aaronmc

iTrader: (8)

Im not sure if this should go in the Internal Engine Modifications or Forced Induction section so I put it here.

Currently Im running a N/A 6L LQ4 but but I'm going turbo. When I initially built the engine I swapped the 317 heads for some 243. Now that I'm going boosted should I swap back? The more I look into switching heads the more it seems like its not worth the cash. So is it worth all the extra money to go back to 317's? I know it'll lower the compression but how much, and how much power would I gain from swapping the 243's for some 317's?

D_reks{5.3}

iTrader: (13)

You should be around 10.5:1 now with 243s and would be around 9.4:1 with 317s Which is good compression for Boost. Not sure how much HP difference there would be on a boosted setup.

acethedragon

iTrader: (2)

for the point in compression you drop, you might lose 15lb-ft, but the gain from the extra boost you can run will be worth it. on the other hand, if that is a stock internal lq4, you cant run too much boost to make up the difference, and a lot of guys have started running over 10:1 compression and forced induction. so keep the heads, be conservative with your boost, and get a great tune on it and you should be good till you build a forged motor

aaronmc

iTrader: (8)

It sounds like for the gain its not worth all the extra work and money. If I want more power Ill just crank up the boost and if the engine goes Ill just build a forged 370 or similar.

Rick_Vor

iTrader: (36)

Leave the 243's on keep it under 9-10 lbs of boost. There are plenty of Corvettes and GTO's running around with stock 11.0:1 compression running 6-8 lbs of boost. I've been running 10:1 for 40k miles without any hickups (knock on wood). The extra compression will be a benefit in a heavy truck by making the engine more responsive off boost (probably about 80% of your running time) and will get better mileage under cruise/freeway conditions.

Spend the money on a smaller or turbo cam. Something around 210-225 and 114+ LSA will wotk well with most turbo kits. You also may want to look at a tighter TC. With a 3800 you wioll blow right by a chunk of that low end torque that a good turbo kit can provide.

Talk to Kyle at KBRacing96 or Rick at Trick Performance (both solid Sponsors of our Forum) and they will steer you in the right direction and can build you a proven, no-hassle kit at a great price.

Rick

aaronmc

iTrader: (8)

Thanks for the info. I already have an ls6 cam waiting to go in right now and I'm going to look for a different converter when I swap over to an 80e.

Kyle is building my kit right now. Its one of his standard intercooled kits but with a 4" DP and MP T76 turbo.

Rick_Vor

iTrader: (36)

LS6 cam will be great you can get away with a stock TC if your running a 4L80E. Your 233/239 and Vig can help fund the project.

Now that I see you are stepping up to a T76 and a 4" DP, I still think the 105:1 is fine but Kyle may suggest you drop the compression to 9.5. if you plan on turning it up. :-)

When it gets down to it, it's all about the tune.

aaronmc

iTrader: (8)

Ya to start I think Ill just run the 10# spring it comes with and see how it does. I don't want to run to much boost until I get the rest of my drive line finished up.

KDavis04ss

iTrader: (16)

Pm me if interested in selling the 3800.

kbracing96

iTrader: (26)

The higher compression will be fine if you tune properly for it. Like has been said, it will make more out of boost power, you just won't be able to run as much timing. Personally, I wouldn't mess with swapping the heads. My next builds will be with more compression.