Stock Bottom End Capability
Thread Starter
Instructor
Joined: Apr 2011
Posts: 218
Likes: 16
From: Littleton CO
Stock Bottom End Capability
I have an L98 with a miniram that I use for HPDE days a good bit during the months of April-October - let's just say 600-800 miles of track time per season is the plan.
Right now it has slight exhaust mods and the miniram. As I am tired of running down C5's/C6's in the corners and having them pull me by 2-4 lengths on the straights I know my next step is an LT4 hotcam, as I still need to pass emissions. However, once I get in there I am about 16 bolts away from pulling the heads as well.
My concern is how much can the stock bottom end take? I replaced the con-rod bearings earlier this year because I mistakenly thought I had a rod knock but it was a dual mass flywheel issue. The bearings I took out looked awesome at 105k miles.
So the question is, should I go with just the cam (springs included of course) or should I go ahead and slap some AFRs on there since it means one less tear down?
My guess is that it is really a matter of rpm and load, so I don't mind short-shifting at 6k or so if that helps it live longer.
Opinions?
Thanks.
--Calvin
Right now it has slight exhaust mods and the miniram. As I am tired of running down C5's/C6's in the corners and having them pull me by 2-4 lengths on the straights I know my next step is an LT4 hotcam, as I still need to pass emissions. However, once I get in there I am about 16 bolts away from pulling the heads as well.
My concern is how much can the stock bottom end take? I replaced the con-rod bearings earlier this year because I mistakenly thought I had a rod knock but it was a dual mass flywheel issue. The bearings I took out looked awesome at 105k miles.
So the question is, should I go with just the cam (springs included of course) or should I go ahead and slap some AFRs on there since it means one less tear down?
My guess is that it is really a matter of rpm and load, so I don't mind short-shifting at 6k or so if that helps it live longer.
Opinions?
Thanks.
--Calvin
Drifting
Joined: Dec 2007
Posts: 1,647
Likes: 4
From: Argillite KY
I would think that your plan is good considering that you have to pass emissions testing also. The LT4 cam, although not on my favorites list, has passed many smog checks. Like Cuisinart said it will be done by 6000 max and even with new heads should not hurt your bottom end. Get a nice set of AFR's or have yours done by one of the better porters and you will at least stay with and probably beat quite a few of those C5's and C6's down the straight. Show them why we drive C4's when you get to the twisties. 
But most of all......have fun out there.
But most of all......have fun out there.
Thread Starter
Instructor
Joined: Apr 2011
Posts: 218
Likes: 16
From: Littleton CO
On the car lengths topic I will say that I am only talking about 100 feet of difference down a 2,200 foot straightaway starting at 60 mph out of the last turn exit. That is basically about 0.5 seconds at the end of that straight at the speed I am going. In order to pick up that 0.5 seconds I need about an extra 35 foot lbs across the board. I think I will be able to pick that up with the Hotcam, or at least come darn close. I am not talking about hanging with Z06s here, or anything, I am talking about the standard run of the mill 350HP LS1's. Obviously, the 400 to 430HP C6's are a bit different story, so that would be a typo in my first post
Burning Brakes
Joined: Nov 2008
Posts: 995
Likes: 1
From: Naples Campania
If you were in Cali, I would say that the hotcam is about as aggressive as I would go. Colorado isn't as bad, so you can probably do something with a little more thump and not worry about it.
Might as well do the heads with it.
Heads, cam and tune and that should pull in that 100 ft pretty quickly.
Might as well do the heads with it.
Heads, cam and tune and that should pull in that 100 ft pretty quickly.
