max speed
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Get your Vette off the jackstands & get the rear wheels back on.
Go find a deserted 2- lane black top country road.
Launch your Vette from a dead stop.
Keep your foot planted firmly on the gas & do not lift.
Aim your Vette straight.
Let the trans up shift on its own in Overdrive gear selector position.
If your Vette has the original valvebody...........
It will upshift to from 3rd to 4th gear at 110 to 118 mph.
Mine upshifts 3-4 @ 114 mph.
I have a hard time thinking its the torque converter.
You have no upshifting issues from 1-2, 2-3, you are missing 3-4 I think.
Race your vette flat out top end.
Feel & listen to the engine rpm's during the automatic gear change upshifts.
Brian
Instructor
Joined: Feb 2010
Posts: 106
Likes: 0
From: deltona fl
What do you mean by you could not road test it ?
Get your Vette off the jackstands & get the rear wheels back on.
Go find a deserted 2- lane black top country road.
Launch your Vette from a dead stop.
Keep your foot planted firmly on the gas & do not lift.
Aim your Vette straight.
Let the trans up shift on its own in Overdrive gear selector position.
If your Vette has the original valvebody...........
It will upshift to from 3rd to 4th gear at 110 to 118 mph.
Mine upshifts 3-4 @ 114 mph.
I have a hard time thinking its the torque converter.
You have no upshifting issues from 1-2, 2-3, you are missing 3-4 I think.
Race your vette flat out top end.
Feel & listen to the engine rpm's during the automatic gear change upshifts.
Brian
Get your Vette off the jackstands & get the rear wheels back on.
Go find a deserted 2- lane black top country road.
Launch your Vette from a dead stop.
Keep your foot planted firmly on the gas & do not lift.
Aim your Vette straight.
Let the trans up shift on its own in Overdrive gear selector position.
If your Vette has the original valvebody...........
It will upshift to from 3rd to 4th gear at 110 to 118 mph.
Mine upshifts 3-4 @ 114 mph.
I have a hard time thinking its the torque converter.
You have no upshifting issues from 1-2, 2-3, you are missing 3-4 I think.
Race your vette flat out top end.
Feel & listen to the engine rpm's during the automatic gear change upshifts.
Brian
forgot one key thing. go do this by yourself. IF something were to go wrong, you dont want to be responsible for somebodys death.
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
If the converter was slipping enough to lose 30 or more miles per hour in high gear, I would think that it would have killed the trans due to the excess heat generated.
I would suspect a slipping band first.
Pro
Joined: May 2010
Posts: 679
Likes: 18
From: Vernon Hills Ill
To some, it's just a video game. Do whatever without consequence,until something goes wrong. Hopefully no one on public streets would have to pay the price.
Thread Starter
Instructor
Joined: Jul 2005
Posts: 101
Likes: 0
From: Astrakhan city no
What do you mean by you could not road test it ?
Get your Vette off the jackstands & get the rear wheels back on.
Go find a deserted 2- lane black top country road.
Launch your Vette from a dead stop.
Keep your foot planted firmly on the gas & do not lift.
Aim your Vette straight.
Let the trans up shift on its own in Overdrive gear selector position.
If your Vette has the original valvebody...........
It will upshift to from 3rd to 4th gear at 110 to 118 mph.
Mine upshifts 3-4 @ 114 mph.
I have a hard time thinking its the torque converter.
You have no upshifting issues from 1-2, 2-3, you are missing 3-4 I think.
Race your vette flat out top end.
Feel & listen to the engine rpm's during the automatic gear change upshifts.
Brian
Get your Vette off the jackstands & get the rear wheels back on.
Go find a deserted 2- lane black top country road.
Launch your Vette from a dead stop.
Keep your foot planted firmly on the gas & do not lift.
Aim your Vette straight.
Let the trans up shift on its own in Overdrive gear selector position.
If your Vette has the original valvebody...........
It will upshift to from 3rd to 4th gear at 110 to 118 mph.
Mine upshifts 3-4 @ 114 mph.
I have a hard time thinking its the torque converter.
You have no upshifting issues from 1-2, 2-3, you are missing 3-4 I think.
Race your vette flat out top end.
Feel & listen to the engine rpm's during the automatic gear change upshifts.
Brian
Thread Starter
Instructor
Joined: Jul 2005
Posts: 101
Likes: 0
From: Astrakhan city no
When I checked it on the jack, the result was the same. I think , without load must be the difference between speeds , but there was no difference...
Oil is o'kay . I don't know what is it. I decided to install dana 36 with stock 2.79 & then check the speed.
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Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Nothing is slipping inside ,because the tranny is working in this way all 3 years. No difference between 1 day & today time.
When I checked it on the jack, the result was the same. I think , without load must be the difference between speeds , but there was no difference...
Oil is o'kay . I don't know what is it. I decided to install dana 36 with stock 2.79 & then check the speed.
When I checked it on the jack, the result was the same. I think , without load must be the difference between speeds , but there was no difference...
Oil is o'kay . I don't know what is it. I decided to install dana 36 with stock 2.79 & then check the speed.
One day you will discover that the original valvebody that your C4 left the factory with is long gone.
I have been telling you that over & over.
It may take you 10 more years to realize that I think.
Brian
Thread Starter
Instructor
Joined: Jul 2005
Posts: 101
Likes: 0
From: Astrakhan city no
Than I used procharger on the engine. The trany brake down. I asked somebody to help me to rebuild tranny to held about 600 hp . Pete Kane asked me , what i want to do with the car. At that time drag racing was
trendy in our place. I told him - drag ! He send me all parts to rebuild tranny & new custom made TC. Everebody told me to change Dana36 to Dana 44 , because 36 will brake down ....I bought Dana 44 with 3.55. Thats all. Then drage racing finished in our town. Now my car is street car without compressor , only 383 with 440 hp engine & street tires. With esp on it rides normaly only on the 3d & 4 th gears. On the 1st & second it try to spin ,but esp stops it. Now I need another rear end to realize good start & speed with street 315 tires.
Thread Starter
Instructor
Joined: Jul 2005
Posts: 101
Likes: 0
From: Astrakhan city no
Today I checked the rear end. It is really 3.55 . Again tested car on the road. The tranny is working perfectly. All gears shifts , nothing slips....
It is torque converter make such big slip, because of it small size & drag mission. I have read many articles today. It's written there ,that drag ,smaller size TC with high stall speed are good for sharp start ,but lose the car speed on high rpm.....
My final decision....I ll install stock 2.79 Dana 36. I think it is the only way out of this situation .....
It is torque converter make such big slip, because of it small size & drag mission. I have read many articles today. It's written there ,that drag ,smaller size TC with high stall speed are good for sharp start ,but lose the car speed on high rpm.....
My final decision....I ll install stock 2.79 Dana 36. I think it is the only way out of this situation .....
Safety Car
Joined: Sep 2001
Posts: 4,161
Likes: 554
From: Glenbeulah Wi
What is the problem you are trying to fix? The car will only go 125 MPH at 5500 rpm at WOT or???
What some people are pointing out is that at WOT the transmission will downshift from 4th or overdrive to 3rd gear and it will not shift back to overdrive or 4th gear until you take your foot off the gas. Only corvettes and some 350 GTA's and Camero's had the correct factory valve body to allow WOT 4th gear operation. All other 700 R4 will downshift into 3rd gear at WOT even when the shifter was placed in overdrive or 4th gear. You need to get a Corvette valve body to allow WOT 4th gear operation. Since your car appears to only go 125 MPH at WOT and is running 5500 RPM it appears your valve body parts or entire valve body have been switched to one that will not operate in 4th gear at WOT.
Changing the gears or torque convertor is not the correct answer, fixing the forced 3rd gear downshift is the answer.
What some people are pointing out is that at WOT the transmission will downshift from 4th or overdrive to 3rd gear and it will not shift back to overdrive or 4th gear until you take your foot off the gas. Only corvettes and some 350 GTA's and Camero's had the correct factory valve body to allow WOT 4th gear operation. All other 700 R4 will downshift into 3rd gear at WOT even when the shifter was placed in overdrive or 4th gear. You need to get a Corvette valve body to allow WOT 4th gear operation. Since your car appears to only go 125 MPH at WOT and is running 5500 RPM it appears your valve body parts or entire valve body have been switched to one that will not operate in 4th gear at WOT.
Changing the gears or torque convertor is not the correct answer, fixing the forced 3rd gear downshift is the answer.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
If you're sure your tranny is hitting 4th gear and the converter is slipping, get a different converter with less slippage and a lockup. You will have the advantage of your lower rear gear to get out of the hole and good top speed. I always lock up my converter so going through the traps in 3rd, there is no slippage.
Thread Starter
Instructor
Joined: Jul 2005
Posts: 101
Likes: 0
From: Astrakhan city no
What is the problem you are trying to fix? The car will only go 125 MPH at 5500 rpm at WOT or???
What some people are pointing out is that at WOT the transmission will downshift from 4th or overdrive to 3rd gear and it will not shift back to overdrive or 4th gear until you take your foot off the gas. Only corvettes and some 350 GTA's and Camero's had the correct factory valve body to allow WOT 4th gear operation. All other 700 R4 will downshift into 3rd gear at WOT even when the shifter was placed in overdrive or 4th gear. You need to get a Corvette valve body to allow WOT 4th gear operation. Since your car appears to only go 125 MPH at WOT and is running 5500 RPM it appears your valve body parts or entire valve body have been switched to one that will not operate in 4th gear at WOT.
Changing the gears or torque convertor is not the correct answer, fixing the forced 3rd gear downshift is the answer.
What some people are pointing out is that at WOT the transmission will downshift from 4th or overdrive to 3rd gear and it will not shift back to overdrive or 4th gear until you take your foot off the gas. Only corvettes and some 350 GTA's and Camero's had the correct factory valve body to allow WOT 4th gear operation. All other 700 R4 will downshift into 3rd gear at WOT even when the shifter was placed in overdrive or 4th gear. You need to get a Corvette valve body to allow WOT 4th gear operation. Since your car appears to only go 125 MPH at WOT and is running 5500 RPM it appears your valve body parts or entire valve body have been switched to one that will not operate in 4th gear at WOT.
Changing the gears or torque convertor is not the correct answer, fixing the forced 3rd gear downshift is the answer.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
You need to settle this issue with Pete K. then.
I don't think Pete K. would stick his neck out time & time again here on C4 tech.
I don't think he sells junk.
Pete K. & me don't always see EYE to Eye on opinions with Corvette Auto transmission or engines...............but he has been doing this for a long time too.
I do respect Pete K. & think he is a very good transmission & engine mechanic.
Pete K mentioned earlier that the 2-4 band may be slipping in overdrive 4th gear range on you.
That is possible too.
I think the factory original 1992 Corvette valvebody is missing & long gone.
Either way in time you will find the problem & correct it.
Brian
Drifting
Joined: Dec 2007
Posts: 1,647
Likes: 4
From: Argillite KY
It sure sounds like you're in 3rd gear. If you use the Top Speed Calculator above and and tell it 1.0 for the ratio (4L60E 3rd gear) and 25" tires it says 115 MPH. That's real close to what you're telling us. The other posts are correct. If the converter were slipping you would have some serious transmission fluid overheating issues. If the clutches were slipping they would have destroyed themselves by now. Surely in Russia you can find a good straight road. The road that runs just east of Sennoy looks straight. Go for a little drive and count the gears and see where it's shifting.
Team Owner
Joined: Dec 2007
Posts: 20,974
Likes: 261
Yeah if it was slipping and you ran it like that more than likely more than once it would be shot.
If you have not owned the car from new, I'd say it's not a genuine vette trans or parts at least.
I think it's obvious you are in third gear. The RPMS say that and so does the speed. With stock 17 inch wheels you don't need a calculator, it's simple 3.55's on an auto in a c4 are not that low. 3.75's will get you more speed than 120mph with an lt1.
Something is slipping but more than likely it is in 3rd gear.
My stock 2.59's with stock 17" wheels did go up to 90mph in 2nd winding it out in and holding it in 2nd.
If you have not owned the car from new, I'd say it's not a genuine vette trans or parts at least.
I think it's obvious you are in third gear. The RPMS say that and so does the speed. With stock 17 inch wheels you don't need a calculator, it's simple 3.55's on an auto in a c4 are not that low. 3.75's will get you more speed than 120mph with an lt1.
Something is slipping but more than likely it is in 3rd gear.
My stock 2.59's with stock 17" wheels did go up to 90mph in 2nd winding it out in and holding it in 2nd.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
If you used a TRANSGO replacement separator plate for a GM 700R4 like I did.............
There is 1 missing hole for the 3-4 WOT upshift function.
MTV hole.
It must be added.
Square hole.
Need a factory FSM to identify location correctly.
I had to replace my original 87 Vert separator plate.
They steel checkball seat holes were worn out.
I made the missing MTV hole discovery on my own.
I used TORLON Imidized checkballs in my 87 Vert rebuild & blueprint.
Eliminate steel separator plate wear.
Ford Auto trans checkballs.
Makes for lightning fast upshifts too along with dozens of other internal blueprinting & mods I made.
3/16" drill bit.
Add your own MTV hole.
Brian
There is 1 missing hole for the 3-4 WOT upshift function.
MTV hole.
It must be added.
Square hole.
Need a factory FSM to identify location correctly.
I had to replace my original 87 Vert separator plate.
They steel checkball seat holes were worn out.
I made the missing MTV hole discovery on my own.
I used TORLON Imidized checkballs in my 87 Vert rebuild & blueprint.
Eliminate steel separator plate wear.
Ford Auto trans checkballs.
Makes for lightning fast upshifts too along with dozens of other internal blueprinting & mods I made.
3/16" drill bit.
Add your own MTV hole.
Brian
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
At 14 I was wrenching on SBC & BBC Chevelles, Novas, Camaro's, & Trans Ams.
At 15 through 18 we were street racing my buddies & me.
And winning $$$ & Bragging rights.
1980's were great.
Too bad you were still a young kid playing video games at home.
I wasn't.