Newbie Turbo question

[4G63_fiend]

So earlier this year I pruchased a Precision Turbo SC6165E T3/T4 turbo used off a forum. Upon recieving the turbo I realized the amount of shaft play present, and I sent it to Precision who rebuilt it. I currently have an older 16G Godspeed turbo I bought off EBay for my previous dsm(I know bad choice!). With the current setup I was boosting WAY too much on the stock external wastegate, hence my new turbo setup. That said I have yet to install the Precision turbo on my car. I have all my supporting mods listed on my profile and my question is this;
I currently have another head I am going to throw on the car with Brian Crower 272 cams, along with BC SS valve springs and retainers. Along with the turbo I bought a Turbonetics cast iron mani and Tial 38mm WG. I will also be installing Speed Density. My goal for the car isn't huge dyno numbers, but a quick street car that I can take to local events and tear up (autocross, drag strip, and occasional road course) that is still very streetable. I am having AMS tune my setup when its all said and done, but I am starting to wonder if I need a turbo that big for my application. Would I be better off going with a legit MHI Big 16G? Or will I have the same troubles I currently have? I removed my wastegate actuator from the turbo and now the wastegate door is stuck open and I don't boost until around 3500 RPM, which is fine considering my previous problem, but never the less I need an effective sollution. Any input??

 

[WES_393]

You need to figure out your actual horsepower goals. One person's definition of a quick street car might be very different from another. But from the sound of it, you would probably be happy with 350-450hp. A 400hp street car is (in my opinion) very fast.

That PTE 6165 is way too big of a turbo. Not only too big for your goals, but your supporting mods won't handle even 10psi on that turbo. If your setup can't handle anything a 16g can put out, your definitely not ready for anything like a 6165. I think you would also be very disappointed with anything that large for a street turbo considering how long it would take to spool.

If your looking for 350-450hp, there are plenty of bolt-on options that would better suite your goals. Evo 3 16g, 20g, Holset HX's, FP Green, etc. All of the ones I mentioned can be used with a stock manifold and O2 configuration so long as you have the right parts. That PTE (depending on what turbine housing you have) is going to take some custom work just to be installed, will require you to replace almost every supporting mod you have, and is seriously overkill for any street car IMO.

 

[4G63_fiend]

You need to figure out your actual horsepower goals. One person's definition of a quick street car might be very different from another. But from the sound of it, you would probably be happy with 350-450hp. A 400hp street car is (in my opinion) very fast.

That PTE 6165 is way too big of a turbo. Not only too big for your goals, but your supporting mods won't handle even 10psi on that turbo. If your setup can't handle anything a 16g can put out, your definitely not ready for anything like a 6165. I think you would also be very disappointed with anything that large for a street turbo considering how long it would take to spool.

If your looking for 350-450hp, there are plenty of bolt-on options that would better suite your goals. Evo 3 16g, 20g, Holset HX's, FP Green, etc. All of the ones I mentioned can be used with a stock manifold and O2 configuration so long as you have the right parts. That PTE (depending on what turbine housing you have) is going to take some custom work just to be installed, will require you to replace almost every supporting mod you have, and is seriously overkill for any street car IMO.

Thank you for the input and sorry for the lapse in response! I would be happy with anything around 350 hp. And while I realize it is a large turbo, I anticipated quite a bit of turbo lag. But as far as not handling anything a 16g can put out, I seem to be pushing too much air for the wastegate opening on my internally gated 16g. (Hence why I purchased this turbo to begin with). My real question I guess considering would be if I purchased a legit MHI 16g would I run into the same problem? If so I will look into getting either the Holset or an externally gated 16g. Would I be unhappy with my limits of another 16g tho? I know I have not hit them yet, but no telling what the future holds!

 

[mikemustbebored]

I'd take a look at this post as it seems like he/she shared your hp goals. http://www.dsmtuners.com/forums/new...s-pros-cons-td05d-16g-vs-suoers-td06-20g.html

 

[Greenie]

you need to figure out what type of horsepower you plan to be trying to reach

 

[destruckeclipse]

A Godspeed ebay 16g has no comparison to a real 16g. A EvoIII 16G would be a huge leap better then that turbo, and it sounds like your wastegate problems may stem from the fact its a piece of crap (to put it simply).

The PTE6161 is going to give you a super late spool, something I personally would not consider street friendly or fun unless you plan to only do highway pulls or something of that sort. That turbo is far too large for what you want to do.

As stated you probably want something in the 20g/hx35/fp green range. If I was you I would sell that and get a legit evoIII 16g and max it out, then decide if you want bigger or not. You can pickup good ones in the classifieds for cheap and bolt it on.

 

[inspire]

A big 16G will be good to that power rating. Or if you feel froggy get a 20g. Your goals on power depend on the supporting mods you have for them, you said you have them so you should be set to go if your using a 16g now. Tune is crucial even at this power rating. 325 is more than enough to zip past most streetable cars. There is always going to be someone faster out there though.

 

[Seamus]

I guerss you already have link or something? just buy an mhi 16g or put together a 20g with some 1050 or 1150cc injectors and you'll be good to go. No need to use an external wastegate, but its nice to have.

 

[project98dsm]

you need to figure out what type of horsepower you plan to be trying to reach

Indeed. This is important because you're going to want to find an "all around" turbo. You don't want one that is too big for your goals. There is a rule that it is better to have too much than not enough. This is somewhat true. But you want to find one that will suit your goal in it's efficiency range. You don't want a 40r, for example, for a 400whp car. That turbo will never see it's efficiency range. Like stated earlier, something along the lines of an FP Green or Green XL, HX35, or something along those lines would be a great turbo. You won't have to worry about running out of breath with either of those, and it will be right along the lines of their ranges. At the same time you don't want to go too small that you'll have to run the piss out of it to make your numbers.

 

[WES_393]

Thank you for the input and sorry for the lapse in response! I would be happy with anything around 350 hp. And while I realize it is a large turbo, I anticipated quite a bit of turbo lag. But as far as not handling anything a 16g can put out, I seem to be pushing too much air for the wastegate opening on my internally gated 16g. (Hence why I purchased this turbo to begin with). My real question I guess considering would be if I purchased a legit MHI 16g would I run into the same problem? If so I will look into getting either the Holset or an externally gated 16g. Would I be unhappy with my limits of another 16g tho? I know I have not hit them yet, but no telling what the future holds!

My point is there should be no such thing as "too much air" with any turbo your running if you have appropriate supporting mods. I'm pushing 25-27psi on a small 16g with the internal gate with no problems. For 350hp, a big 16g could do the trick. A legit Evo 3 would definitely get you to 350hp. No need for fancy external gates or manifolds, the problem is your supporting mods and tune, not your turbo. You'll need something bigger than 580cc injectors to start.

Also, the PTE 6165 will spool in the mid-late 4k RPM range regardless of what you do and is good for over 500hp. You won't even be putting that turbo to it's abilities at 350hp. Like I said, it won't be bolt on either. You'll need a manifold, downpipe, oil feed/drain setup, etc. The Holset is also overkill for this situation and is also much more of a project than bolting up a 16g. Stick with a bigger/better 16g or 20g and get the right supporting mods.

 

[project98dsm]

If 350 is your goal, take Wes' advice. A big 16g or MHI EvoIII will treat you nicely. Just worry about supporting fuel mods and something to tune with and you'll be set. Dealing with an HX35 can be a headache, just depends on how much you want to go through to play. One of the most beat to death topics is proper oil drain, and there is a maniacal amount of threads/pages dealing with this. There's no reason to not make 350wheel on Mitsu turbo/o2 housing/turbo manifold. And if your "too much air" issue that you're worried about is in reference to boost creep, that's an easy fix, though I'm not quite sure what it is you're referring too. Certainly you're not trying to hint that you feel your 16g flows too much air for your goals...

 

[brownie956]

First off, the above advice is good. The PTE is way too much turbo for what you need. Think about exactly what you want for HP numbers, and get a turbo that is right in that efficiency range and/or close to peaking its power potential for maximum responsiveness. The too much air that you speak of regarding your internal wastegate, sounds like you're experiencing boost creep. That doesn't necessarily mean the turbo is too small for the application. There are a few different approaches to minimizing boost creep including tuning, porting, or going with a slightly smaller exhaust. Lots of information out there regarding this. Good luck!

 

[4G63_fiend]

when I said I was flowing too much air I meant that with this POS turbo I cant stop it at 12 like it used to on my old car. It always held fine on the old car, but I didn't have all the mods I currently have on the vehicle. I know the I didnt hit the flow limit of the 16g, just that it seems the hole for the wg opening is too small, causing me to push way too much boost. Even with the regulator off, I can still see 20+ psi if I go anywhere over 5k rpms. I also realized the oiling issues and manifold differences and have them taken care of. I was already thinking this turbo would be too big, which is why I posted this. I would like to stick with a 16g, I just didn't know if buying an MHI true BIG 16g would take care of my problem. Thank you all for the input and I am going to follow yours and my own advice on this and sell my Precision.