Hey guys I'm considering changing cams in my Ls2 C5Z. Currently my setup is fast 92, Ls2 tb, tfs 220's, 1 7/8 kooks, and 239/244 111 lsa cam and put down 489/442. Im wanting better driveability and I'm sick of the surging with the setup that I have. I'm considering a Btr stage 2 Ls2 cam. Roughly how much power will I be leaving going this route and will it be noticeable on the street? Thanks

 

leave the cam and get a better tuner

 

I tend to agree with you Dennis, however, he's got a C5 and their computers are a LOT slower than the C6 computer so they aren't as forgiving with the big cam.

That said, there are a lot of calibration areas that can be adjusted for street (closed loop) driving, I got my car running very smoothly but I had to cruise around a lot and make it misbehave and note the time in the scan where it was misbehaving - then I could go back and adjust things in those areas until I got it dialed in. In particular, I had some timing jumps from cell to cell based on load that were causing bucks. Using HP Tuners' extrapolation feature, I smoothed these timing jumps and that got my cruise very smoother.

There are many of these type of ideas that a seasoned tuner wiling to spend the time to street tune your car can tame a lot of the concerns.

In your case, I'd say not all; that 111 LSA is going to cause a lot of reversion at low throttle settings and that's hard to tune out. Frankly you might find a SD tune more agreeable if you've got your MAF still trying to do its thing.

You could also install Cometic .040 gaskets to raise your SCR to about 11.4 - the extra compression will help tame that cam. If you want to make it even better, shave the heads a bit. Pushrods are cheap. I'm running 11.9 and have no problem on pump gas (though I can't run much timing at torque peak).

 

Thats exactly what i was thinking Joe SDtune, but still needs to be a qualified tuner who has done many c5 tunes with that combo and usually can pull a tune from his archives and get it real close and fine tune the rest with a few adjustments

 

Fwiw it has a SD tune now. Also CR is 11:1

 

I don't have a number for you that it'll decrease, but you can see in my sig what my car made with a g5x3 and AFR heads. Your heads are likely 20/10 better than mine so you can get an idea of what my cam would do in yours.

I'd get a tuner to do some work before I started spinning wrenches.

 

you can see what mine made with a cartek cam its an automatic with 373 gears and a 3800 rpm converter with 343 ported heads stock valves milled just to clean up and 11.1 maybe 11.3 on 93 pump it ran 10.16 @132mph on an easy launch peddling for traction, dont know the cam specs but sounds big, no surging idles smooth, i know what the timing is from logging so it cant be high in the compression

 

I'm not so much worried about a dyno number but will I be able to feel a difference in the car seat of the pants? I would think the smaller cam would have more low end and midrange than what I have?

 

cant see how with that much tq, with my tq i still managed a 1.34 1.35 60 ft part throttle and has power from start to max rpm in every gear, i would find a real tuner and you will be very happy

 

you could also buy hp tuners pro log it and get some help from guys like JoeG

 

So you recommend keeping the cam I have and having the tune looked at? Is SD the best way to go in your opinion?

 

SD is just easier for the tuner, I think Maf is better as it adjusts for weather conditions and i think im not 100% but you can do a combo with efi live and hp tuners, i dont know that for fact but have been told, my tuner Julio @ Cartek did my tune and its great, smooth idle no surging and its a very safe tune , I know your in Georgia but there has to be someone down their

 

MAF is better, that's why the OE's went to it, it's a feedback system that takes barometer, IAT, ECT, MAP and O2's into account when deciding how much fuel to put in. Speed density incorporates rpm and load only and it fuels what the table says regardless of weather and other engine parameters. Open loop is pretty much speed density so Dennis, yes, our closed loop MAF tunes turn into SD tunes (with a few other modifier tables thrown into the calculation) when we go to open loop. Your mileage will be better with MAF. The reversion might have your 02's messed up though and it can be difficult to tune down low. With that 111 LSA its just never going to be perfect at low rpms, that's a lot of overlap. I got a 114 LSA cam for that reason, it's easier to live with.

Will you feel the power reduction? Only when you floor it and only above 4500 rpm. But yes you'll feel it then. But if you're not drag racing and going for a record every time, then the milder manners might be worth it to you.

I would personally start with a good street tune before I started swapping hard parts. Where are you located? You can get some good recommendations here or maybe your tuner can do it.

 

I vote for going with a smaller cam...

 

I have been here and done this, smaller cam, more LS,

I had a 238/242 on 112 and I went back to a 228/234 and lost 25 FT/TQ - this on my 406 CI L98 type C4

EDIT>>>>>> I am not recommending that you go to the cam mentioned above, but I would suggest something like a 232 intake with a 14 ls or a cam in the 4 degree valve overlap or less range

 

Looks like I'm going with the Btr stage 2. I was actually hoping I would gain torque through the midrange. This cam is pretty flat til 4k rpm or so.

 

I don't know the specs of that cam, but if you have specific drivability and torque curve goals, you might consider contacting Patrick G and have him spec a cam to meet your goals. An off the shelf cam may or may not be your best option.

 

I have all the confidence in Brian Tooley with this cam. He said it would give me what I want. I know Patrick G is the man as well

 

I'm really not a fan of giant cams because they are so hard to get right. I think you will be pleased with a more moderate cam, it should feel faster and i doubt you'll lose much at the drag strip.

 

I hope so. Little nervous about it honestly. I don't want the car to feel like a terd lol