webelo

I need to relocate my oil pressure sending unit this winter, so I figured I'd swap out my LS1 intake to an LS6 intake. What do I need to make this happen? What horsepower gains am I looking at? Will I need a tune?

tblu92

In addtion to the manifold you will need a "coolant bypass kit"--avail from most corvette suppliers----Also--while you have the intake off it is a good idea to replace the LS1 valley cover to a LS6 valley cover--About $75---The LS1 cover PCV system is notorious for sucking oil up inyo your intake manifold---The LS6 one hepls to eliminate much of it--
Just look in the inside of your manifold with the throttle body off and you'll be shocked to see how contaminated it is with oil--


ALSO--Why are you re-locating the oil sending unit ?? and to where??

manley845

Power depends on application. What else do you have done? But, probably 5-10hp.

I agree with the valley cover idea, I will be doing this soon. I shoulda done it when I installed the BBK intake.

Any dealership should have the newer water coolant parts. It's just two block-offs for the rear and a new cross-over for the front. You can also cut, crimp, and solder the original pieces, but not you might feel better about using the right parts.

webelo

Doesn't switching to the LS6 valley cover require some modifying of the block?

My oil pressure sending unit crapped out on me this year and I'm going to relocate it to just under the fuel rail covers following one of the posts on here.

VET IT B

I will be watching this one, I plan on the same mod in January. Mark

tblu92

YES Thks for the reminder---You have to cut-off or grind off a small piece of aluminum on the front corner of the pass side--It's really not a big deal or a big job -- I used a standard Dremmel tool --- most important thing and most time consuming was taping and masking the valley so no shavings would get into the Eng-------

Have you looked into your TB opening yet on your LS1 manifold ?? This will convince to do do it----LOL---

ALSO here is a great link on how to do both the intake manifold swap and the LS1 to LS6 PCV conversion---Lists all the GM part #'s you will need and has detailed photos on how to cut off the alum piece for the PCV valley swap
http://ls1howto.com

CLICK on photos for full screen view !!!!

VET IT B

Should I replace the two knock sensors while I am in there? Only 40K miles, but 11 years old.

LoneStarFRC

No, not really. They are solid-state devices and very robust. Seldom, if ever do they cause problems. If you just like spending the extra cash though, go for it.

Jims79

[QUOTE=tblu92;1576081421]In addtion to the manifold you will need a "coolant bypass kit"--avail from most corvette suppliers----Also--while you have the intake off it is a good idea to replace the LS1 valley cover to a LS6 valley cover--About $75---The LS1 cover PCV system is notorious for sucking oil up inyo your intake manifold---The LS6 one hepls to eliminate much of it--
Just look in the inside of your manifold with the throttle body off and you'll be shocked to see how contaminated it is with oil--


Not that I'm saying don't buy the cover. But doesn't a catch can do the same job? I didn't know about the v-cover when I did my swap so I installed a catch can. Also I cut some of the ribs under the LS6 so I could keep my stock coolant pipes. Not to be cheap but I read somewhere that the #7 cyl over heated and the LS1 setup was a good system to have. Again I'm not sure which is better. Oh to answer one question I do know the correct answer to, you don't have to re-tune after the swap. G/L

0Josh@SpartanLSX

Yes, it IS better to retune but you don't "have" to. I usually see a lean spike in A/F when swapping LS6 intakes on the older LS1 engines, and it needs a tiny bit of massaging to get in line.

With a tune, an LS6 intake is worth an easy 10-12rwhp over the LS1 intake. I've confirmed it on the dyno before. It's worth even more on a cammed engine.

Jims79

But that may not be the OP's only mod. So like myself I waited until I did all the mods I planned on before I had my tune. I agree if that's his only mod then a mail order tune would be the way to go. A dyno tune on a stock LS1 even w/an LS6 intake would be way over kill and for what a 10hp gain maybe??

The Wrench

while you're in there, check the gaskets for the knock sensors; I had one installed crooked from the factory, and the sensor had oil all around it.
Also, be sure to torque carefully and in the correct pattern.

One cool addition - I took out the two nasty little foam strips that keep dirt/water out from under the manifold, and found a big piece of identical foam in a home computer shipping box. Cut it to match the underside of the manifold. This has to help reduce heat soak a bit - at least as good as a throttle-body bypass or a hood seal - Ha.

DG

webelo

I haven't noticed that my LS1 burns oil and I really don't feel comfortable taking a dremel to my block... so I think I'm going to bypass this mod. I haven't checked my TB yet, but when I do and if I find oil, I'll consider a catch can.

I do have a couple other mods (corsa exhaust and breathless intake) and I'm running the hypertech program. As it it is now, I think I'm running a bit on the lean side. I also get a little ping at low RPMs and under load (possibly because of hypertech? or a combination of mods?) Between the exhaust, CAI, and ls6 intake mani, I think it might be time for a tune.

tblu92

There have been issues with the early 97-99 knock sensors--When the go bad you will get horrible pinging all the time--Typically with mods you need to "de-sensitise" your knock sensors with a tune--Certain mods allow the sensors to pick up new strange noises and pull out timing---LT headers especailly
I agree a tune is not mandatory with a manifold swap--just drive 50 miles or so to let the fuel trims learn out however any C5 will benefit from a tune--and with the swap you can gain a few extra ponies with "fine tuning"--

lucky131969

Hmmm...that's interesting. If the knock sensor goes bad, or it senses pinging/knock(real or false), the PCM will pull timing. How exactly does a bad knock sensor CAUSE pinging?

tblu92

Because when it fails---it will not remove any timing-----
It's kinda complicated
The knock sensors store data as a referance to remove timing--
Every time you fill up or put in over 10 gallons or so of fuel the stored data is re-set ---The stored data records "occurances of knock"--When the occurances on knock reach a certain point--the timing table swithes to the "low octane mode"---
( as a side note if you typically never fill up your tank--you may notice your car becoming lazy---Thats because you never re-set the Knock sensors to return to the "high octne table" )
A bad sensor will never build up data to remove normal signs of knock and is always on a newly re-set mode---With today's crappy gas the knock sensor system is great to keep your engine from pinging--Getting some KR is normal with todays gas--A good sensor will record these occurances on knock and remove timing accordingly with the stored data--- and reset at fill-up-( the data is actually recorded by your ECM and the sensor is just the tool by which it recieves it)
This is a laymans explanation---what actually happens is the ECM changes the parameters of the "listening" part of the sensors--changing the sensitivity ,filter settings and frequencies---

GT2BHPPY

Check out the TPIS website, they did a bunch of test using different manifolds. I was surprized by how little gain they achieved and at the rpm that gain occurred.

Jims79

Sounds like you need one. ECS has a good mail order tune for under $200. They support this web site & did my street tune. Good guys. You should give them a call before you do anything else.

Jims79

True. The gains are mostly in the high rpms over 5000.

lucky131969

I don't see how the knock sensors "store data", as they are only piezo-electric, and read by the PCM. Based on my understanding, the knock sensors learn based on two things: bias voltage, and min/max noise. Since it monitors these functions, I don't see the correlation with filling up with 10+ gallons of gas, or low/high octane tables. I also don't see why the knock tables would reset, and have to learn the base min/max noise again, based on filling up with gas. If you can point me to where you obtained this information, it would be appreciated.