Turbo or Super Charged? Pros and Cons of both
01-10-2007, 12:33 PM
#161
no, I mean if go WOT and look at the boost gauge - which is usually easiest to do when in 6th gear to slow down the accelleration to the point that you can actually read the gauge
My car idles at around 1350 rpms and I actually don't know the exact boost # I'm making at that rpm, but I am making about 1.5 psi at 2000 rpms
My car idles at around 1350 rpms and I actually don't know the exact boost # I'm making at that rpm, but I am making about 1.5 psi at 2000 rpms
Last edited by sentry65; 01-10-2007 at 01:27 PM.
01-10-2007, 12:36 PM
#162
oh btw for anyone curious, here's my boost graph overlayed with ZZtop's with his exhaust and tune
I just dotted mine in since I haven't scanned mine in yet (I can if it's really necessary though
)
I do make about 1.5 psi at 2000 rpms though according to my boost gauge
again, this is my car running at 10psi when it should be running 12 but the belt was slipping
ignore the sloppy parts - hp and tq was on the same chart so i erased them
I just dotted mine in since I haven't scanned mine in yet (I can if it's really necessary though
)I do make about 1.5 psi at 2000 rpms though according to my boost gauge
again, this is my car running at 10psi when it should be running 12 but the belt was slipping
ignore the sloppy parts - hp and tq was on the same chart so i erased them
Last edited by sentry65; 01-10-2007 at 12:40 PM.
01-10-2007, 12:41 PM
#163
Originally Posted by priscilla ls1
+1
Best post thus far.
Turbo is great for a strait line but you get lag inbetween shifts and if you are cornering. I say if I am at WOT hitting 13psi and take my foot of the gas and my psi drops down to 0psi it will take me about 2 seconds to get back up to my 13psi that I was at (this is called LAG!), where as you are SC you are at your peak psi the moment you hit the gas at WOT.
Best post thus far.
Turbo is great for a strait line but you get lag inbetween shifts and if you are cornering. I say if I am at WOT hitting 13psi and take my foot of the gas and my psi drops down to 0psi it will take me about 2 seconds to get back up to my 13psi that I was at (this is called LAG!), where as you are SC you are at your peak psi the moment you hit the gas at WOT.
01-10-2007, 12:43 PM
#164
Originally Posted by sentry65
no I have more backpressure at idle than the big turbo setups with huge exhausts and test pipes 
But yeah just off of Idle I already have some boost coming out of the vortech - not a huge deal though, but it's there. A lot of TT setups can start making some boost as early as 2000 rpms though - possibly even 1800 rpms in some cases.
It's a trade off though. Usually the turbo setups making gigantic numbers with bigger turbos and huge exhausts take longer to spool up the turbos than say a kit like the JWT kit which has tiny turbos
But yeah just off of Idle I already have some boost coming out of the vortech - not a huge deal though, but it's there. A lot of TT setups can start making some boost as early as 2000 rpms though - possibly even 1800 rpms in some cases.It's a trade off though. Usually the turbo setups making gigantic numbers with bigger turbos and huge exhausts take longer to spool up the turbos than say a kit like the JWT kit which has tiny turbos
my kit comes with the biggest turbo's in any stock TT kit for the Z.. and i am hitting full boost at 3200 rpms.. so i am not sure where this huge turbo bigger lag thing is coming from..
you must be thinking about older turbo's like the T-78's and T-88's that supra's use to have.. those things use to hit full boost at 5500 rpms.. now they have hybrid turbo's that make 1000 whp and are making full boost way earlier than before
01-10-2007, 12:45 PM
#165
Originally Posted by doug
i don't have lag inbetween shifts.. if i shift at 9 psi .. by the time i get into the next gear.. i am already 3 PSI.. i know this because if i get off the gas my car lurches forward.. and it usually only does that between 2 - 4 PSI
in a turn though where you're half throttling at 4-5k rpms then quickly roll your foot back into WOT as you come into the straight, the turbo wasn't fully spooled and has to respool itself back up.
I don't think it'd be a huge deal, but it's probably noticeable when you're balancing the car on the knife edge of traction during a turn
01-10-2007, 12:46 PM
#166
Originally Posted by doug
my kit comes with the biggest turbo's in any stock TT kit for the Z.. and i am hitting full boost at 3200 rpms.. so i am not sure where this huge turbo bigger lag thing is coming from..
you must be thinking about older turbo's like the T-78's and T-88's that supra's use to have.. those things use to hit full boost at 5500 rpms.. now they have hybrid turbo's that make 1000 whp and are making full boost way earlier than before
you must be thinking about older turbo's like the T-78's and T-88's that supra's use to have.. those things use to hit full boost at 5500 rpms.. now they have hybrid turbo's that make 1000 whp and are making full boost way earlier than before
even the SFR kit comes with bigger turbos as standard in their kit btw
01-10-2007, 12:47 PM
#167
Originally Posted by sentry65
no there's bigger turbos out there than the stock greddy turbos
even the SFR kit comes with bigger turbos as standard in their kit.
even the SFR kit comes with bigger turbos as standard in their kit.
01-10-2007, 12:50 PM
#168
right
I thought we were just talking about huge power, not which standard kits have the biggest turbos
the point anyway for example, the bigger JWT BB700 turbos compared to the standard JWT BB530 turbos - there's a little more lag and slightly later spool with the bigger turbos and they're of the same techology. That's just how it is. Honda and Porsche are working on dual-vane designs or something which is kinda like two turbos in one, but those are for the next era of turbos
that was all I really meant.
Bigger turbos have more lag and later spool than smaller turbos. The newer ball bearing designs do help though - no denying that
I thought we were just talking about huge power, not which standard kits have the biggest turbos
the point anyway for example, the bigger JWT BB700 turbos compared to the standard JWT BB530 turbos - there's a little more lag and slightly later spool with the bigger turbos and they're of the same techology. That's just how it is. Honda and Porsche are working on dual-vane designs or something which is kinda like two turbos in one, but those are for the next era of turbos
that was all I really meant.
Bigger turbos have more lag and later spool than smaller turbos. The newer ball bearing designs do help though - no denying that
Last edited by sentry65; 01-10-2007 at 12:59 PM.
01-10-2007, 01:00 PM
#169
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Originally Posted by BriGuyMax
Lag to me and most of the boosted public is the time when you go full throttle until you hit full boost or full spool (call it what you want). For me it's about a 1/2 of a second or less(as long as I'm above 2500rpms).....for you it's waiting for your tach to near redline. So in the true sense of the word lag (which I think is a bad way to label and centri-SC) you have more of it. Although I wouldn't call it lag in your case...I'd call it a linear boost curve....which is nothing like a turbo's boost curve.
Please go run your car so we can see what it will do.
Please go run your car so we can see what it will do.
Originally Posted by wikipedia
A lag is sometimes felt by the driver of a turbocharged vehicle as a delay between pushing on the accelerator pedal and feeling the turbo kick-in. This is symptomatic of the time taken for the exhaust system driving the turbine to come to high pressure and for the turbine rotor to overcome its rotational inertia and reach the speed necessary to supply boost pressure. The directly-driven compressor in a positive-displacement supercharger does not suffer this problem
Originally Posted by wikipedia
Lag is not to be confused with the boost threshold; however, many publications still make this basic mistake. The boost threshold of a turbo system describes the minimum turbo RPM at which the turbo is physically able to supply the requested boost level. Newer turbocharger and engine developments have caused boost thresholds to steadily decline to where day-to-day use feels perfectly natural. Putting your foot down at 1200 engine RPM and having no boost until 2000 engine RPM is an example of boost threshold and not lag.
01-10-2007, 01:05 PM
#170
I'm sure we all have Corky Bell's BOOST book...can look it up in there too. I have no doubt he got the definition right as well
the term isn't a big deal or anything, it doesn't change how these cars drive with different FI, but so many people get it wrong when they talk. I've refered to "lag" the wrong way in other threads too because the definition wasn't called into question just to make my point (otherwise only a few people would understand since they don't understand the correct meanings)
the term isn't a big deal or anything, it doesn't change how these cars drive with different FI, but so many people get it wrong when they talk. I've refered to "lag" the wrong way in other threads too because the definition wasn't called into question just to make my point (otherwise only a few people would understand since they don't understand the correct meanings)
Last edited by sentry65; 01-10-2007 at 01:08 PM.
01-10-2007, 01:07 PM
#171
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Originally Posted by doug
i don't have lag inbetween shifts.. if i shift at 9 psi .. by the time i get into the next gear.. i am already 3 PSI.. i know this because if i get off the gas my car lurches forward.. and it usually only does that between 2 - 4 PSI
01-10-2007, 01:07 PM
#172
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Originally Posted by Kf3
Well guys thanks, I think...
anyway I've made my decision to go with an APS TT kit and built motor.
anyway I've made my decision to go with an APS TT kit and built motor.
Your car is going to be wicked fast!!!!
01-10-2007, 01:10 PM
#173
Originally Posted by charged
If I had the money, I would have done the same thing. Just for the APS setup w/built motor your talking $15k-20k, big bucks. What about the rest of you car, suspention, braking, wheels, drivetrain ect. When you Do engine mods like that you have to build the rest of the car for balance. GOOD LUCK.
Your car is going to be wicked fast!!!!
Your car is going to be wicked fast!!!!
agreed, the APS TT kit rocksI even had a downpayment on one at dynocomp at one point before I changed my mind and got a refund
one thing I don't like about the APS route though - and has nothing to do with the quality of the kit - which is TOP NOTCH, is if you need a part from APS, you'll have to wait like 3-6 weeks depending on what it is. One guy blew his engine and APS turbos with a missed shift and it was a loooong wait to get replacement parts by boat from austrailia.
Their turbos are not really repairable BTW. APS has some sorta custom design that only their shop has replacement parts for. They're not a standardized turbo like what the JWT or greddy's have. Dynocomp was saying if the kit used standarized turbos they could have done the repair work themselves and it would have all been done fairly fast
There's been at least another member on the forums who was trying to get replacement parts and was having trouble doing it without paying up the nose.
Last edited by sentry65; 01-10-2007 at 01:25 PM.
01-10-2007, 01:26 PM
#174
Originally Posted by sentry65
oh btw for anyone curious, here's my boost graph overlayed with ZZtop's with his exhaust and tune
I just dotted mine in since I haven't scanned mine in yet (I can if it's really necessary though)
I do make about 1.5 psi at 2000 rpms though according to my boost gauge
again, this is my car running at 10psi when it should be running 12 but the belt was slipping
ignore the sloppy parts - hp and tq was on the same chart so i erased them
I just dotted mine in since I haven't scanned mine in yet (I can if it's really necessary though
)I do make about 1.5 psi at 2000 rpms though according to my boost gauge
again, this is my car running at 10psi when it should be running 12 but the belt was slipping
ignore the sloppy parts - hp and tq was on the same chart so i erased them
Just looked at on of my logs . This is with a T-trim blower , that produces more boost and more boost sooner . Cruising in 3rd gear [AT5] with a 3.5 rear and at 2000rpm [ -5.5 in. vac. because of cams ] going to wot takes 1500rpm . And at 3500rpm Im making 4.9psi of boost
01-10-2007, 01:29 PM
#175
exactly right Booger, I was mentioning that on the top of this page, post 161. Otherwise I can't read the boost gauge fast enough
in my case just to get the car into gear with the ATS clutch, you end up reving to like 2000-2200 rpms while letting the clutch out
you're definetly running more boost than me with the T-trim, even your exhaust is more open than mine
in my case just to get the car into gear with the ATS clutch, you end up reving to like 2000-2200 rpms while letting the clutch out
you're definetly running more boost than me with the T-trim, even your exhaust is more open than mine
Last edited by sentry65; 01-10-2007 at 01:33 PM.
01-10-2007, 01:29 PM
#176
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Originally Posted by doug
since i am dumb and stupid.. then please explain this to me..
how is it that two cars... same exact cars... one with a turbo.. one with a supercharger.. the turbo car is making more down low power, mid range power and top end power than the supercharger? according to your explanation.. the turbo car should have had less power until mid range.
again.. if you read what i wrote.. i did not say turbo's don't have lag.. i said.. and i say it again... SC's having less lag than turbo's is a myth
how is it that two cars... same exact cars... one with a turbo.. one with a supercharger.. the turbo car is making more down low power, mid range power and top end power than the supercharger? according to your explanation.. the turbo car should have had less power until mid range.
again.. if you read what i wrote.. i did not say turbo's don't have lag.. i said.. and i say it again... SC's having less lag than turbo's is a myth
01-10-2007, 02:28 PM
#177
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Originally Posted by Fishey
As shown in wikipedia here is the definition in keypoints.
What they say about your "definition"
What they say about your "definition"
Nice work
EDIT: I think you're confused about what I said...boost threshold which is what you think I defined is when I hit the gas @ 1000rpms and see around a pound of boost, it's the point in which the forced air overcomes the vacuum being produced by the engine.
01-10-2007, 02:45 PM
#178
From what I know, lag is the response time it takes for a turbo to react from the instant the gas pedal is pressed to when the turbo first begins to actually push additional air into the engine, not including the extra time after that moment for the turbo to actually fully spool.
it's the time for the turbo to compress enough air to the moment right before it actually has a positive effect on engine power, not the time the turbo is spooling and actually making the additional power
it's pretty fast on modern turbos, especially at reasonable rpms and especially if you were running full boost a moment beforehand like when you shift where the turbine might already be carrying some spinning speed
it's the time for the turbo to compress enough air to the moment right before it actually has a positive effect on engine power, not the time the turbo is spooling and actually making the additional power
it's pretty fast on modern turbos, especially at reasonable rpms and especially if you were running full boost a moment beforehand like when you shift where the turbine might already be carrying some spinning speed
Last edited by sentry65; 01-10-2007 at 02:52 PM.
01-10-2007, 03:15 PM
#180
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WOW! After reading all nine pages of this thread. I have to say my decision to go with the APS TT kit has been reaffirmed.
Correct me if I'm wrong but here's what I've gathered from the thread:
-turbos generate more overall power
-power generated by a turbo and "turbo lag" are in no way correlated
-Superchargers are loud
-superchargers deliver power quicker than a turbo
-lag generated by a TT kit goes undetected
-turbos are good for drag racing
Correct me if I'm wrong but here's what I've gathered from the thread:
-turbos generate more overall power
-power generated by a turbo and "turbo lag" are in no way correlated
-Superchargers are loud
-superchargers deliver power quicker than a turbo
-lag generated by a TT kit goes undetected
-turbos are good for drag racing