baronsmith98

iTrader: (2)

Have a 370 Wiseco pistons, scat rods, 10.5:1 compression, cam in sig. Was originally going to spray but now thinking about single turbo setup. Possibly 76-78mm turbo, thinking e85 and intercooler. Top rings were .021" 2nd were .023". really only want to run about 10 psi and have a hp goal of around 700 at the crank which is conservative I think. Is e85 needed with this amount of boost and compression? What are the limitations with my ring gap? A cam change will be in order. I think with the low boost this engine could live a long time and be really fun at the same time. Just looking for opinions from people who have done this and things they have learned or wish they did.

ZONES89RS

iTrader: (25)

10 PSI on 93 would be border line for what you have with not really worrying. You wouldn't need a innercooler with your combo. And if you went E85, your tuning window becomes huge compared to pump gas. If you have the money and time, do it.

speedtigger

iTrader: (16)

Check out a member named 3pedals build. He has a first gen Camaro with a blow through setup that run really well.

3pedals

iTrader: (3)

spray some water/meth at it, and run it in the low 11:1 A/F range, and it will live on 93 @ 10psi. But 10.5:1 compression is pushing it BIG TIME! if you go beyond 10psi, you best run some better gas.
Pick your turbo wisely.
I have no experience with e85, cant help you there

baronsmith98

iTrader: (2)

Thanks 3pedals for the info I've read your build and its awesome. Do you have any suggestions for turbo size?

3pedals

iTrader: (3)

whats your budget for the turbo itself? and whats your goals hp wise? Also what kind of driveability are you after?

kainedogg

iTrader: (23)

Subd for the answers this thread will provide.

Is there such a thing as a budget blowthru carb?

baronsmith98

iTrader: (2)

I have about 5k to spend on everything. Fuel system, carb, meth injection, turbo system. I would really like to get 650 rwhp with this setup. I drive this truck just on my days off here and there having fun. I do drive the truck on the street but I beat on it the whole time. I don't do road trips with it. I almost don't want the turb to start spooling up until about 3,500 rpm if that makes sense? I figured that would help conserve some of the meth injection and the driveability would almost stay like it is now but when I slam it she will really scoot! Let me know if this is a dumb idea. I always do a lot of research before I pull the trigger on something and I am in the process of that with turbos right now. Trying to learn as much about it as I can. I was going to put nitrous on this truck but just have been liking the idea of a turbo on it. I realize I don't have a ton of money to do this but I thought I may be able to get my feet wet with it. I'd really like for this motor to live for a while too. Thanks for the answers and any advice.

3pedals

iTrader: (3)

what vehicle? how much does it weigh?
Going to need ALL the info to give you realistic advice.
5k is tight but doable

newschool72

iTrader: (12)

I am in the process of getting all my goodies together now to put my blow-through setup together. Im at about 5k now and I have all the big players bought. All that's left to purchase now are all those little odds and ends things. Plugs, longer plug wires ,air filter , a few clamps and silicon hoses, etc. If you buy good used stuff, you should be able to get set up for 5ish. I shopped around and the only used thing I bought was the turbo itself.
If you want to run a borg warner turbo, and there are a lot of them around used, they have a map calculator you can use that really accelerates the learning curve on picking a unit. They also have a few tutorials on how to use the mapbot (that's what they call their calculator), that goes a long way towards teaching you all the details you need to know to make an educated choice. Its always money ahead to ask people that have already done it too, like 3pedels. Its a steep learning curve, that's for sure! The more I study it , the dumber I feel , LOL.

baronsmith98

iTrader: (2)

92 GMC Sierra regular cab roughly 4000 lbs est. Th350 3,800 circle d. Ford 9" 3.89. Moter specs in sig. Thanks for response new school yes there is a ton to learn on forced induction. I will probably research at least a year before I do anything

speedtigger

iTrader: (16)

No kidding? For which car?

newschool72

iTrader: (12)

The 72 Camaro . Been working on it for the last year or so, undercover, lol. I designed and built my own triangulated 4 link, got QA1 coil overs all around, did some aero work, changed up to 4.10s with a taller rear tire (305-35-18 MT DR SSs), 3" stainless exhaust, built a steel 15 gal cell with a 1 gallon box hanging down from the bottom with my pump in it. Now its time for my first forced induction setup !

3pedals

iTrader: (3)

OK, there are a few ways to do this.
I think your ring gaps are fine.
If you are going E85, the 10.5:1 compression is fine. If you are going pump gas, you may want to drop the compression to 9.5. a custom thicker head gasket would be the easiest.
for reference about fuel, I ran a 600rwhp( 10psi) tune safely on 91 pump gas with a water meth kit, non intercooled, at 9.5:1 compression.
Cam: I would recommend a smaller cam, but it depends on how you want it to run - the cam you have now will work with 7000rpm and the bigger turbine turbo, and easily make 1000hp.
for a truck that I ASSUME you want to have great lower rpm torque, I would get a cam with ~ 218/218 114+4, or 220/220 114+4. even a 224/224 114+4 would work well.
These engines are happy with almost any cam, the bigger ones just shift the power up in rpms.
for reference I run a 227/235 114+4 in my 6.0, and It make peak hp @ 6700 and pulls hard up to 7500.

I am a believer that Borg Warner turbos are the most reliable, low buck turbos out there, so I would spend a few extra $$ on 1 over a china turbo.
My turbo recommendation is a BW S475. They can be had for $650 up to $1100 depending on the turbine size. Turbine sizing is almost MORE important than the compressor size, so you will need to make decisions about how you want the truck to drive - rpm where turbo spools, max rpm of engine, ultimate HP(consider the future).
To meet your 700hp goal the smaller $650 BW S475/83-1.1ar would work well, and still have the ability to make some more power if you want to turn it up a bit. this one is best suited to a lower HP goal and lower rpm ceiling.
If you are ok with the turbo spooling up around 4000rpm, and want to turn the engine up to 7000 or a bit higher on the shifts there is a S475/96-1.32 A/r that is same price - $650. the cam you have now may work with this turbo, BUT the tradoff is that the combo will be pretty 'soft' below 3500-4000rpm.
for reference my turbo was a BW S480/92-1.1A/R, It made 800rwhp @16psi on my 6.0, and 1067 at flywheel when I had it it on engine dyno. A BWS476/92-1.1a/r would be able to make the same HP.

there are a handful of china turbos that would work ok too, but will be maxed out basically not far from your hp goal, and they usually have restrictive turbines that wont like to turn rpm. we can go into those if the BW is not what you want.

I assume that you will be fabricating the whole turbo kit? this is easy in a truck like yours. Use the truck manifolds, cut the flanges off and weld on some 2.25" or 2.5" vbands. I would route the crossover under the converter, and build a merge on pass side. There are MANY ways to route the hot pipes, If you want to go into that, I'm happy to share my opinions and experience.
this can all be done out of steel for cheap, or SS if you want to spend some $$. There is a really nice pass side manifold available from KBracing, that mounts the turbo and merges the driver and pass side together, but is it slightly pricey at $550. you could easily build a 'kit' at home for way less $$.
Cold side can be done out of steel too, for the tightest budget, but Alum looks nicer and blow off valves usually come with alum weld flanges.

Blowthrough carbs are not cheap, but if you want a blowthrough combo to run great, you will NEED to ante up an get a good 1, I ran a CSU and I LOVED it, well worth the $950. It drove well, and kept the air fuel damn close to perfect under boost. my datalogger proved it.

The truth is that Blowthrough is less $$ than EFI, but it is possible to go EFI for close to same $$. the bennefit of efi is that you get datalogging built in.


Lastly, Rear gears will work just fine, BUT the TH350 will die immediately, you would be wise to sell it now while it works well, and upgrade to a th400. Your 3800 converter might work with your 600rwhp goal, but Im guessing the turbo combo might drive through it. At least it fits a th400 too, and you could try it before changing it out.
Barrett

baronsmith98

iTrader: (2)

Wow this has to be the most complete and thorough response I've ever seen on tech. Haha I appreciate the time you took and you make some great suggestions. My biggest decision I think is deciding between e85 or pump. I have given though to the transmission as well ha. The info you give about the turbos is greatly appreciated I see a have a lot to research!

newschool72

iTrader: (12)

The turbo I picked is close to the smaller one Barrett chose for you. A S400SX (S474). 74mm compressor, with an 83mm turbine. I bought mine used with 2 turbine housings (.90AR and a 1.25AR) so I can play with the spool up and see which one works best for me. It sounds like your gonna study this for a while before you pull the trigger, so I will keep you posted as to which AR works out the best, where. Mine will most likely act a little different than a stock S475 because of a few upgrades it has, but I would think the AR and where it starts to kick in would not change too much. The MapBot seems to think the 1.25AR will work better across the board on engines our size. Both ARs were in the efficiency window at 2000rpms at 3-5psi range, but the .90 AR started getting chocked up above 5500rpms, where the 1.25 held in there pretty good up to 6500, where I topped my RPM table out.