Let's play dissect the time slip!

[moparman63]

kinda what i figured....way more head than my indys.

[CDMBill]

And I thought they were SBF numbers. Kidding James. Now that you have a solid baseline you can start working through all the suggested 'improvements' listed by the Bangshift cognoseti. I'd still start with a proper ARB, Wolf Race Craft or similar as other folks here will know the current hot set up. I just want to sit back and learn.

I can't help it but all this Fox bashing makes me want to pick one of those ready to go rollers from Racing Junk and run SSR/NA/BB.

[JeffMcKC]

Bill, pick one that comes with one of those Nascar Flag poles like they use in the party lots, it so you can Identify your Mustang in the lanes from all the others

[CDMBill]

Good idea, I hear the ones with number 14 on them are cheaper at the moment.

[Lilracr]

Good idea, I hear the ones with number 14 on them are cheaper at the moment.

Only cheaper if it's been on top of other cars

[BBR]

And I thought they were SBF numbers.

Ow ow ow ow ow

[Lilracr]

330-340cfm is very common on a SBF intake port for a 400+ inch motor.

I am sure you have a fair amount of power in the intake and heads, but there should be a bunch of other fruit elsewhere.

[BBR]

Ohhhh yeah I know there is. I just don't wanna go there yet and I will want to upgrade to a forged crankshaft before I do!

First order of business is looking at improving the first 330 feet and improving airflow into the existing carb.

[milner351]

What throttle blade diameter do you have now James?

Can you swap out the main body for a higher flow unit without it being choked by the butterflies?

I don't recall which CFM carbs used which diameter butterflies, getting rusty.

[BBR]

The butterflies on this baseplate are 1.80". I actually considered going to a 4150 1050 main body before I helicoiled this one. I decided to not mess with modifying this carb any further and just jump in with a 1050 4500 later. After all, if I stayed with a 4150 based carb, I'd still be wondering 'what if'......

[CDMBill]

I think a 1050 is marginal for a 545. If you are going to step it up give it what it needs.

[Racingcritters]

I'll add a little more to your dilemma. A few years ago I built a 521 w/A429 heads "pocket ported" and a port matched intake and 1000hp Holley,swapped to otb 4500 manifold and otb Holley 1050(8082), first dyno run made 41 more hp.
On a second 521 with better heads same carb, data suggested I'd run out of carb. So as Bill suggests build for the future.
N.B. both were pump gas (chevron 94) 10.1cr.

[MoparBilly]

James, back to actually "Dissecting the time slip". In the Super Street game with so many ways to manipulate where you are on the track, (ie T-stop methods) It was often more beneficial to track segment times, than just looking at straight incrementals. The reason is obviously a bad 60 would carry through the entire pass. Most of the Jegs or Summit log books have provisions for recording those "segments" 60-330, 330-660, 660-1000, 1000-1320. Requires a little calculator work to bust them all out, but when you start digging through 10-20-30 passes all broken down in this way, especially if you have weather, and tune-up data, some strong analysis can be made that doesn't require a racepak...but, I'm sure you keep logs religiously, right?

You posted your best slip obviously, and that provides a great baseline, now break down the "ugly timeslips" and figure out which segment is the least consistant, then figure out why.

[TheSilverBuick]

but, I'm sure you keep logs religiously, right?

He's got a 3-ringed binder with the car! I've seen it!

[BBR]

Indeed I do. Haha.

Billy I have been looking at the other slips and they all show a trend toward it being slow in the first 330 and then picking up in the last half. 27 mph was typical for Ennis and Gilliam, but 24-25 is the norm pretty much everywhere else.

Casey's brother has an arb for a fox that I might look at sometime to see if that's what I want to do.