Going Back to the Track This Friday

[RedbirdV6]

<blockquote>quote:</font><hr>Originally posted by Shirl:
I never saw it on the timeslips page. I was wondering if you didn't have a slip or something. But anyway, nice 60ft.<hr></blockquote>

Thats right, cause it was never put up on the timeslips page for some reason, wonder why

[Magnus]

Whose slip wasn't put up? I put up every slip that qualifies with what info I'm provided with.

[Pro Stock John]

**Torque Converter Comments**

I'm gonna have to say a few things here. I have had a few torque converters and I feel that I am qualified to make some generalizations regarding size and application...

In the way of qualifications I have run as big as a 4800 rpm stall converter. I have cut a 1.48 off the footbrake and with out a power adder. I have cut 1.7's on drag radials, a 346ci motor, and with heads and cam.

First off, don't change your torque converter unless you want to go faster. If you want to ET better, get a bigger one. Stock 'verters are tight for a reason... fuel economy.

Now for racing, the ultimate setup would be a converter that was like 1200 to 1500 rpms lower than your shift points. That's for a hardcore setup. Stock eliminator cars run like 5500-6000 stall converters!!! A comp eliminator car might run a 7200 'verter and shift at 8500!

Now for a street car, and for some of you wanting 12's boosted or with nitrous, and 14's NA, you should not bother installing a converter unless you go at least 3000. I'd go 3500 personally.

I'm not going to respond to any of Shirl's 'verter threads anymore, since I think she gives out bad advice. She comes across as not having the patience to listen to people who more experienced with 'verters.

With a supercharged setup, you would need even more 'verter. Your peak HP might be pushed like 300-500 rpms higher than stock. So how come her combo has had issues? Shift points. The only reason her car is working with spray is that it's lowering her peak hp and tq. If a stock 3.8 makes peak at like 5900, well a blown setup might make peak at 6400. (Shirl have you changed valve springs too, you should be running bigger springs since the boost is not going to work long term with stock springs). In an ideal world, assuming she continues to spray it, I'd run at least a 3600 stall, but personally I would run a 4000 stall. Keith's was maybe a 3500 and he could have went bigger.

My 2003 setup is a 348ci LS6 motor and a Vortech YS trim pulleyed for 20 lbs of boost. I will be shifting at 7200 rpm and will be running a T400 and a 5000-5400 stall.

Shirl might also want to dyno her car. She should shift at 5-10% AFTER her power peak. My project power peak will be 6800.

I'm not trying to be a jerk but I had to get this off my chest.

Sometimes with boards like this, heck even MY OWN board, www.ls1tech.com, we have a tendency to reinvent the wheel and not take outside feedback too well.

I have a 9.10@150mph NMRA buddy who has been advising me on my build (Bob Kurgan).

Take care, I'm done.

[ May 05, 2003: Message edited by: Pro Stock John ]</p>

[Pro Stock John]

I don't mean to be harsh.

But I have put a lot of time into converter selection and the the only time a stock converter is better is when you are focusing on fuel economy or if you are towing a trailer. I encourage Shirl and others to play with shift points and try to dial in their combos more... I think that Shirl should be in the 11's right now.

Here is a pic of me going 1.49 in 2002...

http://www.pbase.com/image/5269912

Here is a 1.53 in 2001...

http://www.ls1tech.com/moderators/psj/p9150016.jpg

And here is a 1.57 in 2000...

http://www.ls1tech.com/moderators/psj/psjmfba2bg.jpg

All different converters, different wheels, and different size slicks...

Let me know if I can help.

John, the v8 guy who admires the hardcore folks on this board and gets frustrated when he can't reach out and help more...

[ May 05, 2003: Message edited by: Pro Stock John ]</p>

[Shirl]

Thanks for the advice, but the #'s speak for themselves. The stock converter was better and brought the MPH and ET back to where it was. I agree that the car needs to be dynoed. I'm working on that and some tuning/traction issues. The person that installed the converter use to work on Nascar Corvettes and is one of the top GM mechanics in the country. He has immense experience in racing. He knows what he's doing. That converter was no good. Plain and simple. It killed my gas mileage too. I'm not sugar-coating my experience. So don't say "Shirl gives bad advice." Hell, I didn't give any advice at all. I just said that it didn't work for me. And for $923 friggin' dollars, that converter should have been the best one on the market. I would've been satisfied going 2 tenths faster, than .5/10mph slower for $923. How can anyone justify that? I appreciate your help, but you need to realize that you didn't have this converter in your car. I believe it was inefficient. It also felt VERY tight. In your opinion, what is a decent converter company? Thanks for the input again, let's keep this on a friendly level.

[ May 07, 2003: Message edited by: Shirl ]

[ May 07, 2003: Message edited by: Shirl ]</p>

[jmorgan]

your conveter didnt really hurt your et it only hurt your mph and if you actully learned how to launch on a converter im sure you would of seen better results

maybe you got a ****ty conveter but did you not still run a 12.7 with this ****y converter at like 103 mph


the same time and when you trap at 107


i know there is no way you can know how your conveter likes to be launched after one visit to the track
besides the last time you went to the tract the weather was good i bet it wasnt that good when you had the yank in there


and if you tell me you didnt spin with the yank thats BS slacker couldnt dead hook a 100 shot out the hole on DR's to save his life and that was before the heads cam and 3.73's and your putting out more power then he did with your 75 shot and 6 psi

[Shirl]

Here we go again :rolleyes: [img]graemlins/thumbsdown.gif[/img]

[Magnus]

<blockquote>quote:</font><hr>Originally posted by Shirl:
I believe it was inefficient. It also felt VERY tight<hr></blockquote>

That's the key right there, it felt VERY tight. Perhaps it was even tighter than her stock converter.

A VERY TIGHT converter is going to be more effecient than a very loose one.

I still have these ideas:
She was having fueling issues (MPH doesn't take THAT big of a hit from a converter).
She was hitting the rev limiter from the looser converter (VERY POSSIBLE)
The converter was f'd by Mike (Possible too, just get a Vig 3200 and be done with it, less effecient than the yanks but proven on our cars)

And yes, it does not only take 1 time at the track, It takes SEVERAL. Converters are all different, you can't just run to the track and learn it in 1 day.

[Pro Stock John]

[QUOTE]Originally posted by Pro Stock John:
[QB]A few comments...

1) How big are these converters, what testing did you do?

2) A bigger than stock converter is hard to choice, but let's say stock is 1500, well I wouldn't bother putting in anything smaller than a 2800-3000 stall. A 3000 stall should feel soggy in normal street driving. The rpms should be higher moving from a dead stop. My 4500+ stuff would do like 2500 before the car would even move. Passing folks I'd see like 3500 rpms without the trans downshifting.

3) An aftermarket converter if it was too big, would flash really high and would be hard to hook. It would also run thru the gears faster. BUT, it would also 60ft and ET better. So a tradeoff might be better ET's and lower MPH. I think Keith's setup worked like this... his mph was not very high with stock motor compared to some of the guys will a lot less boltons.

4) Another thing to try or check out. What spline are the 3.8 A4 trannies? 30 spline? Can you use LT1 (93-97 F-body, C4 AND C5) style converters in your cars? I think a used 3200 PI would stall lower since a 3.8 would put out less torque... so there might be some nice deals lurking out there if they are interchangeable, anyone know? 3rd gen stuff went 30 spline at one point so there is a lot of stuff out there for them too.

And I'm sorry, but IMHO, your observations regarding torque converters aren't backed up by telling us how they stall up or any other detail... Why not get the one you took out checked out and loosened some more?

In Chicago it costs $250 to get a converter swapped what are you paying over there?

With your MPH in some of your runs you should be going at least 12.2 right now. Probably a combination of too tight a converter and maybe low shift points. I have friends who have gone 12.0-12.2 with 110mph trap speeds at like 3400 raceweight. You should be shooting for 88-90 at the 1/8th to run low 12's. I think an 11.99 could happen too.

I went 11.75@112mph back in 2000 FWIW, that was on a 1.57 and with 91mph at the 1/8th.

As another example, I was going 98mph at the 1/8th with the 422ci and it should have went 124-125mph on the big end but I suspect that my converter was too loose and it was eating up mph but helping ET.

You know, maybe a stock 3.8 converter is like a 1800, maybe a 1500, I don't know. But you guys should know.

It's basic dragracing when you look at what size converter to run.

I agree with Keith, that a PI3200 would be a good converter to use since at it's worst it would still be like a 2800 in a 3.8 car as I pointed out above.

Lastly, the 'verter is the single BEST and more important mod for an A4 car.

If I had a 3.8 V6, here is what I would do...

98 3.8 Camaro:
-air lid, filter
-ftra or equivalent it does work
-PI 3200 or something like that
-trans cooler, 19000 gvw is fine
-nitto drag radials
-lca's
-!front swaybar
-ditch the cats, maybe a custom ORP into a bullet and turndown to save weight
-better valve springs, maybe some 1.6 rockers, and if could increase shift points by 200-300 rpms I would try it.

At the track I'd do a good 6-7 burnout on my first run. I'd stall up the converter to like 1200 on the first run, then 1600 on the next one, and so forth until I knew the sweet spot of the 'verter. Yank stuff likes to be launched with as much rpm as the brakes will hold.

I'm sure that a properly set up 3.8 A4 that is not a tank should run 14.5's all day long.

If I had a blower on my car, I'd run a bigger intank fuel pump, 24lb svo injectors, slight colder plugs gapped at .035-.040...

Superchargered setups run best with a looser converter because (1) the looser 'verter will get you into the blower's powerband faster and (2) the looser 'verter will keep the car in a higher powerband since it won't drop as much.

I'd probably shift as high as I could but if I fel the car nose over I would go a little lower. With just a blower I'd go for 900 o2's, and anything lower than that might be too lean.

If I ran dual power adders I'd go for 11.5:1 AF, maybe 950 02's if I was running dry nitrous. The injectors have to pump the extra fuel. I'd be autotapping the duty cycle of the injectors at this point to make sure they are not maxing out.

Good luck, I read your magazine article quite a few years ago, you should be the first 3.8 in the 11's if you can match all the parts together.

Regards,

John

[Pro Stock John]

I talked to Vicki at Precision Industries, and she said the 3.8 A4's use a 27 spline converter. So you can't use the LT1, C4, or C5 stuff which is all 30 spline. Hope that info helps the bargain hunters that means the the 3rd gen 27 spline stuff (earlier 3rd gens) would work.

[LordoftheBling]

i agree 100% with PSJ

i have a A4 with a 3500 PI that i got from Vicki who is by far the best customer service represenative at Precision.

all i need is some weight reduction and some skinnies and this car would move.. and a cam would make it that much better..

[Shirl]

Thanks for the info John! (I will post more later when I get the chance).

[Magnus]

I will also add another shoutout to Vicki. I delt with her PERSONALLY every time I had a converter issue/question. She is a GREAT person to deal with and I owe a lot of thanks to her.

She even put my car up on their website. [img]smile.gif[/img]