Twin turbo LL2 buildup

[SofaKingWeToddDid]

adding more shit to make it less complicated?? maybe im missing something here. i would rather run more piping now, then have two turbos to worry about later.

[2.8-350TBI]

well, the turbos are tiny; a single one would choke at 3000 rpm's. Plus, later on i'd like to add a bigger set of twins. Thats why I want twins. Plus, I like manifold lengths to be even, im OCD like that. Or for simplicity's sake, would it be easier to add the supercharger (detroit diesel 4-53)?

Either way, I can make the intake manifold at the college, and also the exhaust manifolds.

Tell me what you guys would do, keeping in mind that this is a budget build oriented for just a fun daily driver.

[pocket-rocket]

Budget and performance don't usually go together so well in once sentence... Also if you are going for simplicity, twins aren't the way to go. There are a few knowledgeable people that have posted up in this thread, and you seem to be taking their advice that has come from tinkering, making mistakes, and trial and error, and are throwing it to the wind when you came here to ask for help. I see the want for using the two rotary mufflers you have now because they are free, but it also almost seems like you want twins for the "TT" bragging rights. Have you done your homework to see if they will perform the way you want them to? Research is worth it's weight in gold, especially when it comes to something like boosting your vehicle.

[2.8-350TBI]

Pocket rocket, I am not putting you guys off, I am gathering info and tips to see which way I should take my project. Its not going to have any major work done to it anytime soon, so im just trying to gather some feedback. I agree that most of the guys here are very knowledgeable; After all, that is why I joined this board. If I dont sound like I dont know what im saying, I practically dont, im 17, this is my first car, and is my first project, so bear with me.

as for twin turbo, I would like to go single (simpler, what was I saying...), but the turbos are way too small to only use one. You read me?

[no_doz]

get a t25-fab some turbo headers or turbo manifolds-bigger injectors, arp connecting rod bolts, a flybynight tune ($100) and a $150 set of hypereutectic pistons, boost gauge, intercooler, misc piping & oil lines, & a set of 3x00 heads & intake, theres no reason why you cant put at much to the wheels as most of the late 80's early 90's small block v8's.

honestly if this is your first car i would say get a set of forged pistons, high compression if possible, get a stock set of rods & have them shot peened & treated for hardness, stiffer valve springs, a 3x00 topend with tune & high ratio rockers (if you go 3400 topend)-with all that & a set a headers you should be making some pretty nice power (nothing crazy-but nice as it is), & then work on what you need for the turbo stuff, if you start with a stout NA engine you will be much better off in the long run & could put something big on & push TT numbers-300-400whp, then you just need to worry about what trans to take the power lol.

[SofaKingWeToddDid]

find someone with a car like a mazda precidia and trade them two for one. lol they have a 1.8 V6!!

[2.8-350TBI]

get a t25-fab some turbo headers or turbo manifolds-bigger injectors, arp connecting rod bolts, a flybynight tune ($100) and a $150 set of hypereutectic pistons, boost gauge, intercooler, misc piping & oil lines, & a set of 3x00 heads & intake, theres no reason why you cant put at much to the wheels as most of the late 80's early 90's small block v8's.

honestly if this is your first car i would say get a set of forged pistons, high compression if possible, get a stock set of rods & have them shot peened & treated for hardness, stiffer valve springs, a 3x00 topend with tune & high ratio rockers (if you go 3400 topend)-with all that & a set a headers you should be making some pretty nice power (nothing crazy-but nice as it is), & then work on what you need for the turbo stuff, if you start with a stout NA engine you will be much better off in the long run & could put something big on & push TT numbers-300-400whp, then you just need to worry about what trans to take the power lol.

no_doz, thank you so much for the info, that hit the money right there. lol I will be saving up for all of this, and in the not too distant future, ill see some boost.

Now from here for two days, ill be taking a vote:

T-25 turbo or 4-53 supercharger???

Ill do whichever gets more votes...

As for the twins, ill be looking for some to trade my (2) IHI rhf4's for one t-25

[robertisaar]

T25 is too small.... for low boost it may be fine, but a T25/28 is what came on TGPs... it ALMOST chokes a Gen 2 3.1...

i'd go SLIGHTLY larger if you're planning on more power in the future, that way, you would literally only have to turn up the boost and possibly re-tune it...

[2.8-350TBI]

Thats one vote for turbo...

This is a 2.8 however, and I plan on keeping it that way, but when I get everything pieced together, ill be looking at my specs and find my turbo with that based on its compressor map.

[robertisaar]

find my turbo with that based on its compressor map.

thats the only REAL way of doing it...

http://www.squirrelpf.com/turbocalc/

GREAT tool, so long as you know the basic info of the engine you're dealing with...

[Joseph Upson]

no_doz, thank you so much for the info, that hit the money right there. lol I will be saving up for all of this, and in the not too distant future, ill see some boost.

Now from here for two days, ill be taking a vote:

T-25 turbo or 4-53 supercharger???

Ill do whichever gets more votes...

As for the twins, ill be looking for some to trade my (2) IHI rhf4's for one t-25

17 yrs old, listen grasshopper :-), this is not a voting matter. You have a goal of 5-8 psi on a 2.8L to suit your purposes not ours. Take it from someone who is in the planing of undoing a twin turbo setup. It looked great in terms of creativity and actually works well, but as stated earlier, it has complicated things and due to existing options was not necessary although part of the reason I did it was because like you I had two perfectly good turbos that were right for the job.

I wish I had taken the single turbo approach from the start, but instead I'll be removing good parts and pieces to change it and that results in wasted money and time, lots of time.

Review what you want to accomplish, investigate the best means and materials to accomplish it and compare it to other options. You're going to be very hard pressed to get 300 hp out of a 2.8L. This is your first turbo project, keep it practical.

Leave the engine as is except for maybe the intake, turbo it, buy another engine and take your time building it to the appropriate specs. Don't use a built engine as a testing and learning tool.

[2.8-350TBI]

Again, thanks for the input guys, I decided im going with a single t25 turbo, good tuning, and an aluminum port fuel injection intake manifold that ill be making myself.

[no_doz]

why go through all the effort when a set of 3400 heads, 3400 LIM, & 3500 UIM, ported & gasketmatched-will be sfi or mpfi & breathe as much as that little 2.8 could want to-& with all of this you wont be pushing 300-but 240 to 250 at the crank is within reason with high ratio rockers, the thing is for 300 most turbos wont flow enough at that low of boost & efficiency will be horrible, if you build it with forged pistons & the other mods you could go with a T4 & push 300+ with a good tune but much more psi.

[SofaKingWeToddDid]

you should just put rockets and wings on it and paint lightening bolts down the side and flames on top.

[no_doz]

you should just put rockets and wings on it and paint lightening bolts down the side and flames on top.

not before the autozone plastic spinner hubcaps