update, took the torque tube out of the car, bearings and couplers are good, pilot bearing shaft is worn. that won't cause the issue i'm having since the cam install. it must be in the tune some where.

 

That's a lot of work, I'd go ahead and replace everything anyway

 

Do you have a log of your car with HPtuners?

 

see attached. this isn't the latest as that log is huge and exceeds the file limit. at all steady cruising light throttle under ~2800 rpm i feel it.

the car currently runs open loop up until the high rpm that is richened up which reduced the effects. if i load the closed loop tune with correct ~14.7 afr i can litterally feel the switching o2's mechanically in the car while light throttle.

i'm replacing the input shaft and Clutch/Flywheel assembly while it's apart. should have it back together this weekend.

thanks

 

I can connect you with someone who can help you if you want. He helped me tremendously.

 

Ok guys.. i haven't driven the vette in a while been busy, been driving it to work the last couple days, been cooler out. the surging is definitely there in this car since the cam swap. i even used another tuner to tune the car. funny thing is i installed the same cam in my friends 2010 vette with same headers and it drives fine without surging using my tune. unless TSP messed up the grind on one of the cams (mine) i ordered both cams at the same time. I'm pulling the cam out and searching for a replacement.

 

I would just do a smaller cam. 223/231 115+3 .595/.587

 

Not trying to hijack the thread, and If I should start a new one just let me know. Anywho, I'm pretty set on this cam for my build too but drivability is most important for me. I see a lot of the same, "I have some surging but didn't bother to tune it out," comments and this makes me worry a little. I love driving my car and want to keep it that way. Has anyone found the reason everyone seems to experience this "surge?" Is there anyone with this cam that doesn't have this issue? I'm not trying to throw shade at this cam, I know everything comes at the expense of something else, I just want to make sure I'm making the right decision. I tend to be very "in tune" with how my car is running and I know I'll be really annoyed if I experience this. I have no problem going with an off the shelf cam but I tend to like the less mainstream stuff, I just want to make sure I can have a smooth driving car once all is said and done. I don't mind leaving a bit of power on the table for better manners but if both could be had, as many state, I'd love to have both, haha!

 

surge/bucking is all tune dependent. A cam with 4-5 degrees of overlap is going to have some of that but it’s manageable. A cammed car is not ever going to behave like a stock cam car. If you don’t want that, I would do a negative overlap cam. Keep in mind bigger isn’t better. LS3 style ports also suffer from reversion above 5 degrees of overlap. It’s not worth the extra 10-15hp for the car to drive like ***. Spins cam is good but I would run it with more compression. Minimum 11.5-11.7. Shave the ls3 heads down to 65cc chambers and use .040 headgasket.

 

I'm running Cam Motion LS3 TITAN 2 on the 8620 core type, stock LS3 heads, stock 10.7:1 CR.
Pulls strong through entire RPM range, has a slight lope at idle, excellent street manners.

Cam Motion LS3 TITAN 2

• Duration at .050": 222/230
• 113 Lobe Center Angle with a 110 Intake Centerline
• Lift with 1.7 Rocker Arm Ratio: .595"/.587"
• Zero (0) degrees of overlap

 

i was just looking at this or the stage 3. i'm going to call cam motion tomorrow.

 

Regardless of the cam chosen, raising compression makes the cam's manners improve quite a bit, increasing volumetric efficiency.
Increasing the compression ratio, the engine draws in more air-fuel mixture during the intake stroke because of the increased vacuum, which improves volumetric efficiency.
More overlap however allows cylinder pressure to drop by pushing it out during the overlap period.
When you get it pushed out of the exhaust valve, you get the fuel being burned in the exhaust manifold causing chop to the idle.
The efficiency improvement is about 4% for a full compression point and the power improvement is at all rpms, not just at top.

 

I'm running a 0 overlap cam. 226/234 115+4 with lift at .620 lift on both sides. It's big enough to make some pretty decent power, but small enough to not cause drivability issues. It fits me to a "T". Not suggesting anyone use it. "Anyone" might think it's too big or too small. I don't care. It will idle along in 6th gear with no bucking or surging. It will even go up and down mild hills at idle in 6th gear. It also pulls clean and strong from idle to 7K rpm. In my LS3, it makes 500 at the wheels using ported and milled heads with ported intake mani and throttle body.

Spin's cam is very well thought out and a really good effort at really good power increases with minimal drivability issues. It you want fewer drivability issues, just know that perfect manners will get you minimal power gains. At some point, if you want perfect manners and a huge power increase, you need to WAKE THE **** up and know what you're getting into. Perfect manners and big power increases requires positive manifold pressure.

There's no free lunch here. There is NO cam that doesn't have drivability issues yet makes huge power increases. I don't give a damn how good your tuna is. I've been to plenty of the magic tunas yet only one would I recommend (Pat G, Victoria, Tx).

Modding a Vette is just about the most fun you can have with your clothes on. Enjoy the journey. Make smart decisions on your inputs.

 

i agree with everything you said old motorhead. it took me years before i settled on spins grind. yesterday i fixed the power seat in my buddies 2010 base vette that i put the other spin grind cam in so i could reach the pedals. i took it for a drive and it does have something going on in the same rpm that my car has except i have to "look to feel it" in his car. mine it's apparent. it seems as if there is excessive drivetrain slop in my GS compared to his base, both are manual cars. for some reason and i think that's magnifying the feel.

 

You can have 700rwhp with stock perfect manners if you get a paxton from ECS and the stock cam.

 

What do you think those heads could add over the stock LS3 heads? My set up with just Cam, exhaust & tune DYNO at 495HP/453TQ... plan to add heads next.



SPEED SAFE, NICK

 

Stock LS3 heads come with an as cast 260 cc intake port that flows 315 - 320 CFM.....and around 220 CFM on the exhaust. The numbers aren't bad but they are very inefficient (the port is on the big side)

My aftermarket clean sheet design is a 12 degree head utilizing the AFR LS3 castings which I designed back in 2014 just before my departure there and the launch of Mamo Motorsports.

The LS3 product I offer now is an improved version of that design (my MMS 26X head) and it has a finished CNC ported volume which is the exact same size as a factory as cast LS3 head (260 cc's) but flows a whopping 390 CFM!!

Besides the gains in peak volume (70 CFM) think about the gains in airspeed that creates getting all that additional flow thru the same size port.....that does amazing things for throttle response as well as power and torque output

The exhaust is very impressive also with a 50+ CFM gain over stock (272 CFM versus 220 CFM!)

PM, email or shoot me a call and we can discuss in more detail, but in the meantime here are some cylinder head **** shots of what we are discussing

 

https://ls1tech.com/forums/dynamomet...k-results.html

here’s a good thread. Most stock cube guys get fixed on the ls3 head as the king. If it were me these are the heads I’d run. With a 62cc chamber and .040 head gasket. I’d also run Tony M ported fast. Leave the stock 90mm gm tb.

 

I appreciate a good set of heads and all that goes with them. I just don't see the value in spending thousands on heads only to be limited to low 500's at the wheels. Leave the heads alone and add a blower for slightly more $'s. 700 wheel with better manners can be had. If you're looking to go really fast, and want really good manners, for not much money, that's the obvious way to go.

 

Centri blower w/ 8rib conversion so you can consistently make 700+ whp requires a legit fuel system. No aux pumps and BAP. You’re in it for over 10-12k without installing. You also are gonna need welds and tire. Let’s not forget all the threads we see about “I’m overheating” so add in a prospeed or gspeed fan. You see where I’m going with this? Your math isn’t mathing.