Given the discussion about boost levels later in this thread, you'd probably be looking at a 300M input shaft, stronger chain and sprockets, and maybe a chrome moly output shaft...
I am fairly sure nobody has broken an output shaft... If anything a few pump shafts have broken, but never an output shaft?
when 80# injectors are CHEAPER than 60s now, why in the hell would you be going that small, then turn around and put a 110lb/m turbo on it?
I also challenge you to make sense of the reasoning behind running a turbo at HALF its flow rating, just to get 5% more "efficency" out of it.
Originally posted by Isolde: Up to 15 psi, it's really not necessary. I can link you to several threads if you'd like to see what stock 5.3s can take. Including one car running high 9s in the 1/4 mile.
All the modern LSx engines can handle a bit of boost in stock build, sure. I wasn't suggesting it as a necessity, but asking what he was doing with it. I don't know what his plans are for racing or whatever with the vehicle. For 1/4 mile, it doesn't really much matter, since the 2-3 seconds at the high end of pressure isn't going to be enough to blow the heads off; for a few runs at least. Consistent trips down the track might weaken things up over time, though. But if your goal is pull a single 9s run in the 1/4 mile, then there are certainly more important things to worry about, and you won't need that much boost even, to get there with the LS4 in a Fiero.
when 80# injectors are CHEAPER than 60s now, why in the hell would you be going that small, then turn around and put a 110lb/m turbo on it?
I also challenge you to make sense of the reasoning behind running a turbo at HALF its flow rating, just to get 5% more "efficency" out of it.
Well the injectors are easy, I have a set on the shelf in the garage that I'm not using for anything else.
I'm not looking for a challenge... But to me It's simple, just as people port their heads to gain that 5% or change headers for 5% or a better flowing intake for 5% It's all of the little things that make the hole better. Increasing efficiency is key to any project.
Sorry, I guess I don't understand your issue here... Turbos react to the amount of load applied to the turbine, 90% of of its life will not be at MAX boost unless it's in a pure racing application. It's happy putting out minimal boost until that 10% is required when a farting ricer comes up beside you asking for embarrassment...
Whatever turbo ends up in the car will be monitored and AR's adjusted for back pressure / boost ratio to achieve max efficiency at peak power...
I also plan on building one of these to help spool on larger turbos.
I'm not looking for a challenge... But to me It's simple, just as people port their heads to gain that 5% or change headers for 5% or a better flowing intake for 5% It's all of the little things that make the hole better. Increasing efficiency is key to any project.
People port their heads for 30% gains, not 5%.. If you told someone that they wouldnt make any power under 4500 rpms, but they could make 5% more power past that, and it would cost them $1500 to do it, they would look at you very confused. I could put a giant cam on a motor, and it would be way more efficient, but it probably wouldnt be any faster than a properly sized cam, it would most likely be slower.
The saddest thing here is the fact that you can eliminate the inefficient boost, by simply putting a bigger intercooler on it. A true "have cake and eat it too" situation. This math might be a bit complex, but try to follow along.
A typical air/air intercooler can create a temp drop of about 75% over ambient, water to airs, could possibly do more than that. So lets assume a pretty typical blower outlet temperature of 200F and assume a temperature rise over ambient of 125F. Drop the intercooler in, and you end up with 110F engine temperature.
Now lets assume the same situation using a turbo that is 5% less efficient, because it is HALF the size of this T6 converted to T4 monster. Your blower outlet temp is now 230F, and you now have a 155F rise over ambient, and your crappy intercooler takes it down to a 118F inlet temperature.
Wow, the world is ending you now have a inlet temperature that is a whole 8 degrees higher than before! Lets go down to ebay, and get a $80 water to air intercooler that is conservatively 85% efficient (even though ice water could get it to nearly ambient, because the intercooler is properly sized for this airflow), and now you are MORE efficient than your giant turbo with a less than 100F inlet temperature.
Dobey, that 9 second car isn't a one shot deal, the guy makes at least a half a dozen runs, EVERY weekend. That 5.3 gets beaten, hard. And yet it lives. The car is gutted, and is built for the dragstrrip. But the engine is stock except for a cam, pushrods, and valve springs. If you copied his combo into a Fiero, you'd be lucky to run mid 10s. High 9s are not the slam dunk you seem to think.
darkhorizon, why are you such a freek on this? I mean Damn...
I used your 5% number just to prove a point that every bit counts to the sum of a project no matter how insignificant you may think it is... Why do you care that I'm buying a larger compressor wheel than needed? Will it not work with a higher efficiency? I do understand how inter-coolers work as I have designed my fair share but thanks for the lesson anyway...
Given the discussion about boost levels later in this thread, you'd probably be looking at a 300M input shaft, stronger chain and sprockets, and maybe a chrome moly output shaft...
Thanks, sorry to reply so late as I got distracted... Did you have any shops that you recommend?
Given the discussion about boost levels later in this thread, you'd probably be looking at a 300M input shaft, stronger chain and sprockets, and maybe a chrome moly output shaft...
Are you saying that a 300M input shaft and chain are stronger and can be installed in a 4t65ehd?
Originally posted by darkhorizon: People port their heads for 30% gains, not 5%..
30%? You're not going to get 30% porting your heads. At least not on an LS4. Maybe on a Briggs & Straton you will. Ported heads on a stock LS4 might net you 30hp, but that's 10%. On any head port job it's going to get you 5-10% hp increase. On an otherwise stock LS4, that's going to be between 15-30 hp. Porting the intake might gain a few more hp, but probably only 1-3% on the LS4 intake. So you're still about 55 hp short of getting that initial 30% out of the LS4. And yes, people pay large amounts of money for very little hp gain, all the time.
The heads comment was mostly referring to "old day" iron head type stuff. Heads coming out of GM in the last few years here have been pretty much ported out nicely from the factory. 30% gains are typical from 3800 head porting.
I didnt "troll" or "freak out" on this thread for reasons that should just be "ignored"... I just hate seeing good projects go down in flames because the goals were too extreme, and in this case it is too extreme for no reason. I also get a bit frustrated when "engineers" come into threads saying their "advanced engineering training" told them this was the best option, but they offer no explanation behind it.
For the "its a v8 thread" remark.. you missed the boat, severely.. Try reading the thread next time. I probably would have "freaked out" more if it was a 3800 thread honestly.
In my years porting and flowing heads, very few designs get past 20% with basic clean up porting, and things like newer Hondas never even see 5% with a basic clean up job. they start out very very good. The heads that come on the LS4 are best left alone, especially if mild boost is to be added. Switching to the LS6 valves is extra beneficial for boost, as are better springs and pushrods. Even with a stock LS4 cam.The boost takes care of the flow, so keeping the original mixture motion will help more than porting.
Hey Isolde, I'm going with Ferrea stainless valves, Patriot hardened push rods and Patriot Gold springs (with the titanium retainer kit). I do have a set of CNC'd LS6 heads that I'm on the fence about using. I think it would really help as the low lift numbers were much higher which would increase my daily driving NA TQ/HP down low when not on boost...
My original plan was to get everything installed as stock, DYNO tune and have a little fun this summer with mild boost. Then make a winter project of making the tranny stronger, changing rod bolts, replacing heads ect... and turning it up a bit for next year...
Frank
[This message has been edited by TurboTec (edited 04-15-2010).]
I had plans to do an LS6 intake conversion along with a set of custom made headers. I like the turbo idea but I have no experience building a setup and buying one will be 4-5k?
Originally posted by Rickady88GT: I had plans to do an LS6 intake conversion along with a set of custom made headers. I like the turbo idea but I have no experience building a setup and buying one will be 4-5k?
Will the LS6 intake fit on top of the DOD valley cover? Or are you going to delete the DOD also, and have to modify an LS2/3 valley cover to fit the intake? I'm going with an LS2 intake/valley cover on mine, but interested in seeing what you do for an LS6 intake, as it's slightly different, and I don't think anyone else has done it yet? At least, none of the Fiero swaps anyway. Maybe some of the GP/Impy guys did it?
Will the LS6 intake fit on top of the DOD valley cover? Or are you going to delete the DOD also, and have to modify an LS2/3 valley cover to fit the intake? I'm going with an LS2 intake/valley cover on mine, but interested in seeing what you do for an LS6 intake, as it's slightly different, and I don't think anyone else has done it yet? At least, none of the Fiero swaps anyway. Maybe some of the GP/Impy guys did it?
I am a member of a few forums and one of them is LS1tech. It covers the LS4. A few guys over there have swapped the LS6 intake. Most have deleted the DOD/AFM because of lackluster "performance" The DOD is only good for 2-4 mpg. BUT that depends on who you talk to and how they drive the car. In town I drive mine in third gear because the DOD only activates with the shifter in "D" and it kicks in at around 20mph and sounds crappy (I don't have a muffler) and just feels like it needs a tune up REALLY bad so I prevent it from turning on in town. On the freeway I use fourth gear and it activates but I hate it. It vibrates and is embarrassing when I give people a ride in it. I have polly mounts that are unforgiving and transmit the odd fire four banger vibrations straight into the seats. BUT from tank to tank calculated MPG is 25. That is better than I got with the stock 2.8. I don't think I want to keep the DOD. This is a toy and I want it to be fun. Others have gone thru the trouble keeping the DOD with manifold swapps. The stock LS4 manifold is VERRY restrictive. It is complete crap. Shame on GM for lack of performance engineering. Some claim that the LS6 swap is good for 30HP, I don't know but it is DEFINATLY going to bump up the power from the stock manifold. But maybe they handicapped the LS4 to save the tranny? Who knows. ------------------
[This message has been edited by Rickady88GT (edited 04-16-2010).]
Hey, I'm on LS1Tech also. I have no experience with running Ls4s, but I've driven a pickup with an AFM-equipped 6.0L, and I'm all in favor of deleting the AFM. It's too annoying. Can't GM refine it? The LS6 intake is about 10 hurses better than the LS2 intake, despite the difference in TB size. And for just 5.3L, you don't need a 90 mm TB, stock or boosted.
Hey, I'm on LS1Tech also. I have no experience with running Ls4s, but I've driven a pickup with an AFM-equipped 6.0L, and I'm all in favor of deleting the AFM. It's too annoying. Can't GM refine it? The LS6 intake is about 10 hurses better than the LS2 intake, despite the difference in TB size. And for just 5.3L, you don't need a 90 mm TB, stock or boosted.
That seems to be what most people say. The LS6 manifold is an upgrade even for an LS2.
Most have deleted the DOD/AFM because of lackluster "performance" The DOD is only good for 2-4 mpg. BUT that depends on who you talk to and how they drive the car. In town I drive mine in third gear because the DOD only activates with the shifter in "D" and it kicks in at around 20mph and sounds crappy (I don't have a muffler) and just feels like it needs a tune up REALLY bad so I prevent it from turning on in town. On the freeway I use fourth gear and it activates but I hate it. It vibrates and is embarrassing when I give people a ride in it. I have polly mounts that are unforgiving and transmit the odd fire four banger vibrations straight into the seats. BUT from tank to tank calculated MPG is 25. That is better than I got with the stock 2.8. I don't think I want to keep the DOD. This is a toy and I want it to be fun. Others have gone thru the trouble keeping the DOD with manifold swapps. The stock LS4 manifold is VERRY restrictive. It is complete crap. Shame on GM for lack of performance engineering. Some claim that the LS6 swap is good for 30HP, I don't know but it is DEFINATLY going to bump up the power from the stock manifold. But maybe they handicapped the LS4 to save the tranny? Who knows.
Thanks Rick, this is why forums are so great, you get true "first hand experience", DOD delete for me... I also agree with you on the intake... I understand as to why, being GM took a cost saving approach to save money and use a DOD platform that covered other LSX motors but it's no excuse for this very poor design. On the other hand this same cost savings measure gives us the opportunity to retrofit with other platforms like the LS6 or LS2. Hell the LS1 intake is a huge improvement over the LS4... LOL
It's Funny GM developed one of the best flowing "stock out of the box" low cost cylinder heads ever produced the same year with the L92 / L76, go figure... If only the LS4 had a 4" bore!
Frank
[This message has been edited by TurboTec (edited 04-16-2010).]
Originally posted by TurboTec: It's Funny GM developed one of the best flowing "stock out of the box" low cost cylinder heads ever produced the same year with the L92 / L76, go figure... If only the LS4 had a 4" bore!
But the LS4 already has the same #243 heads that sit on top of the LS2 and LS6. The only differences are the valves and springs, and the fact that the LS4 isn't a 4" bore.
But the LS4 already has the same #243 heads that sit on top of the LS2 and LS6. The only differences are the valves and springs, and the fact that the LS4 isn't a 4" bore.
LS6 isn't 4" bore, either. However, the LS4 can be bored to 3.898", and use LS6 pistons. Then you can build an LS6 into the LS4 block, have the packaging of the LS4, but the exact results of the LS6. This is good for anyone wanting to go with a manual trans, because the LS4 was never offered with a manual trans, but the LS6 only came with a manual trans. The L92 / LS3 heads are interesting, except that the ratio of flow to port volume is the worst of any LSx head ever. But MAST has fixed this by releasing their own version, based on a whole new casting. These are so good they totally justify skipping the LS4 and tackling the LS3 block instead. And the LS3 block can be bored to 4.125". Combine with a 4.8 crank to get a high powered 5.7L that'll rev forever.
But the LS4 already has the same #243 heads that sit on top of the LS2 and LS6. The only differences are the valves and springs, and the fact that the LS4 isn't a 4" bore.
The 4" bore comment was directed to the L92 heads with the 2.160" valve... I've got a set going on my 72 corvette build with an L76 intake. I'm going to use the 243's on the Fiero with an LS2 intake and FBW TB.
Not sure, but GM says it's safe to 3.905", the O.D. of the cast-in iron sleeves are the exact same for LS1, LS6 and LS4 blocks. Again, that's according to GM themselves. I did it to my LS4 before I sold it. It looks fine, but the O.D. of the sleeves is larger at the very tops than it is from an inch down to the very bottom, which is all the same. Sorry if that's a confusing way of describing it.
Hey need any help droping that 2.8 out ....i'm your man !!!!!....will like to work off that drive train if i could....lol ~Tom
Sorry guys a lot going on with Family and work this spring, I've had no time... So sadly I haven't touched the project until today...
I removed the LS4 harness, all drive accessories, water pump and intake getting ready to remove the DOD valley cover, stock cam and lifters. I'm going with a LS3 non DOD valley pan, LS2 intake and a new cam which should work well with the 243 heads without loosing any snap down low but giving a nice bump up top.
Its GM's all purpose cam the same cam that's in the newer "F" bodies, 6.0L Vortec, 5.7L corvettes and GM's "327" 5.3L HO crate motor...