Yank converter update

[c&cgn]

Originally posted by ijames
With this Yank the tires spin at about 5-6 psi with ds showing 3300-3500 rpm (don't have a solid number yet for this). I take 3-8 seconds to get to the stall, so this puts a lot of heat into the converter and I let the car idle for several minutes or just go for a drive afterwards to cool it back down. I don't heat up the Nittos and leave the right rear airbag at 5 psi. See why I say this Yank is LOOSE? If I can get over 3400 rpm without fully loading it, think what a transbrake would get. I call it 3400 or so.

I don't have a Yank convertor but I found the same thing the first time around with my 9.5" l/u convertor. The rpms were really high but the boost was quite low. I ended up on street tires with 3600rpm and only 5psi boost. Best 60' I could manage at the track was a 1.62. I did better with my D5. Funny thing is the convertor felt excessively tight around town and wouldn't spool the turbo as fast as I thought it should.

After having it tightened up, it now stalls around 3200 with 6 psi and feels way better on the street. I can still flash this convertor to 4000 rpm at the track with 28" slicks and the brake prop valve fully adjusted. 60' times since tightening have been 1.5's.

Good luck getting it all worked out.

 

[ijames]

Went to the track again but 60's are still bad. First pass was about 2.05, 12.8 at 108ish. Launched at about 2-3 psi and immediately spun, lifted, got back on it, spun, lifted, eased on and they held. Added 1 psi boost. Second pass left at 0-1 psi and it kind of bogged a little then spun at about 20 mph when the boost was fully up, and got about 2.01, 12.7, 109.3. They waved me on again so I hot lapped it and tried launching by mashing down after the top yellow lit and then flooring it at the last yellow. Mistimed it but did okay, about 2.0 or so, 12.8, 108.7. Had about an hour til the next pass and it was very crowded so I knew I wasn't going to stay 2 more hours for one more pass. Tried the same technique but timed it a little better, just heard a tiny chirp, and got my all-time best 60' with a Yank converter: 1.949. Oh yeah, 12.46 at 109.4. So the mph is definitely about what the modified D5 gave. The bottom of 3rd gear definitely feels "flat"; the engine just doesn't feel like it's pulling as hard as with the 2800 but the et and mph are pretty close to what I got with the D5 with equivalent 60's so I think the seat-o-the-pants just needs recalibrating. I think that the only answer is better tires (or a much bigger turbo - yeah, that's the ticket ). I hope to borrow a set of QuickTime Pros from a friend to see how they do, or I guess it's on to slicks. I love the way the Nittos drive on the street but they just won't hold it now. Before when I would spin them on the street I would never get smoke and would leave faint stripes. Now if you build 1-2 psi boost and floor it the car sits still for a second then lays two solid black stripes with enough smoke to cover the road from curb to curb. Oh, first pass I did a big burnout, second was just til I saw smoke, third was in between, and fourth was lots of smoke again. I don't really think a big burnout helps the Nittos but this track won't let you drive around the water box on Friday nights so I have to do a decent burnout just to dry them off.

 

[c&cgn]

It's tough to accurately gauge anything without traction. You definately need slicks!

 

[ijames]

This is kinda off-topic for straight trans stuff now, but since I started this here I'm going to add to it here . Borrowed a friend's 8" Hoosier QuickTime Pro's on T-Type rims and went to the track tonight. Make 10 passes trying different launch techniques. Best 60' was 1.70 and also got three 1.77-1.80's, but I felt the car spin a few feet on every one of those (and you could see the speed rise then level off in directscan). This was building 3-5 psi boost and flooring the gas simultaneously with letting off the brake. I tried going with 2-3 psi and got no spin but only got a 1.90. Best et was 12.30 at 109, with the 1.70, and got several 12.45-12.55's at 107-108. I tried building a few psi, then flooring the gas in about 1 sec then releasing the brake but that spun worse. There might be a magic timing where the boost coming up gets the car to start rocking back, then releasing the brake plants the rear since that's kind of what the 1.70 felt like but I could never reproduce it. I had to lower my right rear airbag from the 30 psi or so I run with the Nittos down to 17 psi to get two even black stripes, and I was running 15 psi in the QTPros. I guess I'm still not convinced it's better than the 2800 - need to find a friend who'll loan me some real slicks to see .

 

[lazaris]

Carl,

Its begging for a slick with a harder launch. Put a set on and watch your 60' drop. I run 11.5 psi in my MT 28x10.5 ET Drags.

 

[TurboBob]

How's your suspension set up?

IMO, it's pretty hard to get better than 1.7 - 1.8 without setting the suspension up.

i.e. removing the front swaybar, drag shocks, rear control arms, etc.


Slicks will help too, tall ones.

Bob

 

[ijames]

Stock 268K mile front suspension and bushings except the right upper control arm bushings which need replacing again (I get about 50K per set and this will be my 4th set ). Billet HRPartsNStuff lower control arms with urethane bushings, stock uppers (not boxed) with 1LE bushings, stock sway bar. Front springs are 6 year old TRW or Moog stock replacements. Rear springs are from an 86 Caprice, a little taller than stock and maybe slightly stiffer. Rides great, sits stock height in front and about 1/2" higher than stock in rear. One airbag on the right rear. KYB's all around. T-Type rims in front (Centerline Stars to go on after the front bushings and an alignment) with BFG TA Radial 235/60-15's. I'm not running out of rpm range yet but I do intend to go to 28" tires when I get some new ones for the track. What's the widest 28" tall slick that would work okay on a T-Type 7" rim? Is 9" it or can you go to 10 or 10.5"?

 

[TurboBob]

On a 7" rim I wouldn't go wider than 9".

There's a pair of Goodyear 28 x 9's for sale on the board tonight....

Do you get much front suspension rise on launch? KYB's and the front swaybar are going to be limiting factors.

Any extra height in the rear works against you for weight transfer, and geometry.

A "good handling" street car is not going to launch well. floppy front shocks and no swaybar will make a large difference.

I like tall slicks since IMO they make a 'long' contact patch as well as having more sidewall to hit.

My best 60' with my 'fast car' was 1.42 and the car wasn't great at cornering.

Bob

 

[TurboTR]

Carl you might try less air in the QT's next time too. I drive around on 10 psi in the 28 x 11.5's And get them good and warm too.

TurboTR

 

[ijames]

They were good and hot. I had to let the smoke clear before I could see the tree to stage on two passes. My friend said he goes down to 12 psi but they are hard to drive there. The rear end was swaying some at 15 and I didn't want to go further the first time out.

I just checked some saved directscan runs, and comparing 12.50+/- .04 107.5+/-.4 passes, with the modified D5 2800 stall I needed 4.94 seconds to go from 30 to 80 mph while with the Yank I needed 5.38 and 5.60 seconds. Guess my seat of the pants wasn't off after all when I thought it felt soft at the bottom of 3rd gear. On average that's 0.55 seconds - where's my 11? Even if I solve the traction problem the only solution to the slippage is to either shift 500 rpm higher or lock the tcc.

 

[c&cgn]

Bringing this post back from the dead. Anyone have any updates on how the Yank convertors are performing? How are they holding up to a TR's abuse?

 

[87LtdT]

I'm new to this thread but not to the Yank converter....bought mine a little after Carl and Tim, and somewhat on the recommendation from Bob. My first had the autolocking feature but it just didn't seem to work very well and was tight. I never had the "folding fin" problem, but it was only at the track for 3 passes...all 1.9X 60'.

Mike replaced it free late last year with either a 9.5" or 10" standard lockup and it should have the Kevlar clutch material. It drives around town fine, but say at 50mph WOT it "sings/whines" or otherwise makes a noise that sounds like it is slipping...this noise continues well into the 80-90mph range. My 2-3 shift is only a couple of hundred rpm drop.

Bob has taken a brief look at a couple DS files and says all good...I dunno. I have not locked it up at WOT nor have I been to the track but the slipping sound and the only 200 rpm drop concerns me that all is not well. I have not called Mike to talk about it...been going to just haven't yet.

I'd like to hear from Carl, Bob, & Tim on their early 2003 experiences.

Bob Kolhouse

 

[ijames]

Only been to the track twice in 2003, for 5 passes total so far (doggone rain). Still on the Nittos, and it's just like last year. My posi clutches are about gone, so I'm sure that's hurting the 60's, and I haven't tried slicks yet. Stall speed and rpm drop on the 2-3 are right where they were last year. I did try locking it up twice (not at the track), in the chip at 85 mph. Both times I could hear a squealing noise, and directscan showed that the rpms held constant from the lockup speed to maybe 90-91 mph, then the rpms started climbing again. They didn't drop any, so obviously the tcc was slipping big time. I don't recall the rpm at 90+ mph to see how much less it was than unlocked, but I'm pretty disgusted that the clutch won't hold like Mike said it would. Maybe that's why he took out the posilock feature?

 

[TurboBob]

Carl, I may have asked this, but what fluid are you running? Dextron 3 is too slippery for the kevlar to grab correctly.


That said, I am running Dextron 3 and will be switching to F soon as my WOT TCC engages too softly also. I'm not worried about longevity of the clutch, I would just like a more positive lock at WOT.

Otherwise the unit has proven bulletproof in mine and friends cars. Transbrake launches included.

I think the whine may be related to high shift extension of the converter making the pump whine a little. Mine doesn't whine AFAIK, but I will be looking deeper into it.

Bob

 

[87LtdT]

I spoke with Mike one week ago and he advised that he no longer uses Kevlar in Buick clutches....including mine that I received in Jan 03.

I've not been able to lock my converter at WOT yet...so can't answer but I'm confident that the "whine/squeal" I hear at WOT is something slipping...Mike advised that Bob's whined before but now after his latest converter.

Bob, can you confirm exactly when you got this "latest converter"??

Bob Kolhouse

 

[ijames]

Bob (oops, just notice that both Bob's had responded , this is for TurboBob), I'm running dexron III. My clutch isn't kevlar, and isn't their original carbon ceramic. It's supposed to be in between the two (see my first post). It isn't a whine, it's a squeal/scrape only when I locked it up those two times. This also isn't the fluid cavitation noise that my first one had.

 

[87LtdT]

Any more news here???

I've been to the track once but no lockup...not a converter problem, it was an electrical problem with the white switch above the brake switch. OK now but I have no lock up info...still makes the whine/squeal though. But this noise is DEFINITELY not lockup related...cause it wasn't geting electrical power to lock.

Ran 115 at track but poor 60' resulted in 12.2-12.3 times. Only get 425 rpm drop at 2-3 shift.

Bob

 

[87LtdT]

Any more news here???

I've been to the track once but no lockup...not a converter problem, it was an electrical problem with the white switch above the brake switch. OK now but I have no lock up info...still makes the whine/squeal though. But this noise is DEFINITELY not lockup related...cause it wasn't geting electrical power to lock.

Ran 115 at track but poor 60' resulted in 12.2-12.3 times. Only get 425 rpm drop at 2-3 shift.

Bob

 

[TRDirks]

My 2003 Experience

My Yank "seemed" to be working great. The one thing I did not like is that it seemed to be a little on the loose side and when I locked it up the rpm's didnt drop much and times did not improve. Most of my runs were with my fully ported roller motor and 60-1 Hi-Fi turbo @20psi w/ time in the 11.70-90 range and mph from 113-115. A couple months ago I put on a t66BB and 72lb inj. and shortly after that the motor had a roller lifter get divorced (ie. the bar that holds two lifters together fell off) which took out my roller cam. I put in a low mile stock motor and then figured that the Yank was too loose for the stocker since I was leaving the line @4200rpm and around town drivability kinda stunk. I just recently swapped out the Yank for a 3k stall PTS 9/11. The 9/11 seems to pull much harder than the Yank did. WOT lock up is much more pronounced, around town is better and I am having more of a traction problem in the WOT at about 20 mph range. With the yank it would hit much softer when nailed and the shiftes were much softer. The 9/11 feels much better to me all around?? I did do a stall test with the Yank before taking it out and with the 9/11 right after and the rpm at boost were identical (see below)

0psi-- 2600
5psi-- 3200
10psi-3600
15psi-3800

While doing the 10 and 15psi test I could tell without a doubt that the 9/11 wanted to lift the front end more than the Yank did.
I dont understand how they can both stall the same rpm but feel so different?? Maybe the Yank is just a little loose? Or is something else wrong with it?

 

[ijames]

Thanks for the update, Tim. Any data yet on rpm drop at the 2-3 shift with each converter?