Turbo V6 Camaro

#1
Hello everybody,

I am looking for some recommendations on parts for my turbo L36 Camaro. So far, the engine is completely stock other than a 180 degree thermostat, EGR and EVAP delete, Autolite 605 plugs gapped to .055", a fuel pump hot wire, and about 2 psi of boost through a front mount intercooler (the lowest I can make my Precision PW40 go). I am not looking to make a racecar out of this. In fact I want to drive it daily. That being said, I was planning on buying a set of 42# injectors, Walbro 255, LS6 valve springs, and a tune from Intense.

Is there anything else I should look into? Being turbo and intercooled, am I speccing this out a bit short? I don't want to upgrade the T5 trans or tiny 10 bolt, so that comes into play as well. I am not completely against running E85, but I was hoping to stay away from upgrading the FPR and dealing with low availability in my area.
 

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#2
What size is the turbo? On e85 you'll need 80s and a dw300 st least. People with these m90 3800s say that the stock pump and 60s are fine on e85 but that's a bunch of BS. Then again they say that meth is better than e85 and every alcohol injection pump is the same so not really the smartest bunch...
 

fast NY Six

Active Member
#3
Very cool setup you have there. Is there anybody in your area that can tune the car for you? A mail order tune might get you close but, a tuner and wideband would be ideal. I would expect 400hp to be attainable with that setup without meth or e85 comfortably. zzp is another option for a tune, I could never get a response from intense.
 
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#4
Very cool setup you have there. Is there anybody in your area that can tune the car for you? A mail order tune might get you close but, a tuner and wideband would be ideal. I would expect 400hp to be attainable with that setup without meth or e85 comfortably. zzp is another option for a tune, I could never get a response from intense.
Thanks! Yeah, the mail order tune is intended to get it started and running well enough to make sure I don't have any mechanical issues. Then I'll drive it up to the dyno in Indy. I don't know about 400hp. I currently have a stock FWD exhaust manifold on the passenger side that will likely restrict exhaust flow pretty bad. With a stock T5 and open 10 bolt, I don't want to push it much higher than 300hp anyway. I certainly think that e85 would be a nice alternative to 93 since there are a few stations around me, but if it turns out to be too much of a hassle I'll settle for 93. I just don't want to have a lot of KR and wish I had more alcohol later.
 
#5
What size is the turbo? On e85 you'll need 80s and a dw300 st least. People with these m90 3800s say that the stock pump and 60s are fine on e85 but that's a bunch of BS. Then again they say that meth is better than e85 and every alcohol injection pump is the same so not really the smartest bunch...
According to the ebay ad its a ".68A/R P-trim turbine housing, 67/90mm compressor wheel, 74.1/64.56 turbine wheel" I'm admittedly not a turbo expert, and I have no idea what that means. I just know it worked for another guy with a very similar setup to mine. It may be off, but it feels good even with my NA tune and waste gate wide open. It should spool quick.
 

Nasty

empty wallet
#6
This sounds like it will be a low boost setup for a while, think 10 psi or less. I will recommend based on that. You will not be able to run high boost levels without good springs, 125# and higher. This would required the double row timing chain upgrade. If doing that, add a small turbo cam. ST1 is more than enough, they can go 500+ whp. Idles near stock & easy to tune. Your stock drive train, such as clutch/trans/rear would likely need upgrading also if going with that type of power.

Injectors; 42's and 60's cost the same. 60's idle better. Make zero sense to buy 42's (assuming new). 80's cost just a little bit more. Choice comes down to 60's or 80's. For the power level you are talking, 60's would flow more than enough even with E85...80's for room to grow.

Fuel pump; I don't really recommend the Walbro 255 any longer. There are better choices. As mentioned, DW300 is a good pump. The AEM E85 pump is another good choice. Any of them though, including the 255, would get you to your goal. I would stick with an E85 compatible pump, just in case you decide to use it. I don't see a need trying to fit the larger 450 in there, not for your power level.

What are you using for a fuel regulator. For some reason I thought the stock F'Bird regulator was not 1:1. Very curious.

Your turbo is huge for your goals. Since you have it, use it. I am surprised you don't get a fair amount of lag/slow initial spool, and maybe some surging. Maybe the manual trans vs auto is forgiving? I believe the ZZP Z3 kit, intercooled, makes 400hp @ 10psi using a smaller 62mm turbo. Those 6262's have been 600+ too the wheels in high boost applications. That 67mm is way large for your setup, but will work though.

A valve spring & retainer upgrade is a good idea. Since it sounds like a cam & timing chain are not planned, the LS6 springs are priced right and better than the worn stockers by far. Maybe add some higher ratio 1.9 rockers & 105" springs?

Plugs; I would recommend Autolite 104's for the low boost levels you will likely be using. You will likely need too run a tighter gap than you have now as you start turning up the boost. It is a balancing game between eliminating spark blow out and idle quality. You can start out where you are at, and if you don't get any high rpm misfires, then so be it. Otherwise, keep tightening them up until it is smooth up top.

If you are using the fwd front manifold for your passenger side header, maybe switch to the ZZP Plog? I am not a big fan of those, I have bought a couple of the stainless steel ones, and they have cracked. I am on #3, and will see how it goes.

I would think you can get to your goals on pump 93 without any trouble, but plan for E85 now, just in case your goals change.

Good luck and have fun!
 
#7
This sounds like it will be a low boost setup for a while, think 10 psi or less. I will recommend based on that. You will not be able to run high boost levels without good springs, 125# and higher. This would required the double row timing chain upgrade. If doing that, add a small turbo cam. ST1 is more than enough, they can go 500+ whp. Idles near stock & easy to tune. Your stock drive train, such as clutch/trans/rear would likely need upgrading also if going with that type of power.

Injectors; 42's and 60's cost the same. 60's idle better. Make zero sense to buy 42's (assuming new). 80's cost just a little bit more. Choice comes down to 60's or 80's. For the power level you are talking, 60's would flow more than enough even with E85...80's for room to grow.

Fuel pump; I don't really recommend the Walbro 255 any longer. There are better choices. As mentioned, DW300 is a good pump. The AEM E85 pump is another good choice. Any of them though, including the 255, would get you to your goal. I would stick with an E85 compatible pump, just in case you decide to use it. I don't see a need trying to fit the larger 450 in there, not for your power level.

What are you using for a fuel regulator. For some reason I thought the stock F'Bird regulator was not 1:1. Very curious.

Your turbo is huge for your goals. Since you have it, use it. I am surprised you don't get a fair amount of lag/slow initial spool, and maybe some surging. Maybe the manual trans vs auto is forgiving? I believe the ZZP Z3 kit, intercooled, makes 400hp @ 10psi using a smaller 62mm turbo. Those 6262's have been 600+ too the wheels in high boost applications. That 67mm is way large for your setup, but will work though.

A valve spring & retainer upgrade is a good idea. Since it sounds like a cam & timing chain are not planned, the LS6 springs are priced right and better than the worn stockers by far. Maybe add some higher ratio 1.9 rockers & 105" springs?

Plugs; I would recommend Autolite 104's for the low boost levels you will likely be using. You will likely need too run a tighter gap than you have now as you start turning up the boost. It is a balancing game between eliminating spark blow out and idle quality. You can start out where you are at, and if you don't get any high rpm misfires, then so be it. Otherwise, keep tightening them up until it is smooth up top.

If you are using the fwd front manifold for your passenger side header, maybe switch to the ZZP Plog? I am not a big fan of those, I have bought a couple of the stainless steel ones, and they have cracked. I am on #3, and will see how it goes.

I would think you can get to your goals on pump 93 without any trouble, but plan for E85 now, just in case your goals change.

Good luck and have fun!
Wow! Thanks for the thoughtful and well written reply. I've typed up similar posts in 3800 discussions, and have pretty much gotten the same consensus on the fueling mods, but I think you just put the last nail in the coffin for 60# injectors. I hadn't considered other pumps yet. Is the Walbro not E85 compatible? I was planning on running a stock regulator for a little while until I could find a decent looking solution for custom fuel lines; however, an adjustable boost referenced regulator will be on my to-do list.

Valve train is something that seems to be up in the air with a lot of people. I'm not looking to break any records, and I am really hoping to nurse this T-5 along for a while. My thought on the big picture is that my manifold will likely be the bottleneck of air flow, so bigger rockers and/or cams will probably not do me a lot of good. I think replacing the 150k mile stock springs with the slightly beefier LS6 springs will be a nice maintenance item if anything. If I ever get around to building a nicer exhaust I will consider a full valve train and maybe ported heads. Hopefully, even with the big turbo, I won't need screaming RPMs anyway.

I wondered about the turbo. You're the first person to give any feedback on that. It honestly feels very much like my GN with the stock turbo. It has a little more lag, but with the manual I can manipulate it a little more. I guess if I find a deal on a 6262 that's a bolt-in replacement for my 6765 I'll have to consider it. I'm really capping this build to the limitation of the trans and the fact tha tI want to drive this car to work on a regular basis. I'm thinking 8psi max pressure with the stock valve train and LS6 springs. The big power stuff is reserved for the other engine I have in the garage. I think it would be cool to run TSM with a 3800 someday...

Thanks again!
 
#8
Just remember that according to all the well respected people in the 3809 groups who actually know what they're talking about theres no reason to port heads or put in a cam when you can just put on a bigger turbo
 
#9
But on a less ridiculous note, I would go with comp or crow 105# on the stock timing chain. The ls6 springs have too high of a spring rate. Ideally the thing to do wod be 125# springs and a double row timing chain
 
#10
But on a less ridiculous note, I would go with comp or crow 105# on the stock timing chain. The ls6 springs have too high of a spring rate. Ideally the thing to do wod be 125# springs and a double row timing chain
Oh really? I was under the impression that the LS6 springs were pretty light although I've never actually seen numbers. Good tip. I must have read that from one of those well respected 3800 guys. Lol
 
#11
Intense advertises the LS6 springs as:

Installed load is 90 pounds at 1.800", 115 pounds at 1.720", and 300 pounds at 1.230".
Coilbind height is 1.160".

The Crow 105s:
  • Installed load is 105 pounds at 1.800", 127 pounds at 1.720", and 293 pounds at 1.200".
  • Coil bind height is 1.125".
It still seems like the LS6 springs are lighter.
 

Nasty

empty wallet
#12
HM is correct, there is no need to port the heads to make good power on a 3800. I believe stock 3800 heads flow similar to a GN 8445 ported head that was still using stk 8445 valves. They will get the job done. If the heads were off for some reason, I would maybe do a performance valve job & studs at most. Unless you are trying for BIG power, don't sweat leaving the heads alone.

Walbro does make a 255 E85 pump. The AEM 340 E85 flows more at higher rail pressures. The DW300 even more so, especial v2. The Walbro tends to be louder also. It may just be bad luck, but both of the ones I bought, 1st one for the GN and the 2nd one for the Fiero, both were a bit too loud for me. In the GN I could tolerate it, due to its location, but the fuel tank is under the center console in a Fiero, and it had to go. I have used both the DW300 & AEM 340, both were very quiet.

Your stk FB intake will outflow your goals effectively. I remember someone did a head flow test with the manifolds installed. The FB intake flow difference was less than 3 cfm at low lifts and maybe 7-8 cfm at higher lifts, using stk heads. I think there was a few cfm higher penality accross the board using ported heads. Not a huge difference. I also seem to recall someone else saying at higher air speeds the front cylinders were rich and the rears lean with the FB intake, as air skipped over the front ports at high velocity. I think they were in the 600 whp area, others say they never experienced this. Most will never be at that level. 1.9 Rockers or even a ST1 cam will not create a need to change the intake. I would run the FB intake and not look back.

I was going to try to be creative with the FB fuel rail. I cut off the regulator from the fuel block & removed the remaining return pipe. My intent was to plug & tig the remaining hole in the fuel block closed. This would then create a returnless rail. Then put the aftermarket 1:1 regulator on the firewall, and connect the regulator to the rail. However I am now in limbo, maybe thinking about just using another billet rail and set up a coventional return system. I was reading somewhere about returnless systems heat soaking fuel in the rail.

If you find a direct bolt in "lesser" turbo for a killer deal, then great. If not, just use what you already have. While you are not likely to be using the 67mm turbo in its peak efficency range @ 10psi or less, it will still make the power you want. You own it, don't spend more than you need too.
 
#13
My apologies to Howling Mad. I thought you were kidding. It's no secret that there are a lot of "know-it-alls" in the 3800 community with very questionable credentials, so I sensed some sarcasm. Anyway, it's good to know that the stock heads will go a long way. I will save those for my engine on the stand. My Camaro isn't worthy of parts with that price tag anyway!
 

Nasty

empty wallet
#14
Intense advertises the LS6 springs as:

Installed load is 90 pounds at 1.800", 115 pounds at 1.720", and 300 pounds at 1.230".
Coilbind height is 1.160".

The Crow 105s:
  • Installed load is 105 pounds at 1.800", 127 pounds at 1.720", and 293 pounds at 1.200".
  • Coil bind height is 1.125".
It still seems like the LS6 springs are lighter.
They start off lighter, but they ramp up spring pressure faster as it is compressed. By the time you are at .300+/- lift, the LS6 spring will likely have more pressure than the 105's. That continues the more lift there is. In the specs noted, the LS6 springs are already @ 300# at only .570 lift. The Crow 105's are only at 293 @ .600 lift.

The 105's are about as good as you are going to get on a single chain.
 
#15
HM is correct, there is no need to port the heads to make good power on a 3800. I believe stock 3800 heads flow similar to a GN 8445 ported head that was still using stk 8445 valves. They will get the job done. If the heads were off for some reason, I would maybe do a performance valve job & studs at most. Unless you are trying for BIG power, don't sweat leaving the heads alone.

Walbro does make a 255 E85 pump. The AEM 340 E85 flows more at higher rail pressures. The DW300 even more so, especial v2. The Walbro tends to be louder also. It may just be bad luck, but both of the ones I bought, 1st one for the GN and the 2nd one for the Fiero, both were a bit too loud for me. In the GN I could tolerate it, due to its location, but the fuel tank is under the center console in a Fiero, and it had to go. I have used both the DW300 & AEM 340, both were very quiet.

Your stk FB intake will outflow your goals effectively. I remember someone did a head flow test with the manifolds installed. The FB intake flow difference was less than 3 cfm at low lifts and maybe 7-8 cfm at higher lifts, using stk heads. I think there was a few cfm higher penality accross the board using ported heads. Not a huge difference. I also seem to recall someone else saying at higher air speeds the front cylinders were rich and the rears lean with the FB intake, as air skipped over the front ports at high velocity. I think they were in the 600 whp area, others say they never experienced this. Most will never be at that level. 1.9 Rockers or even a ST1 cam will not create a need to change the intake. I would run the FB intake and not look back.

I was going to try to be creative with the FB fuel rail. I cut off the regulator from the fuel block & removed the remaining return pipe. My intent was to plug & tig the remaining hole in the fuel block closed. This would then create a returnless rail. Then put the aftermarket 1:1 regulator on the firewall, and connect the regulator to the rail. However I am now in limbo, maybe thinking about just using another billet rail and set up a coventional return system. I was reading somewhere about returnless systems heat soaking fuel in the rail.

If you find a direct bolt in "lesser" turbo for a killer deal, then great. If not, just use what you already have. While you are not likely to be using the 67mm turbo in its peak efficency range @ 10psi or less, it will still make the power you want. You own it, don't spend more than you need too.

My apologies to Howling Mad. I thought you were kidding. It's no secret that there are a lot of "know-it-alls" in the 3800 community with very questionable credentials, so I sensed some sarcasm. Anyway, it's good to know that the stock heads will go a long way. I will save those for my engine on the stand. My Camaro isn't worthy of parts with that price tag anyway!
Sorry, that was a little bit of a joke, while the heads do flow well for stock heads there are gains to be had porting. I wouldn't go with the expensive aluminum heads, but I would definitely clean up the castings some of the ones I've done were pretty rough. But with a 67mm turbo I dont think you will even need to worry about it unless the heads are already off
 
#16
This is great info guys. Thanks a ton.
They start off lighter, but they ramp up spring pressure faster as it is compressed. By the time you are at .300+/- lift, the LS6 spring will likely have more pressure than the 105's. That continues the more lift there is. In the specs noted, the LS6 springs are already @ 300# at only .570 lift. The Crow 105's are only at 293 @ .600 lift.

The 105's are about as good as you are going to get on a single chain.
Forgive me. I have never had to spec out valve train parts before. I think I understand what these numbers are, but entirely what they mean. Did the specs I pasted in my previous message refer to cam lift and and your specs to valve lift? Are you assuming a stock rocker ratio? Thanks
 

Nasty

empty wallet
#17
The specs you posted were spring pressures at various spring heights. The spring height started out at 1.8" and became less as the valve lift height increases (compressing the spring). The spring pressure goes up as it gets compressed. Knowing the pressure of the spring at the various heights and knowing the cam profile & rocker ratio to get your valve lift can help you better match your cam and springs. Boosted cars should also factor in the manifold pressures. You are limited by the stock chain, the 105# seat pressure springs are your best choice. If you go double chain, you can use higher seat pressures, 125-130# are good choices, they would allow more boost psi,1.9 rockers or small turbo cam. If going with a cam, that would be your minimum. Most see more power using a 150#+ with higher boost psi. If you eventually go with a cam, don't over cam it. You don't need a big cam to make good power. Most vendors have good recommendations, though I feel they sometimes recommend too light of springs and too much cam.

BTW, think of cam lift as the profile of the cam lobe before you factor in the rocker arm ratio. Your stock cam has a cam lift of .258 and your stock rockers are 1.6 so your valve lift will be .258 x 1.6 = .413. Likewise, my ST2 cam has a cam lift of .325, and I am using 1.65 rockers, this gives me a valve lift of .536. (.325 x 1.65 = .536)

Another example :LS6 spring: Starting with a 1.8" height, they measured 90#. At the 1.23" height they measured 300#. 1.80 - 1.23 = .570".
So at a valve lift of .570 the spring is 300#.

Now I am rambling...it has been a long day...
 
#18
I see. Thanks for working with me. I guess I didn't realize the stock cam had that much lift in it. Since the car is already together with stock springs I might just leave it alone until I can do it right. Maybe I'll get a mild turbo cam, stiff springs, double roller chain, and a new oil pump. Some time before that I'll work on getting a power log or making a custom header. Thanks again. I think I've got the information I need.
 
#20
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Not a 3800 know it all. LoL...
I'll keep you all posted. I'm thinking the AEM E85 pump, 60#s, and tuning myself with HP will be the way I go. There won't be much to update on it this winter though. Since I found free winter storage for the GN, I decided to take on my rust issues while the garage was free. The floors and wheel wells look like trash. So far I have one wheel well almost patched, and one rear seat bucket is completely fixed. I'll end up doing weld in subframe connectors while I'm at it. The technical stuff will resume once I'm done.

Here's the current status... sad times in the kingdom.
 

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