Re: Need help picking a turbo plz
[Re: MNobody]
#1614137
04/30/14 05:41 PM
04/30/14 05:41 PM
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Joined: Apr 2010
Posts: 1,049 ohio
all spooled up
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super stock
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ohio
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I have a twin 66mm gt35s turbo 318. this is what I run for turbos compressor side a/r .70 trim 55 66mm inducer turbine side a/r .82 trim .82 64mm inducer thay work great there good for 550hp each
Last edited by all spooled up; 04/30/14 07:42 PM.
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Re: Need help picking a turbo plz
[Re: all spooled up]
#1614141
04/30/14 11:45 PM
04/30/14 11:45 PM
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Joined: Feb 2005
Posts: 4,884 Michigan
MNobody
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Quote:
I have a twin 66mm gt35s turbo 318. this is what I run for turbos compressor side a/r .70 trim 55 66mm inducer turbine side a/r .82 trim .82 64mm inducer thay work great there good for 550hp each
I thought the turbine side needed a smaller AR and Trim, how fast do they spool? I'm afraid the already low compression i have might be an issue, just askin thanks!
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Re: Need help picking a turbo plz
[Re: MNobody]
#1614142
05/01/14 08:20 AM
05/01/14 08:20 AM
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Joined: Mar 2006
Posts: 9,974 MI, usa
dvw
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Quote:
Quote:
I have a twin 66mm gt35s turbo 318. this is what I run for turbos compressor side a/r .70 trim 55 66mm inducer turbine side a/r .82 trim .82 64mm inducer thay work great there good for 550hp each
I thought the turbine side needed a smaller AR and Trim, how fast do they spool? I'm afraid the already low compression i have might be an issue, just askin thanks!
Not to burst you bubble but that car will weight at least 3300 w/o driver.
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Re: Need help picking a turbo plz
[Re: dustergirl340]
#1614144
05/01/14 09:57 AM
05/01/14 09:57 AM
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Joined: Feb 2003
Posts: 1,942 Metro Detroit
OUTLAWD
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top fuel
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Metro Detroit
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What year 318? It probably has a steel crank. I'm not sure the bottom end is the limit here.
Draw through? I'll just say compressing air is a lot easier than air/fuel. Plus increased charge cooling with blow through.
GT45. will make plenty of power, and be straight forward and easier to tune.
Not 2900. maybe if you have a 7.25 rear and no interior. My dart was fairly light for a street car. ~3200 with full bench interior, iron headed small block, alum rad, alum MC, alum wheels, manual steering, glass hood.
Faster, Faster until the thrill of speed overcomes the fear of death...
71 Swinger - slowly collecting dust/parts 66 Belv. II - just a streetcar 88 Mustang - turbo LS beater
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Re: Need help picking a turbo plz
[Re: dizuster]
#1614145
05/01/14 11:21 AM
05/01/14 11:21 AM
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Joined: Nov 2013
Posts: 742 Southern Alberta
Uberpube
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super stock
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Southern Alberta
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500hp total?!
I'm not sure if you can put two turbo's on a V8 and only make 500hp... lol
All kidding aside...I'd try two Mitsubishi 14B turbo's off the DSM stuff (Eclipse/Talon). Small enough that they'll spool, and they will support 500hp on a 318 with no issue. They are internally wastegated too, so it'll save you that expense.
Also why 7.25:1 compression? Are you trying to run non-intercooled 87 octane?
The low compression will hurt the spool up time as much/worse then the A/R will.
On my turbo car, everytime I dropped compression the spool got better and it made more power everywhere. I am in the process of dropping from 8.5 to 7.8. It seems counterintuitive but on a boosted car the lower the CR the better.
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Re: Need help picking a turbo plz
[Re: MNobody]
#1614146
05/01/14 11:26 AM
05/01/14 11:26 AM
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Joined: Jan 2005
Posts: 3,639 Oakland, MI
dizuster
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Oakland, MI
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Stock lower end so i figured i'd be nice to it, 500 will be plenty for a 2900 pound street car...for now.
I'll let you weigh it when you're done... but you're right 500hp is safe on the stock lower end as long as you’re careful with the tuneup (boost/timing/fuel).
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I have a 360 block waiting but money is tight and i figured i'd get the bugs worked out first, new to boost don't need to scatter a good block.
Nothing wrong with the 318. It will require just a little bit more RPM then the 360, but it will make plenty of power. Lots of 302/331 mustangs out there making 1000+ hp. The only benefit of the 360 block is the bigger main if you're going to run a cast crank. And it will spool slightly better because of the bigger engine size. But nothing to worry about.
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I want the twins for the cool factor nothing else,
Nothing wrong with that. Just know you're in for more fab, more money, etc... You can easily meet your goals with one small turbo and less work, but I get it. My motor would be a lot faster in an A-body too… different is ok.
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i'm doing a twin carb draw through. I already have 2 complete turbo units from a couple old Buicks to get the carb manifolds(liquid cooled). Blow through is not an option please don't beat that Horse
I am more than happy to beat this dead horse to save you despite yourself... lol
Think about this REAL hard for a second. If you're already defending this because EVERYBODY is telling you not to do it...you should have a DAMN good reason not to go blowthru. And "cool factor" is certainly not a good enough reason. Drivability, power, difficulty to tune, and most importantly the ability to get help from people, all outweigh whatever reason you think you should do drawthrough!!!!!
If this is your first turbo project, and you’re still asking simple questions about A/R and sizing, you’re probably not in a position to try something extremely difficult, and outside the mainstream.
Do yourself a favor and build it blow through. The project will be complicated enough as it is, and you will have a steep learning curve just to make a conventional turbo deal work. There is no good reason that you would want to make this 10x harder on yourself. You’ll end up frustrated with a pile of broken parts.
Isn’t a twin turbo 318” cool enough? LOL
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Re: Need help picking a turbo plz
[Re: Uberpube]
#1614147
05/01/14 11:53 AM
05/01/14 11:53 AM
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Joined: Nov 2003
Posts: 1,969 Chandler, AZ
Duner
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Quote:
On my turbo car, everytime I dropped compression the spool got better and it made more power everywhere. I am in the process of dropping from 8.5 to 7.8. It seems counterintuitive but on a boosted car the lower the CR the better.
I wonder how much of that perceived better spool was because the engine was already working so much harder just to run that it was already on the threshold of building boost?
Was that on a V8 engine?
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Re: Need help picking a turbo plz
[Re: MNobody]
#1614148
05/01/14 12:52 PM
05/01/14 12:52 PM
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Joined: Dec 2013
Posts: 403 Romulus, MI
GTS340
mopar
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mopar
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Romulus, MI
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Quote:
Stock lower end so i figured i'd be nice to it, 500 will be plenty for a 2900 pound street car...for now. I have a 360 block waiting but money is tight and i figured i'd get the bugs worked out first, new to boost don't need to scatter a good block. I want the twins for the cool factor nothing else, i'm doing a twin carb draw through. I already have 2 complete turbo units from a couple old Buicks to get the carb manifolds(liquid cooled). Blow through is not an option please don't beat that Horse
Draw through really??? Don't know why anyone would make a conscious decision to pursue something that is sure to be extremely frustrating and time consuming. It's challenging enough to do with blow through! Might want to switch to points ignition, bias ply tires, and 4 corner manual mechanical brakes to keep moving forward with the latest and greatest cutting edge technology!
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Re: Need help picking a turbo plz
[Re: GTS340]
#1614149
05/01/14 01:06 PM
05/01/14 01:06 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Romeo MI
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I think he has a pair of OLD manifolds and carbs from the early set up... there is a reason they dropped that set up... I worked on a buddies old V6 with that draw through set up... what a PITA to get it right
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Re: Need help picking a turbo plz
[Re: dvw]
#1614150
05/01/14 01:21 PM
05/01/14 01:21 PM
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Joined: Feb 2005
Posts: 4,884 Michigan
MNobody
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Quote:
Quote:
Quote:
I have a twin 66mm gt35s turbo 318. this is what I run for turbos compressor side a/r .70 trim 55 66mm inducer turbine side a/r .82 trim .82 64mm inducer thay work great there good for 550hp each
I thought the turbine side needed a smaller AR and Trim, how fast do they spool? I'm afraid the already low compression i have might be an issue, just askin thanks!
Not to burst you bubble but that car will weight at least 3300 w/o driver.
She's been lightened up a bit but 2900 is prob a little on the low side
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Re: Need help picking a turbo plz
[Re: MNobody]
#1614153
05/01/14 02:20 PM
05/01/14 02:20 PM
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Joined: Jan 2005
Posts: 3,639 Oakland, MI
dizuster
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If i go blow through i have to change the regulator,pump,add a return line to the cell, pay to have the carb modded.
You can't say, "I am ok with the cost of two turbos, two carbs, and two intakes, and I am a 26 year fabricator." And then in the same breath that adding a new pump, and running one return line as being reasons against going to the better carb system.
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From what i've read blow through has it's fair share of problems on the street with it's tuning.
Compared to EFI maybe. But other then that, not at all. I have made one high speed air bleed change, and jetting changes... that's IT. Also, if you think putting two separate carbs WAY upstream, in a home made intake manifold is going to work better at idle/cruise then setting a carb on a regular intake... you're in for a surprise.
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So really, why shouldn't i do draw through?
If you are honestly asking that question, you have clearly not looked into the reasons yourself. -Cold starts can be awful... and considering you are in Michigan it's a real concern around here? -Draw through severely limits your turbo choices because you'll need a carbon seal type to keep it from sucking oil at anything but WOT. -There are VERY few people to help you when this doesn't work or has issues (since the rest of the world has abandoned this technology decades ago). -Can't use an intercooler. -No BOV system to protect the turbo/carb from backfire.
Etc...
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I have a friend that ran a draw through setup on a 350 nova back in the day and it was very streetableand fun to drive.
My guess is the time that has passed between "back in the day" and "now" has faded your memory of just how bad it was.
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I was a metal fabricator, i am now a carpenter of 26 years and my Dad was a mopar mechanic for 36 years i know a little bit about building things from nothing.
I don't think anyone questioned your fabrication skills. But since you've NEVER built or tuned a turbo mopar, you'd think you would be a little more open minded to those that HAVE done it.
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Just needed some help picking turbo sizes. You guy's need to broaden your horizons
Pretty gutsy comment to make to a bunch of people with a LOT more experience then you who are trying to help.
So you never answered the question. Aside from being stubborn...why WOULD you want to do a draw through.
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Re: Need help picking a turbo plz
[Re: MNobody]
#1614154
05/01/14 02:32 PM
05/01/14 02:32 PM
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Joined: Dec 2013
Posts: 403 Romulus, MI
GTS340
mopar
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mopar
Joined: Dec 2013
Posts: 403
Romulus, MI
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Quote:
If i go blow through i have to change the regulator,pump,add a return line to the cell, pay to have the carb modded. From what i've read blow through has it's fair share of problems on the street with it's tuning. So really, why shouldn't i do draw through? I have a friend that ran a draw through setup on a 350 nova back in the day and it was very streetableand fun to drive. I was a metal fabricator, i am now a carpenter of 26 years and my Dad was a mopar mechanic for 36 years i know a little bit about building things from nothing. Just needed some help picking turbo sizes. You guy's need to broaden your horizons
Sounds like you've got a firm decision on draw through and have all the resources you need to make it work great. Good luck
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Re: Need help picking a turbo plz
[Re: dizuster]
#1614155
05/01/14 04:01 PM
05/01/14 04:01 PM
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Joined: Feb 2005
Posts: 4,884 Michigan
MNobody
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Quote:
Quote:
If i go blow through i have to change the regulator,pump,add a return line to the cell, pay to have the carb modded.
You can't say, "I am ok with the cost of two turbos, two carbs, and two intakes, and I am a 26 year fabricator." And then in the same breath that adding a new pump, and running one return line as being reasons against going to the better carb system.
Quote:
From what i've read blow through has it's fair share of problems on the street with it's tuning.
Compared to EFI maybe. But other then that, not at all. I have made one high speed air bleed change, and jetting changes... that's IT. Also, if you think putting two separate carbs WAY upstream, in a home made intake manifold is going to work better at idle/cruise then setting a carb on a regular intake... you're in for a surprise.
Quote:
So really, why shouldn't i do draw through?
If you are honestly asking that question, you have clearly not looked into the reasons yourself. -Cold starts can be awful... and considering you are in Michigan it's a real concern around here? -Draw through severely limits your turbo choices because you'll need a carbon seal type to keep it from sucking oil at anything but WOT. -There are VERY few people to help you when this doesn't work or has issues (since the rest of the world has abandoned this technology decades ago). -Can't use an intercooler. -No BOV system to protect the turbo/carb from backfire.
Etc...
Quote:
I have a friend that ran a draw through setup on a 350 nova back in the day and it was very streetableand fun to drive.
My guess is the time that has passed between "back in the day" and "now" has faded your memory of just how bad it was.
Quote:
I was a metal fabricator, i am now a carpenter of 26 years and my Dad was a mopar mechanic for 36 years i know a little bit about building things from nothing.
I don't think anyone questioned your fabrication skills. But since you've NEVER built or tuned a turbo mopar, you'd think you would be a little more open minded to those that HAVE done it.
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Just needed some help picking turbo sizes. You guy's need to broaden your horizons
Pretty gutsy comment to make to a bunch of people with a LOT more experience then you who are trying to help.
So you never answered the question. Aside from being stubborn...why WOULD you want to do a draw through.
Because thats what i'm going to do and i don't see where i'm being stubborn that seems to be your dept. You have your way i have mine. And i'm not questioning anyones expert opinion, i've heard all the cons over and over. I'm looking for help doing it my way not yours.
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