Inaccurate

You currently have a 79% Racing mixture. To avoid possible flaring issues and unnecessary minor clutch wear in the future, I advice that you take remedial action to lower the percentage.

Do not use DW-1. I have not heard the latest news regarding it, but from what I have heard it is only *rumored* to be synthetic. Meaning, that I doubt the DW-1 is synthetic. Even if it was a "synthetic", it would not be a true synthetic like Redline ATF. Stay with all Redline ATF.

Regarding the harsh shifts - there is no way to avoid harsh shifts if you use any amount of Racing ATF. Racing ATF (as used on our forum) is meant to reduce wear on the clutches to make the trans live much, much longer. The Racing ATF does this by making the clutch grab harder. And, the clutches grabbing harder will give a harsh shift. If you can not compromise by having harsh shifts, then do a 3x3 with D4. But, your clutches will wear a bit faster and the shifts will not be executed quickly.

If you want to stay with the Racing to help your trans to live longer, then you
should do a single refill (your Refill #4) as shown below.

Refill #4 = 2 quarts D4 + 1 quart Racing

The above will produce a 60% Racing mixture.

For any subsequent refills (If you choose to do any additional refills in the future), you should use 2 quarts Racing ATF and 1 quart D4. The Racing percentage would be gradually approaching 65% with each subsequent refill.

Inaccurate

@Swoosh

How I derived the 65% value was explained in the opening post of this thread. I have quoted it above for reference.

Swoosh, my man, you are a sharp guy. I didn't expect anyone to catch this detail. I am very aware of the difference that I had 0% FM in my mixture and others have some residual FM in their mixture. But, I did not want to confuse the readers any more than necessary with too many details (variables). I knew the issue of Lightweight and it's viscosity would arise. It is going to get very ugly for the average person very fast..... way too complicated and way too confusing for the average person. So, I did not discuss residual FM issue (variable).

Additionally, I wanted to take a very conservative approach with my advise..... to error on a weak Racing percentage versus being on the cutting edge of too much Racing percentage. Please be sensitive that our fellow Acurazine members have had their transmission replaced because of this situation. We owe it to our fellow forum members to be conservative with *their* transmission.

swoosh

iTrader: (5)

^^^ now that explanation....

I down to thee again....

paperboy42190

iTrader: (7)

i contributed to this thread too, cuz i am proof that the racing atf caused my tranny to fail. in a sense, i could say that if i never joined acurazine i might have saved myself $2200 for a tranny rebuild....i was so convinced by everyone's posts about the redline type f fluid. my transmission shifted perfect before the type f fluid.

one thing i noticed is that its always the 2-3 shift that fails for everyone. there was also another member with the 2-3 flare who didnt use the type f fluid, which is why i ruled out the type f fluid when my tranny was going bad. also, why does it get worse and worse? eventually i had a small flare with the 3-4 shift too. also, my 1-2 shift was HARD, no joke. yes i had the type f fluid but when the tranny started to flare, the 1-2 shift just became so hard, it almost jerks the car as if i had like a stage 4 clutch or something. is there a limit when even going back to oem fluid wont fix the flaring?

Inaccurate

It is not *always* the 2-3 shift that develops the flaring. In my case, it was my 3-4 shift that had flaring and my 2-3 shift was ok. According to my theory (as stated in the opening post), the flaring will develop in various shifts based upon which one (or more) of the five clutch packs that has the tightest clearances.

And according to my theory, the flaring and awkward shifting becomes worse with time because the detergents in the ATF lose, with usage/mileage, their ability to act as a pseudo FM. As the detergents breakdown with mileage, the ATF mixture is losing FM. The detergents lose their ability to act as a FM rather quickly in my experience, usually within approx 6,000 miles.

Also, there appears to be a fine line (or very discrete tipping point) where the flaring is induced. That is, one moment the FM are adequate to prevent flaring. Then the trans loses a small fraction of FM and the flaring is suddenly there in full force. A very abrupt onset. And this is another reason why I advocate for everyone to stay far, far away from that threshold.


Regarding the "point of no return" - At this point, I would not rule anything completely out. But *within reason*, there will be no unusual wear or damage due to the flaring or awkward shifting. Reducing the Racing percentage will return everything back to normal. If not, then it was not the Racing ATF that caused the issue in question.

I consider the flaring issue to be normal and expected. As was stated in the original Racing ATF thread where the Racing fluid got introduced to the forum, I stated that I expected to run into some sort of drivability issue due to too little FM. I also stated at the time that when any drivability issues arouse that I would re-introduce more FM back into the mixture to alleviate the drivability issue without any harm to the transmission. And, I still feel that this is true and that the plan (pushing the boundaries of the Racing ATF percentage) is "on schedule".

People have had their transmission replaced due to not reverting back "to the last known good configuration". That is, the first step that should had been done was to go back to the previous ATF used prior to the Racing ATF when the flaring developed.

Inaccurate

You would still want to do the third refill (with 2 quarts Racing ATF + 1 quart D4) in order to rinse out your old fluid. I assume your orginal fluid was Z1. It takes three refills of whatever to flush out an adequate amount of that old Z1. This is why you always see the "3x3" term being thrown around on the forum.

Inaccurate

By the wording of your post, I take it that you are looking for feedback from other members other than myself. This is ok but please let me know if I drew the wrong conclusion and you want me to clarify something for you.

By the way - If you did your Refill #5 with 3 quarts of D4, this would make your mixture to be 52% Racing.

av2600

iTrader: (1)

when you say d4, do you mean redline d4 atf fluid or something else?

Inaccurate

Good question atrac7. The time is ripe for us to discuss this topic in this thread.

I have avoided discussing the Redline Lightweight ATF up to this point because I did not want to make this thread anymore complicated than necessary. However, "it is what it is". So, let's discuss Lightweight ATF and ATF viscosities.

I limit my discussions and recommendations to just the Redline brand of fluids.

Redline offers three fluids that we are interested in using for our TL -
1) D4 ATF
2) Racing ATF
3) Lightweight ATF

The Racing and Lightweight are both Type F fluids. The Racing and Lightweight are identical except for their viscosities.

The problem is that the Racing is too thick and the Lightweight is too thin (thus it's name). There is no problem with the D4. The D4 is just right.

This is why you see other people running a combination of Racing and Lightweight. We mix the two to create a mixture with a normal viscosity (being not too thick nor too thin).

Since we are ready to discuss the Lightweight ATF, I will now amend my recommendation to be as shown below. My recommendation is the same as my opening post except for revising the viscosity.


For anyone that is beginning to use Racing ATF for the first time

Refill #1 = 2 qt Racing ATF + 1 qt Lightweight ATF
Refill #2 = 2 qt Lightweight ATF + 1 qt Racing ATF
Refill #3 = 1 qt D4 + 1 qt Racing ATF + 1 qt Lightweight ATF

The above will produce a 65% Racing mixture with normal viscosity.

For any subsequent refills (If you choose to do any additional refills in the future), you should use 1 quart D4 + 1 qt Racing ATF + 1 qt Lightweight ATF. This will indefinitely maintain a 65% Racing mixture with normal viscosity.

Inaccurate

Redline D4 ATF (PN #30504) (click here)

The-Chemist

I'm glad this thread came out when it did. I've been introducing racing atf into my tranny over time. I did a 3x3 with castrol multi-vehicle about 15k miles back to get the z1 out. I have since done a 1x3 twice at oil change intervals, the last 1x3 being about 3k miles ago. I was planning on doing a 1x3 at every other oil change to keep relatively fresh fluid in there at all times. typical residence time of 45k miles.

I have to say that with 2 thirds racing fluid my tranny shifts f-ing great. I love it. Thanks for all your research and I'm sorry to those folks who had to replace their tranny.

I will run mine as is for about 5k more miles until the next oil change. I am then going to do a 1x3 with racing, lightweight racing, and d4. at that point I will be maintaining my 65% and will go to 1x3 every other oil change.

Do you think there is any mixing issue between castrol multi-vehicle and RRacing?

thanks again for doing the leg work.

Inaccurate

According to the Society of Automotive Engineers (SAE), all conventional ATF's are fully compatible with one another.

I feel that you are 100% safe with inter-mixing the Castrol and Redline brands.

And thanks for the positive review of the 65% Racing mixture.

swoosh

iTrader: (5)

Inaccurate:

For the people who have done a 4x3 with Racing Type F and hence very thick oil and no FM's can you say how to get down to regular viscosity and 65% racing with the 5th drain and refill...

Da Answer

^^ that's the answer I'm looking for...

Inaccurate

Recommendations have been revised to produce a mixture having a normal viscosity. It is the same as in my opening post except for revising the viscosity.


To obtain the optimal percentage, please follow one of the procedures below that best fits your current situation.




For anyone that is beginning to use Racing ATF for the first time

Refill #1 = 2 qt Racing ATF + 1 qt Lightweight ATF
Refill #2 = 2 qt Lightweight ATF + 1 qt Racing ATF
Refill #3 = 1 qt D4 + 1 qt Racing ATF + 1 qt Lightweight ATF

The above will produce a 65% Racing mixture having a normal viscosity (7.5 cSt @ 100º C).

For any subsequent refills (If you choose to do any additional refills in the future), you should use 1 quart D4 + 1 quart Racing ATF + 1 quart Lightweight ATF. This will indefinitely maintain a 65% Racing mixture having a normal viscosity.




For anyone that has already completed a 3x3 using all Racing ATF

You currently have a 79% Racing mixture. To avoid possible flaring issues and unnecessary minor clutch wear in the future, I advice that you take remedial action to lower the percentage.

You should do a single refill (your Refill #4) as shown below.

Refill #4 = 2 quarts D4 + 1 quart Lightweight

The above will produce a 60% Racing mixture having a nearly normal viscosity. The resulting viscosity will be just slightly thicker than normal. It would be 8.4 cSt @ 100º C. Normal is 7.5 cSt @ 100º C. This is an insignificant difference in my opinion.

For any subsequent refills (If you choose to do any additional refills in the future), you should use 1 quart D4 + 1 quart Racing ATF + 1 quart Lightweight ATF. The Racing percentage would be gradually approaching 65% with each subsequent refill. And, the viscosity would be gradually approaching 7.5 cSt @ 100º C with each subsequent refill.




For anyone that has already completed a 4x3 using all Racing ATF

You *MUST* take remedial action. You currently have a 87% Racing mixture. You must lower the percentage to avoid possible flaring issues and unnecessary minor clutch wear in the future.

You must do a single refill (your Refill #5) as shown below.

Refill #5 = 2 quarts D4 + 1 quart Lightweight

This remedial action will produce a 65% Racing mixture having a nearly normal viscosity. The resulting viscosity will be just slightly thicker than normal. It would be 8.5 cSt @ 100º C. Normal is 7.5 cSt @ 100º C. This is an insignificant difference in my opinion.

For any subsequent refills (If you choose to do any additional refills in the future), you should use 1 quart D4 + 1 quart Racing ATF + 1 quart Lightweight ATF. This will indefinitely maintain a 65% Racing mixture. And, the viscosity would be gradually approaching 7.5 cSt @ 100º C with each subsequent refill.

Acura_TL

Inaccurate,

I've done the following so far.

3x3 with D4.

More recently a 3x3 with the following

2 quarts racing + 1 quart lightweight
2 quarts lightweight + 1 quart racing
2 quarts racing + 1 quart lightweight.

I’ve had absolutely no issues, shifts are crisp, no flaring at all.

I’m thinking of doing my next drain & refill with

1 quart racing + 1 quart lightweight + 1 quart D4

Question is what percentage of racing atf will this put me at?

How close to normal viscosity would I be at?

I’d like to be at or below normal viscosity, I live in Wisconsin it gets pretty COLD here in the winter.

Also thanks for all the work/testing you've put in, I'd still be running crappy Z1 fluid if it wasn't for that!

Edit: just saw your post above, maybe I should go with: 2 quarts lightweight + 1 quart D4 to get to a lower viscosity?

paperboy42190

iTrader: (7)

One more question, does the same apply for ppl with dw1 fluid as opposed to z1? I heard dw1 has a diff amount of fm so the amount of type f fluid required might not be the same

Inaccurate

Your current mixture is 79% Racing having 7.7 cSt.

If you did the 1 quart racing + 1 quart lightweight + 1 quart D4, this would put your mixture at 74% Racing having 7.6 cSt. This is not advisable. You must lower your racing percentage to at least 65%.

Please don't do the 2 quarts lightweight + 1 quart D4 either because of the same reason above. This would still leave you with a 74% Racing mixture.


If you do the following single refill shown below

Refill = 2 quarts D4 + 1 quart Lightweight

This would put you at the recommended level of 60% Racing mixture. The viscosity would be 7.3 cSt. So, we are stuck and unable to get your viscosity to be thin if we do just a single refill. However, this is the route that I recommend for you.



If you do the following *two* refills shown below

Refill "A" = 2 quarts D4 + 1 quart Lightweight
Refill "B" = 2 quarts Lightweight + 1 quart D4

This will give you a 63% Racing mixture having a 6.7 cSt viscosity. This is still an insignificant difference in viscosity in my opinion.

Acura_TL

Thanks for the advice!

If I do the 2 refills you show above, what mixture would I use for 3x3's after that assuming I want to keep about the same viscosity?

Thanks again!

Inaccurate

The 65% Racing mixture is ideal regardless of the prior fluid. There would be no meaningful difference if the person prior had DW-1, Z1, Mobil 1 Synthetic, Castrol ATF, etc.

The FM difference between DW1 and Z1 is extremely minor in relationship to the swings in FM that we are discussing in this thread. After a person has done a 3x3 to drain out the old DW1 or Z1, that extremely minor difference has become extremely insignificant.

It is true that there would be more residual FM in the mixture if the person prior had Z1 versus someone that prior had Mobil 1 Synthetic or D4. When I developed the optimal percentage value to be 65%, I had taken into consideration the possible swings in residual FM after a 3x3.

Deriving the optimal value to be 65% was not an exact science. It was meant to be an attempt to obtain the ultimate shifting performance and the ultimate clutch life while keeping *everyone* far enough away from possible flaring issues. "Threading a needle" so to speak.

jhumbo

iTrader: (1)

How do we know that to be true? If Honda ATF-DW1 had half of the FM of ATF-Z1 that would make a big different. If we know that it is 90% of ATF-Z1, then I agree with your comment, then the difference is negligible. Is there a spec on the fluids that specifies how much FM is in the fluid? . . . I guess my impression is that we don't really know and are assuming. Is that correct?

Inaccurate

For any subsequent refills (If you choose to do any additional refills in the future),

you could use 1 quart D4 + 2 quarts Lightweight ATF. The Racing percentage would be gradually approaching 65% with each subsequent refill. And, the viscosity would be gradually approaching 5.8 cSt @ 100º C with each subsequent refill.

Or, you could alternate every other refill like below.
Refill "A" = 2 quarts Lightweight + 1 quart D4
Refill "B" = 1 quart D4 + 1 quart Racing ATF + 1 quart Lightweight
The Racing percentage would be gradually approaching 65% with each subsequent refill. And, this will indefinitely maintain a 6.7 cSt viscosity.

Acura_TL

After you do one 3x3 with redline (or any other atf), there will only be about 20% of the original fluid left I believe. (correct me if I'm wrong on that percentage)

Even if DW1 had half the FM of Z1, there is only 20% of it left in the tranny.
Half the amount of FM in 20% of the fluid = negligible in my opinion.

atrac7

Once more, thanks for the extremely informative post/explanation. Upon reading all this, I think I have come up with what I consider "my ideal" mixture. I know you're getting these a lot, with us all throwing you our customized mixes, but your input would be appreciated. I realized that I would prefer to lower the harshness of the Racing as much as possible, whether it be lightweight or the full Racing Type F.

What do you think of this combination to attain that while still helping my transmission in the long run?

Refill #1 = 2 qt Racing ATF + 1 qt Lightweight ATF
Refill #2 = 2 qt Lightweight ATF + 1 qt Racing ATF
Refill #3 = 2 qt D4 + 1 qt Lightweight ATF

Pretty much, instead of having one Type F full, 1 Lightweight, and 1 D4 for the LAST REFILL, I have dropped the full Type F all together and instead kept 1 qt of Lightweight and 2 QT of D4.

I figure I'd throw in that last extra quart of D4 to help in any to gain back some of that "smoothness" in the shifting. What is your opinion on this? I am sure that this will not cause too much of an issue in terms of keeping the transmission healthy. Question is, for this last bit that I propose:

Refill #3 = 2 qt D4 + 1 qt Lightweight ATF

Should I have the 1 qt of racing fluid to be LIGHTWEIGHT, or the "full" Type F racing?

Thanks once more friend, been extremely helpful thus far

usmarinedelta

iTrader: (1)

Just out of curiosity, how do we know that tranny failures are linked to clutch pack wear? I thought it was the 3rd/4th gear switches, I didn't read the "interesting conversation with my transmission builder" tho.
Reason I ask is because my old rsx which now has 120k miles with nothing but Z1 fluid and shifts perfect. I just did a 3x3 with dw-1 fluid and for my next 3x3 i'll most likely do straight d4 just for peace of mind that it's synthetic and tolerable to higher temps. I noticed that alot of people were afraid to say something that their type f fluids were causing problems for quite awhile now, and when they did the op's normally get bashed on or corrected by some wanna be know it all. It's good to know that people are starting to take a stance that straight type f fluid can cause problems, like one member "cayos" his transmission failed after the fluid change, for me my fluid caused immediate harsh shifts, and people say this "saves" my tranny but honestly the shock and hard thumps cannot be good for the structure and moving parts of the transmission. I also heard hard mechanical shifts which scared me, all went away when I did dw1, but will do 3x3 with d4, haven't heard of people having problems with d4 yet.

TampaJim

Redline D4 could not meet the design specifications of DW-1, simply because it supposedly meets the Z-1 criteria. This isn't Neapolitan ice cream ... it has to be vanilla OR strawberry OR chocolate - not all of the above.

DW-1 is different than Z-1 in viscosity index and the combined additive package (there is one specific additive in the new formula that didn't exist in the older one). Idemitsu has designed the new fluid to address the new needs in the six speed automatic design and to replace the Z-1 with a better product.

Latito

What are the downsides to using a mixture of 2 Racing + 1 D4, skipping the Lightweight? From what you're saying this will lead to a thicker mixture of ATF, I'm wondering how bad this is or what the general effects of that might be. Most of the issues you're describing seem to be attributed to the lack of FM - are the issues also related to a thicker ATF mixture or does that have another set of issues?

Hacura

Hi Innacurate,

I did a 3x3 with D4 last spring and stayed clear from the Type-F since it was still being tested , what would be the best course of action if I wanted to introduce Type-F now? I'll also be replacing 2nd, 3rd and 4th gear switches.

I'm only gonna have time for a 3x1 while doing the switches so I was thinking to go 2qts Type-F and 1qt Lightweight?

Appreciate your help.

leedogg

Ahh wish I had found this post earlier. Wasnt sure why my tranny was 'flaring' thought my pressure sensors needed to be replaced again. It felt like it wasnt shifting at the right points. Just about to do a tranny 3x3 to try and resolve it. Question: I've got some leftover Amsoil ATF, will that work in place of D4?

Hacura

Lee, I think either Amsoil or Redline will be better than OEM stuff but I'd stick to Amsoil all the way if you're going that route. If you'd like to switch to Redline then skip Amsoil alltogether.

leedogg

I would, but the problem is I only have 3 quarts of Amsoil (hence leftover) and 15 quarts of type F. will take time to order D4 I kinda want to fix my atf mixture asap since i'm experiencing these 'flares'

usmarinedelta

iTrader: (1)

^^^ In that case just run the amsoil until the d4 gets here to mix with you type f. That's what I'd do.

Inaccurate

@atrac7

To help you decide what your Racing percentage (if any) should be to suit your taste, you could do the following.

Because you have not done any refills yet, you can use this to your advantage.

Do the Refill #1 (2 qt Racing ATF + 1 qt Lightweight ATF). Drive with it for at least a week. Perhaps drive even longer than a week until you have developed a good feel of the Racing ATF personality. Then, you will be in a better position to decide what direction you should take next for your Refill #2. Contact me (this thread, another thread, or PM) and I will help you to pick what your Refill #2 should be based on your reaction to the Refill #1.

The above paragraph is what I recommend for you. However, below, I will proceed to answer your questions from your most recent post.

If you changed the Refill #3 to be 2 D4 + 1 Lightweight, this would give you a 52% Racing mixture. This would be ok because you are below the 65% maximum limit. You would still be receiving the benefits of crisp shifts and longer clutch life in my opinion. However, I would *not* want you to think that the shifts would be less harsh. In my opinion, any amount of Racing ATF is likely to produce harsh shifts. It is up to you if you want to give it a try or not. This is why I recommend you to try racing atf for just your first refill. If you think the shifts are too harsh, we can use your next two refills to make the shifts smooth again.

If you changed the Refill #3 to be 2 D4, then I recommend that you use the Racing ATF and not the Lightweight. That is, I recommend for the Refill #3 to be 2 D4 + 1 Racing. Because your primary goal is protecting the trans, and not performance, this is why I picked the Racing and not lightweight. The slightly thicker viscosity will protect the trans more than a slightly thinner viscosity.

Inaccurate

Conjecture. It is common knowledge among people (aka mechanics) that understand automatic transmissions (not just the TL, not just Honda, but all autos), that the clutches wear out with usage. There are other common failure modes too such as hardening of the internal seals. But, Honda trans seem to have excellent seals that age well with time without hardening.

It is also common knowledge among people that understand how autos function that FM is used to make the clutches slip much more than otherwise in order to produce smooth shifts for driver comfort. From here, it is pretty safe to draw the conclusion that this slipping is grinding the clutches down. This is the black slime that we see on the TL's drain plug. Worn away clutch material. How do I know that the black slime is clutch material? Again conjecture based on my mechanical aptitude and knowing how autos function and having rebuilt autos firsthand myself.

If you were to see these clutches, then you would understand the danger involved with this wear. The clutch material is extremely thin. There ain't much material there to be rubbing away..... especially just because the poor driver doesn't want to feel the slightest g-force during shifts. I am so thankful that my wife doesn't complain like that. Her RL shifts (and downshifts) fairly aggressively. And thankfully, she doesn't complain so that I can keep the Racing fluid in her car to protect the clutches.


Think of the clutch material like gasoline in your tank. Both will be depleted with usage. Both will cause your car to run perfectly until the resource is completely depleted. Once depleted, the clutches will suddenly begin to slip, forcing you to immediately to get a rebuilt trans. Just like your car runs perfectly until the last drop of fuel is gone, so will your trans appear to function perfectly too. But be aware, that you are consuming clutch material (remember that black slime on the drain plug), which is a limited resource, and it will be completely depleted some day. With most cars, the car dies of a graceful death before all of the clutch material has been depleted. However with the TL, that luxury smooth shift does come with a cost. That smooth shift is costing clutch material to wear away at a faster pace than most typical utilitarian cars.

I believe that a person must be willing to endure a harsher shift in return for a trans that will live much much longer. If a person is not willing to sacrifice a butter smooth shift, then that person should not use Racing ATF in my opinion.

Additionally, the Racing ATF is not for the faint-hearted. The Racing ATF does it's magic by making the clutches grab with authority. Thus, there will be clunk sounds and jerks coming from the trans. Based on my old age, understanding how trans work, being intimate with the internals of autos, years of drag racing, blah, blah....., I can assure you that those clunk sounds and jerks are doing absolutely no harm to trans or car. However, I can assure you that the butter smooth shifts and luxury feel *is* causing harm to the clutches by making the clutches wear at an accelerated rate.

blkaspec

Wow, I haven't been on here in a while but glad I did. I have already done my 3x3 during my last oil change (combo racing and lightweight racing), but when you guys are talking about D4, you are talking about Redline D4 ATF fluid, correct? Just making sure before I put in my order. Thanks!

p.s. I need to keep my eyes out for these flare issues...thanks for the heads up!

Inaccurate

Yes sir Redline D4 ATF (PN #30504) (click here)

Inaccurate

The flaring is related to the level of FM and appears to be unrelated to the viscosity. I base this on my flaring experience. My flaring was the same whether the fluid was cool or hot. Thus, we can say that viscosity doesn't effect the flaring.

With the flaring issue aside, the viscosity of the atf is of little concern. It is only something for the obsessive–compulsive people (which includes me) to fret over.

Using all Racing and no Lightweight would not harm anything. The Racing is thicker than normal atf. However, it is ok and will not cause issues. But it is my obsessive–compulsive opinion that the Racing is too thick.

On the other hand, the Lightweight is too thin. Unlike the Racing, the Lightweight *will* possibly cause harm if it was used entirely by itself. The Lightweight is possibly too thin to adequately protect the gears in the automatic transmission. I have been using 100% Lightweight before I had the flaring issue. I was willing to risk some gear damage in return for less parasitic drag for performance reasons. However, I never did find any metal on my magnetic drain plug.

Inaccurate

Because you already have fresh synthetic atf in your trans, your procedure would be slightly different. Normally, a person must do 3 refills to adequately flush out the old fluid. But in your case, you are just making your mixture to be a 65% Racing mixture and not trying to flush out the old junkie fluid. So, you will only do the first two refills. Here is your procedure below -

Refill #1 = 2 qt Racing ATF + 1 qt Lightweight ATF
Refill #2 = 2 qt Lightweight ATF + 1 qt Racing ATF

The above will produce a 65% Racing mixture having a normal viscosity (7.4 cSt @ 100º C).

For any subsequent refills (If you choose to do any additional refills in the future), you should use 1 quart D4 + 1 quart Racing ATF + 1 quart Lightweight ATF. This will indefinitely maintain a 65% Racing mixture having a normal viscosity.

I recommend that you do the Refill #1, then drive with it for at least a week. Perhaps drive even longer than a week until you have developed a good feel of the Racing ATF personality. Then, you will be in a better position to decide if you wish to pursue the full-blown 65% Racing mixture.

If you are unhappy with the shifting (too harsh, etc.) after your Refill #1, then do a single refill with all D4. This would put your mixture at 24% Racing and hopefully the harshness would be eliminated. If not, you would need to do another refill of all D4, which would make it a 14% Racing mixture.

Indy04TL

Inaccurate, let's see if I have got this right. Starting with Z1 last May, I did the following:

Refill # 1 2 qts Racing, 1 qt Lightweight
Refill # 2 2 qts Racing, 1 qt Lightweight
Refill # 2 2 qts Racing, 1 qt Lightweight

As I understand you, you are recommending doing a refill # 4 using 2 qts of D4 and 1 qt of Lightweight to bring the mixture down closer to the 65%. Am I reading you correctley?

As always, thanks for all the time and research you put into this!!

Inaccurate

No If it is Amsoil Super shift Racing ATF (click here).

Yes if it is Amsoil Synthetic Multi-Vehicle Transmission Fluid (click here).