I just bought this car and have a tune scheduled next weekend so I figured I would throw a few other changes into the mix so I won't have to keep re-tuning with each small change.

The car has a Honker, 228/232/598/600/113 cam, springs, LG LT's and an UP. The car has bucking like crazy at any rpm under 4K. WOT and progressive throttle is just fine but at 20-30% throttle, it bucks like crazy. So I need a retune. Anyway, on to the pics.

Like a few of you, I will tear into anything.

Word of warning.

If I could do this again, I would be happy to pay the charge to port this intake. I spent a week (off and on after work) messing with this thing. Cut my hands multiple times since it very sharp inside and my arm got stuck in the intake God knows how many times!

I cut out the posts, the breather tube sticking out and mildly ported the runners as far as I could reach. It came out great, IMHO.

This is the 2nd intake I have ported and it needs to be smooth, that's my advice. Again, IMHO, just pay to have this done.

Throttle body, very basic to port and polish just be careful NOT to go beyond where the blade rotates to maintain idle.



I did not get a pic of the LS3 mouth before I ported it, I forgot. Here is the mouth with the posts removed and the vacum post removed. There is still plenty of plastic dust in there, I had not cleaned the intake yet.





Stock runners




Ported runners, not cleaned yet.




Bottom showing the JB Weld to replace the post holes. It took 2 (packages) of JB Weld.



Few random pics






I left the "insulation" intake cover off when I put it back together, no additional noise as far as I can tell. The coil covers are gay to me so they will be trashed.



Car still bucks but it has more power at any rpm under the curve. It's easier to launch since it takes less throttle BUT it does spin with much less throttle. I have TSP 1 7/8 C6 headers on the way and I will have it all retuned together. I will also be added TEA LS3 heads soon and then a small 100-125 shot. I will say even right now this car feels as quick as my KB Cobra was, no joke. Thanks for looking.

Thank you for your input on the JB Weld Spin.

 

Great work!
Enjoy

 

Thank you

 

Have you tried reinstalling your stock intake system (filter/ducting) to see if that stops the bucking?

Nice work, BTW.

 

That's an excellent idea, I wish I had it to try. The car came with a few mods but none of the original ones.

Anybody in Ft. Lauderdale got a stock intake I can barrow?

 

looks good, i think if you spend that kind of time on the exhaust you be shocked as well. You can do it really easy just blueprint it (take some blueprint paper use it like an exhaust gasket and take the areas where the exhaust and head dont match exact). The porting is great and any smoothness or taking out restrictions you will see gains but anything that comes in needs to go out smooth and fast as well.

 

Looks like a lot of work. I think you're right, pay someone else to do the work.

 

Just to put it in perspective on the time/cost trade-off, I do exactly that work to manifolds for 250 and the TB combo is 350 for both.....how many hours did it take you to complete the job?

In my opinion, you did a great job on the manifold and TB.

Just a word of caustion for those that will attempt this: Do not open the intake manifold's runner wider than the head's intake runner. You will lose power if you do that.

 

I would estimate about 9-11 hrs of actual porting and sanding for both. I also agree to just pay someone who is skilled in doing it and saving time, such as yourself.

Also, excellent point about the runners. I tried not to open them much at all but it is surprising how quick the runners port.

Personally, unless you're a major DIY'er, I would not attempt this at all. Pay and have it done right while saving the down time and the scraped knuckles.

$350 for both is an amazing deal, I was just out of money.


Also, concerning the bucking. I actually cut a section of window screen and placed it over the maf housing of the Honker and that was enough to smooth the airflow and it improved 50%.

It is an airflow issue, not tune. I will edit the post, 21CMC's tune has nothing to do with the bucking, it's my maf with the Honker. I will be trying a new CAI or maf to correct it, though I will still retune it for the ported intake/tb.

I guess very few LS3 cars have bucking issues with CAI's and mine is one of them.

 

Do you have any before and after pictures showing the posts.

 

Actually a lot of LS3 cars had bucking issues with CAI's..The severity of it was the variable. Mine was not very severe, but I could feel it. Callaway has a "diffuser panel" to go over the filter assy to help stop this. Mine did it with a K&N, and took a diffuser to get rid of the surging.
BTW, great job on the port work....