vibration after holeshot today. need opinions

Pulled a hard hole shot today, everything went good except when I left of the throttle I had a really bad vibration, I stopped the car, the vibration is going with the engine at engine speed. Couldnt go much over 2500 rpm and its very very noticeable, I still have good oil pressure. And babies it home for about 5 miles. I'm guessing the new B&M flex plate cracked??? I just put it in. Convertor isn't slipping any, this is behind a 440 pushing 500-530 hp. What is the absolute best flex plate I can buy to put in this. I'm guessing / hoping that's the issue so I'm gonna order a new one anyhow if that's not ny problem I can use the extra flex plate anyhow. So guys what are your thoughts about this.

Have you crawled under it to look for bad u-joints, cracked tailshaft housing or broken motor/transmission mounts? Lot's of things can break on launch. The B&M flex plate is a stout piece, I'd just start with good look around under the car.

so it vibrates with engine rpm? does it in park and neutral?

Well never tried it in park only in neutral and drive. It vibrates when I'm setting still in neutral and even worse under slight load, it happened all of a sudden Right as I left off the throttle, I have all brand new engine and tranny mounts. Its Def. Between the crank flange and the tranny. Converter doenst slip any and shifts fine. Just bad vibration worse at 2500-3000 rpm

Sure it's not in the engine?

Check the vibration damper for missing rubber.

It could be in the engine, I won't rule that out totally yet I just re bearinged the bottom end rods and mains this past spring my oil pressure seems normal still , I figured if it was the main bearing vibrating I ( thought ) I would have lost oil pressure , I have a fluid dampner on it now for two years. ,

this might be way off but any possibility it dropped several cyls for whatever reason

Bet you tore and engine mount. New or not that's the first thing Id check.

My first thoughts are I hoped you looked at your car closely before even posting this on the internet to find out what is wrong.

Then my second thought is I would look at my car closely before I ordered any parts for it.

Can't you just look to see if the flex plate cracked?

It sounds like your motor is out of balance, like a weight flew off of the torque converter or flex plate? Make sure the front of the motor is good( balancer, pulleys). Then I'd pull all 8 plugs and look at them. Hopefully it's not in the motor, but sounds like it.

If it were in the main bearings i would think id loose oil pressure I'm pretty sure. I have felt bad main bearings it has a deep thumpy vibration, that's kinda how this this, but my oil pressure is good. Is there any possibility that it could be in the converter? It doesn't seem to slip its a tci street fighter 3000-3500 but flashes to 3800 in my build

Def pulling the tranny out today after looking a bunch of stuff over

How hard of a holeshot? Hard enough to over-rev and kiss a valve? As stated look over everything carefully, if nothing obvious jumps out at you maybe do a quick compression check. DAMHIK

I'm pretty sure I checked all possible easy fixes before posting this, also I posted this to see if anyone else may have had the same issues and could give me insight before I tear everything out. , and I've got so many diff projects going that ordering parts and having stuff on hand that I might not need right now is still going to be used reguardless

interesting topic/sorry for your misfortune. do post what it ends up being

What damper?

Check fan blades, I would pull v/covers to check rockers and push rods. Try to determine if it's vibration or miss.

The dampner been on it for two years, it's the chrome 440 source fluid dampner

had a friend years ago that broke a connecting rod. The small end was still on the crank swinging around when it was running, yeah it vibrated a bit
A compression test will go along ways toward diagnosing the root cause.

I know it's a long shot, but I had something similar happen to me one time on one of my cars. Pulled hard and starting vibrating and not running right. It turned out a plug wire vibrated off the cap and I was running on 7.

Sounds like you are into the engine, but did you check plugs and wires. I had a period of time that every time I got on the gas hard, it would start to vibrate. I was shaking loose the number 7 plug wire off the plug. How about connections on distributor cap?

One of the worst vibrations I ever had was with a b&m flexplate, almost shook my teeth out. Took it out, gave it away & got a mopar Sfi flexplate. Haven't had a problem since. Dave ss/ea #1355

Well I think I found my problem, dropped the tranny drained the fluid which is pretty decently new, it looks like very silverish metallic red paint , and not just a little bit either it's full of silvery very very fine metallic particles. I'm geussibg my convertor is toast

what brand is it?

Tci street fighter 3000-3500 stall but in my build its more like 3800 stall, least that's what I flash it to