9kredline Posted September 12, 2005 Share Posted September 12, 2005 Got a question on a turbo setup I'm piecing together, but it's my first go so I wanted to field some questions past the forced induction gurus. The motor is an '02 LS1 and is going into a '91 300ZX slicktop, and I figured if I'm going to do a project I'm going to do it right, so... I researched all the ways to add twins to the motor since the stock locations probably won't work like the V6, and the consensus is a set of GM 6.0L cast truck manifolds flipped and reversed so the turbos mount in the front of the engine compartment. Fitting it is the easy part... My goal is ~500+/- horse power on 93 octane and I don't plan on boring the block past stock cubes until the motor needs a rebuild. So here's my questions: 1. What turbo/size will match my motor for the quickest spool yet get me to or close to my horsepower goal? (stock 347ci) Two T3s seem too small, so maybe two T3/4s? 2. Will I need anything more than larger injectors (I'm thinking maybe 42#), an ECM re-tune for the added air/fuel, and possibly higher volume fuel pump to feed the motor sufficiently? Any advice or wisdom beyond this would be appreciated. Like I said, this is my first turbo endeavor, but I'm set on it and I think it'll be a great learning experience. Quote Link to comment Share on other sites More sharing options...
desert dog Posted September 12, 2005 Share Posted September 12, 2005 TD04-50's. I researched this mod for a Chevelle project. Yes, larger injectors. 42# ought to be big enough, ECM retune for the bigger injectors. I have a complete chart of turbo size vs. engine displacement at home. I can double check when I get home. Big power can be made with TD04-50's... Quote Link to comment Share on other sites More sharing options...
9kredline Posted September 13, 2005 Author Share Posted September 13, 2005 TD04-50's. I researched this mod for a Chevelle project. Yes' date=' larger injectors. 42# ought to be big enough, ECM retune for the bigger injectors. I have a complete chart of turbo size vs. engine displacement at home. I can double check when I get home. Big power can be made with TD04-50's...[/quote'] The TD04-50s(-09Bs?) were stock equipment in the 3kGT VR4s with the 13g compressor wheel, correct? I might've found incorrect information but, if they are, would they become maxed on such a large motor? It has two pushing 183ci/3.0L, where I would have one pushing 174ci/2.85L. I'm hoping they they have a great deal of potential or I've been stumbling about the wrong info. I hope the first, because they would probably come cheap from the 3kGT guys looking to upgrade. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted September 13, 2005 Share Posted September 13, 2005 If they were stock on a 3000GT, then they are too small for your application. Do you plan on running an I/C? If not, then you want decent size turbos that will not require you to run a lot of boost to get power so you can keep the heat and backpressure down. You are probably going to have to modifiy the exhaust manifolds to fit the turbo so you might consider a pair of stock Buick GN turbos. They use a 3-bolt flange as opposed to the more common 4-bolt but they are available, relatively cheap and can support more than your goal. The GN was rated at 247hp (yeah, right!) at 12psi and the stock heads are atrocious so a LS1 will be moving a lot of air. Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 13, 2005 Share Posted September 13, 2005 If you are looking for used turbos I would agree with Scottie. I ran one on a 3.0 Toyota truck motor. Spool was pretty good. 12 psi in the low 3k range. You are almost twice the displacement with alot better motor too. GN turbos are t3/4's. Compressor is a T4 S trim (37 lbs.) Turbine is a little bigger than the standard T3 though, still alot smaller than a T4 though. I wouldn't run anything smaller on a big V8. It would give you enough room to crank it up a little as I'm sure you will be able to running 93. 600hp on pump shouldn't be a problem. Quote Link to comment Share on other sites More sharing options...
9kredline Posted September 13, 2005 Author Share Posted September 13, 2005 I was thinking the same about them being inadequate, which means I was probably reading about the wrong turbo. Yes, the motor will be intercooled. Either by an Apollo or similar front mount, or if I can get my hands on one from tractor-trailer to modify down to my size. Thanks for the info, the both of you! As you said it's simply a modified t3/t4, but doesn't seem like something you'd come across every day. Should I lurk on the GN forums and wait for someone to upgrade their turbo or is their a more direct route? Hate being the newbie all over again, but I guess you have to build up from zero when it comes to new things! Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted September 13, 2005 Share Posted September 13, 2005 Should I lurk on the GN forums and wait for someone to upgrade their turbo or is their a more direct route? Do not lurk and wait, post a WTB. When these guys upgrade, they usually just put the stocker on the shelf as very few Turbo Regals owners are looking for stockers. If you are looking for 500+hp on pump gas, make sure you get an I/C that can flow that CFM w/o restriction, else it defeats the prupose. If you are running pump gas you are more prone to detonation so you must do everything possible to keep the heat down. Another alternative would be to inject alky (methanol) which might even preclude the need for an I/C and simplify the plumbing. Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 13, 2005 Share Posted September 13, 2005 You also don't want the carbed turbo. I think 87 was the first year of the intercooled model. Scottie? Quote Link to comment Share on other sites More sharing options...
desert dog Posted September 13, 2005 Share Posted September 13, 2005 OOPS... Brain farts... Gotta keep an eye on us old guys... Check that... Make that TO4E-50's... Sorry 'bout that. Here is the map for it... Quote Link to comment Share on other sites More sharing options...
9kredline Posted September 13, 2005 Author Share Posted September 13, 2005 Hey, no prob DD! I knew something was up, just didn't want to make it seem like I was ungrateful for the helpful info. Now the right turbo to search for, and I did, I just wanted to make sure we're on the same page... Here's one of the sites I found that looks like I can use as a reference for the T04E: http://www.speedshopthagard.com/garrett/T3TO4E.html What A/R housing were you suggesting with the 50 trim compressor wheel? And I'm really new to reading these maps, and I've been reading tutorials but the way I understand them is if I wanted "maximum power and efficiency" I would want to install wastegates and an ebc to keep the airflow at ~33lbs/min and the psi at ~ 21psi? Although I don't quite see how you limit the airflow rate, seems like it would be a constant with the size of the compressor. Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 14, 2005 Share Posted September 14, 2005 OOPS... Brain farts... Gotta keep an eye on us old guys... Check that... Make that TO4E-50's... Sorry 'bout that. [/left] That's alot of air for only wanting 500 HP. 2 of those would easily be enough for 900hp. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted September 14, 2005 Share Posted September 14, 2005 You also don't want the carbed turbo. I think 87 was the first year of the intercooled model. Scottie? Oops, should have been more specific. 86-87 Intercooled is what you want. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted September 14, 2005 Share Posted September 14, 2005 That's alot of air for only wanting 500 HP. 2 of those would easily be enough for 900hp. Agreed. GNs running 21psi with the stock turbo are around 350hp. Quote Link to comment Share on other sites More sharing options...
desert dog Posted September 14, 2005 Share Posted September 14, 2005 http://www.turbocalculator.com/how-to-read.html Turbonetics has the best explanation on how to read a compressor map... T04E-50 isn't that big... I was planning on running about 18 lbs on my project Chevelle. Here is another good description page: http://www.automotivearticles.com/Turbo_Selection.shtml Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 15, 2005 Share Posted September 15, 2005 http://www.turbocalculator.com/how-to-read.html Turbonetics has the best explanation on how to read a compressor map... T04E-50 isn't that big... I was planning on running about 18 lbs on my project Chevelle. Here is another good description page: http://www.automotivearticles.com/Turbo_Selection.shtml One or two? One wouldn't be enough for an LS1, maybe a lower boost L28. Two would be enough for 900hp though. Quote Link to comment Share on other sites More sharing options...
desert dog Posted September 15, 2005 Share Posted September 15, 2005 No it would have been a twin turbo. I was looking to build a max effort LS1. The estimated total weight of the car was 4100 lbs. with a custom Dynatrac Dana 60 axle with 355-45-17 tires, a tricked TH400 and a gearsplitter OD unit. I was estimating 800 WHP at 18 psi. Gas prices effectively killed that project though. Quote Link to comment Share on other sites More sharing options...
9kredline Posted September 15, 2005 Author Share Posted September 15, 2005 You guys are throwing out a lot of awesome information. I did the calculation on this page ( http://www.automotivearticles.com/Turbo_Selection.shtml ) for lb/min rate I would need for a 347cid block at 190degF (+460 Rankin) with 85% volumetric efficiency, 6500rpm redline, and a manifold pressure of 29.4 (Atmosphere + 14.7psi boost) and I got a combined total of 67.5lbs/min, which would mean I would need a turbo that flowed roughly 34lbs/min on each bank to effectively reach 2x atmosphere. That sound about right? I haven't done anything beyond checkbook balancing since I left college for the AF. I redid the calculation for full boost to hit at 5500rpm and it gave me ~57lbs/min for a flow rate on each bank. Maybe somethings up with my math. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.