regorih

Well I got bored again and decided to replace the LS6 intake with a Pro Flo intake. I initially wanted a Holly High Ram intake but I was just too tall. My target goals are to make more power and more importantly I want to see my peak HP move up in the power band. Right now the set up peaks around 6200rpms and I would like to see that around 6900-7000rpms.

What first started out as an intake swap quickly turned into a top end re-fresh (over two years and 20k miles when I last opened up the engine). When I took the LS6 intake off I found that the intake was covered in oil, lots and lots of oil. When the intake came off I saw all the runners covered in burnt oil and at this point I knew the pistons would look similar and did not feel comfortable just swapping the intake without addressing this new situation.








Long story short I pulled the heads off and tore them down to cleaned them off as best as I could including removing valves and removing all burnt oil and carbon deposits. I also clean up the piston which came out good. While the heads were off I also replaced the 20k miles valve springs with a new set.











I initially bough the LS1 pro flow intake but as some of you know the top bolt hole in the throttle body was too high and caused bad high contact point in the hood. Needless to say I sent it back and started with the LS2 version.

regorih

After buying an LS2 and LS3 throttle body and harness I did not want to go through the trouble of recalibrating my throttle body and after many night of soul searching I came up with a solution. I ordered some ½” aluminum plate and cut all the mounting points on my stock TB and started cutting after I made some mock up cad drawings to make sure it would be possible.







Just to clarify this is a stock C5 throttle body, all I did was remove the mounting points and had plate welded on with the bolting patter of a GM LS2 throttle body





cleaned up

JoeyG

Nice, don't be scared when your cutting the car's cowl area. JUST TAKE YOUR TIME, and have fun when it's done.

regorih

This is the point I’m at. I have some clothes dryer ducking connecting the charge pipe an TB while I wait to have my charge pipe fabbed up.
I have done other small changes and while I know my goal is ambitious I’m shooting for 900rwhp on boost only with my 347 LS1 and D1SC.
Small notes: I did have to cut the cowl hood and firewall and plastic around the windshield wipers. Stay tuned for number in two weeks or so. In the mean time I’ll be driving this thing to work and back and enjoying it.

Roger

regorih

I'm alredy done

95wht6spd

Why do you want to raise power band?

ajrothm

Nice job Roger! I can't wait to see it after you get it all finished.. A little maintenance work like you did goes a long way.

You dynoing it at G Force again?

I'll be VERY surprised if you hit 900rwhp with a D1.. Hell an honest 850 would surprise me.. Wishing you luck bro!

tbrent

Nicely done! I wish I had your skills. I hate to bother you with questions but what hood is that and any pics of it closed and any massaging you did to it? I was just asking Joey about fitting a tall intake under my hood!(MCM supercharger hood)

Very cool

dopefedz

He has already hit 850 before these changes.

regorih

This is un corrected

corrected


Other changed include:
3.5 to a 3.4 pulley
New set of 80lb injectors same as old once
More meth injection
Replaced questionable fuel pump
Pro flo intake
New valve springs and a velocity stack

regorih

If you take a look at my dyno graph you can see how power peaks around 6,000rpms and then starts to fall . I would like to see that curve continue up and not level off and fall. If this intake does that, top end power will kick *** instead of losing steam.

5 Liter Eater

Pretty sure you'll pick up lots by replacing that dryer ducting.

ajrothm

Nice numbers for sure out of a D1sc. That was on G force's Dyno right? So 836 in STD will be 815hp in SAE, which is pretty much in line for a strong D1sc setup. Should pick up some with your latest mods for sure.

We dynoed my buddy's new 402/D1sc setup at G force, it made 835 hp SAE, with the 4.00" pulley, 4" intake pipe/big mouth filter. The tune was REALLY aggressive tho...(20* of timing).. We didn't leave it like that. About to put a 3.55" pulley on it and retune. Shooting for 850hp SAE with a realistic timing number of 15* or so..

I'll be very curious to see what yours makes when you're done.

ajrothm

My car noses over the same way... Mine peaks around 6000, holds it to 6400, then noses over... Even with more boost coming in after 6400, power still drops. I thought it was my little cam that causes it but... Maybe it's the stock ls6 intake.

I'm sub'd to see what your power band does... If it holds/gains power til 6800, I'll be doing a proflow as well.. Lol

regorih

Yes, Mike at G-Force tuned the car.

Roger

regorih

no I dont mind at all. I keep no secrets, ill find out and take some pics. It all turned out good and the hood closes as good as before besides the heat extractor hole I made

skull

any more pictures of what you cut from the cowl. like a picture without the intake and a picture with it on

4DRUSH

And why did you mod the TB?

You couldn't have just drilled & tapped holes for LS2 TB in the alum intake?

kromberg

It would not have fit the 'clothes dryer ducking'.

regorih

Both intakes come pre drilled for an ls2 TB. I opped to stay with the ls1 TB because I dirent want to have a mis matched TB to my car. I've read where ls2 TB are not as responsive on 1999 cars even after they have been calibrated with HP tuners. Also, since the ls1 top bolt hole is like 1/2" taller than the ls2 TB it was hitting on my hood when I closed it making to hood bulg around that contact point. This is what I came up with and it's working better than I expected.
My mods are definitely not for the faint of heart. At the end of the day the TB mod was only made to accommodate hood clearance issues