APS twin turbo on a stock 346 ls1

**TNTramair** · 10-20-2008, 06:33 PM

Originally Posted by ls1camino

Except for the intake tubes sucking shut at around 12 psi...I have 2 solutions for this problem floating in my head, but no one on LS1Tech wants to listen to anyone with a post count lower than 200

im listening...what do ya have?
we allready have a few ideas amongst the owners that we're gonna be trying when the time comes. the filters are rather restrictive and changing or removing them all together should take care of the issue. other than that, the new ducts have been made and are available for purchase through aps.

**99TAWS6** · 10-20-2008, 08:14 PM

I have street pro cutout after my ypipe but no cats .See how that does. If not maybe go true duals later.

Yeah I am willing to look at ideas on the ducts ,etc. I figured could just put some stint type of thing in there ..flexible muffler pipe or something. I don't think the filters are problem read somewhere they tested them and they are not a factor. Just crappy silicone or too thin on the standard ducts. I may also bite the bullets and get the aps ones I can be impatient sometimes and really don't necessarily have time to frack with the tubes maybe. At least should have till next spring to find out if the tubes work and wouldn't mind waiting a bit longer yet to see if they hold up with time.

I am hoping for sure to figure out the sway bar thing but have read some guys have already fixed that issue too. I have friends that are handy with maching so really don't think that will be big problem anyway.

There are several potential issues and I will attack each one as needed in my build. I am used to having to tweak things after all we mod the hell out of our stock cars don't we?

Biggest concern I have is turbos don't have problems .That is bigger pain than this other little stuff.

Tnt did you torque the stuff that had the copper washers or just guess on them? They gave no torque spec in the manual but buddy with mits turbos gave me some torque specs. Oil feed banjos were something think 15ft pounds and the water banjos were like 22. I would think the other fitting could be torqued to 22 also. And will still get specs maybe for the oil return but that has gasket not copper crush washer.

The kit is still pretty well thought out and there is quality there even if a few corners might have been cut. Every FI system has had some bugs and things. ATI,sts..all have their things. So do our cars..crappy rear end..optispark in the lt1s..intake manifold leak in the lt1s.piston slap in the ls1s..etc.

So we can't expect perfect turbo system..I would like to see gaskets for the turbo to exhaust manifold connection and the turbo to downpipe connections. RTV is bit of a pain in the butt,especially on the turbo to downpipe connection. Does anyone know if the gasket to the exhuast manifolds is just a common size?

**TNTramair** · 10-21-2008, 05:12 AM

Originally Posted by 99TAWS6

Tnt did you torque the stuff that had the copper washers or just guess on them? They gave no torque spec in the manual but buddy with mits turbos gave me some torque specs. Oil feed banjos were something think 15ft pounds and the water banjos were like 22. I would think the other fitting could be torqued to 22 also. And will still get specs maybe for the oil return but that has gasket not copper crush washer.

we did torque them down to spec but not sure how much off the top of my head. we had to go back in and retorque them though cause after start up a few fittings started to leak. all was well after that though.

**RedVertTA** · 11-03-2008, 07:13 PM

Don't go above 10psi.

If your going to do both the cam+heads and turbo, you will need a new rotating assembly.

**side2000** · 11-03-2008, 07:25 PM

youre limited by the compression ratio on stock heads but if you get a set of ARP rod bolts you shouldnt have a problem runnin as much boost as you can w/ stock heads on pump gas. 8's all i would do....redvert is right, either do a mean naturally aspirated build or turbo dont try to do both-you can get 500 + to the crank with either setup. personally i'd get head n cam package so ya dont gotta wait for turbos to spool but if ya just have to get those TT's you'll be fine in stock trim + rod bolts.

**El Toro Loco** · 11-03-2008, 07:49 PM

anyone know the price of the aps system

**99TAWS6** · 11-03-2008, 07:51 PM

They have upgrade system for 6499 shipped I think on ls1tech.com.Not sure on the standard think its only 500 less so if so would likely get the upgraded one .

**matt89** · 12-03-2008, 06:52 PM

just get a turbo kit from a trusted manufacturer and keep it under 8-9 psi with stock internals. just make sure you have plenty of tuning and fuel to go with it and she should live a long life! I wouldn't go all motor. It's more expensive to get the same hp and tuning is more involved. a 525slp h/c kit vs any turbo kit: the n/a parts alone are about 5K not to mention you have to put them in. Where the averave guy can put most turbo kits in and you are at 500hp and way less labor to install it. Sure stress from either or can break an engine, but with a massive cam and other things that go along with it, there is more stress in an na motor than there is in a turbo motor. A friend of mine has a 720whp big block firebird and has to rebuild his motor every year and it just broke due to the cam shaft scoring itself just a tad and when he took it apart it damaged some other parts because of the mega stiff valve springs. And drivability in another thing all together. When I am not in the gas, my car drives like stock. N/a at the same power? Guess again.

**RedVertTA** · 12-04-2008, 08:14 AM

Originally Posted by matt89

just get a turbo kit from a trusted manufacturer and keep it under 8-9 psi with stock internals. just make sure you have plenty of tuning and fuel to go with it and she should live a long life! I wouldn't go all motor. It's more expensive to get the same hp and tuning is more involved. a 525slp h/c kit vs any turbo kit: the n/a parts alone are about 5K not to mention you have to put them in. Where the averave guy can put most turbo kits in and you are at 500hp and way less labor to install it. Sure stress from either or can break an engine, but with a massive cam and other things that go along with it, there is more stress in an na motor than there is in a turbo motor. A friend of mine has a 720whp big block firebird and has to rebuild his motor every year and it just broke due to the cam shaft scoring itself just a tad and when he took it apart it damaged some other parts because of the mega stiff valve springs. And drivability in another thing all together. When I am not in the gas, my car drives like stock. N/a at the same power? Guess again.

N/A not as reliable as forced induction? I'd beg to differ. N/A is as reliable as it gets, with forced induction you have to worry about cracking the manifold, boost control, tons of extra pluming, pre-detonation, potential valve damage due to high boost, and making sure the cam has absolutely zero overlap, and not to mention all the heat issues, especially on a hot day. Believe be, I personally warped the heads and fried the pistons on my last car with a forced induction setup, the risks are very real and they are not to be taken lightly.

Generally I see your point if you're trying to reach turbo power on just heads + a massive cam on a stock bottom end, the cam would have to be huge, you may not have a very good idle quality and that is a valid reliability issue, but its better than the heating issues that come with forced induction. Many people on this website are making 500+ horsepower on heads and cams with no issues. I wouldn't personally do it, I'm one of the few who doesn't like the sound of choppy idle, and I'd like a car that actually has torque worth a damn through most of the rpm range. I don't know what happened to your buddy with his BB, something's obviously wrong there and I wish him the best of luck trying to get his bird running again, but I assure you N/A is very safe.

**99TAWS6** · 12-04-2008, 08:37 AM

Agree na can be very safe and its pretty easy nowadays to get to around 550 engine hp with decent heads like afr 205s, a reasonable cam that isn't crazy on lift or duration and that can actually idle without a stupid amount of lope. Some good longtubes and your basic bolt ons ,fast intake possibly..

I disagree a bit on the turbo being that bad for most of the things you said. The factory put turbos on millions of vehicles thr the years and offered warranty on them. Semis, tons of diesel trucks and lots of cars are running turbos.
Now you start cranking up the boost on stock engines or going to far on timing or too lean you can hurt things. Common sense. I know several buddies running sts systems for past several years at low boost no problems. I know a few that did blow up their stock engines too.

To go for big FI power you have to know what you are doing. To go for reasonable 500 to maybe 600rwhp is not that bad. And a proper set up system like mine does not have any big overheating problems. Possibly if you live in nevada you might need to get bigger rads ,high flow water pump etc .

The turbo plumbing is hardly some big jumble of pipes. Couple downpipes off the turbos going to nearly stock exhaust. Couple of intake pipes and couple of pipes to the intercooler. Some oil and water lines run to the turbos. And yes did have to take the pan off to install the gravity feed fittings. No scavenger pump on my system.

And yes do need at least a bigger single pump some bigger injectors and some tuning.
But its not overly complicated.

You had some bad luck with turbos..it can happen. Less chances of bad luck with NA builds but turbo builds don't have to be scary things.

**RedVertTA** · 12-04-2008, 08:48 AM

Originally Posted by 99TAWS6

Agree na can be very safe and its pretty easy nowadays to get to around 550 engine hp with decent heads like afr 205s, a reasonable cam that isn't crazy on lift or duration and that can actually idle without a stupid amount of lope. Some good longtubes and your basic bolt ons ,fast intake possibly..

I disagree a bit on the turbo being that bad for most of the things you said. The factory put turbos on millions of vehicles thr the years and offered warranty on them. Semis, tons of diesel trucks and lots of cars are running turbos.
Now you start cranking up the boost on stock engines or going to far on timing or too lean you can hurt things. Common sense. I know several buddies running sts systems for past several years at low boost no problems. I know a few that did blow up their stock engines too.

To go for big FI power you have to know what you are doing. To go for reasonable 500 to maybe 600rwhp is not that bad. And a proper set up system like mine does not have any big overheating problems. Possibly if you live in nevada you might need to get bigger rads ,high flow water pump etc .

The turbo plumbing is hardly some big jumble of pipes. Couple downpipes off the turbos going to nearly stock exhaust. Couple of intake pipes and couple of pipes to the intercooler. Some oil and water lines run to the turbos. And yes did have to take the pan off to install the gravity feed fittings. No scavenger pump on my system.

And yes do need at least a bigger single pump some bigger injectors and some tuning.
But its not overly complicated.

You had some bad luck with turbos..it can happen. Less chances of bad luck with NA builds but turbo builds don't have to be scary things.

It wasn't even a turbo, it was an S/C, I can't even imagine what you turbo guys have to deal with, they mostly generate more heat than S/C.

Sorry if I sounded negative, I wasn't trying to imply that turbos are bad, just pointing out that there's a lot more to consider and more restrictions as far as your build options go.

**99TAWS6** · 12-04-2008, 09:00 AM

Again a properly thought out system shouldn't have big heat problems.
If you block the rad with big intercooler and don't have proper airflow happening you could have issues.Definitely living in hot climates will mean you might have to do more stuff ,ls1 rads are not very good, lt1 had bigger rad for one solution ,there are rads from ron davis, becool,etc that are much bigger capacity. Edelbrock makes high flo water pump now and some ebay ones no idea on their quality. Sometimes you might need addtional fans.

But FI can add up pretty quickly especially if you go big like I did. Its not a cheap build once you do a fully forged up motor , big fuel setups, new rear end, stronger clutch and tranny,etc.etc. And people with FI tend to be greedy ,not a good idea with the stock stuff.

It all comes down to goals for power and driveability. I have seen some crappy driving NA cars and some lousy driving Turbo cars. You can go way too big on the turbo and have really bad lag or narrow powerbands. One reason to go with a kit like new sts kit or my aps kit. I do have a problem with one turbo issue that has to be fixed on mine.
But overall the quality of the kit was first class although it also was 5500 at the time shipped not that cheap but not bad for a twin turbo kit with huge intercooler. First class tig welded. Stock type exhaust manifolds, great intercooler that fit nice with some modding under the front bumper,every nut and bolt ,great instruction manual.

Some guys are great at modding and can put together a kit pretty cheaply off ebay or wherever.I am not as handy with welding and all that so bought a prebuilt kit. Not many complaints.

**RedVertTA** · 12-04-2008, 02:06 PM

Originally Posted by 99TAWS6

Again a properly thought out system shouldn't have big heat problems.
If you block the rad with big intercooler and don't have proper airflow happening you could have issues.Definitely living in hot climates will mean you might have to do more stuff ,ls1 rads are not very good, lt1 had bigger rad for one solution ,there are rads from ron davis, becool,etc that are much bigger capacity. Edelbrock makes high flo water pump now and some ebay ones no idea on their quality. Sometimes you might need addtional fans.

But FI can add up pretty quickly especially if you go big like I did. Its not a cheap build once you do a fully forged up motor , big fuel setups, new rear end, stronger clutch and tranny,etc.etc. And people with FI tend to be greedy ,not a good idea with the stock stuff.

It all comes down to goals for power and driveability. I have seen some crappy driving NA cars and some lousy driving Turbo cars. You can go way too big on the turbo and have really bad lag or narrow powerbands. One reason to go with a kit like new sts kit or my aps kit. I do have a problem with one turbo issue that has to be fixed on mine.
But overall the quality of the kit was first class although it also was 5500 at the time shipped not that cheap but not bad for a twin turbo kit with huge intercooler. First class tig welded. Stock type exhaust manifolds, great intercooler that fit nice with some modding under the front bumper,every nut and bolt ,great instruction manual.

Some guys are great at modding and can put together a kit pretty cheaply off ebay or wherever.I am not as handy with welding and all that so bought a prebuilt kit. Not many complaints.

I kinda get the impression you think I don't know how to run a forced induction setup and that you think that's why I blew the motor.

The detail I forgot to mention was that I was not responsible for the mods done to the car with the blown motor, the previous owner was (A cheap son of a bitch as it turned out later) and he cut a lot of corners without telling me (I let him have it the next time I saw him

). I this In this case I'm talking about my previous vehicle, not the one I drive now, in fact it was not even an f-body or an ls1 car. And yes it was noon on a hot July day in Florida driving uphill.

I know these things your talking about and I have worked on forced induction cars before without problems, I just wasn't responsible for this particular build and I trusted this guy (Bad mistake, I'll never do it again). If I had been in charge of the build I'm confident the results would have been different.

BTW what's wrong with your APS? You mentioned it has a problem but you didn't say what. Just curious.

**99TAWS6** · 12-04-2008, 02:18 PM

My aps has a problem with one of the turbos. It appears to have come with a cracked center housing. Maybe was dropped at some point. I installed my brand new 408 and the aps kit. Fired up the car and lucky we were carefully monitoring for leaks, oil level, etc. First weird thing was car seemed to be taking in too much coolant. Then fired up the car and ran it for a minute or two then checked the oil. It was milk! Huge coolant leak into the oil pan from one of the new turbos! So of course shut it down instantly.
Drained oil and disconnected the water lines to the turbos ,they can run with just oil cooling but its not the best thing to do but was going to be putting the car away in a few weeks for winter so just drove it like that and kept it pretty much out of boost for the engine break in anyway.
So have to remove that turbo..not that easy as it requires dropping the bmr crossmember to get it out and send it off to APS for warranty or possibly upgrade the center cartridge in them possibly.
So had some bad luck that could have been very bad luck if hadn't caught the problem pretty much instantly.
I was worried at first it was cracked afr head, cracked new block or blown or wrong head gasket. Hard to blow head gasket at zero ps1 just idling and was pretty sure the engine shop would have magnafluxed the block and the afr heads were brand new and think they would check them also.
So thankfully just a bad turbo. As said it boosts and works fine but can't connect the water cooling to it. Thankfully they get most all their cooling from the oil.

I have lots of other turbo cars ,had many many dsm cars have two still.
Had turbo bike in the past as well. Stick to my guns if you buy a good kit and don't get greedy they can be very reliable.

**RedVertTA** · 12-05-2008, 12:59 PM

Damn, that sucks, but its good you caught on it before it caused more damage.

You didn't mention that problem on your build thread: http://www.ls1.com/forums/showthread.php?t=99547

Off topic: Is your FAST intake a 92 mm? And how much were you looking for for the t56?

BTW noticed the 2 talons in the back and the one with the big intercooler, nice.

**99TAWS6** · 12-05-2008, 01:11 PM

Yeah I never mentioned it I guess. I have been running it with the water cooling not connected and just oil cooling. Works ok but will get them fixed over winter. I may upgrade to bigger turbos since have to do some screwing around removing them and reinstalling . The bigger ones can do 1300 engine hp the smaller ones about 900 to 1000 engine hp. My motor is built to take it.

I have the fast 90 with nick williams 90 tb. Its not really worth going up to the 92 mm fast setup. I might but not a high priority at this time. Especially being forced air application.

Yeah I love my talons too. Both are getting super modified the red 97 is already very highly modifed but has been sitting a year or so now not sure whats up. Pretty sure my supposed high perf clutch blew apart. Will likely be dissecting and fixing it in next few months. The black one is going to be my trailer only race car. Its already pretty much gutted out to save weight. Being awd auto should make a great fun 1/4 mile car. The 97 is a street car and lots of fun too.

Also have a 96z vert project to finish up. Lots to keep me busy.

I have my current t56 and tex twin sold to local buddy. Going to 4l80e flt stage 5,yank stall and am assembling the little parts to do that for spring. Just need to get rear end..dana 60 with 3.54 gears is the plan for that, finish up my dual pump fuel system and alc injection and direct port nitrous and project is done. Hoping our dollar comes back up against yours..76 cents today.

Will wait a bit to order that big stuff.

**RedVertTA** · 12-05-2008, 01:20 PM

Wow I just now notice we jacked this thread. :LMAO:

I've been told our Fast manifolds split under as much as 10psi though, don't know if you've had problems but good luck with the bigger turbos.

**99TAWS6** · 12-05-2008, 01:38 PM

oops yeah off topic a bit..
You are mistaken on the fast. There are two 1000 hp builds with the fast 90 on the afr website taken from magazines. There are number high boost dynos of forced induction super and turbo cars with the fast intake in the ls1 dyno book you can buy.

There are lots of fast builds on high hp boosted dynos on ls1tech.
Past 20psi possibly be some problems. Some of the problems were leaking not blowing apart. You can likely put some rtv between the shells and loctite the bolts holding the shells together. But I am not planning on going over 20psi. Fast has burst panel kit to protect the intake at like 34psi.

**Wesman** · 12-05-2008, 04:17 PM

Originally Posted by F-BodyBlur

We are running dual cut outs on each side of the y-pipe on the APS kit and the car made almost 50whp more on 6.5psi with the cut outs open...

Thats a huge gain, no doubt due to the restriction of a Y-pipe system.

Thats the last thing I'd want to run on a twin turbo car, you have so much air to move and nowhere for it to go when both downpipes crash into a Y-merge.

I'd say at the mininum you would want 3" down to 2.5" duals, ideally 3" front to back though.

**99TAWS6** · 12-05-2008, 04:25 PM

Guys have made big power thru yipe setups on twin turbos. A cutout helps immensely of course even single one in the intermediate pipe. True duals are great too of course but hardly absolutely necessary.