FlashLCD33

iTrader: (8)

Well Saturday was the first test and tune of the year, and the track was TERRIBLE. I only managed one good pass where I dead hooked.

Street Car-
Mild 408ci
TH350 w/ brake
Vigilante 4500 converter
12 bolt with 4.10s
3550lbs with driver
Mickey 325/50/15
6700rpm rev limiter
QA1s front set on 90/10, Comp Eng. rear on 50/50
2300DA

I was running 11.60-11.70 spinning the first 20' or so on most passes and trapping around 119mph. I finally dead hooked it once and managed an 11.30@115 because I was on the limiter somewhere around the 1000ft area and let off. What do you guys think? I did the calculator and it showed around 135mph. I know there is converter slip, but do you think 15mph or more is correct?

And if so, where should I put my gearing? I was also planning on spraying this car once in a while so I'm a little disappointed that I was out of gear that early. I was looking for a 10 sec pass!

Here's a pic on the line. I didn't have the trans brake stalled up all of the way because of the poor track conditions, but it still came up pretty nice for a very mild iron block car!



1.49 60'
7.20 1/8th
95mph 1/8th

Bhogan909

iTrader: (6)

If all your passes were around 119 spinning I seriously doubt you'd pick up 15mph hooking and run 135. With that being said, I do find it strange you were on the limiter with 28's and 4:10's at the 1000ft mark. What is your shift extension? Your 1/8 mph is right on for 120 mph, not close to 135 territory. Seems like to me maybe your tranny is slipping or your converter isn't very efficient? Do you have any dyno numbers, where does your car make peak power and where do you shift the car?

FlashLCD33

iTrader: (8)

No no no, I wasn't saying the car would run around 135mph. I meant the calculator shows 135mph for 28s/4.10s/1:1, and I thought it was odd it was off roughly 15mph from the 120ish I must have been at.

I'm 95% sure the trans is not slipping. It came out of a 1000rwhp twin turbo car and was just refreshened 1000 miles or so ago when I put it in. I'm going to guess maybe the converter isn't right.

Here is the cars dyno slip


That was back when it was a 6spd, otherwise unchanged engine mods for now. I must say it was an EXTREMELY conservative tune though. Timing was around 18 degrees and the knock sensor sensitivity was DOUBLED for some reason, so on the HPT logs it was showing a ton of false knock every time it went WOT with the cutout open. Some timing was put back in it and the sensitivity was changed, now there isn't a hint of knock on 91 octane.

Pro Stock John

iTrader: (34)

I went 134, 7000 rpms shifts, 4.10's, 150 shot, 3300 raceweight, on 28's so you have massive converter slippage (Vig's kinda suck sometimes for that though it wouldn't be that bad), or something is going on. Go over your combo.

FlashLCD33

iTrader: (8)

I'm not sure what could be going on other than trans slipping but like I said before I'm just about positive it isn't. I'm going to guess a loose converter, but I think 15mph off is a pretty substantial amount.

The trans still has bright red fluid as well... like I said before, just refreshed, and only has 1000 miles and roughly 10 passes on it.

I have my shift light set at 6500 and the rev limiter was 6700 I believe. We tried to up it to 7200 to squeeze out a full pass but I think he changed it to 6200 on accident because it was bouncing the limiter before the light ever came on. I would guess it would have been a 120-121mph pass.

xpndbl3

iTrader: (23)

when I was trapping 117 I was at 6300 at the stripe with 4.11/28" tire IIRC with 8% slip

92slowmaro

iTrader: (22)

hey man im having the same problem with my setup. although im running a th400 w/ 4.10s and a 4500 vig converter... i talked with some transmission people the other day and there thoughts are they my converter is slipping to much(800rpms or so). i called up ls1tech sponser fti and there gatna restall/fix the converter for me.

so my guess is your converter. hope this helps...

Pro Stock John

iTrader: (34)

I was going 123mph NA and was around 6200 going thru the traps I'm going off memory.

I was running a Fuddle 4800 8" that was much more efficient than a Similar Vig that I tried.

Make sure your trans is not fugged up before you make any decisions. I think I could have gone 136-137mph on spray I had that much room.

JL ws-6

iTrader: (50)

You have a bigtime slip issue. First, put another qt of tranny fluid in the car, make sure it's full, I mean until you get something coming out the overflow once it's up to temp it's not really full.

Try that first and see what happens. You have a TON of slippage going on right now, I don't care what the converter is, that's a TON. You're looking at about 19%, and that's figuring 1 inch ot tire growth, and the car beign at 115 mph @ 6700 rpm. That's really bad.

Toss that qt of fluid in and see if that does anything, regardless what the dipstick says, and if that doesn't do anything, I'd be looking for a new converter. Power you're making the car should be in the 10's somewhere.

FlashLCD33

iTrader: (8)

Thanks for the advice fellas. I agree it should be an easy 10. I'll try that extra quart.

I did go 119 on every other pass, except when i dead hooked, then I was out of gear.

92slowmaro

iTrader: (22)

JL, what is considered normal slippage for none lock up converters? 4-5%? just wondering, im dealing with about 10.9%. im going to try dumping some more fluid in it and see what happens... but im leaning towards getting the converter redone...

JL ws-6

iTrader: (50)

Depends on the converter's intended build. If it was built for an n/a setup, I'd expect to see 8% or so tops, nitrous/blown/turbo converter, I'd want to see it down around the 2 to 3% range.

Now, if you take a converter that was built for 400 hp and put 600 to it then it's gonna be WAY loose, put 400 to a converter that was built for 600 and you'll be way tight... you have to have it built to what you're running, or you can play russian converter roulette and just take your chances with one and see what happens, but I guarintee you WILL go thru at least 6 before you get one that is a hit.

FlashLCD33

iTrader: (8)

JL I think you hit it right on the money. I found out today the Lokar dipstick I got with the trans is actually for a TH400 and my understanding is they read completely different. I thought something was funny when it took 2-3 quarts less than I was anticipating.

I hope this stupid mistake didn't cost me a trans :-x The fluid still looks very red and doesn't smell burned though. I'll try adding 2 quarts and I'll put it back on the strip this weekend to hopefully see some big gains! Thanks again for the help, it seems that it's such a stupid little problem, I just overlooked it

I was just guessing it was an extremely loose converter since I bought it used and every other Vig I've experienced in friends cars was pretty loose. We'll see what happens! I think this should be a pretty easy 10 sec car, and it's a full weight street car other than rear seats and I switch to drag wheels/tires for the track. Gotta love bein 20 and poor building a toy. I need to put this bitch on a diet, at least it's free!

DopdBrd

iTrader: (25)

Your car is ugly and I hate you. The end.







On a side note, why did your car see knock retard with the cutout open?

FlashLCD33

iTrader: (8)

It was showing knock all of the time, especially when the cutout was open, I'm guessing just because it's loud and vibrates where it sits? I don't know. I had the same issue with my last car when it was on the dyno at TSP.

DopdBrd

iTrader: (25)

Hmmm......i was getting TONS of knock retard and my cutout was open.

Old Geezer

iTrader: (3)

From the looks of the leave pic, I'd suggest you get the launch attitude straightened out, first. That would go a long way toward getting to the 10's. Maybe, keep the runs restricted to the 1/8th mi, until you get the leave set up the way it should be???

JL ws-6

iTrader: (50)

Car needs a swaybar on it for sure.

FlashLCD33

iTrader: (8)

Geezer, that's what I've been working on. I've been running 1/8th to try to get it to hook right since I'm not legal for a full pass. I'm a little strapped for extra spending cash, but a drag sway will definitely be going in with the cage. I wil have the coin for both this week when one of my extra vehicles sells.

The good news is, I added 2 quarts today and what a HUGE difference. I noticed it was much tighter just leaving my driveway. I gave it a WOT pass and the RPMs stay in check now instead of peaking very quickly. It feels MUCH stronger!

Weather permitting, I'll put it on the track this weekend and see the results! Should be a lot better all around I believe. Any way to make the car leave more level before I have a sway, besides an airbag?

Thanks for all of the input fellas.

DopdBrd

iTrader: (25)

Airbag would be a cheap/easy/fast fix. Buddy of mine had one in his Mustang and I think it was a summit special for around 40 bucks.