In the 'coulda/shoulda/woulda' infamous way, I started modding my C6 6-speed with the premise that I would never take it to the next step, and as a result, may have shot myself in the foot.

Current mods are:

LPE intake & stage II heads
Comp Cams 228/232 114 LSA .588/.595 lift cam & 921 springs
stock rockers
Kooks 1 3/4" LTs with cats & x-pipe
Magnaflow axle-back exhaust
Formato ported intake & tune

dyno'd at 450 RWHP/400 RWTQ on a Dynojet

What (if) anything can I do to increase the HP without doing a major replacement of (already upgraded) components. I was thinking of a FAST intake, but I remember Jeremy stating tha twould need to be ported as well now to see any significant gains. Do not wish to go the FI/NOS route.

I think I've essentially hit the wall with this configuration.

Thanks.

 

PM sent

 

I'll be interested in what others have to say on this thread as well.

You are in the same boat I am in right now. See my mods in my signature. My tuner told me I had already "picked all the low hanging fruit". Any significant gains from this point forward would be through added cubes. It was not real clear what could be used off of my current engine, but I assume not much. He was saying I could expect to pay in the $7K to $10K range for the toltal project. He was thinking about stroking a LS3 block as the base. This is probably 2 years away from me, so we did not get into the details of what would be done. I wonder if my headers could be used on a LS3 stroker?

I thought 205 AFR heads or DTE 4.10 gears would be my next leap, however, I'm not sure right now. If you ultimately plan to build a stroker, I'm not sure I would want to add more parts on my LS2 that may not transfer to a bigger cubic inch engine.

I keep on thinking this addiction to RWHP and RWTQ will go away one morning when I wake up. I do not think this is going to happen any time soon!:

I totally understand your fustration right now!

 

Well, what puzzles me is when I see dyno's of similar mods (albeit different, and likely more costly parts) putting down 480-500+ RWHP. I guess I wound-up at the destination I chose. The car is wickedly fast, I didn't spend 'too' much, and it is an eminently drivable daily car. From observations of similar cars, those that have ponied-up the extra $$$ for top-shelf parts (i.e. FAST vs. ported OE, LG vs. Kooks, huge cams vs. milder ones, AFR vs LPE heads, etc) have paid almost twice the project cost, and given up quite a bit of drivability to get to those higher #'s.

At this juncture, I am not interested in building a stroker, as if that would obviate the majority of the mods I've done already.

I was 'kind of' thinking of upgrading to a Z, but I doubt a stock Z would be significantly faster than this car (unless I started the mod parade all over again). Plus I love driving with the top off.

 

Well getting a FAST and having it ported is still cheaper than any other route you could take. I'm thinkin in a year I might have my ls2 block resleeved to make it a 427. I think they charge $2500 for the resleeving plus install and all that, probably looking at about $6k. But you did say you wanted something not major, so your best bet is to go with the FAST.

 

Yes, but $1,000.00 for the FAST + another $150-$300 for porting (which is in addition to the custom porting I had done on the OE intake) for *maybe* 10+ RWHP is a bit difficult to swallow.

I forgot to mention also that Jeremy also ported the TB.

 

Upgrading to the Z06 is also another possibility for me. That's a decision also another couple of years down the road for me. I'm leaning more towards saving for a used Z06 rather than stroking a motor for my current C6. I want to drive a Z06 and see how it compares to the current power of my car.

 

Me too, but I have my car so dialed-in right now that having to start-over (and be without the removable top) isn't exactly attractive. Nor is the idea of listing it here & hearing the usual litany of 'why buy a used 05 when you can get a new 08 for under $40k'

 

After sleeving the block I assume you need new pistons, connecting rods, crankshaft, etc... Can your current heads and intake manifold be used on sleeved LS2 427? I believe LPE sells the short block as a package.

 

Well part of the package with MTI would include pistons rods, etc. My current heads and intake and all that would be reused. The combustion chambers on my heads would also be bored out for the bigger cylinders though. Wont be cheap, but cheaper than buying and building an LS7 or LS3 block.

 

You can get a new Fast intake from ebay for $740, get it ported for $250 or less, then sell your ported stock intake for $225. Thats $765 out of your pocket if you do the install yourself. And it may only be a 10 hp gain on top, but much much more in the midband. It is a worthwhile mod.

 

You can always buy a lsx block and go 454 but thats $$$$$$

Jogar....did you get dyno'd this past weekend?

 

Forgot to mention, I didn't see an underdrive pulley in your setup there. If you dont have it that would also get you another 10 hp and thats about $250. Lightweight flywheel and you could pick up a few more ponies. Gears I think would be a great next step for you.

 

Yes I did...sending you a pm, too pitiful to say here, lol.

 

I have very similar mods - same heads and intake, same cam (228/232), melrose headers, FAST, and 3:15 gears (I have an A6).

My next stop is either FI with a maggie, or doing a 403. The guys at LPE say that the stage 2 heads will handle a 403, but above that you need more head work or different heads.

I would recommend gears - I'll probably end up going with the maggie, but that's for a year from now. I'm currently in the middle of a widebody project, which should be done in two weeks.

edit: fwiw - my dyno was around 425.

 

GRRRRRR!

I've heard the UDP kits were about as beneficial as the Vararam intake spacer (which I removed at Jeremy's request).

 

Odd, Ive heard all the contrary, and I've actually seen some dyno's from the pulley only and they are getting around 9, 10 hp.

Edit: ok im lying, I've actually only ever seen ONE dyno from a pulley only install but he did pick up 9 hp. lol

 

my shop doesn't recommend UDP due to charging/electrical issues. Nor electric water pumps, because you dont know when they break.

 

On a stock car there may be a charging issue. If you have a cam, you have to raise the idle anyway, so that increase more than makes up for the loss with the UD pulley. My car has one installed and no problems of any kind whatesoever.

 

There have been some great numbers posted on the L92/L76 or something heads and intake with cam. You could always sell what u have.