How much hp/tq would a TURBO with 6 lbs. of boost get????
04-23-2001, 09:45 PM
#1
What's the MAXIMUM hp/tq estimate if you had MORE than enough fuel pressure, no intercooler, and everything else stock.
It's a Garett T3/T4 hybrid if that helps.
Basically, what is a reasonable amount of gain possible with only 6 lbs. of boost? Is it worth $3-$4K? Actually closer to $3K.
It's a Garett T3/T4 hybrid if that helps.
Basically, what is a reasonable amount of gain possible with only 6 lbs. of boost? Is it worth $3-$4K? Actually closer to $3K.
04-23-2001, 09:56 PM
#2
Senior Member
Join Date: Jan 2001
Posts: 308
Originally posted by IceY2K1
What's the MAXIMUM hp/tq estimate if you had MORE than enough fuel pressure, no intercooler, and everything else stock.
It's a Garett T3/T4 hybrid if that helps.
Basically, what is a reasonable amount of gain possible with only 6 lbs. of boost? Is it worth $3-$4K? Actually closer to $3K.
What's the MAXIMUM hp/tq estimate if you had MORE than enough fuel pressure, no intercooler, and everything else stock.
It's a Garett T3/T4 hybrid if that helps.
Basically, what is a reasonable amount of gain possible with only 6 lbs. of boost? Is it worth $3-$4K? Actually closer to $3K.
04-23-2001, 10:14 PM
#5
Originally posted by Desert Pearl
I agree it's possible, but I wouldn't want to try it. Is Turbo95Max running a single turbo or a twin setup?
I agree it's possible, but I wouldn't want to try it. Is Turbo95Max running a single turbo or a twin setup?
04-23-2001, 10:15 PM
#6
Originally posted by Desert Pearl
No intercooler??? and you live in Arizona??? Better be careful. Typically you will get about 8hp per lb of boost you are running. Our car could probably take 6psi without doing anything... which is about the limit you'd want to run without an intercooler. Just curious here... how were you thinking of hooking it up? I mean how would you tie in the exhaust portion of the turbo setup? I think on a V6, a supercharger kit would be easier.
No intercooler??? and you live in Arizona??? Better be careful. Typically you will get about 8hp per lb of boost you are running. Our car could probably take 6psi without doing anything... which is about the limit you'd want to run without an intercooler. Just curious here... how were you thinking of hooking it up? I mean how would you tie in the exhaust portion of the turbo setup? I think on a V6, a supercharger kit would be easier.
Is 8hp per lb. of boost estimate to the wheels?
The guru I was B.S.ing with lives here in Tucson, so he knows about the AZ heat. He said 6lbs. max withOUT an intercooler. He uses some trick ceramic oxide whatever coating to help manage some heat issues. I'm a little doubtful, since he usually builds 1300+hp twin turbo 120mph boat and 250mph salt flat top speed engines. This is all just hypothetical until my warantee wears off anyways. Just curious of what a 3-liter engine with 6lbs. of boost could yeild. It would be cool to see what he could do.
04-24-2001, 02:08 AM
#7
Senior Member
Join Date: Jan 2001
Posts: 308
Originally posted by IceY2K1
Is 8hp per lb. of boost estimate to the wheels?
Is 8hp per lb. of boost estimate to the wheels?
My Eclipse was making 260hp to the wheels at 17.5psi but it was putting down 247hp at 14psi, a difference of only 13hp for 3.5psi. However that was peak vs peak. If you look at a particular rpm, like 5250, it was making 250 at 17.5psi, but only 219 at 14psi... a difference of 31hp! So kinda depending it could vary from 4hp/psi up to over 10hp/psi. This was just on my Eclipse. The 8hp/psi figure is just a rough estimate across the board (all rpms, most cars, ...).
He uses some trick ceramic oxide whatever coating to help manage some heat issues.
04-24-2001, 07:15 AM
#8
Guest
Posts: n/a
I would definitely NOT risk a non-intercooled setup. Our engines run 10:1 compression, VERY high for a turbocharged setup. Even if someone can show you proof (calculations/etc) that 6 psi is safe, do you really want your engine to run on the hairy edge of detonation like that? I'd hope not. It only takes one hiccup from an injector to detroy one or multiple cylinders. Cylinder doesn't get enough fuel, cylinder dies. That simple. Play it safe and get an intercooler. It's the right approach to this project.
Things you HAVE TO DO with an custom turbocharged setup on the Maxima (at least have to do for a PROPER setup):
- Intercooler
- Larger injectors (300Z twin turbo injectors?)
- Custom remapped ECU from JWT/other to compensate for the larger injectors and to reduce ignition timing...reduced ignition timing is another "right thing to do"
- Higher flow fuel pump (300Z twin turbo pump?)
and of course the turbocharger, exhaust manifold, custom intake and exhaust tubing, blow off valve, and waste gate.
All in all, it's a very expensive project. Plan on well over $5000 to do it right, more like $6-7000.
Things you HAVE TO DO with an custom turbocharged setup on the Maxima (at least have to do for a PROPER setup):
- Intercooler
- Larger injectors (300Z twin turbo injectors?)
- Custom remapped ECU from JWT/other to compensate for the larger injectors and to reduce ignition timing...reduced ignition timing is another "right thing to do"
- Higher flow fuel pump (300Z twin turbo pump?)
and of course the turbocharger, exhaust manifold, custom intake and exhaust tubing, blow off valve, and waste gate.
All in all, it's a very expensive project. Plan on well over $5000 to do it right, more like $6-7000.
Originally posted by IceY2K1
Basically, custom bent everything. The ROUGH estimate was about $800-1000 for the intake and exhaust tubing.
Is 8hp per lb. of boost estimate to the wheels?
The guru I was B.S.ing with lives here in Tucson, so he knows about the AZ heat. He said 6lbs. max withOUT an intercooler. He uses some trick ceramic oxide whatever coating to help manage some heat issues. I'm a little doubtful, since he usually builds 1300+hp twin turbo 120mph boat and 250mph salt flat top speed engines. This is all just hypothetical until my warantee wears off anyways. Just curious of what a 3-liter engine with 6lbs. of boost could yeild. It would be cool to see what he could do.
Basically, custom bent everything. The ROUGH estimate was about $800-1000 for the intake and exhaust tubing.
Is 8hp per lb. of boost estimate to the wheels?
The guru I was B.S.ing with lives here in Tucson, so he knows about the AZ heat. He said 6lbs. max withOUT an intercooler. He uses some trick ceramic oxide whatever coating to help manage some heat issues. I'm a little doubtful, since he usually builds 1300+hp twin turbo 120mph boat and 250mph salt flat top speed engines. This is all just hypothetical until my warantee wears off anyways. Just curious of what a 3-liter engine with 6lbs. of boost could yeild. It would be cool to see what he could do.
04-24-2001, 08:34 AM
#9
Originally posted by Keven97SE
I would definitely NOT risk a non-intercooled setup. Our engines run 10:1 compression, VERY high for a turbocharged setup. Even if someone can show you proof (calculations/etc) that 6 psi is safe, do you really want your engine to run on the hairy edge of detonation like that? I'd hope not. It only takes one hiccup from an injector to detroy one or multiple cylinders. Cylinder doesn't get enough fuel, cylinder dies. That simple. Play it safe and get an intercooler. It's the right approach to this project.
Things you HAVE TO DO with an custom turbocharged setup on the Maxima (at least have to do for a PROPER setup):
- Intercooler
- Larger injectors (300Z twin turbo injectors?)
- Custom remapped ECU from JWT/other to compensate for the larger injectors and to reduce ignition timing...reduced ignition timing is another "right thing to do"
- Higher flow fuel pump (300Z twin turbo pump?)
and of course the turbocharger, exhaust manifold, custom intake and exhaust tubing, blow off valve, and waste gate.
All in all, it's a very expensive project. Plan on well over $5000 to do it right, more like $6-7000.
I would definitely NOT risk a non-intercooled setup. Our engines run 10:1 compression, VERY high for a turbocharged setup. Even if someone can show you proof (calculations/etc) that 6 psi is safe, do you really want your engine to run on the hairy edge of detonation like that? I'd hope not. It only takes one hiccup from an injector to detroy one or multiple cylinders. Cylinder doesn't get enough fuel, cylinder dies. That simple. Play it safe and get an intercooler. It's the right approach to this project.
Things you HAVE TO DO with an custom turbocharged setup on the Maxima (at least have to do for a PROPER setup):
- Intercooler
- Larger injectors (300Z twin turbo injectors?)
- Custom remapped ECU from JWT/other to compensate for the larger injectors and to reduce ignition timing...reduced ignition timing is another "right thing to do"
- Higher flow fuel pump (300Z twin turbo pump?)
and of course the turbocharger, exhaust manifold, custom intake and exhaust tubing, blow off valve, and waste gate.
All in all, it's a very expensive project. Plan on well over $5000 to do it right, more like $6-7000.
2)Larger injectors are NOT possible without an ECU change, because during start-up when the engine is in open loop you would get too much fuel.
3)I wish JWT would make a remapped ECU, but no luck yet.
4)He stated a higher flow fuel pump is not necessary without knowing how much fuel the stock one puts out, so it may need to be upgraded. Basically, the extra fuel is supplied by a "special" fuel pressure regulator which adjusts the fuel pressure AND has an additional valve/baffle/whatever that opens up as boost is increased.
5)Rough numbers were $300-350 for turbo w/wastegate, $800-1000 for tubing(bending??), $200-300 for blow-off valve(???), fuel regulator, ceramic coatings, etc., etc..
04-24-2001, 08:48 AM
#10
What? $2000 for an intercooler? It is recommended that you get the intercooler because of the exhaust heat.
I believe larger injectors aren't necessary because not many SC'ed cars have them upgraded. You do need another fuel pump (I heard Walbro was good) to pump out extra fuel when necessary. With all the extra fuel, you'll need a fuel pressure regualator... since our car has 2, is it better to use 1 or 2? Hmmmmmm........
All in all... I have come up with a number close to $3500 for all the parts (excluding tubing, gauges, and labor) for the turbo setup.
I believe larger injectors aren't necessary because not many SC'ed cars have them upgraded. You do need another fuel pump (I heard Walbro was good) to pump out extra fuel when necessary. With all the extra fuel, you'll need a fuel pressure regualator... since our car has 2, is it better to use 1 or 2? Hmmmmmm........
All in all... I have come up with a number close to $3500 for all the parts (excluding tubing, gauges, and labor) for the turbo setup.
04-24-2001, 09:56 AM
#11
I read on the Z31 site that if you are not pushing more than 8 psi, the intercooler is not needed. Maybe it's different for a high compression VQ engine but I don't know. Also you have to consider the pressure losses of the intercooler. So I guess if you want 6psi at the maf, you gonna have to set the wastegate at 6psi+ ie.. 7.5 or 8psi to compensate for the pressure losses.
Unless someone really knows for sure, it's not set in concrete that this guy needs larger injectors, large capacity fuel pump or whatever. The 4-5th gen SC'ers are running similar psi w/o injector and pump upgrades so I would think in a general sense, the turbo application would be similar. You may or may not have more heat becuase of the turbo. Whether or not that affects the fuel/timing requirements can't really be determined until you get it running. If you think your gonna get away with just guessing on the psi, timing and fuel requirements without a full set of guages watching what's going on, that's asking for trouble. Your gonna have to get everthing installed and maybe run 3-4 psi and see what the timing is going, see what kind of injector duty is going on and observe what kind of exhaust temps is happening. If it looks okay then raise it to 5 psi and do it again. If something looks fishy, back it down before you damage anything.
But the question is again, why re-invent the wheel? Stillen has already developed a supercharger for the VQ and has done all this for you. If you can only run 6psi, exactly why would anyone want to spend the extra $$ for delevopment? 6psi is 6psi. The engine doesn't know/care whether it's coming from a SC or a turbo. Plus in general superchargers run cooler anyway. Upping the boost is easy and even intercoolers are available for the sc(I think) What even more power? Add nos like some have been doing.
It doesn't make sense to run a turbo system capable of mega hp when your longblock can only handle 4-7 psi anyway.
Unless someone really knows for sure, it's not set in concrete that this guy needs larger injectors, large capacity fuel pump or whatever. The 4-5th gen SC'ers are running similar psi w/o injector and pump upgrades so I would think in a general sense, the turbo application would be similar. You may or may not have more heat becuase of the turbo. Whether or not that affects the fuel/timing requirements can't really be determined until you get it running. If you think your gonna get away with just guessing on the psi, timing and fuel requirements without a full set of guages watching what's going on, that's asking for trouble. Your gonna have to get everthing installed and maybe run 3-4 psi and see what the timing is going, see what kind of injector duty is going on and observe what kind of exhaust temps is happening. If it looks okay then raise it to 5 psi and do it again. If something looks fishy, back it down before you damage anything.
But the question is again, why re-invent the wheel? Stillen has already developed a supercharger for the VQ and has done all this for you. If you can only run 6psi, exactly why would anyone want to spend the extra $$ for delevopment? 6psi is 6psi. The engine doesn't know/care whether it's coming from a SC or a turbo. Plus in general superchargers run cooler anyway. Upping the boost is easy and even intercoolers are available for the sc(I think) What even more power? Add nos like some have been doing.
It doesn't make sense to run a turbo system capable of mega hp when your longblock can only handle 4-7 psi anyway.
04-24-2001, 03:24 PM
#13
1) Increased turbo lag from the intercooler and the extra 4ft or so of piping
2) Extra expense when the benefits might not offset it.
3) Fitment issues. Not everyone likes to cut their oem bumper up.
4) Possible compressor surge and off throttle idle problems.
In some cases, water injection is a better alternative.
2) Extra expense when the benefits might not offset it.
3) Fitment issues. Not everyone likes to cut their oem bumper up.
4) Possible compressor surge and off throttle idle problems.
In some cases, water injection is a better alternative.
Originally posted by Pmp-n8a
look at it this way...why would you NOT want an intercooler? more money yes...but why NOT play it safe?
if i were to do a turbo set up it would be the intercooler or nothing
look at it this way...why would you NOT want an intercooler? more money yes...but why NOT play it safe?
if i were to do a turbo set up it would be the intercooler or nothing
04-25-2001, 01:50 AM
#14
Turtle turtle... Moderator
iTrader: (25)
Join Date: Aug 2000
Location: San Bruno, Petaluma, SF Bay area
Posts: 4,857
ahhh i see we're on my favorite topic. If your going with under 8psi boost i think you can go safely without an intercooler. Of course if you live in the temps or say Arizona or Texas id urge you to consider again. If you run 6psi boost it might not be worthwhile to spend the extra money on an intercooler, but keep in mind if you want to upgrade in the future youll have to redesign your intake setup. I think you can get away with minimal fuel upgrades with 6spi boost.
04-26-2001, 12:05 AM
#15
Senior Member
Join Date: Jan 2001
Posts: 308
Considering Alex lives in Arizona, I suggested he get an intercooler. He could get a small sidemount from an Eclipse, 300ZX, or whatever. He should have room to make it fit without hacking his car up too much at all. If he were going to do this, he should do some homework and be sure that the SMIC he's getting doesn't have too much pressure drop... maybe limit it to 1psi or so, which knocks out the Eclipse SMIC (it's more like 2-2.5psi drop). I threw out the number of $200 earlier but this is just for a used SMIC, no piping. The custom piping should be able to be done for another $200-$300 plus some extra if he wanted it Jet-Hot or powder coated. I agree that the proper gauges would be a must for this project. An EGT gauge, boost gauge and a Techtom MDM-100 would seem to be MUSTS!
Jeff82se brings up a good point in his last post. Water injection would provide some margin of safety if you aren't going to run an intercooler. This would be a cheaper alternative also. Hey Jeff, could you explain item #4 in your last message... how does adding an intercooler contribute to "possible compressor surge and off throttle idle problems"? Just curious where you came up with that one.
Jeff82se brings up a good point in his last post. Water injection would provide some margin of safety if you aren't going to run an intercooler. This would be a cheaper alternative also. Hey Jeff, could you explain item #4 in your last message... how does adding an intercooler contribute to "possible compressor surge and off throttle idle problems"? Just curious where you came up with that one.
04-26-2001, 03:52 PM
#16
If you have long intake tubing ie.. intercooler and long tube runs, you can get surging. It sometimes happens when the throttle plates are shut and the intake charge is still moving. The intake charge hits the closed throttle plate and bounces back into the turbo compressor. When the plate is opened back up the maf might see turbulent flow from the air bouncing back and forth. One cure is utilizing a blow off valve or a recirculation valve. Problem w/ the B/O valve that opens into the atmosphere, is that the the blown air is already measured by the maf and results in a faulty reading to the ecu. The 240sx turbo install by SCC deals with this and some idle problems they had when the pressurized the intake.
Originally posted by Desert Pearl
Considering Alex lives in Arizona, I suggested he get an intercooler. He could get a small sidemount from an Eclipse, 300ZX, or whatever. He should have room to make it fit without hacking his car up too much at all. If he were going to do this, he should do some homework and be sure that the SMIC he's getting doesn't have too much pressure drop... maybe limit it to 1psi or so, which knocks out the Eclipse SMIC (it's more like 2-2.5psi drop). I threw out the number of $200 earlier but this is just for a used SMIC, no piping. The custom piping should be able to be done for another $200-$300 plus some extra if he wanted it Jet-Hot or powder coated. I agree that the proper gauges would be a must for this project. An EGT gauge, boost gauge and a Techtom MDM-100 would seem to be MUSTS!
Jeff82se brings up a good point in his last post. Water injection would provide some margin of safety if you aren't going to run an intercooler. This would be a cheaper alternative also. Hey Jeff, could you explain item #4 in your last message... how does adding an intercooler contribute to "possible compressor surge and off throttle idle problems"? Just curious where you came up with that one.
Considering Alex lives in Arizona, I suggested he get an intercooler. He could get a small sidemount from an Eclipse, 300ZX, or whatever. He should have room to make it fit without hacking his car up too much at all. If he were going to do this, he should do some homework and be sure that the SMIC he's getting doesn't have too much pressure drop... maybe limit it to 1psi or so, which knocks out the Eclipse SMIC (it's more like 2-2.5psi drop). I threw out the number of $200 earlier but this is just for a used SMIC, no piping. The custom piping should be able to be done for another $200-$300 plus some extra if he wanted it Jet-Hot or powder coated. I agree that the proper gauges would be a must for this project. An EGT gauge, boost gauge and a Techtom MDM-100 would seem to be MUSTS!
Jeff82se brings up a good point in his last post. Water injection would provide some margin of safety if you aren't going to run an intercooler. This would be a cheaper alternative also. Hey Jeff, could you explain item #4 in your last message... how does adding an intercooler contribute to "possible compressor surge and off throttle idle problems"? Just curious where you came up with that one.
04-26-2001, 11:39 PM
#17
Senior Member
Join Date: Jan 2001
Posts: 308
Originally posted by Jeff92se
If you have long intake tubing ie.. intercooler and long tube runs, you can get surging. It sometimes happens when the throttle plates are shut and the intake charge is still moving. The intake charge hits the closed throttle plate and bounces back into the turbo compressor. When the plate is opened back up the maf might see turbulent flow from the air bouncing back and forth. One cure is utilizing a blow off valve or a recirculation valve. Problem w/ the B/O valve that opens into the atmosphere, is that the the blown air is already measured by the maf and results in a faulty reading to the ecu. The 240sx turbo install by SCC deals with this and some idle problems they had when the pressurized the intake.
If you have long intake tubing ie.. intercooler and long tube runs, you can get surging. It sometimes happens when the throttle plates are shut and the intake charge is still moving. The intake charge hits the closed throttle plate and bounces back into the turbo compressor. When the plate is opened back up the maf might see turbulent flow from the air bouncing back and forth. One cure is utilizing a blow off valve or a recirculation valve. Problem w/ the B/O valve that opens into the atmosphere, is that the the blown air is already measured by the maf and results in a faulty reading to the ecu. The 240sx turbo install by SCC deals with this and some idle problems they had when the pressurized the intake.
04-27-2001, 09:09 AM
#18
Really. What happens when your pressurize the auxillary air bypass valves? 
Originally posted by Desert Pearl
Nothing says you have to vent the blow off valve to atmosphere. Just put a BOV return after the MAF and everything should be okay as far as idling goes.
Nothing says you have to vent the blow off valve to atmosphere. Just put a BOV return after the MAF and everything should be okay as far as idling goes.
04-27-2001, 05:16 PM
#19
Senior Member
Join Date: Jan 2001
Posts: 308
Originally posted by Jeff92se
Really. What happens when your pressurize the auxillary air bypass valves?
Really. What happens when your pressurize the auxillary air bypass valves?
05-01-2001, 09:18 AM
#20
I think the differences between the Eclipse and the maxima is that the Mitsu was originally designed for boost while the maxima was not. Brings a whole new set of varibles in.
I bet Turbo max could answer. I guess als long as the idle circuits were not seeing boost at idle, it's probably okay.
I bet Turbo max could answer. I guess als long as the idle circuits were not seeing boost at idle, it's probably okay.
Originally posted by Desert Pearl
Maybe you know more about our intake than I. What auxiliary air bypass valve are you talking about? I am basing my comment on the setup I had on my Eclipse where the BOV return tube is just after the MAF.
Maybe you know more about our intake than I. What auxiliary air bypass valve are you talking about? I am basing my comment on the setup I had on my Eclipse where the BOV return tube is just after the MAF.
Thread
Thread Starter
Forum
Replies
Last Post
litch
4th Generation Maxima (1995-1999)
123
01-04-2024 07:01 PM