Need Cam help

[SSVictor]

Just installed a Btr stage 2 N/A cam to a L99 with vvt and dod delete and the car is lunging forward when it’s downshifting to 2nd and 1st gear. I’m having to put it in neutral when I’m stopping at a light or stop sign. Do I need a torque converter?

[hunter1660]

New tune for new cam???

[SSVictor]

It’s been tuned and everything at the shop. It shifts good and everything it’s only whenever I’m stopping and it downshifts into first

[Ashen 6.2]

Not a lot of info to go on here.. Is a stall converter recommended for that cam?

[SSVictor]

It states that stock converter works perfect with this cam. Here’s the link to the cam https://briantooleyracing.com/btr-ca...-32538134.html

[brettstoner]

I have the same cam and understand exactly what you mean. The factory converter is tight. At low rpm the cam has a natural lope and more overlap so you get the lope and bucking/surging. With the factory tight converter it transmits that force and you feel it. You can tune some of that cam surge out so it will idle nicely but to get rid of that surging/bucking/push on brakes you need a looser converter. Oddly enough I just ordered mine yesterday from Circle D. I am tired of it myself. LOL. You shouldn't be stalling. Sounds like idle and drivability is not properly tuned. With a good tune you can run a factory converter with that cam, but based on my experience you will have much better drivability with a new torque converter. If I were you I would go back to the tuner, take him for a drive, and have him fine tune it. If he can't/won't then would look to the likes of Pat G, Shane H, etc. to have it fixed. Either way if you want better drivability I would consider a converter as well.

[SSVictor]

Thanks

[SSVictor]

Originally Posted by brettstoner

I have the same cam and understand exactly what you mean. The factory converter is tight. At low rpm the cam has a natural lope and more overlap so you get the lope and bucking/surging. With the factory tight converter it transmits that force and you feel it. You can tune some of that cam surge out so it will idle nicely but to get rid of that surging/bucking/push on brakes you need a looser converter. Oddly enough I just ordered mine yesterday from Circle D. I am tired of it myself. LOL. You shouldn't be stalling. Sounds like idle and drivability is not properly tuned. With a good tune you can run a factory converter with that cam, but based on my experience you will have much better drivability with a new torque converter. If I were you I would go back to the tuner, take him for a drive, and have him fine tune it. If he can't/won't then would look to the likes of Pat G, Shane H, etc. to have it fixed. Either way if you want better drivability I would consider a converter as well.

What stall torque converter do you recommend running? Would a 2800 be fine?

[brettstoner]

Originally Posted by SSVictor

What stall torque converter do you recommend running? Would a 2800 be fine?

Sorry I can't give you good advice on that one. I don't have enough experience. Circle D recommended I go with a 258mm, triple disc, 3200-3400 for my setup (14 Caprice, 3.45, 4300 weight with full fuel and driver, NA now but going LSA in 3-5 yrs). Give me 2 months and I will tell you if their advice is good or not. LOL. I would recommend contacting Circle D or Yank for their recommendation.

[1JEWLDSSRS]

Originally Posted by brettstoner

I have the same cam and understand exactly what you mean. The factory converter is tight. At low rpm the cam has a natural lope and more overlap so you get the lope and bucking/surging. With the factory tight converter it transmits that force and you feel it. You can tune some of that cam surge out so it will idle nicely but to get rid of that surging/bucking/push on brakes you need a looser converter. Oddly enough I just ordered mine yesterday from Circle D. I am tired of it myself. LOL. You shouldn't be stalling. Sounds like idle and drivability is not properly tuned. With a good tune you can run a factory converter with that cam, but based on my experience you will have much better drivability with a new torque converter. If I were you I would go back to the tuner, take him for a drive, and have him fine tune it. If he can't/won't then would look to the likes of Pat G, Shane H, etc. to have it fixed. Either way if you want better drivability I would consider a converter as well.

Great advice here. Sometime you can get away with a stock TC with these cams if your tuner does the trans tune for it. Most folks I know that have a stage 2 cam are running "looser" converters just because of that issue, pushng thru the brakes at stop lights and bucking at low speeds. I would call Circld D and see what they suggest. Personally me, I had a 3200 in mine for about a year and it wasn't enough for my setup, so I went with a 4200-4500 Circle D and man what a hell of a difference!! One of my friends is running a Yank 3600 and really likes it. Don't go too small as you might not like it. Big stalls are not to be feared as they can be tuned to give the car near stock driving manners, but pack a big wallop when needed. Good luck sir!!

[Ashen 6.2]

Originally Posted by 1JEWLDSSRS

Great advice here. Sometime you can get away with a stock TC with these cams if your tuner does the trans tune for it. Most folks I know that have a stage 2 cam are running "looser" converters just because of that issue, pushng thru the brakes at stop lights and bucking at low speeds. I would call Circld D and see what they suggest. Personally me, I had a 3200 in mine for about a year and it wasn't enough for my setup, so I went with a 4200-4500 Circle D and man what a hell of a difference!! One of my friends is running a Yank 3600 and really likes it. Don't go too small as you might not like it. Big stalls are not to be feared as they can be tuned to give the car near stock driving manners, but pack a big wallop when needed. Good luck sir!!

Agree ^^^^ I had a 3600 with my SS2 and wished i had gone with 4k or more.

[KW Baraka]

Originally Posted by SSVictor

Just installed a Btr stage 2 N/A cam to a L99 with vvt and dod delete and the car is lunging forward when it’s downshifting to 2nd and 1st gear. I’m having to put it in neutral when I’m stopping at a light or stop sign. Do I need a torque converter?

My heads/cam LS3 (in my Impala) has the BTR Stage-3 cam....I do not have the surging on deceleration that you're having. As a matter of fact.....it has perfect road manners.

If I were in your position, I'd have my tuner address that surging.....AND.....I would consider a 2800 to 3200 stall convertor.

Brands I'd consider are Yank, Circle-D and Precision Industries (Vigilante).

Best of luck with whatever YOU decide to do.

KW