[jlo]

I got issues with a customers car. 1.5 seconds rpm stall on the 1st to 2nd gear change. Its a glide with a 4.57 rear gear & 29.5x10.5x15 tire. The car is 3595lbs. ETs are junk cause of this! I tried everything that was said on a thread on the trash or be trash forum, from up the shift point to adding timing at that point & did absolutely nothing! The car goes 138.11 at the 1/8 to 173.58 at the 1/4 with this issue. The car is shifted at 8700rpm normally & went to 9000rpm. The timing is 19 total at that point & put 2degrees back in for 1 second that's a total of 21 with a big jet on a single fogger. The 02s are reading 12.8 so i don't think I'm off on the tuneup, it wasnt lacking power at that point. The torque converter is slipping 6% at the finish line. The rpm drop on the gear change is 1300rpm, it drops to 7400rpm every time & it sits there for quite a long time, when it decides to recover it goes through at almost 9100rpm at the finish line. Does anybody has any suggestion on whats going on with this thing? Its a customers car, not the one in my signature just in case your wondering!

 

[Hutch]

Your pulling some weight and with a glide , it will hang on stall after the gear change and thats what its doing. It is still multiplying torque at that point and accelerating. Have you ever seen a glide car do anything different? Your going 1.8 - 1:1 , thats a big change.

Hutch

 

[z289sec]

Agree

I agree with that fact, I am in the same situation as your customer too. The only problem is in our class all of the cars are within a 100 or so pounds of each other. And my car is the only one doing this on the data file. Even though the cars are around the same weight and the transmission ratio is the same. When I am beside one of the other cars in our class. I am right there with them all the way through low gear, and as soon as it hits second, they fly ahead of me. But when it starts to accelerate again, I stay right with them. But it's that two or three car lengths after the shift that is killing me.

Hutch, you think putting a more aggressive rear ratio will help?

 

[Mike Beck]

I just put myself into a similar situation. I have a 'Glide with a 1.80 gearset. I have 4.30 gears in a 3200lb car with a convertor that stalls at 5600. I used to have 29 * 10 Hoosiers. I recently went to 30 * 10.5. Now when I shift (at 6800) it falls back into the stall of the convertor and takes about a second (according to the data logger) to get through this area. I lost a .10 in the 1/4 because of this. I am going to try raising the shift point which I purposely do low. It is a bracket car and just in case I thought I missed the light I would shift at 7200 rpm to pick-up a few .0x to at least make a race out of it, I never hold any!

I want to see if the shift point changes things. I can also put the timing back in it that the motor wants anyway.

 

[z289sec]

Let us know

Let us know if it helps. I am going to try going from a 4.10 to a 4.30 and see what happens. I will also try the shift point as well. But let us know if it helps, especially if you take it out before the weekend.

 

[Hutch]

Its a pretty simple deal . If the converter was eliminated the car would accelerate to its shift point , then gear change and fall to the rpm determined by the ratio change then accelerate from there and would not sit there at an RPM flatline.
When you see the flatline its just sitting on the converter. The only way to stop that is to accelerate in first gear to a point that won't allow the rpm fallback (determined by ratio) to land on the stall speed and you will not have the flatline in your graph. If the gear is changed it may make a very slight difference as it will take away some load from the converter and it may act slightly tighter but don't hold your breath.


Hutch

 

[jlo]

Your pulling some weight and with a glide , it will hang on stall after the gear change and thats what its doing. It is still multiplying torque at that point and accelerating. Have you ever seen a glide car do anything different? Your going 1.8 - 1:1 , thats a big change.

Hutch

Dump the glide & put a TH400? Would changing the stator in the torque converter help with the glide? 1.69-1.1 its the gearing!

 

[Hutch]

Dump the glide & put a TH400? Would changing the stator in the torque converter help with the glide? 1.69-1.1 its the gearing!

I don't know enough about your combination to pass judgement on the T400 decision.

Do you need 7400 stall speed with the nitrous on?

Hutch

 

[jlo]

I don't know enough about your combination to pass judgement on the T400 decision.

Do you need 7400 stall speed with the nitrous on?

Hutch

I dont know! Thats why I'm here asking! Most people are afraid of asking questions cause they think they know it all but I dont know it all. I would like to fix this problem if possible. Can it be fix? What do you need to know?

 

[MCMIKE]

Dump the glide & put a TH400? Would changing the stator in the torque converter help with the glide? 1.69-1.1 its the gearing!

What's Bradco say ?

 

[jlo]

What's Bradco say ?

To put his back on & gear the heavy brick! Someone told me to try one that i had sitting on the shelf but it didnt to the trick. We are going back to Bradco's! His torque converter had 0% slip with the 4.30 & the 4.57 gear, little after the gear change. 4.71 is going in next & see what that those. The R25 BWM is 6.8% that is 9083rpm at the finish line. Even if Brad's slips 2% with the 4.71 gear the finish line rpm wont be that high. The engine peeked power at 8400rpm so if it goes through at 8800rpm or less & it helps the rpm stall on the gear change, life would be better!

 

[Hutch]

I have the answers for you Jimmy but this recent post you just made reminded me a lot of the shyt kicking you gave me over the thrust bearing post this past winter.
I don't want to get into that again and I see once again you have all the answers anyway so why don't we leave it at that and I won't subject myself to another kick up the nuts.
You would think I would learn after the first time.

Hutch

 

[jlo]

I have the answers for you Jimmy but this recent post you just made reminded me a lot of the shyt kicking you gave me over the thrust bearing post this past winter.
I don't want to get into that again and I see once again you have all the answers anyway so why don't we leave it at that and I won't subject myself to another kick up the nuts.
You would think I would learn after the first time.

Hutch

Hutch why do you have to go there! I have done nothing but ask you for some of your knowledge & you give me smart comments! If you dont want to help just say so!
McMike asked a question so I answered it! If you don't think is the correct thing to do in my last post then tell me what you think or point me in the correct direction. That simple!
I like to get to the bottom of things as you know already. Is the fix for this problem top secret just like everything else in this business is? If you got the solution put a dollar figure on it & let me know! I'm willing to pay top dollar for it, if it works! I know money & top secret info go hand in hand!
You have a technical section here to help people not to make them feel like crap!

 

[Hutch]

You have a technical section here to help people not to make them feel like crap!

And I do help people, a lot of them and I keep no secrets that sacred.
I tried to help you this past winter if you remember and you turned it into a shitstorm. For that and where I feel this is heading, let me out before it starts again with you.

Hutch

 

[Collinsautomotive]

Sounds like the motor is fighting the converter. IS this a bad thing ? depends on the situation. The other possability is that the transmission is somehow binding on the shift. Did anyone rule this out yet ?

what are the incrementals ? 60 330 660 1000 1320 ?

 

[jlo]

Sounds like the motor is fighting the converter. IS this a bad thing ? depends on the situation. The other possability is that the transmission is somehow binding on the shift. Did anyone rule this out yet ?

what are the incrementals ? 60 330 660 1000 1320 ?

I dont have my customers time slip with me but I think in one of the runs it went 60' 1.296/ 330' 3.496/ 1/8 5.3? at 138mph/ 1000' 6.9?/ 1320' 8.12 at 173. On that pass it stalled for about 1.1 seconds on the gear change.

 

[jlo]

And I do help people, a lot of them and I keep no secrets that sacred.
I tried to help you this past winter if you remember and you turned it into a shitstorm. For that and where I feel this is heading, let me out before it starts again with you.

Hutch

If you want to bring a dead horse back well here it is! The thrust issue was resolve by putting a simple restrictor in the pump! It didnt have one! The car is running with the same trans & torque converter with out hurting anything! No mods to the bearings, no coating to the crank of any kinds, no surface finish to the face of the thrust on the crank, .007 end play no problems! Thats a done deal! The racers from this website help solve this problem by telling me to dyno the trans & check the cooler pressure, not by you! You were just sticking up for the guy at fault at the time, but that was all water under the bridge into you brought it up again!
Shitstorm? When thousands of dollars are being thrown in the garbage because of a simple mistake someone made dont you think anybody would turn into a shitstorm! I do! & so did the customer!
I got on here asking for your help! I thought everything was cool between us but I guess I'm wrong! This rpm stall on the gear change will get resolve with or without your help! Just like the thrust issue! Customers are #1 in my list.
By the way, If i knew it all why am I here asking you! I do know one thing for sure this customer has a problem & we are going to get to the bottom of it!

 

[z289sec]

Fyi

If you want to bring a dead horse back well here it is! The thrust issue was resolve by putting a simple restrictor in the pump! It didnt have one! The car is running with the same trans & torque converter with out hurting anything! No mods to the bearings, no coating to the crank of any kinds, no surface finish to the face of the thrust on the crank, .007 end play no problems! Thats a done deal! The racers from this website help solve this problem by telling me to dyno the trans & check the cooler pressure, not by you! You were just sticking up for the guy at fault at the time, but that was all water under the bridge into you brought it up again!
Shitstorm? When thousands of dollars are being thrown in the garbage because of a simple mistake someone made dont you think anybody would turn into a shitstorm! I do! & so did the customer!
I got on here asking for your help! I thought everything was cool between us but I guess I'm wrong! This rpm stall on the gear change will get resolve with or without your help! Just like the thrust issue! Customers are #1 in my list.
By the way, If i knew it all why am I here asking you! I do know one thing for sure this customer has a problem & we are going to get to the bottom of it!

Hey man... just FYI so you will know, I tried going from a 4.10 to a 4.30 gear. And ran the shift point all the way to 8000 from 7400. No matter where the rpm dropped to it still flatlined and took over 1.2 seconds just to start climbing again. Also, the rpms at the finish line are the same no matter what the gear or shift rpm. With the 4.10's and shifting at 7400 it was 7039. With the 4.30's and shifting at 7400, 7600, 7800....etc. it was 7058.

A whopping 19 rpm's

So long story short, if you find out what is up with this guys car......keep us in the loop!!
Thanks

 

[Collinsautomotive]

What the slip rate on teh converter ?

I dont have my customers time slip with me but I think in one of the runs it went 60' 1.296/ 330' 3.496/ 1/8 5.3? at 138mph/ 1000' 6.9?/ 1320' 8.12 at 173. On that pass it stalled for about 1.1 seconds on the gear change.

 

[jlo]

Hey man... just FYI so you will know, I tried going from a 4.10 to a 4.30 gear. And ran the shift point all the way to 8000 from 7400. No matter where the rpm dropped to it still flatlined and took over 1.2 seconds just to start climbing again. Also, the rpms at the finish line are the same no matter what the gear or shift rpm. With the 4.10's and shifting at 7400 it was 7039. With the 4.30's and shifting at 7400, 7600, 7800....etc. it was 7058.

A whopping 19 rpm's

So long story short, if you find out what is up with this guys car......keep us in the loop!!
Thanks

I will be glad to share with you or any one thats interested on this issue our results. Thats why we are here trying to find answers, Maybe Hutch can tell you the fix since he said he had the answer to this problem & he doesnt keep any top secrets from anybody!