Ls1 Exhaust Systems

[Thunder]

I can imagine the car would sound awesome with the valves in place just behind the middle mufflers because removing the rear pipes and resonator made it sound awesome..

Greg, what extractors and size do you have on this Green VY SS, https://youtu.be/2PfB7qhRHts , sounds like porn.

The other video clip on 4>1 doesn't work.

On the auto's we usually fitted tri-y's unless the customer specifically wanted 4>1.

That video clip was a while ago, but I am pretty sure it would have been tri-y's.

The 3.5" system, combined with Ballistic 100cpsi Racing cats sounds great no matter what extractors are fitted.

Adding a cam makes it even better.

4>1 will give a higher dyno number - probably 20rwkw extra.

4>1 will give a quicker 1/4 mile time but you probably need a stallie as well.

However, 4>1 are doggie down low on the 5.7 litre, but the addition of diff gears will help the low - mid range acceleration.

What a dyno sheet doesn't tell you is how much extra fuel you will use on a street car, or how low the extractors sit when you go into shopping centre carparks or steep driveways. Most cars are driven on the street 99% of time and only go to the track, or a dyno day every now and again.

Cheers

Greg

[AngryRB]

This link works, https://youtu.be/O1bXPNy1Yn4

Its not a 5.7 , so not a direct comparison but on this engine the diameter of the runners doesn't loose torque , which you'd think it would , be good if they compared down low though.

Wondering if the 4 into 1's are doggy down low due to design or poor tuning?

what about collector length, should there be a certain length of pipe after the header to get the most torque?

Edited March 23, 2015 by AngryRB

[Ben C34]

Man, you guys are making it sound like the car becomes a pig to drive just from header design....

OK, mines a manual, but stock diff gears, of course it would really wake up with gears,

I'm running a 232/234 , 112 lsa with pacemaker 4 into 1, drive it daily and its fine. Certainly not a dog,

Perhaps there's more down low to be had with tri y's, but I don't care. I don't mind revving the car.

[AngryRB]

I tried a stock exhaust gasket over a VX LS1 shorty header and the size of the tubes are smaller than the gasket but the cast ones match it perfectly, so are the 1 5/8's runners smaller than the ports on and ls1 head? looks like the 1 5/8's is the OD not the inside..

[AngryRB]

Ok, done a complete back flip and ive booked her in for pacemaker 4 into 1's, 3inch 100cell cats, gonna see how it turns out and decide later wether the catback stays or goes...

Either way it will just keep getting modded if its not what I want.. stay tuned .. time to get some meat on the bones of the ls1 lol..

...

[zebra]

you should buy some tri-ys as well...and compare....for science

[Thunder]

The pipe measurement is always the OD size, and the stock ports are only about 1.5"

The 5.7 engine lacks power and torque down low. The 6.0 litre engine has plenty of power and torque down low.

The stock engine is doggy down low, which is nothing to do with the exhaust, however, going too big on the extractors and exhaust makes the problem worse, not better.

On a manual, you can rev the engine and dump the clutch, and if it has a cam it has a lot more power and torque right through the rev range. A cam would add 40rwkw - 60rwkw. (60rwkw is more power than some 4 cylinder cars)

An auto needs a stallie to give a similar effect.

Diff gears will also increase the torque and acceleration.

A cam makes it go a lot better, and sound aggro.

My point was this, and I am only guessing at prices here, but the extractors & cats $1800, Stallie $2500, Diff Gears $1700, Cam/Lifters/Injectors/Tune $5000 = around $11,000 yet you could buy a VZ or a VE with a 6.0 litre engine cheaper. The 6.0 has far more power and torque than a 5.7 litre and a lot of these second hand cars already have a string of mods done to them.

The same as the droning issue. $680 gets a system that sounds great and is designed to be drone free. If the old system was ebayed you may get $400 which means changeover = $280. The valve option was $1200 for the kit, plus fitting.

Let us know what they are like in a month or so, and compare your fuel usage as well.

[AngryRB]

Update- Got extractor and cats fitted today, although ended up going PH5360 which is a 4 into 1, 1 5/8 primaries , 2.5inch outlet, the exhaust shop strongly advised against 1 3/4's so I took his advice.

Results- feels like its picked up torque, on the same 80km/hr inclines it no longer labours at 1500rpm in 4th, it picks up speed and the drone seems to have softened. On cruise its quiet, on full throttle has a decent V8 note, could still be better though, the sureflow sounds more beefy, and there's a fair bit of piston slap noise that wasn't there before when its more than just a partial throttle.

[bozodos]

You won't lose shit. Anyone feel free to prove me wrong with comparative dyno sheets on the same car with tri y vs 4 into 1.

From my own experience, exhaust shops don't like to fit 4 into 1 extractors and weld in cats because it = more fiddly work for them. The cats will hang low, the collectors of my pacemaker 1 3/4" sit about level with the bottom of the car, the Sureflo cats sit low due to being a round cat and a VZ (OEM cats were positioned higher up).

I would reccommend against this setup if you drive over lots of big speedhumps with anything lower than FE2 - my H&R springs at about the same height as Super Lows make them fairly painful if not crab walked over. If you can live with that, fair enough. It's always the cats that scrape, I've had mine patched up once after 20000km or so.

I'm not into custom exhausts because I like to know what it will approximiately sound like before having it installed.

[AngryRB]

The smaller 1 5/8 4 into 1's that I got are pretty close to the power steering rack boots, they put a heatshield on, and doesn't hang down to bad, it would be legal id say...

I've done 1500km's with the Di Filippo catback now, after a long drive on weekend it would have had plenty of heat in it, seems to develop of loud drone after a good hour which included some long hill climbs.

I'm not sure about the amount of piston slap noises, the RB's are definitely a much nicer motor to modify and sound sweeter, i'll have to ask the exhaust shop to check for leaks, they probably slapped on the old manifold gaskets.. Its gone from sounding silent with stock manifold to sounding like a clapped out tractor at times.

Edited March 29, 2015 by AngryRB

[Count Grantleyish]

The smaller 1 5/8 4 into 1's that I got are pretty close to the power steering rack boots, they put a heatshield on, and doesn't hang down to bad, it would be legal id say...

I've done 1500km's with the Di Filippo catback now, after a long drive on weekend it would have had plenty of heat in it, seems to develop of loud drone after a good hour which included some long hill climbs.

I'm not sure about the amount of piston slap noises, the RB's are definitely a much nicer motor to modify and sound sweeter, i'll have to ask the exhaust shop to check for leaks, they probably slapped on the old manifold gaskets.. Its gone from sounding silent with stock manifold to sounding like a clapped out tractor at times.

+1

So far I don't find LS are that good as people make them to be.

[AngryRB]

Thunder- I agree that buying a VZ would be a lot better, I don't have a lot of $$$ though and the ute only cost me 5K so just want to have some fun with it and keep it sensible ( I hope) and do it small step at a time. I actually prefer the older VU ute look, the VZ's seem quite plain looking and plastic inside, hmm I guess it does mount up though over time....

Still thinking about this catback wether it could sound a lot better with the sureflow or if changing the X pipe would make it sound better/deeper?? I think the rear resonator is whats making it sound droney at low revs and generally a bit quiet, stuffing around with the X pipe could turn into a waste of money though.

Another thing is the cats that got fitted are 100cell , but I think they are a cheap brand, $140 for the 2, is it just a brand name or are all 100cell cats pretty much going to give the same sound????.

Edited March 30, 2015 by AngryRB

[Thunder]

Thunder- I agree that buying a VZ would be a lot better, I don't have a lot of $$$ though and the ute only cost me 5K so just want to have some fun with it and keep it sensible ( I hope) and do it small step at a time. I actually prefer the older VU ute look, the VZ's seem quite plain looking and plastic inside, hmm I guess it does mount up though over time....

Still thinking about this catback wether it could sound a lot better with the sureflow or if changing the X pipe would make it sound better/deeper?? I think the rear resonator is whats making it sound droney at low revs and generally a bit quiet, stuffing around with the X pipe could turn into a waste of money though.

Another thing is the cats that got fitted are 100cell , but I think they are a cheap brand, $140 for the 2, is it just a brand name or are all 100cell cats pretty much going to give the same sound????.

The cats will give the same sound if they are 100 cell. The difference will be how long they last before they start rattling or fall apart.

Fitting a merge will smooth out the note and make it quieter.

It may help the drone, but the exhaust will sound tamer.

The 3.5" exhaust sounds louder & deeper and doesn't drone.

My comments about the VZ were mainly aimed at the 6.0 litre engine which is far better than the 5.7 litre.

The amount you have to spend on a 5.7 litre to get it going like a 6.0 litre, it is cheaper to buy a car with the 6.0 litre in it and mod from there.

You may find a newer model that has already been modded, or you may find an older model with a 6.0 litre engine fitted, so keep your eyes out as you may find a bargain.

Cheers

Greg

[AngryRB]

Ok, thanks greg, I might just end up changing the catback to your sureflow and weigh up the 6L options.. newer is usually better

Will have to see what I get for the DPE, ill be in touch..

[AngryRB]

Has anyone fitted a VCM cam, on youtube "how to choose an LS camshaft for an auto with stock converter - VCM

VCM 21 sounds porn..

Would a cam help to cut drone out and increase the deep throatie sound??

Edited March 31, 2015 by AngryRB

[bozodos]

LS1s tend to be overrated when people drop cams that are too big for street driving (like 232/234 @ 112LSA) with the fairly average standard heads, then are surprised why it's a dog under 5000rpm. I see it a LOT.

VCM21 is a nice cam, a number of people have used it. I personally would use a Comp 215/223 LSr on a stock stall and headed LS1, I used the next grind up the 219/227 on my L76.

LS engines are ticky to start with, and the thinner walled extractors exacerbates it - mine with double valve springs and header locking bolts sounds like a sewing machine. I found it can also be exacerbated by too thick oil.

I had the X pipe changed to a H on my twin 3" XForce, it got rid of the rasp, there is still a touch of drone when going up slight inclines in 6th that I find perfectly reasonable, but I've always had loud cars.

[Ben C34]

I run a 232 234 112 cam and it certainly isn't a pig. And it doesn't need 5000 to come alive. Compared to stock the power and torque started climbing substantially from 2500 rpm. Perhaps the Ines you experienced were shit tunes.

Not for a split second would I want a smaller can. Auto its a different story.

Edited April 2, 2015 by Ben C34

[Ben C34]

[AngryRB]

Really good improvement in those graphs, what brand of cam is that? must be the first Ls1 dyno graph ive seen, be good if the torque was bit earlier for the street but it must be fun to drive with manual.

[Ben C34]

Its a comp cam. The aggressive lobes, can't remember at the moment.

Realistically it doesn't need more low torque, cos low revs your just cruising, when you want to boot it you rev it out. Easy.