4R70W Lentech Trans Review/Belt Slip ????

[Born To Run]

Well i picked up the car on Fri night from Lentech Automotive in Ottawa Ontario.I had the 5 speed manual trans removed & the Lentech terminator installed,3 speed manual valve body,with a non lockup converter,a 12 volt switchable overdrive feature,trans break & B&M ratchet shifter.My findings are as follows:

On the highway in overdrive @ 75 MPH the RPM's are 2400-2500,over a measured distance of 140 miles i got 21 MPG.(My manual got 22 MPG)Remember i have a Kenne Bell 2.6L 10 psi blower.I find the mileage & RPM's to be inline & acceptable.
Noise on the highway is about the same.When cruising in town you can hear the trans pump noise sometimes,it has a constant 200 psi line pressure.
Driving in town having to shift the gears with no clutch takes some getting use to.
When shifting from 1st to 2nd with moderate throttle it sometimes feels like i have been rearended,the trans snaps ya into 2nd & throws the car ahead ( i now understand torque with a new respect) the car responds with a shock to the differential & the rear wants to break loose with the car almost fishtailing to the left (Stock Pirellis in use) air temp was 32F last night.The shift from 2nd to 3rd with moderate throttle is about the same.
I am fearful of the unknown in my car now,fear is a allie like the first run i made in Frank Hawley's Drag school in his door slammer.I ran a 1.2 60' 145 MPH @ 9.3 sec.
Overall the transmission is doing its job very well.
But with any modification there are some minor problems.The cruise control does not work in overdrive,but Lentech are calling SCT on Monday to see if they have a program for this issue,unless you guys know what to do.
The other problem is when i shift from 1-2 with moderate throttle i have belt slip with a squeal & sometimes the car stumbles for a second then takes off when it all catches up.Do you guys have a suggestion for this,what will it be like when i go full throttle at the track,its gonna squeal & slip & fall on its face.
Also why is the belt slip occuring in the first place.

 

[ZmanM3]

Interesting, I don't know if I could give up shifting. Sounds like you do have some minor kinks to work out. Sorry I don't have the answers for you.

 

[yzfone]

I've got the lock-up, and my cruise only works with the convertor locked up. It must have something to do with the computer reading seeing the speed between the engine and the trans not matching like it should with a manual trans. I hav'nt researched a cure for mine though, since it does work when locked up.

 

[PNR Welding]

Well i picked up the car on Fri night from Lentech Automotive in Ottawa Ontario.I had the 5 speed manual trans removed & the Lentech terminator installed,3 speed manual valve body,with a non lockup converter,a 12 volt switchable overdrive feature,trans break & B&M ratchet shifter.My findings are as follows:

On the highway in overdrive @ 75 MPH the RPM's are 2400-2500,over a measured distance of 140 miles i got 21 MPG.(My manual got 22 MPG)Remember i have a Kenne Bell 2.6L 10 psi blower.I find the mileage & RPM's to be inline & acceptable.
Noise on the highway is about the same.When cruising in town you can hear the trans pump noise sometimes,it has a constant 200 psi line pressure.
Driving in town having to shift the gears with no clutch takes some getting use to.
When shifting from 1st to 2nd with moderate throttle it sometimes feels like i have been rearended,the trans snaps ya into 2nd & throws the car ahead ( i now understand torque with a new respect) the car responds with a shock to the differential & the rear wants to break loose with the car almost fishtailing to the left (Stock Pirellis in use) air temp was 32F last night.The shift from 2nd to 3rd with moderate throttle is about the same.
I am fearful of the unknown in my car now,fear is a allie like the first run i made in Frank Hawley's Drag school in his door slammer.I ran a 1.2 60' 145 MPH @ 9.3 sec.
Overall the transmission is doing its job very well.
But with any modification there are some minor problems.The cruise control does not work in overdrive,but Lentech are calling SCT on Monday to see if they have a program for this issue,unless you guys know what to do.
The other problem is when i shift from 1-2 with moderate throttle i have belt slip with a squeal & sometimes the car stumbles for a second then takes off when it all catches up.Do you guys have a suggestion for this,what will it be like when i go full throttle at the track,its gonna squeal & slip & fall on its face.
Also why is the belt slip occuring in the first place.

I myself always hear the squeal. I changed the belt and still same thing. I thought at first this is why im building no boost in 1st gear. But I changed the belt and nothing changed. I see you are still running the 8 rib set.
How does your boost look in 1st gear?

 

[flounderlipps]

Time for a 8 rib

Time for a 8 rib.

Look out Paul, a KB with an auto.
I'm gonna pay his bus fare down here just to race you.

 

[Born To Run]

Trans swap

I myself always hear the squeal. I changed the belt and still same thing. I thought at first this is why im building no boost in 1st gear. But I changed the belt and nothing changed. I see you are still running the 8 rib set.
How does your boost look in 1st gear?

My boost is fine,the car feels like there is more power available!! The belt slip has to do with power tranfer.I may order another thump_rrr billet tensioner & have him clock the spring for a tighter tension,as the saleen blown cars do not have as much belt rap as us Kenne Bell guys.

My cruise control works if i am not in overdrive!!

 

[Born To Run]

Trans swap

Time for a 8 rib.

Look out Paul, a KB with an auto.
I'm gonna pay his bus fare down here just to race you.

I have a 8 rib set up with a billet thump_rrr tensioner.

 

[PNR Welding]

Time for a 8 rib.

Look out Paul, a KB with an auto.
I'm gonna pay his bus fare down here just to race you.

Well i have an appointment with JDM in the beggining on january for a retune and going to a 3.0 pulley at 13.5 psi

 

[thump_rrr]

My boost is fine,the car feels like there is more power available!! The belt slip has to do with power tranfer.I may order another thump_rrr billet tensioner & have him clock the spring for a tighter tension,as the saleen blown cars do not have as much belt rap as us Kenne Bell guys.

My cruise control works if i am not in overdrive!!

Hey Randy,
I can send you one with more tension if necessary.

 

[Born To Run]

Trans swap

Peter,this will probably be my next step,how much more tension can we safely go to 25% 40%??? Can i trade in my other tensioner you sold me??

 

[thump_rrr]

Peter,this will probably be my next step,how much more tension can we safely go to 25% 40%??? Can i trade in my other tensioner you sold me??

Don't worry Randy I'll take care of it.
Let me see how much more torque I can get out of it and I'll get back to you.
Is it the type of trans making the difference?
Have you tried different hole locations on your adjustable idler pulley?

 

[silverpoison]

My boost is fine,the car feels like there is more power available!! The belt slip has to do with power tranfer.I may order another thump_rrr billet tensioner & have him clock the spring for a tighter tension,as the saleen blown cars do not have as much belt rap as us Kenne Bell guys.

My cruise control works if i am not in overdrive!!

Try to move down one hole on the KB suppied tensioner that is located on the driver side.

 

[Born To Run]

Trans swap

Don't worry Randy I'll take care of it.
Let me see how much more torque I can get out of it and I'll get back to you.
Is it the type of trans making the difference?
Have you tried different hole locations on your adjustable idler pulley?

Yeah,its the transmission causing the problem,this thing shifts like nothing i have ever experienced,the torque converter really does multiply torque.It shifts so fast it & so firm,the belt slip occurs when i shift from 1-2 or 2-3.Everything happens so fast it is hard to tell if the slip occurs on a quick shift decell or the accell.I have not tried to move the pulley,i guess i can.Peter see how much load you can safely apply re clocking the spring.Its funny, i can squeeze the belt together just below the blower & the tensioner moves easily(using 2 fingers pinching the belt).Lets get to work on this ASAP.

 

[ChevyKiller]

On your set-up, tighter is better. I would also try what eduardo suggested. Move your idler down 1 hole if you can to tighten the belt.

It really sounds to me like you've just got a little too much slack.

Are you running an overdrive on the crank pulley? That will definitely shorten the life of your belt if it is loose even a hair.

 

[Born To Run]

Trans swap

On your set-up, tighter is better. I would also try what eduardo suggested. Move your idler down 1 hole if you can to tighten the belt.

It really sounds to me like you've just got a little too much slack.

Are you running an overdrive on the crank pulley? That will definitely shorten the life of your belt if it is loose even a hair.

What the hell is a overdrive on the crank pulley.The only overdrive is in the transmission & i have to turn it on when i want it.
Len called me today,says belt slip happens all the time under moderate throttle as the inertia of the blower keeps going but the torque converter pulls the rpm's down so quick.He said it should not happen when at WOT,i have not tried that yet,i am very respectful of my cars new found power transfer ability.

I will try to move the pulley this weekend,but i still want Peter to make me another tensioner with the spring clocked a little more.

Any other suggestions or what to expect at the track the day i get there???

 

[n0nleft13]

I plan on doing the swap in about a month. After reading this it sounds like getting Peter's tensioner is a must have. Has anyone done the swap using the original tensioner?

EDIT: Just went back through the original thread and forgot it was for KBs only.

 

[canuck power]

I plan on doing the swap in about a month. After reading this it sounds like getting Peter's tensioner is a must have. Has anyone done the swap using the original tensioner?

EDIT: Just went back through the original thread and forgot it was for KBs only.

Check with Pete if he is running one ...i think he runs a Saleen s/cer

 

[thump_rrr]

I plan on doing the swap in about a month. After reading this it sounds like getting Peter's tensioner is a must have. Has anyone done the swap using the original tensioner?

EDIT: Just went back through the original thread and forgot it was for KBs only.

It works on all setups using the 3 bolt tensioner.

I currently have the tensioner installed on S197's with the following setups:
Saleen S/C
Kenne Bell S/C
Whipple S/C

I also have sold several to SN95 owners with the 96-99 front cover.

I will have a production version ready for final testing by next week to fit 03-04 Terminators.

 

[n0nleft13]

It works on all setups using the 3 bolt tensioner.

I currently have the tensioner installed on S197's with the following setups:
Saleen S/C
Kenne Bell S/C
Whipple S/C

Ok, so if to date I haven't had major slip will the 4r70 bring it out more? I only get slip if I shift in or out of 2nd. However when I check the belt it doesn't show any signs of slip dust. Is this one of the if it's not broke don't fix it areas in terms of beefing up the tensioner?

 

[PNR Welding]

Ok, so if to date I haven't had major slip will the 4r70 bring it out more? I only get slip if I shift in or out of 2nd. However when I check the belt it doesn't show any signs of slip dust. Is this one of the if it's not broke don't fix it areas in terms of beefing up the tensioner?

Yea I was in the same situation as you till I put the 4r70w tranny in and then all I heard is belt slip in low RPMs.