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-   -   A4's with cams come in! (https://ls1tech.com/forums/generation-iii-internal-engine/560361-a4s-cams-come.html)

jlashley2001ss Aug 16, 2006 03:54 PM

A4's with cams come in!
 
I thought my car had something wrong. It has the jerkin/jumpin back and forth feeling at low speeds but im thinking its the cam surging causing that feeling. Any of you guys with the A4's have this issue? If so how or did you fix this problem? TIA

RGV_Z28 Aug 16, 2006 04:18 PM

More than likely it's a tuning issue.

Hugger Aug 16, 2006 04:38 PM


Originally Posted by jlashley2001ss
I thought my car had something wrong. It has the jerkin/jumpin back and forth feeling at low speeds but im thinking its the cam surging causing that feeling. Any of you guys with the A4's have this issue? If so how or did you fix this problem? TIA


Welcome to my world. I have been plagued with surging/bucking for quite a while. It's very frustrating. There doesn't seem to be a magical fix for this. Each car is different and tuning should lessen the effects.

Biggs Aug 16, 2006 04:45 PM

While it is doing this, simply tap lightly on the brake with your left foot with out changing your position on the gas pedal, if it stops then it is your torque converter locking up at speeds before the cam has cleaned up.
Get your tuner to raise the speed your converter locks up.

1998z28ss Aug 16, 2006 04:52 PM

Well if its any help I have a T-56 and a 231/237 Tsp cam. If I let it drop below 2000 RPMs in a low gear it bucks/surges like crazy. From what I can tell theres too much load and not enough power. So in my case gears will fix it. But for you I suppose it has to be the torque converter lockup...

Scoundrl Aug 16, 2006 05:37 PM

I had a 229/235 586/595 113.5 in my a4 c5. You need to make sure your tc is not locking under 1500 rpms and having a well tuned VE table (even if you turn the maf back on) is important. This combo worked great for me.

-Ken

gillbot Aug 16, 2006 05:58 PM

check your TCC lockup tables.

jlashley2001ss Aug 16, 2006 06:13 PM

is that my torque converter tables?

PREDATOR-Z Aug 16, 2006 06:16 PM

Also too much timing at low rpms will increase that reaction. It can be cured or at least lessened with proper tuning.
I've been playing with that issue myself, I reduced it but still not perfect.

snake_charmer Aug 16, 2006 07:30 PM

The majority of it will probably be your lockup tables especially if you have a larger stall and have changed the gears. The rest will be related to timing in the lower MAP tables while you are driving and sitting just above the shift points at lower RPMs (under ~1750).

Photochop Aug 16, 2006 07:36 PM

Take your car to a good tuner with some experience under their belt. That cam is small, anyone that knows what they're doing should be able to make that cam as tame as a stock car. Some 3.42s or numerically higher would help you out.

Mine bucked/surged quite a bit when I went from a 228/230 cam to a 242/248 before the tune.

Before the convertor would lock up at 40 mph, now it locks up at 60. With 3.73s I can still feel it surging just slightly til I get up to about 70 mph.

The car would also surge at low rpms, so my tuner bumped up the idle speed when the brakes aren't being applied to 1500 rpm, even there it surges but it's doable. Its kinda funny though, since it surges like it does between 1K and 1500 rpm when you're cruising between 20-40 mph it kinda serves as a cruise control, just let off the gas and the surging causes the car to maintain speed :)

The cam in my car is large, but after being tuned properly I wouldn't have any problems driving it daily, just choose not to because it drinks the gas with the 4400 convertor and that cam. Your car should be tuned to be about 99% as smooth as stock if done right.

NC98Z Aug 16, 2006 08:10 PM

Its all in the tune just repeat after me its all in the tune.

Azrael Aug 16, 2006 08:25 PM


Originally Posted by NC98Z
Its all in the tune just repeat after me its all in the tune.

We have the same issues, and I totally agree with everything has posted especially this comment above!

We need our car tuned again, but might as well wait a little while, since our heads are almost finished and then ready to go on... :bang:

slimcracka Aug 16, 2006 08:25 PM

i dont mean to high jack but i dont have a cam (as in aftermarket) and it does this at 40mph.. the stall locks at 38 and if im just crusing at the same speed (40) then this starts to happen and i dont know why with it being the stock cam and a baby stall..can someone help me please...

Azrael Aug 16, 2006 08:27 PM


Originally Posted by slimcracka
i dont mean to high jack but i dont have a cam (as in aftermarket) and it does this at 40mph.. the stall locks at 38 and if im just crusing at the same speed (40) then this starts to happen and i dont know why with it being the stock cam and a baby stall..can someone help me please...

The torque converter is locking/unlocking causing a surging/jerking, usually while cruising or coasting/decellerating...

beardWS6 Aug 16, 2006 08:52 PM

We pulled alittle timing out down low and fixed that same problem for me. GoodLuck!

CRASH Bandicoot Aug 17, 2006 11:43 AM


Originally Posted by jlashley2001ss
I thought my car had something wrong. It has the jerkin/jumpin back and forth feeling at low speeds but im thinking its the cam surging causing that feeling. Any of you guys with the A4's have this issue? If so how or did you fix this problem? TIA

A little more tuning and a 373 gear would solve your problem.

slimcracka Aug 17, 2006 07:31 PM

the rpms dont change and it sounds like i have a 6speed in the car with the clunking of the driveterain...


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