3.8 build (ideas)

[Docta]

Alright, I'm planning my build. Which will be a completely separate engine, outside the car, on a stand. It will be taken down to block, and every bit replaced.
So, if cost was no option, using stock heads (modified however) along with intakes, what would you guys do? The plan is FI; Using 42lb/hr injectors, walbro 255, built 5 speed, 3.73's in the rear. I've got a basic outline, but I wanna hear some input first. Current goal is a daily driven 3.8 with a FFH turbo setup, reliable enough to run 18-22 lbs when on kill mode and make 425 to the tire (@ 7000ft)... Any ideas accepted, along with criticism.

[LETZRIDE]

Re: 3.8 build (ideas)

What would I do?

Ditch the 5 speed, it won't hold the power reliably. Go either 4l60E, or if you MUST stay stick, go to a T56 conversion.

Ford 8.8 rear end, it's the cheaper route of the 3 and holds power into the 9's

Cartunning turbo kit (makes life easy but you need to eliminate A/C)

Kit includes everything you need including a tune and makes 400rwhp on 18lbs on a stock motor

The bottom end is strong on these engines, there is no need to build anything on a stand if you only intend on pushing 4xx rwhp through it.

If you want to start pushing 600+, then yes

I would then run a meth system with it for the hell of it, just to maximize my power...hell I want to run meth N/A

[Docta]

Re: 3.8 build (ideas)

I would prefer T56, yeah. But its hard to find a GTO t56. That's a hopeful kinda thing. Hadn't thought about rear end. The kit will be made by me, Gtp manifolds etc. And with an intercooler would Meth help anything? And as far as building, maybe I'll stay top end.. rebuild that as best as possible.

[Need4Camaro]

Re: 3.8 build (ideas)

I would prefer T56, yeah. But its hard to find a GTO t56. That's a hopeful kinda thing. Hadn't thought about rear end. The kit will be made by me, Gtp manifolds etc. And with an intercooler would Meth help anything? And as far as building, maybe I'll stay top end.. rebuild that as best as possible.

Just wondering why would you need a GTO T56?

For gearing, since you're going F.I. I think 3.73's are ganna be a TAD overkill...As in it would actually slow you down... 3.42's was the magic number from what I've heard but I'm open to correction here.

You'll be putting out atleast 425 RWHP so I'm assuming 6th gear won't be an issue (and will be even more sustainable with 3.42's or 3.73's.

I think Meth technically WOULD help with an intercooler, but I dont think it would help enough to justify implementing the system...

Will take alot of work but that would be an awsome fast car on the gas, economy while feathering it, especially with 6th gear.

[Docta]

Re: 3.8 build (ideas)

If I remember right, warshrike said the GTO tranny has a different input shaft length maybe? Than the Fbody one does and fits with less modification. But I was town between 3.42/3.73, but I have a set of orange box motive 3.42's at my shop, so I might cut that cost and use those. As for Meth, all it does is decrease intake temps right?

[2.8 Bird]

Re: 3.8 build (ideas)

I don't know if they are still around, but Swan Performance can sell you a nice stroker kit that would turn your 3.8 to a 4.1 engine. If you want to go turbo they can sell you a low compression kit (8:1) or a high compression kit (10:1 to 11:1) for NA.

For the tranny you can't have a stock manual. It isn't going to hold.

IMO... if your going to build your V6 up it won't do you any good having it as a DD car.

[WarShrike]

Re: 3.8 build (ideas)

We have a few that dd their boosted cars, but they are well sorted as a whole. It just comes down to being intelligent with the car and not hitting Max rpms and boost all the time.

[1998silverbird]

Re: 3.8 build (ideas)

To let you know I did a built motor 3.8 way back in the day now. I had SSMS stage 1 heads and intake ( before they had other stage heads) diamond high compression pistons bored .20 over, L32 rods, stock polished crank, 210/220cam with 534/547 lifts and everything else associated with valvetrain and what not. This was before HP tuners on a V6 so the only tune I had on it was with a maft Translator Plus. I tuned it on motor with that and it made 225rwhp and 225rwtq. I left the stock tune on it for the 125hp shot of N20 and the car made 370rwhp and 415rwtq. If I could have had a real tune and upped the RPMS higher that car would have been insane. I tried PCM For less but the car didnt run right with that PCM, I also tried an Intense Racing PCM and the same thing with that one as well.

I spent about 5000.00 total in the build. My fault was leaving the stock 5 Speed and stock 10 bolt in as they both broke soon after.

If I were you your motor ideas seem good. I would get a built auto with a nice 3600 stall ( call the tq converter company with what gears and what cam your running and they should be able to match a stall for your needs) as its the cheapest and probably most reliable option, 12 bolt as well. This will rob some power but its more fun to drive your car then to let it sit broke in a parking space while your rebuilding a rear or tranny.

Low compression forged pistons, Forged rods, polished up crank,worked Heads and intakes . Get the ARP bolts what what you need them for ( Like rods, Heads, Crank) but dont go overboard with them like I did and put ARP on everything. Man I must have spent 600.00 in bolts alone.

Find a good tuner to tune your car. Tune is everything.

[CFreed11]

Re: 3.8 build (ideas)

Since it was brought up...I'm curious now. Warshrike, why the t56 from a GTO vs. F-Body?

[Docta]

Re: 3.8 build (ideas)

Since I'm planning, the PLAN is to swap the 6 speed first, after a few small things I need to fix. Get the rear end, probably a 8.8 or 9". AFTER that, I'll rip into the motor. Do a custom cam, 105# springs, valves, retainers, rocker arms, maybe some work to the valve covers. Heads are tentatively going to be port matched, and 3 angle valve job. Block, I'll probably do main studs, and all new bearings throughout. Definitely going to get a higher pressure oil pump while I'm in there. Double roller, too. Possibly delete AC. Then when its good and running cammed, I'll Fab the kit. Most likely a GT3582R. 8-10 lbs daily, 22-24 on kill mode. Ofc, supporting ic, bov, wastegate, etc. Gears at that point will drop back to 3.42.

[1998silverbird]

Re: 3.8 build (ideas)

Since I'm planning, the PLAN is to swap the 6 speed first, after a few small things I need to fix. Get the rear end, probably a 8.8 or 9". AFTER that, I'll rip into the motor. Do a custom cam, 105# springs, valves, retainers, rocker arms, maybe some work to the valve covers. Heads are tentatively going to be port matched, and 3 angle valve job. Block, I'll probably do main studs, and all new bearings throughout. Definitely going to get a higher pressure oil pump while I'm in there. Double roller, too. Possibly delete AC. Then when its good and running cammed, I'll Fab the kit. Most likely a GT3582R. 8-10 lbs daily, 22-24 on kill mode. Ofc, supporting ic, bov, wastegate, etc. Gears at that point will drop back to 3.42.

Tuner is still the key. The tune will make or break it. Is there a tune for a 6 speed tranny?

That what you have there will proably run 10-15 thousand dollars.

[Docta]

Re: 3.8 build (ideas)

Tuning will be done by myself, with hptuners...

[techsan23]

Re: 3.8 build (ideas)

If it were me building a turbo 3.8 I would probably just stab a stattama #4 cam in it and bolt some stage 2 ZZ heads on it, and focus the rest of my funds on the turbo kit, trans and rear end. Of course the fuel pump, injectors, hp tuners and wide band would be on the list too.

Having said that; with no concern to cost if your going to be running 20 lbs of boost your probably planning on lowering compression. I would recommend doing a ton of research before you start ordering parts. You'll want to look into the logistics of running that much boost with 8:1 or 8.5:1 compression on forged pistons. L32 rods would be a good idea. Delete the balance shaft. Have the block vatted, bored, honed and magnafluxed. Polish the crank and have the rotating assembly balanced. As long as you have a good machine shop in mind, they should be able to fix you up on the bottom end of the engine. At least have them short block it for you.

All of the different stage heads I have seen are modified stock heads with the exception of maybe ZZ's aluminum heads. If you pay someone local to work your heads over your not going to save much money, and its a good idea to have them done by a company that has done it hundreds of times to these specific heads. Your going to want the bigger valves in the heads.

You must have an idea of how much lift your planning on having in this custom cam because you described running 105 springs which caps how much lift you can run. Im not a big fan of custom cams unless the specs for it are coming from someone who has run multiple aftermarket cams and want to change particular aspects to achieve a specific difference. Otherwise I think its wise to leave it up to the experts. Since you will be running boost use a cam designed for a turbo. I wouldnt recommend running rockers with a ratio higher than 1.7 with an aftermarket cam because it will start putting unnecessary stress on the rockers bolts. Get your lift from the cam. Roller rockers decrease friction and weigh less than the stockers depending on which kit you get. Unfortunately they cost about $400. You will also need to look into how thick you want your head gaskets to be given valve lift and compression. Cometic steel gaskets will probably be what you will want to use given the boost.

You can also pick up or have your intake manifold ported out. Maybe even look into having someone work over your throttle body for you.

Dont forget your wideband O2.

[Docta]

Re: 3.8 build (ideas)

Well in the little research I did last night, I won't need 22lbs to get my goal of 425. At least not on a built motor. 16 would probably for me just fine... and that gets rid of some of the intense machine work. Still going to do some, but nothing insane...

[WarShrike]

Re: 3.8 build (ideas)

Just got a quote from a local machine shop and it will be $1300 to do the block and heads (porting will be done elsewhere) the way I want it without even getting into doing the mods on the oiling system...