1 to 11.9 to1) Made 561rwhp. It's getting there. Dyno still said 12.5 to 1. Go figure

 

[Rob Raymer]

I just posted one of my dyno sheets to the website: www.LS1Motorsports.com/Project-87TurboBuick.asp

On this particular pull, the FAST WB O2 showed an A/F of 10.44:1.