Yep hit the track then you get to do the chassis tune at the same time.

Well then i have to disagree. My experience with chassis dyno tuning has been i always had to rejet at the track after a chassis dyno tune. I cant remember which way but i think it was richer to achieve max mph. This has happened every time and my car has been on a chassis dyno aleast 8 times. I will agree that i would find best timing on a chassis dyno, but why not just go to the track and find both?

dyno is ease of repeatability and quickness of getting result . I have only used a chassis dyno but found an hour or two is a good thing . Timing loop and AF settings . Really I only depend on the AF number , if that is correct after timing loop then its time to run it down the strip .
and yes the dyno can occasionally throw you a curve ball .

Tex

Yep, you can find best timing on the chassis dyno.

The car on a chassis dyno compared to the same car at the track has two different condition it is dealing with, just like the engine on a engine dyno compared to at the track
On the chassis dyno no moving air is affecting the carb. air inlet temps and no oil is sloshing around in the crankcase, same thing on the engine dyno
Hence the old adage about we don't race dyno, do we

YOU get it but you should after ALL of those years of racing..........

Yep. Your exactly right Cab. The air is all different hence the reason for the jetting changes.

Dave...I have been watching this. I am going to be honest and tell ya that I wouldn't spend another dime till I put it down the track a few times. Good luck!

The season is just about over for me. 40* and rains just about everyday now. Still gonna do the intake and double adj. Shocks on front. Oh, needs the 4.10 gear too. Something else i'm thinking about is the hp deficit the milodon oil pump with 20/50 oil and the mechanical water pump with flex fan is causing. May be 40-50hp right there. I dont always take the easy road. I built this combo trying to make 700+hp without all the electrical components and on pump gas.

Yeah, how many times have you seen engines making 550hp on the engine dyno and put 350 to the tire on the chassis dyno (in street trim). Easy to lose well over 100hp from simple accessories. Check out the recent engine masters air-cleaner shootout. Well over 100hp loss on a 650hp engine by choosing an incorrect air cleaner. Jaguar clutch fan mod is a great choice for most of us if you have clearance issues, other than running a mechanical which will cost 25-30hp alone. Good luck on your build.

I went to Dragway42 last Friday night, got one pass in before it poured rain, hoping to go this Saturday but there's some rain in the forecast again. I agree that you just need to get it to a track, and if the season is over then maybe a chassis dyno session or wait til early spring for a track day. I've raced my whole life and I've never ever used an engine dyno or a chassis dyno. I set the timing at 34 and jet the carb with some homework. Make some passes jetting up and down, then make some passes moving the timing up and down. Then test some shift points etc.

Every car I've switched over to an electric water pump has dropped 1.5 tenths in the 1/4. I'm currently running a mechanical water pump and flex fan and already have the desire to try an electric water pump, but it's a 10 second street car driven to the track so I like my mechanical setup.

this build was intended to be mostly street as well. Gonna run it with all the mechanical components first. I'll get there, just running out of time this yr.

Pretty much what i have always done. I have swapped to electric fan and pump on two cars and seen right around a tenth both times.
Saw a little more gain swapping out bias tires for radials, actually about .013

I like this topic, I have some experience with dyno numbers and track results. Not all dynos are created equal. When I first built my big motor I ran it on a local dyno. I got some great results, 830ish HP. I put it in my car and couldn't get it to run the number. The carb was dead lean and I ran a good 2 or 3/10's off what it should have ran. I was in the 9.20-.40 range and should have been in the 9.oh's @ 2900 lbs. I had little help with carb tuning and the dyno day was a long day to only get 4 pulls.

Over the next winter I carted the motor up to Dwayne and we spent a day dialing the carb in. After his tuning, his results showed 750-775ish HP. We made a lot of pulls, I recall it was close to 20. I had added a little weight in the car by the time it got back to the track. The car ran exactly what it should have run with the power it had. It ran consistent 9.20's with a best of 9.16 with 100 lbs more in the car. I never touched a thing on the carb at the track. The next winter I ironed out a few deficiencies in my combo. We dyno'd again and picked up close to 100 HP. Now I really was in the 830-850ish HP range. Again, I put it in the car and ran exactly what it should have for the power it had. Consistent 9.oh's and a best of 8.94 @ 3000lbs

Track tuning you have changing conditions. If your chassis doesn't hook every time and show a change in ET form a tuning change, the chassis may need tuning too. If you spin your MPH numbers will be higher than if you dead hook. The DA could change 400 feet in a day if it's a few hours between runs. It could change more than that on different days. There is no substitute for good engine data. The whole combo needs to work together if you are chasing ET.

Butt dyno on the street does not work when you spin the tires in any gear.

Yep, the time slip is the best dyno. No two cars of the same RWHP level will ET/MPH the same.

Okay what would be a good type or style water pump to run and be able to keep from losing power

My Moroso has been good to me with factory housing but they also make a remote with the same pump.

The moroso is a drop in electric. It will be i get if need be to get to 9's

I got the NEW Moroso drop in black pump and it rocks and is more efficent and lighter than the old blue pump I ran for years...........