Great thread and great post Spin. I agree 100% with a lot of what you post here, but I have to clarify that Magnacharged cars will break into the 10's with approximately 500 rwhp or slightly less.

I'll be at the track in a couple with weeks with a drag pack and hoping to duplicate what some have done with a magnacharger on street tires....

 

With a street tire there is no advantage of FI over a great H/C package. If you were in C6DVL's car at 525rwhp you will also see that max effort H/C cars give nothing up these days in drievability. The tuning has come so far that I was recently in a customer';s car that had stock heads and a 239 cam. It had zero drievability issues. No bucking, surging, ect.

ECS has the best of either choice and I think a trip down to hang out with Ed )C6DVL and some of the other FI guys in that crowd, I think you will see the gap for power isnt nearly as wide for what is usable. I think you need a H/C package and if you have an LS3 get your car over to ECS and get in on the 6k H/C deal.

One thing I didnt cvover was the reversability of a S/C car for when you sell it. Modded cars do not sell for much over the book value and most people will not buy a modded car no matter who did the install. While you may fetch 50% of your money back if Lingenfelter or Callaway did the install, you also paid more than twice the price of any other tuner so you save nothing. I havent seen any cutting edge H/C packages from either tuner anyway. If you swap cars often and dont want a total loss then get the S/C. Its lots of fun and it can be moved to the next car with minor changes to the plumbing or if its a big change like the C5 to the C6 was, then you can sell the kit for 60-70% of the uninstalled price and get the new one for your new car. H/C and strokers are cost prohibitive for de-modding and sometimes you cant sell the car unless you do reverse the mods. My car would be a nightmare but my friends know my car and some would be willing to pay a premium for it. Thats me though.

 

I have never been in a H/c vette so no I don't know what that response be like. I am still on street tires so wot in 1st and 2nd does cause traction issues. What I was trying to say is that with normal driving I still see boost which is much improved over stock even in lower rpms. Little throttle is needed to close the bov. But the response is bad if I jump on the throttle after being out of it with the bov open. Had to play catch up with a mustang when he went while I was coasting because of this.

The reason I chose sc over h/c was having to deal with a big cam living in a high traffic area. I wanted something that would still drive like stock in traffic but be a beast on open road.

 

Mag cars are at fuill boost at 2500 rpm. It makes the area under the curve far more impressive. ECS's new approach with the restrictor plate makes the argument for the centrifs better. Actually it eliminates it. My car is at 7 pounds boost by 3500rpm.

They (mag cars) make great street cars but that TQ curve really makes traction a tough thing. If you dont get ahead of the power letting the dyno sheet go to your head, and the hoods dont make you sick, they are great s/c's. The boost is made after the MAF and the compressed air when you close the TB blade works differently than the BOV on a Centrif. It was with a mag car I worked on down in Texas that made me notice the respoinsiveness difference. The car had a Mag 122 and I had tuned it as a H/C car about 5 months prior. When the S/C went on, I noticed a big change in how the car responded at part throttle. The pop was gone. He noticed it too but said it was greatly changed with a smaller pulley.

Such fixes arent goging to make any difference on my car because it will just makes more air come out the BOV. What my car really needs is to close the BOV sooner at much less throttle percentage. This will allow any amount of throttle close the BOV and allow some boost to get it perking. Comming off the gas to shift would still prevent compressor surge since it will still open.

The Tial is adjustable isnt it?

 

We have the same kit and the same observations. I kept the nitrous system in my car with a 35 shot for this catch-up symptom that happens if you are anticipating a roll-on and have to stomp it when the BOV has been open and you're at 4krpm's. You have to learn to drive it all over again. As far as part throttle closes of the BOV, on the street coming out of a turn and in say, 2nd gear, 25% throttle doesnt show any boost on the gauge. I want it closed at that throttle position.

On the stock runflats (new ones) my H/C car broke the tires loose in 3rd gear at 70mph on a roll-in for that gear. You're doing great if you have traction in 3rd gear with 100more HP.

As far as H/C power, a 232 cam and trick flow heads makes over 500-510rwhp and will not have any driveability issues in a daily driver. A 232 cam behaves like stock.......no surging or bucking. With gears it makes a 10 sec run and has all the immediate roll on power and low end. Guys with S/C's seem to think that gears are the devil on the street. I have 4.10's on a Z51 and love the power level I have....but then I have a tire matched to the situation.

 

Did I just get hijacked????

Lots of great info, but a little off of my questions...no prob, but can someone please make arguments for which is the best all around street setup?? Thanks guys!!

 

I think you can have a great setup either way. I guess the best way to decide would be if you were able to experience both. I chose sc but I probably also would have been happy with H/C. When I made my decision my only cam experience was with older vehicles that would barely run in traffic. It seems this may be different with these cars but I'm sure there are draw backs with whatever you choose.

 

Spin, you need to make up your mind: You keep talking about part throttle, and how dyno charts are unimportant in the real world, and then you tell me that the superiority of a heads/cam setup is seen on the quarter mile track?
I am sorry, but I have yet to drive in a road that looks like a 1/4 mile track? In the real world, where I drive in, I am rarely standing still waiting at the beginning of a treated surface when I get on the gas... I want power once my car is already moving, and damn right I don't want 100% of that power at 1% throttle! It would be uncontrollable! The gas pedal exists BECAUSE you want power to be progressive, and even under that premise, my car gave up absolutely nothing in part time torque an throttle response as compared to full bolt ons and a tune. Nothing at all and you are welcome to drive it to verify; as I said before: I really don't understand where you are coming fom with your comment that your car lost something once your supercharged it, UNLESS you dropped a bunch of compression when you installed the blower, or unless something else is wrong, such as the blow off valve pretension, as I mentioned a few posts back...
Now, a few points of notice:

Boost = Pressure. When the BOV is completely open, the supercharger is simply moving air but not compressing it; that requires very little power since centrifugals have no internals compression. Most importantly, blow off valves are not on/off switches; if they were the car would be very jerky; boost comes on progressively as you get on the gas and the BOV closes gradually. Assuming nothing else changed in your setup when you put the blower, I am guessing that non adjustable plastic BOSCH blow off valve is not working the way you want it to and strongly suggest you try an adjustable BOV.

You told me to come by "some time" but never set a date. Sorry it didn't work out but I did want to see your car. Regardless, I have yet to see a single heads and cam LS2 engine making more torque below 3000RPM than my car did with full bolt ons and a tune; cams are not the way to gain low end torque, and if the compression remains stock, then I don't see how you would gain throttle response also. I know you bumped up your compression, but most heads/cam setups don't.

Throttle position vs gas pedal position is a variable controllable by the ECU tune btw... If you really do have to push the gas pedal down further before you get the power level you want, you could simply program that in... I still contend that there is something up with your setup though...

OK, now tell me how many people you see competing at the drag strip with said 500whp FI cars? How man are running gears and drag radials? How many are good drag racers?
So if I show up at the drag strip with my street tire clad, pump gas daily driver, and lay down, say, a 12 second pass, does that all of a sudden prove something about supercharged cars? Does it mean my car is slow? Would I be able to run a 10second pass with that same kind of driving if I had a heads and cam car?
If one guy on the forum is able to run 10.9 with bolt ons, when most can not match that with heads and cams, does that prove something about heads and cams? Maybe we should all have an automatic car with drag slicks gears and a really agessive tune? It'd be a lot cheaper than heads, cams or supercharging, and if he can do it, then I guess that means everybody else can, right...
Drag racing requires a lot of skill and it only gets harder as the power levels go up; I know for a lot of people showing up to a chemically treated strip of straight road with tires you could never drive on the street safely and holding the throttle to the floor for a dozen seconds or so represents the holy grail of automotive achievement, and I know you and many others feel like unless I can beat my car and break parts into a low 1/4 mile time at the drag strip I am neither a good driver nor do I have a fast car, but my reality is that I built a daily driver for my own driving enjoyment on public roads; I have only drag raced once in my life, I did 3 pases with my car on run flats and bolt ons, ran a 12.5 @ 117MPH with a 2.15 or so 60 foot, and found it very boring; I could have gone faster for less money in a Mustang if I didn't care about how the car handled. I also got to watch two guys break their cars on the strip that day; hope it was worth it for them...
Don't get me wrong, I will probably be back on the strip next season now that I have a blower, but please forgive me if I am genuinely not impressed that someone with less power can be faster in the 1/4 mile; My car will never be as fast as some on a drag strip, and I don't want it to be; I have no interest in running drag radials, rollcages, short gearing, etc...

To each their own

 

You asked about a comparison of the two and got it plus issues and benfits of both, in detail. I'd be happy for the volume of info prior to buying one and finding these things out for yourself.

Everything talked about was about one of the two mod paths and tells of issues with one or the other. All we have been talking about is driveability, throttle resonse, and how the tires you choose make it react on the street. What else is there to what makes a better street car?

 

Glad we at least agree on that... Almost every single aftermarket BOV is adjustabl. The TiAl is super loud though... I recommend you try a Vortech; they are also cheaper. If you go with the TiAl, get the Tial Q, not the 50... You can muffle the Q...

 

I would go blown with no question. Other forum has a 10.17 @132S/c auto ls-2. So what? The track is all about 60ft.* Thats why the roll off in 3rd gear. On good road takes the traction issue out. Then any kind of driver is going to know his car and be right at the powerband. S/c vs H/C NA side by side, Both LS-2's say anything you want but nah not going to be that close. Flame suit on. Bring that 10.66 car and do a roll with me. In a legal place of course. See what happens to those Quarter Cars.* *
Just like power labs chart if you can find it!

 

I'll take it a step further. I'll do the roll in 2nd gear; we can start at whatever speed you like
For all the talk about tractionless supercharged cars, I find that I can hook up full throttle in 2nd gear so long as my tires are warm, the road is in good condition and I don't just hammer on it. Sure, it will spin 3rd at 80MPH in winter, but I shouldn't be driving it that agressively when the tires are at 40 degrees anyway.

 

My car with its H/C at sea level was everything I need to beat countless other street cars running any amount of boost. A glance at the rear tire was all I needed to know I was going to win. 0-80 or 0-100 is all that mattered and the tire told the whole story. The more boost they bragged about the better I knew I would do since it likely meant they would break the tires loose. I dont want to hear about gay roll-on races that start at 55 and go until the higher HP is satisdfied they didnt loose that bad because they ran you down.

You need to drive a 4.10 geared car becuase its not the drag race part you make it out to be. They would likely shorten the distance in the top gear you currently spin at. I spend lots of time trying to express this to you on the phone but you never bought into it. Your off-the line performance would be way better with gears, your tires and 3 pounds less boost.

You have exactly what we had spoken about, lots up top and not a clue as to why a H/C/gear car would have you by 5-7 lengths before your boost gauge read 3 pounds off the line. I orignially thought you knew this was the trade off before you got the kit and you did it for finacial constraints. I see now you actually bought into all the FI myths. You need a ride in a 4.10 geared 600rwhp car. Yes, 600rwhp strokers can run a 9 second pass with 3.90's.

Its a debate and nothing is intended to disrecpect you. I think you misunderstand the things I post as if they are an attack. They arent. I have Fi and I like it. I think you are attacking some things I know you're wrong about. gears come to mind first. Come out to my house (you are invited) you will see the 10 pound boost on the guage short shifting and ask yourself why this H/C boosted car has traction with 4.10 gears. Maybe you need to see the other side of this equation. I will get you a drive in a local stroker here too to see the difference.

 

The problem here with your input and the input of most others is that you never had a max effort H/C job so you shouldnt be comparing your car with FI to anything but your stock car. You have 3.90 gears whcih according to Powerlapbs, is a no-no on a FI car. Neither of you should be saying you prefer S/C over H/C because you never had it and have no right to make a comparison. What is different on a H/C car that affects throttle response: the stock heads suk. A AFR with its little 205cc runner helps it. Even ported 243 heads dont have the best performance in this area. Some tuners reshape the combustion chamber. All of the after-market choices change either the runner size or the angle of the valves and each has its advantages. Cams make for a snappier response too as does compresssion. Ported intake manifolds and TB also help it. Gears make the car really responsive becuase they change the powerband faster. While they dont add power they do add mechanical advantage and change the rpm so fast that it winds faster and results in a faster redline.... ie it acheives its top speed faster. The cam also changes the characteristics of the power band. The narrower than stock LSA wakes up the responsiveness of the low rpms and midband.

I agree stock vs stock with a s/c....the s/c is better. Your post here is saying that track performance and street performance is different and it isnt different. From 0-130mph (the equivalent of the 1/4 mile) most H/C cars are the equal of any FI car with with stock gears up to 600rwhp. The 1/4 mile challenge supports it. Change the tires to street tires and then the added power for the s/c goes out the window. If you need serious proof....look at the 1/8 mile results for manual transmission H/C cars compared to manual trans Fi cars with the stock H/C and no gears. Its pathetic.

I think the street is even more about the first 60ft and thats why H/C geared cars destroy FI cars on the street at legal speeds (0-70). For the guy that isnt going to do more than 0-80 H/C is the way to go.

S/C's are way faster if the race starts at 40mph in 3rd gear. Not everyone is into that. If its your bag and the initial off the line destruction of a FI guy's ego isnt high on your list....get boosted. Since you are saying here that you only want to compare the car itself with no driver effort than the guy with the most HP wins of course but that means nothing when in the real world over and over again a H/C/geared car is always going to beat you with all these situations averaged in. If you want to continue to build up some imaginary race where you get to always start in your favorite gear from your favorite rpm then go on kidding yourself. It doenst work that way in the real world.

I agree though, its a lot of fun and the pull is sick.

The difference you shouldnt make a comment on is H/C or strokers. A 416 stoker can easily match your current power output with razor sharp response and 550 from a storker is way faster than 550 from FI. Try your roll on in any gear against a power matched stroker like GTOdoug's. He has 550+rwhp with 3.90's. You will lose from any speed, and rpm. He is also running a cleaner 13:1 air fuel ratio so it will last longer.

Lets keep in mind the OP was asking about H/C or stroker compared to stock+FI....not stock compared to stock with FI.

 

Lol. second was my gear too at sea level, but with a 75 shot. You would have lost with 100rwtq and gears against you. I know what youre thinking but this is going to be the real kicker. You would have lost to me even without the nitrous all the way to 130.

We do have some sick cars and thanks for the power ECS and A&A.

 

I seem to be a hit with the local ricer crowd with the BOV now so I dont care. I didnt have any local takers these last few weekends here becuase of the open view nitrous bottle in addition to the obvious BOV sounds. My sleeper is known to all now so what does it matter? I dont care about the volume but the cricket sound of the bosch isnt my bag.

 

I haven't ever heard anyone say anything bad about Tial. That would be my choice.

San

 

I completely disagree with Spin's opinion of Centri cars having any lag problems, IF they are set up properly... Most of you in this thread know my feelings on setup, and as with any F.I. engine 1000cc's to 364ci (in this case) setup is everything... And to answer the O.P.'s original question, yes you can throw a Lumpy cam in the car with F.I., the old myth of certain cams not working well with F.I. have been disproven many, MANY times... There are SEVERAL posts showing dyno runs with different cams being tested on F.I. cars... to make it short and sweet, if it works (the cam) in a N/A car, it works in a F.I. car. I know most of you have been told over the years that this is not true, I followed that school of thought as well, but after much data showing that N/A cams do work fine with F.I. I am a believer as well...

 

Problem? I said 3 times already its not a problem with FI, its a characteristic.

I have been in so many tuner cars and not one didnt have that lag. ECS, vette docs, Cartek, and A&A. The one with it worst had it on a base car with only 6psi. Even a local tuner's kit (RMCR)...Aintqik has it although to a lesser degree because of how rediculous his power was without the blower. His isnt sluggish being a stroker with the FI. His car did run the exact same set-up before and after. He himself commented on it but its so minumal an issue because it is a stroker. But....it did mute it a bit-10%. We are not talking just a few cars. I have been in and driven quite a few fully tuned masterpieces by the best of the best tuners. They werent set-up wrong and we are well into the double digits.

It cant be off boost and not have the drag introduced. Its driving the s/c. My car had the exact same H/C job on it before and after. The compression is at 10.95:1. I know what the performance was from day one before the kit to after it on day 3. The times I'm talking about are when you're at 1800rpm going to 2400rpm in 3rd gear and you go from 25% throttle to 35%. I dont give a rat azz what the dyno sheet says at WOT at 6k, the car is sluggish. If an UD pulley makes a difference than what is a S/C doing in the opposite direction for power down low with no boost? A H/C car has way more punch there especially with gears. For people who have been in my car, I had a really bad habbit of wiplashing the timing chain by blipping the gas pedal for a split second and the car would mash your head back. If I do that now there is zero response unless I push down the same amount on the gas pedal, say the number 1 (one) and then release it to get that same effect. I stopped doing that when people were reporting timing chain failures but it serves to illustrate the delay in response I am trying to describe. This was always at 3k rpms in 2nd or 3rd. Now: nothing in comparison would happen if I did it without holding the gas pedal down for the time it takes the BOV to close and build up from vacume. Its not instant. Its a mechanical valve and needs time to operate. If I take my car to 3500rpms now and the gauge shows -10 (vacume) and I hit the throttle for a spliut second, its not at 7psi like it wold be if I had the car floored and was rolling through that rpm. That is the delay, no matter how sensitive the BOV is. Down low under 2k nothing helps it because the car wouldnt be helped by any boost.

No one is attacking FI. Its a characteristic and its not in the tune. If you think that a H/C car with gears, a 236 cam, AFR heads, high compression, and little 205cc intake runners has the same throttle resonse as your car then you and I arent on the same page nor are you being realistic.