Turbo upgrade - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 04-20-2017, 10:43 PM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Turbo upgrade

Hey guys I'm contemplating upgrading my turbo on my 72 nova. It's a sbc 355 with roller cam afr heads and fast xfi fuel injection. Currently I'm running a gt45 (68mm) turbo on it. I was thinking about upgrading to a s488 (88mm) turbo. Anyone have any idea what kind of power increase I can expect or any advice. Is it worth the money and time? Thanks in advance.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-20-2017, 10:54 PM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Also open to other turbos
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-21-2017, 03:38 AM
64nailhead's Avatar
Registered User
 
Last photo:
Join Date: Dec 2012
Location: Binghamton, NY
Posts: 2,343
Wiki Edits: 0

Thanks: 756
Thanked 609 Times in 502 Posts
You're turbo, if it's not a genuine GT45 (Chinese knockoff), is holding you to a range of 600-750HP, where as the 88mm S488 will run well past 1000hp with no effort. The S488 will take longer to spool and may not be able to run the amount of boost you want if you have somewhat of a NA grind rather than a turbo grind cam.

This choice comes down to your goals and your motor. Your 350 is going to have to run alot of rpm's to get the maximum output from the S488. If your long block can handle that, then fine. My opinion can be described by a present build I'm working on - using an 80mm S480 on 400+ ci SBC that will run to 7K - I expect that we will be able to make 1000+ at or below 14psi. I wish I had it done to give you some more accurate info , but soon hopefully.

Have you looked at an S475? They can be had somewhat cheaper and will quite easily support 800-1000.

What are your goals (HP) and application? And what are your cam specs?
Reply With Quote Quick reply to this message
 
  #4 (permalink)  
Old 04-21-2017, 09:13 AM
hcompton's Avatar
Old & Furious
 
Last photo:
Join Date: Oct 2012
Location: Eastern NC
Age: 44
Posts: 3,010
Wiki Edits: 0

Thanks: 74
Thanked 846 Times in 821 Posts
Quote:
Originally Posted by Pupsvette76 View Post
Hey guys I'm contemplating upgrading my turbo on my 72 nova. It's a sbc 355 with roller cam afr heads and fast xfi fuel injection. Currently I'm running a gt45 (68mm) turbo on it. I was thinking about upgrading to a s488 (88mm) turbo. Anyone have any idea what kind of power increase I can expect or any advice. Is it worth the money and time? Thanks in advance.
What is stopping you from making power now. Is it hot intake air temps? a bigger turbo will solve that problem for sure. Most problems people get into with turbos is going too small. The smaller one spool better but in a v8 thats a useless chase to run since the v8 sill spool a single turbo in no time. Even knowing most turbos can put out 50+ psi of boost. Its useless boost because it comes out of the turbo so hot the motor cant use it. Meth injection early into the hot air stream can help a lot. This would be a my first go. With heavy meth mix mostly pure meth and little bit of water Large high pressure pump to make a fine mist. Let it shoot a bit into the -in- side of the intercooler can help drop intake temps another few degrees.

Once youve tweaked and tuned and played there is nothing left to do but upgrade to the next larger turbo and intercooler and piping. Dont forget the piping if your making 500+ hp and you still have 2" charge pipe then thats needs to be sorted first.

The second common issue is the charge pipe and intercooler themselves being the restriction. I had a powerstroke f250 intercooler on my svo stang and it was over size but had no problems with lag. But that is the largest

https://engineering.mishimoto.com/20...ler-selection/

This link has a lot of good info on it. Some of it newb stuff but also has a few good charts for pipe size and hp output. 2" charge pipe is good for about 400 hp while 3 inch is good to 840 hp. Some goes for intercoolers good ones will have the larger 3-4" in/out pipes to support larger hp. The power stroke one is 4" in/out but its not a free flowing design for a built after market big v8 turbo. I think they top out around 5-600 hp. You can get a much smaller one that fits your car better that will support more hp. Just cost in an issue.

Why not run twin turbos. Assuming the single i not cheaper than adding a second smaller one. But the 88mm upgrade is good for max effort racing with sbc in the 800-1000 hp range. The outlaw 10.5 guys ran two of the 88 most of the time. Which would let them make 2500 hp needed to compete in that class.

Third big thing is exhaust that most just solve buy making a short dump after the turbo. So that it cant hold the motor back.

I would also want to know what cam your running.

But if the car is well sorted there is probably little left to do other than replace the turbos. But if the charge pipe is small or some other parts are not up to the challenge it can old back the entire system. I remember once working with a system and needed a pipe to run close to the fan so i flattened it a bit well went over too much and the car lost a lot of power Replaced the charge pipe with larger stuff and straight sections and ended up finding a bottle neck i didnt know i was facing. For this reason now i always once i get the turbo dialed in pull the pipe from the turbo and put a straight one to the throttle body. With a larger straight pipe and drive the car with the motor cold just to see how much change there is. If its a very violent difference between the two it should be aggressive and make boost freely but should not be much faster overall. Of course this is often a worthless test since the motor gets hot very quickly. Often its hard to tell.

In all the upgrade will require much larger intercooler and piping along with the larger turbo or dual upgrade might be worth the effort to build all that out now and get going forward with the larger piping and cooler and see if that makes things any better. Might find the problem just preparing for the larger turbo and still be ready when its time to upgrade later on.

Hope this helps.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 04-21-2017, 10:24 AM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Wow great info guys actually I was thinking about how well my turbo would spool the 88mm. My redline is 7000-7150 so I cap out there and my goal is around 1000hp my charge temps do get very hot. Even with an intercooler and 3 inch charge pipe my pipes get hot to the touch so they are very warm. I would say they aren't to far off from what my coolant temp is to take a guess. My cam is a edelbrock rolling thunder hydraulic roller .540 lift and Int dur 234 exh dur 238 with a 112 lsa. So I feel with the gt45 I may be capped on power. I don't think that turbo will take be above 650-700 unless I drive the boost levels up really high which then heats my intake temps even more.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 04-21-2017, 10:27 AM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Also forgot to mention that the turbo I plan to upgrade to will require little modifications to make fit. An adapter will fit it to my exhaust manifold then I'll have to well a vband onto the beginning of the charge pipe no big deal and then just fab a new larger down pipe and reuse the same feed and drain lines. Very simple.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 04-21-2017, 11:09 AM
64nailhead's Avatar
Registered User
 
Last photo:
Join Date: Dec 2012
Location: Binghamton, NY
Posts: 2,343
Wiki Edits: 0

Thanks: 756
Thanked 609 Times in 502 Posts
That's alot of cam for a turbo. If it has the 107 ICL, then it's probably not helping. You could put ina smaller cam and make more power - I'm confident. The real test would be to detemine your back pressure ratio. I'll bet with all of the overlap and the exhaust duration that you're at or approaching 2:1 if your GT45 is a journal bearing turbo (what is it?). With that in mind a ball bearing turbo does a much better job controling back pressure as it takes much less pressure to spin them.

What are your intake temps? Over 130? Doesn't your Fast XFI have an intake temp sensor?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 04-21-2017, 11:17 AM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
It is a journal bearing turbo and I forgot to mention it is an eBay special. Please don't judge lol. The fast system has everything yes it has an intake air temp but I have not gotten around to tuning it and driving it since I literally just finished installing it. Actually that's the reason for this post. I was planning on upgrading my turbo for this season and I would rather not waste anytime building and tuning a map for the smaller turbo if it going to replace it right now. I'm a little concerned that my little 355 will have a hard time spooling the 88, am I being dramatic or will it be fine? The up pipes are 2.5
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 04-21-2017, 11:18 AM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I would be willling to put money that the charge temps are 130 or more
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 04-21-2017, 12:52 PM
hcompton's Avatar
Old & Furious
 
Last photo:
Join Date: Oct 2012
Location: Eastern NC
Age: 44
Posts: 3,010
Wiki Edits: 0

Thanks: 74
Thanked 846 Times in 821 Posts
Do you run meth and/or water injection. I would go there next time.

This site has a good list of parts and places to get the parts to build your own meth injection. You can just hook it up to wot and boost controller up to the same setup so if you run out of water you can still drive the car and you dont use any meth/water unless its wide open. Most boost controllers have a wot switch option or at least can read throttle position sensor wot signal and allow you to add in some more boost only when flat floored.

I would add three jets system using an old fuel pump works fine just use a relay for the switch so you dont hit the switch with too many amps. Old 1 gallon fuel cells are cheap and often easy to come buy. Its never enough for gas but works great for meth injection. A gallon is a good bit of run time.

Put one right at the beginning of the intercooler and two behind the throttle body should work great. Carfule with the one behind the intercooler with straight water you might not get it evaporating fast enough to avoid standing water in the cooler. But meth will evap and provide a lot of help cooling the air charge. Also is the intercooler moving enough air. If its not nothing is going to help it. The more air that flows thru them the more the charge temp will drop. But straight meth in the water injector with larger misting jets will support about 5 psi more boost on the same fuel. Some report up to 20 psi more but let be real here. You can only hit the motor with so much meth before it starts to cool off the burn. Using straight water is not recommended on a built on the edge motor.

The cam is big and eddy cams tend to be a bit to main stream to be the best at anything. But not going to point the finger there other than to say there is more to be found with a proper cams.

If its turning 7K at 15 psi and 350 cubes should be pretty fast. But yes you will have zero trouble turning the larger turbo. I would bet with all the fire shooting out the exhaust you could spin 2 of those big turbos without much trouble. One will spool up fast if your going bearing turbo its not an issue.

Im betting larger charge pipes and meth injection gets you at least another 50 hp potential more boost, just more efficient or more timing. What ever works. But more likely to make 100 more hp if you can do a little of each.

Going by the link i posted earlier the 3" charge pipe is good for about 840 HP figure thats a real number (??) then your going to want 3.5" minimum. With really high charge temps you need to sort out the air as much as possible. even if that means slowing it down a tick. Not like its moving to slow inside the pipes. Keep in mind the larger a pipe is the more it flows but not by a addition but a multiple. a single 4 inch exhaust pipe flows more than 2x 2.5" pipes. As the size goes up the ability to flow is greatly increased. Same will be true for the cold side as its called.

I have had problems like this no matter what can be done charge temps shoot up. Always comes down to a large restriction in flow. A small blow off valve or a small pipe or sharp ugly bend is holding airflow from making it to the throttle plate.

This type of upgrade may seem like its going to do nothing but be sure to upgrade the pipe to the largest size needed. The link says 3.5" but i would over shoot i think 4" at least in some paces is the way to go with v8 turbo going for 1000 plus hp without the turbo being in ideal locations where there are few bends or other problems. In places with sharp bends but the room for larger pipe its a good way to go it at least frees up over all flow.

Do you have the hot side of the turbo wrapped. Oil cooler in place with the turbo lines. Can help it live longer and make more power with a slightly cooler over all turbo temps. Wrapping the hot side can also help keep the cold side temps down as there not exposed to the heat from the hot side of the turbo. At least it can block whats radiated over but its a good small thing that can be done.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 04-21-2017, 02:29 PM
64nailhead's Avatar
Registered User
 
Last photo:
Join Date: Dec 2012
Location: Binghamton, NY
Posts: 2,343
Wiki Edits: 0

Thanks: 756
Thanked 609 Times in 502 Posts
Quote:
Originally Posted by Pupsvette76 View Post
I would be willling to put money that the charge temps are 130 or more
Don't guess - find out.

What are your goals? What are the block, rods and pistons capable of withstanding? These questions need to be answered prior to putting on a 600 HP power adder. At least IMO.
Reply With Quote Quick reply to this message
The Following User Says Thank You to 64nailhead For This Useful Post:
hcompton (04-21-2017)
  #12 (permalink)  
Old 04-21-2017, 10:24 PM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
The hot sized is wrapped I do run a water meth injections from Snow and I currently have 3 inch intercooler piping. I'm not sure that the engine makes power wise right now but my goal is 1000hp and I really want to upgrade to the 88mm. After that will come all the accompanying upgrades like larger intercooler and piping. I think the larger turbo is the key to power levels in looking for.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 04-22-2017, 06:39 AM
64nailhead's Avatar
Registered User
 
Last photo:
Join Date: Dec 2012
Location: Binghamton, NY
Posts: 2,343
Wiki Edits: 0

Thanks: 756
Thanked 609 Times in 502 Posts
So you're running meth injection, for racing/dyno applications, meth is all that is needed to keep the intake temps under control. It would be great if you had an intake temp sensor in the manifold (behind the meth) rather than in the intake piping so that you can see the effects of the meth.

Do you have a link to the 88mm turbo you're referencing?

http://www.mandmturbochargers.com/bw...l_783_1018.pdf

I'd recommend the 75mm 171702 on page 62, or the largest I'd go is the 80mm 177287 on page 63 (or equivalent journal bearing knockoffs). I'm assuming the 88mm you're thinking of is something along this line : VS Racing.

The 1.32 exhaust housing is going to be dilemma for you if you expect this thing to spool during street driving. 1.32 is large and will take a good amount heat (engine load) or alot of rpms from a 350 (4000+).

With all this in mind, you haven't mentioned if this is a track purposed build. If it is and you are willing to run this over 6000-7500 rpms, then the 88mm with the 1.32 exhaust AR will work fine IMO. The best of both worlds is a T4 flanged S400 or ball bearing T4. Something from Precision, Bullet, Comp, etc., but they are not cheap. Easily can spend $1500+ on one which I think is somewhat unnecessary.

Another member here, ForceFed, is much more turbo knowledgeable than I, hopefully he will happen along.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 04-22-2017, 09:52 AM
hcompton's Avatar
Old & Furious
 
Last photo:
Join Date: Oct 2012
Location: Eastern NC
Age: 44
Posts: 3,010
Wiki Edits: 0

Thanks: 74
Thanked 846 Times in 821 Posts
Quote:
Originally Posted by Pupsvette76 View Post
The hot sized is wrapped I do run a water meth injections from Snow and I currently have 3 inch intercooler piping. I'm not sure that the engine makes power wise right now but my goal is 1000hp and I really want to upgrade to the 88mm. After that will come all the accompanying upgrades like larger intercooler and piping. I think the larger turbo is the key to power levels in looking for.
I do agree but like any complex system the weakness link or the smallest most restrictive part of the system will be the hold up. So you cant say for sure where the turbo gives out until all the other problems are sorted.

I do think swapping it out will be a needing improvement to reach that power level with pump gas. Just dont want to tell you to rip it out until you have really maxed this system out. Your power levels can be hard to reach without going big all the way around from the beginning.

A simple kit like this can give you intercooler in/out temps and another for inside and out side the throttle body.

52mm Air Intake Dual Intercooler Temperature Gauge Meter Blue Digital LED In/Out | eBay

Get two of those kits and run one on the intercooler to make sure its not getting heat soaked and another on behind the throttle body and one right at the turbo. So you can see if they turbo would allow to to find the over all temp drop from the turbo to the manifold. If not then your not getting the 100 degree temp drops from the meth injection or the drop from the intercooler. But without checking there is no way to find if all this stuff is actually working.

Intercooler can totally fail to lower temps for many different reasons and the meth injection without meth will not lower the temps nearly a much as its claimed. You also need to use the larger jets for a larger motor like a 350. Not sure which kit you got or how its setup but using the largest jets and 50-80 percent meth should give you the largest bump from a typical system. But with tiny jets and large cube engine at higher rpm they can be totally over whelmed.

Get as much pressure as you can from the meth system as well more pressure you get better atomized in most cases and of course more flow.

what boost are you running what psi and mix on the meth injectors. Is the motor knocking when you try to raise boost?
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 04-22-2017, 11:27 AM
Pupsvette76's Avatar
Registered User
 

Last journal entry: no spark and fuel pump issue
Join Date: May 2009
Location: smithtown
Posts: 546
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I don't remember what jet I'm using but it's the snow stage 3 boost kit and I'm using their proprietary boost juice. And yes I was looking at exactly that turbo from vs racing
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Turbo 350 4wd and Turbo 400 2wd RustyRedneck Transmission - Rearend 16 03-22-2017 10:46 AM
What's "Turbo" about turbo 350 and turbo 400 tranny's? lakeroadster Transmission - Rearend 20 12-19-2012 12:24 PM
350 turbo to 400 turbo swap in lemans?? mtmniles Transmission - Rearend 8 01-24-2006 12:40 AM
Turbo 350,Turbo 400,700R4,Or Muncie 4 Speed nightrain_rod Transmission - Rearend 2 04-18-2003 12:35 PM


All times are GMT -6. The time now is 05:56 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.