Only made 2 passes since convertor was waaaaay tooo looose...holy cow!!!

First pass scared the crap outta me, I ran it up and down the hwy to make sure everything was fine before loading up and heading out to the track. Our area has seen rain almost every day for 3 weeks, and we had some nice rain the other day so I knew going out the track might not be the best since it was cooler today, T&T night is notorious in the past for being a joke on traction, rain factored in...I did'nt expect much.

Tried 14psi in the back tires first pass for kicks, T brake @3200rpm (my old setting for race day) let'er eat and the w**** car shook so violently, I've never experienced wheel shake/bobble and I thought initally I broke something..let off the gas, stood back on it and ran a 11.22 @124.78 mph with the tach needle stuck (literally) @6800rpm the entire pass.

2nd pass I took tower lane and got behind some big tired cars, dropped my slick psi to 10 where I normally raced at all these years, same 3200 t brake rpm. Let'er rip and I felt it kinda spin/grab like they do when they dont dead hook, tach needle immediately to 6800 (shift light set at 6K so it's blaring the W**** time) figured this time I'll just wait until it goes off the high end chip @7000, heard the first pop pop just after the 330' and was popping again just after the 1/8mi mark with the needle electronically stuck by mean of the high end chip at 7000 after the 1/8mile mark. That pass I ran a 1.509 60' 10.780 @ 124.97

Engine made peak tq @4900 and peak hp @6200 so I'm blowing clean past any usable power and just riding the convertor the entire track. I think based on the 60' of 1.50 and the fact I'm slipping like crazy, if I can get a convertor to flash @5K I'm going to start having traction issues with my current suspension set-up and be out of rpm before the traps. So new convertor will get ordered, we'll try it again to see where rpm falls (I'll probably just pull the high side out) and then get a taller tire accordingly to drop what little rpm I can.

I think it should run pretty good for a 3700lb slug, esspecially since these passes were through my 2" breather and the lid resting on top of carb vent (super vic put me too tall for my cowl hood so I had to drop it down to shut the hood. and also ran through my 3" exhaust with flowmaster 40 series....once I get the convertor figured out, and tire size figured out I'll pull the air cleaner and drop the exhuast to see where that puts me...obviously if I dont lose much the mufflers stay on, but I would think a 10.50 should be easily attained...I might even pull my stereo system out for that extra .1 it gains me

 

Ya, I'd say that converter is a little loose. I launch at 4500. After I launch, my rpm jumps to 6000 and doesn't drop below that all the way down the track. I was shifting at 6800 so that comes up real fast off the line. I was going through the traps at 7200.

Have you calculated converter slip yet?
Need tire diameter, finish line rpm, finish line mph and diff gear ratio.

 

Using the online calculator is kind of bunk since the tach was stuck on 7K due to high side rev limiter, but if I input all the numbers based off what i did it comes back to 11.99%....I'm sure it may be even worse if I did'nt have the high side chip in it. After the first pass I pulled the wire for my adjustiable 2 step to go against the convertor and see where it went, soon as I matted it it was on 6800rpm. I dont know what a good slippage factor is to be honest, never really got into the percentage thing?

I do know this convertor was originally built for the S10 which is 800lbs lighter and nowhere near my peak tq or complete tq curve for that matter, but regardless it's a 8" race convertor with the CCX stator (soft hit) so it's going to slip more than a CX stator, but with my small tires, it's what I'm being forced to run for any chance of "consistant" traction on race day....I'm expecting a big drop in ET once I get the convertor and tire size to match, cant say I'll mess much with gearing to get optimum since in my situation I'd rather be under geared and leaving ET on the table in trade of consistant 60's...you know how the game is played as well as anybody It's not like I did'nt expect it to do this, the few times I've been able to street drive it between valdeez oil leaks it's done the same thing on the street, so I personally did'nt think it would get any better, or be any different on the track, but a few others around here thought it might tighten it up with 100% traction....does'nt help either these tires are 2 yrs old either...obviously they're still working, and I have no doubt on a race prepped track 60' would've been better, but it is what it is for now. I have a line on a 9" convertor that's at BTE right now getting rebuilt that's for sale, so if I can get the owners price right (Transman is going to talk to him tomorrow) I'll just have it tweaked to what I need since I'm already running a BTE 8", we're hoping they can take the specs of my currently installed convertor, cross it over to the 9" in their possesion, and then make the tweak accordingly and hit it right the first time.

I would like to call ATI as well, but the only thing that makes me nervious is since 99% of all convertors are off the shelf and require a "send it back to us for a tweaking after you see what it does in YOUR car" I really dont want to take the tranney back out again, so hoping since I'm staying all BTE they can use all the info at hand and hopefully get it right the first time out...but we'll see.

I forgot to measure the ride height the other day when I dropped the member to fix the last oil leaking problem, but my brother went for the hwy run tonight with me and the frnt tires were rubbing terribly any time we hit a bump or turned the wheel slightly. Going to order up the BBC trick springs, and just take it to a shop and have them swap them out and then re-align the thing...here I thought when I dropped the factory K member it was going to be heavy...that thing is friggin light!!! I may do the Ed Quay thing and just cut out the center of my factory unit, weld/cap the open ends and then make a removable center section...hard to justify all that money for a tubular k member, rack steering, tubular a arms, and coil overs when I cant realiustically see it gaining much other than clearance....but once stuff is in the car, my starter and oil filter are easily accessable, and I'm not out for max ET so that little bit of weight savings it may have does'nt out weigh financial expediture...maybe when/if I tub it I'll look into it, but not right now

 

Josh at least it's holding together have that oil pump snafu you had on the dyno. Why wouldn't you want to run like a 4500 stall and have it hit peak torque right out of the hole instead of something just above peak torque?

 

The guy that does all our race trannies as well as many others nation wide said I'd want to to be right around the 5000 mark on the hit, so that's what I'm going with. He's helped alot of cars pick up drastic ET with his convertor choices so I'll just let him pick it out. I was hoping there would be enough in this currect 8" to tweak the fin angles to get me where I needed to be, but he said at most it's typically 600 rpm +/- with any certain convertor size/stator combination, and I need to drop about 1800rpm so it's forcing my hand into the larger 9" convertor in order to keep the ccx stator and get it down to where I need it to be.

Now's just the frustrating waiting game to get the new convertor, and the headache of swapping it out. I want to get the springs replaced up front and get ride heigth up in the air a bit with the stiffer springs for more ground clearence as well as give myself a cushion should thing thing decide to go air born I dont bottom out if it does'nt initally carry the front end like I want with a soft touch down....all I can see is a quick pop up and slam down grinding the cross member/headers on the track if I short shift or some reason.

Just glad I was finally able to make a pass even though it's not performing where it should, at least a little light came on at the end of the tunnel so it's just a $$$ matter to finish getting it there...typical shoulda just ran BIL's back up motor and called it a day LOL!! lots cheaper

 

When you change the converter take it to the track and just for kicks make two passes with air cleaner and then two with out filter then go home take the flomasters off and put some magnaflows or dynomax stright thru style turbo mufflers I will bet there is two tenths in just the mufflers. Good Luck.

 

The breather, I'm not so sure. All my other engines ran identical times with the breathers no matter if it was a K&N, $3 paper element or no air cleaner at all, even after I made a carb pan to seal the incoming charge to ambient air through my cowl I saw nothing, but those were also 14x4 where as now I'm stuck with 14x2 and the lid right on top of the carb vent tubes....so this is definately an area I will experiment with.

Same with exhaust, always has run exactly the same corked or open headered, but Im wondering since this motor is quite a bit more than anything I've ever had if it's not snuffing it pretty good...I'll experiement with that as well....even if it picks up .3 open headered...the mufflers will stay on, I like to say I went XX.XX for a on kill pass, but I think in all the years I've tried for an on kill pass once that consisted of jetting/timing, opening everything up and it's never netted me anywhere near what I thought it would. Typically I race with carb very lean for predicablity, I'll tune it to spring air and pull jets until I'm .2-.3 slower and leave it, I never changed jets in the 2 yrs I raced the 388 I had since I could'nt predict the car nearly as well with a perfect tune or fat...scarey lean, the car always stayed pretty tight number wise.

We'll dink around a bit, I'm more concerned about getting the darn thing to start competative racing again...been killing me fighting all these gremlins and missing out on my round money since I'm not out there

 

My experience in the past with the muffler swap from flowmaster to magnaflows with three cars all of them picked up .2 or better as far as the air filter I belive that with a 2" element it will throw off the air flow to the carb.

 

I dont think ATI sells converters off the shelf, every time I've ever gotten a converter from them it had to be built for my cars specs. I dont know why I didnt go with them from the start on my current car but when I did they nailed it on the first try I've always had good luck with Jim Beattie's stuff.

 

Kind of a long shot, my tranny guy got with BTE to see what they thought as to why my convertor would be flashing that high. Right now I'm going to go over and get a line pressure guage and see what that says, BTE thinks it may possibly be a relief valve allowing pressure by, not so much the tranny wont work function wise, but lacking enough psi that it's not allowing convertor to do it jobs...kind of a long shot, but worth it before we start dropping $1K on convertors.