3400 Grand Am GT Build

[Mark02GAGT]

Hey guys, new here really. Lurked the forum before for some general info but I decided to make an account to document all this plus get some help from some more knowledgeable people. My 02 recently started to slowly leak oil from the bottom end, so, instead of paying to have a shop fix it I'm going to take a motor from the junkyard, tear it down and rebuild it for my car. At the same time the Transmission will get rebuilt as it is getting higher mileage and will be less of a hassle to do with the engine already being pulled later on.

My goal is 300-350 fwhp, daily drivable. It will be turbo'd, probably running upwards of 12+ psi. Probably going with a Garrett T3/T4 Turbo - anyone wanna chime in on what size compressor/inlet I should be looking for? I think it should be something this size? http://www.kineticmotorsport.com/pro...M-284-159.html With .63 A/R.
Further turbo parts will include:
Custom headers/3" downpipe (already have em)
TiAl 38mm Wastegate
HKS SSQV BOV
Wideband O2
FMIC, etc.

As for the engine;
65mm TB
Ported & Polished Upper/Lower intake manifolds
36lb Injectors
Walbro fuel pump
EGR delete
180* thermostat
Stage 1 Heads/Cam, .020 overbore if I do get new pistons,
LS6 Valve Springs
Manley Steel Valves
4032 Forged Pistons 9.5:1 compression (??)

And last but not least, rebuilt 4t45e;
Raybestos Blue Clutch Plates, or I've heard Red is better for street cars??
Engineered Performance LSD
3.73 or 3.91 Gears
Anything else that I'll need? I'll admit my knowledge on transmissions is fairly limited lol

And top it all off with a nice, conservative custom tune.

This is the car it'll all be installed on...


P.S. If anyone happens to know where I can find an AED Front Bumper...lemme kno haha been looking for over a year to complete my body kit and still have not found oneee

[AaronGTR]

You can get 300+WHP on 8psi of boost, so 12psi with an intercooler you should have no problem. With that amount of power you'll definitely want the raybestos blue clutches, not the reds. They don't have enough torque capacity. Blues work fine on the street. Got almost 4 years on mine with no problems so far. I know there are a couple different chain and sprockets combinations you can use to change the final gearing, but don't recall what they are exactly. Not many people have tried different gearing yet, so not sure how many changes you need to make in the PCM to make things read/shift correctly, or how much affect it has on fuel mileage and acceleration. With over 300whp though, you might not need higher gearing. First gear is tough to get traction in as it is.

[prophiseer]

Just a thought - but the 36# injectors might be a tad bigger than needed. I'll be up front in saying I have next to no experience with boost, and/or what required for a custom boost setup . . . but, based on what I went through with having just put together a mild N/A motor, the 24# I had selected turned out to be simply too fat for the motor - and that's with a .020" overbore, stage 2 heads, port matched runners through UIM/LIM/CYL, 60mm TB, LS1 springs, stock replaced cam, S&S headers, etc.

Now, I'm sure if I'd get off my rear and get the PCM tuned further for the build (compared to it still being tuned for a stock 3400), she'd handle the 24# just fine - but fundage is tight, so I had to go with a set of 21# I had laying around. I know boosted setups require a lot more fuel, but 36# just seems to me like it might be a bit more than needed for th build. I'd defi get some further feedback from some of the more boost friendly members around here first, though

[AleroB888]

Just a thought - but the 36# injectors might be a tad bigger than needed. I'll be up front in saying I have next to no experience with boost, and/or what required for a custom boost setup . . . but, based on what I went through with having just put together a mild N/A motor, the 24# I had selected turned out to be simply too fat for the motor - and that's with a .020" overbore, stage 2 heads, port matched runners through UIM/LIM/CYL, 60mm TB, LS1 springs, stock replaced cam, S&S headers, etc.

Now, I'm sure if I'd get off my rear and get the PCM tuned further for the build (compared to it still being tuned for a stock 3400), she'd handle the 24# just fine - but fundage is tight, so I had to go with a set of 21# I had laying around. I know boosted setups require a lot more fuel, but 36# just seems to me like it might be a bit more than needed for th build. I'd defi get some further feedback from some of the more boost friendly members around here first, though

You will need 36 lb injectors. I estimate 10 psi to be the practical limit for the stock PCM. Recommend going Racetronix for the fuel pump, dual feed to the fuel rails.

[eckoxl]

You will need bigger that 36#. I'm running a 12+PSI 3.4/3.5 in my Grand Am and I maxed them out real quick. Right now I'm running 42.5 with a racetronix pump. no issues.

[MidnightriderZ24]

i agree, 36# will be the smallest u want to go! i made 358 whp on 10psi on a 57 trim t3/t4 with 36lb injectors at 55psi on a walbro 255 lph pump. you should make around that hp even with the auto trans. good tune will be the key

[blackbombshell95]

If you're going turbo then I would personally stick with a stock TB. Also if you dont already have an EP LSD be prepared to wait 1 year before you get it. I look foward to your updates!

[Mark02GAGT]

If you're going turbo then I would personally stick with a stock TB. Also if you dont already have an EP LSD be prepared to wait 1 year before you get it. I look foward to your updates!

Why would I want to stick with a stock TB?? Doesn't make sense to me haha.

Thank you everybody else for the comments. Where would I find the Racetronix pump for our cars, and when I do get new pistons...should I get 10.5:1 compression? I've been reading that a lot of Turbo builds don't need a compression as low as 9.5:1

[AaronGTR]

i don't know why you would want a stock TB either. With the air flow you are adding with boost I would definitely get a bigger one. Anyway, the racetronix fuel pump is here. http://www.racetronix.com/


With pistons and compression ratio... well, that really depends on a lot of things like how much boost you are running, what turbo specs you are using, what kind of fuel you are running, how good your intercooler is... there is a lot too it. I've heard that with the right set up and low to mild boost levels that you can run slightly higher compression to keep the low end torque up and help spool the turbo faster. Of course to help avoid detonation you'd need a good intercooler, or you could run an alcohol injection system or use E85 fuel. There are a lot of variables and you really need to do a lot of research before picking a compression ratio. I've only skimmed through the basics of the topic myself.

[Mark02GAGT]

Thank you Aaron for the help

Got a couple of progress pics on my turbo headers...
what I started with;



After some work...




Still got a long way to go...there's a shit ton of rust on the headers themselves

[pocket-rocket]

I've been told that paint made for your bbq grill rocks on exhaust to prevent rust. I used it on the header style manifold on my pickup and downpipe, and it still looks good over a year later.

[Mark02GAGT]

Thank you I'll give it a look.

Some more updates on the headers;







Can someone please tell me what those 2 welded holes are for - one on the crossover and one on the downpipe? I'm assuming the one of the crossover is for the wastegate, not so sure on the dp.

Also more good news, I ordered my Turbo last week and it should be here within the next couple of days. I got a completely custom t3/t4 from usedturbos.net. 57 trim with the E housing (3" inlet) They were great I would definitely recommend them for anyones Turbo needs, great prices too.

Also - anyone know a good place to send these pieces to be Jet-hot ceramic coated?? Thank youu

[AaronGTR]

hmm, thinking the one on the DP could be for the O2 sensor?

As for coating, send them to Jet-Hot. They do stuff directly, you don't have to go through anyone else. And their prices are awesome, and they offer multiple levels of coatings too depending on your use and how much heat they'll see.

[Mark02GAGT]

There's a bung on the DP for what I believe is the o2 sensor ill get a picture when I get a chance...I thought this one was something different

[IsaacHayes]

I agre 36# will be fine or you might need more if you go 12psi+. You'll need that. My N/A motor uses 30 or 32# injectors (can't recall right now) and they fall right around 80% duty cycle from all the calcs IIRC. My small port 3100 with stock log manifolds 2.5 mandrel exhaust and 3400/3500 intakes & 65mm TB hits over 90% duty cycle with stock injectors.

With boost a larger TB isn't super nessasary, but our TB's are small to begin with, and with that much boost it will just be a restriction. Your charge pipes will probalby be 2.5" so going to 65mm TB is very close to that, so you won't have any bottle neck there. True, forced induction helps overcome restrictive intake manifolds/etc but it just makes sense to keep everything 2.5" up to the plenum.

If you are going for a DD and not an all out race mostly car, I'd stick with 9.5:1 or around there. The thought used to be go lower than factory, but many people run boost on stock ratio with great results. Going higher compression will leave you less safety margin and you won't be able to hit as much boost without alk injection/really high octane as mentioned above. For the extra work/headache the extra point of compression won't be worth it IMO. 9.5:1 with boost will be good.

I was wondering what those welded up tubes were too.. Perhaps waste gate, and the other an O2 bung?