I don't understand why you think the rubber water lines will heat up as much as you say, it just doesn't make sense. I would be interested in hearing more specifics on this. As well Seen4ever made some very good points that you did not respond to. I would like to hear your reasons/ technical explanation for the above comment.

Chuck

 

hey now, i was just stating some things I know, not trying to pick fights and get called a hater again.

another FYI. the TRD reflash to me, appears to change timing. Everyone talks about how the ZPI car without the reflash has 30 more lbs of torque. Torque is a function of timing on the car. with a VVI car, this can be accomplished by adjusting the cams via VVI or by changing the timing of the ignition. Either way, it appears that TRD is removing timing from the factory ECU in order to be more conservative. My guess is that they don't want to rely on the factory knock sensor, as in reality a knock sensor is a 'too late' sensor. it picks up detonation as its occuring, so problems are happening and it hears it and attempts to retard timing enough to stop the detonation.

Without really being in the car and seeing the A/F curve and seeing the spark plugs, its unclear to see if its something that needs to be done. Then again, it could just be adjust the VVI.

It would be interesting to see TRD reflash on turbo car & SC car, then stock ecu on the same car. Just for test purposes. As the correct VVI adjustment could allow IM pressure to be less than EM pressure which very much helps with boosted cars. There is also the other angle of a turbo will create more backpressure than the SC will.

As someone upgrades thier exhaust parts with the SC on the car, thier boost levels will most likely drop, as the IM pressure will decrease due to the car being able to consume more air, as the exhaust is freer flowing. its kind of the beauty of the SC. with a turbo, you like boost. With a SC, if you start with 9psi, and then upgrade to 3in exhaust, a nice designed header, s-pipe, no cats, then boom, you may be at 6psi, but the SC is still producing the same amount of air. to raise boost up, you free up the intake on the SC, aka larger intake tube.

i've had a SC'd prelude for a number of years, so learned a few things.

 

No one called you a hater, it's cool man. I believe Chuck was referring to ZPI responding to you. You gave some good info.

Oh, it's VVT-i.

 

I agree completely. There is a reason that the TRD reflash is pulling timing. I've said a couple times before on here that the cars run agressive timing when not adjusted with the turbo kits. Thats part of the reason the cars make so much torque. TRD knows this and understands how it works and im sure their reflash is SAFE. Very safe in fact, since the car retains its factory warranty with the S/C installed. They do testing and product development before the cars are even released and they know what it takes to melt a piston, or crack a ringland. Ahem.

The VVT-I cannot solve the problem alone as it only adjusts the timing for the Intake Cam, not overall cam timing or ignition timing.

I know everyone here wants power power power. But at what cost? Are you willing to replace an engine in your car? Do you have the funds, and the means to go weeks without your now daily driven vehicle waiting on a replacement engine and a shop to do the work? If you do, like some people and some sponsors on this board do, then go for it. Make the power, and build the engine when something fails. If you don't then you should sit back and think about why TRD, and some companies are making less power then others. Especially if you dont personally understand the dynamics of engine theory and design.

(end of rant)

Charles

 

What question is that? You need to compare the price of a SC + Additional cost of parts and labor to make it to 300 whp with it, vs. Just a straight bolt-on Stage 1 turbo kit from ZPI that will put you right at 300 whp roughly with probably more TQ too.

 

... good point lol. but which is more reliable in the long run? the SC or Turbo? also which is better for a Daily Driver? also im new to all this and i have never had a boosted car before. but then again my tc wont be getting any boost for a while cuz money is tight right now.

 

However, you also have to take reliability into consideration. I'd much rather pay more money to have a reliable fast car. And don't anyone try to tell me that a stage 1 bolt on turbo kit will be nearly as reliable as a TRD s/c tC with supporting mods. Just not even an arguement. My s/c was 3600 installed. This kit included EVERYTHING down to the last zip tie. A very, well-engineered, reliable, conservative setup. Not to mention a very complete kit. Lets not forget about the potential of this thing. It can hold 20 psi!!!!

The ZPI stage 1 is 3800 + installation (which we all know can be very pricey, if done at a competent and reputable shop). With the turbo kit, you also might wanna save some money for axles as I've read about turbo'd tCs having TOOOO much torque and snapping them like fresh string beans.. Don't forget the 300 dollars for the jumper harness(similar to Dezod's p'n'p harness)

So when it comes down to it, I suspect that both setups will be VERY comparable in price when its all said and done. This is just my opinion of course. I could be wrong. Doubtful, but possible.

 

On that note, the Stage 0 (which still puts out more power than the supercharger, and is less money) is the more reliable route. It's probably more streetable too. So, if you want to through reliability into the mix, then I would say drop down to a Stage 0, and still be cheaper in the long run. It's only 50hp less than a Stage 1. You probably will still keep up with a S/C 300whp TC, if not beat one since the boost pours on much early in a turbo.

You also have to take into account, that the WHOLE reason people have been eating up the S/C left and right, is because WARRANTY was a big issue for them. NOW those same people are talking about Upgrading! It's a toss up right now to find out how much HP you are going to be able to squeeze out of the S/C WITHOUT voiding the warranty (which warranty was the whole reason and deciding factor for just about everyone that bought the S/C, to which also justified the cost of it).

FYI, if you are one of those people who are S/C, and now you are screaming for more power, then you should have went the cheaper route to begin with. I'm not by any means an expert on S/C, but I find it a little difficult to believe that you are going to make it to 300whp with out voiding some part of the warranty you paid for.

 

ok so all in all which is more reliable... stage 0 turbo (with intercooler i gotta have that if im getting a turbo) or the sc (with suppoting upgrades)? the amount of power that each one makes doesnt really matter to me. i just want to upgrade the power of my car without sacrificing reliability of my only car.

 

As far as the comments about the air to water intercooler, judging off the size of the lines and the placement of the intercooler I feel that this will be a inefficient design. This is preference not that of fact. I have seen no facts on this intercooler or specifications but judging off of how hot the engine bay temperature reaches in a tC I do not feel that this will be sufficient. But it is also too early to tell, this may be the best design ever created by man, we just don’t know yet this was my opinion.

As far as the timing issue goes, our turbo tC made 50 more whp and 60 more ft lbs. This is on the same ECU configuration as the SC tC that we dynode, this and the Turbo both where on the stock ECU. The timing maps would have been the exact same. The truth is we do not know what the reflash does. It will have to take some fuel out as the car runs rich on 410 injectors but we really do not know. No one at TRD is talking and the unit was built by an outside company. We are in the process of getting the module hacked so that we will know what they are changing and why. Until this all comments are speculation including ours.

We have had no problem with the stock ECU adjusting fuel or timing on 6psi. Do I recommend this on 10 psi absolutely not. This is why our stage 1 kit comes with a pre-tuned Emanage. The VVTI is defiantly another part of the equation that we have not played with. If it is anything like that of a Subaru there is probably plenty of power to be unlocked with proper tuning of such.

-Kenny

 

OH yeah!! An IC is a must have for me too. I recall a dyno of a Stage 0 w/ FMIC net of 247 whp, 257 TQ (give or take a few).

 

Charles, what kind of timing do these things run? as i assume that they are atleast dialing back some timing in boost, well as much as the MAF is programmed to do. My inherent issue with MAF... different rant.

But we all know that timing drivers your torque curve, which is also when your injector pulse peaks. I forgot that on the tC that VVT-i is only intake, so it can only do so much to decrease pressure within the IM.

I will say a car running 6psi with a 2.4l could probably run in the mid 20 degrees worth of timing. As honda's run between 28-30 degrees at WOT 0 vacuum. on 6 psi on a street DD honda, i tend to put them in the 24-27 degrees of timing, but then again, thier heads flow more and I don't have to worry about my intake cam changing.

But you do speak the truth, is 20whp worth riding the bus for a week? that's what it comes down to. Especially when you are looking at a 3200lb car. 20whp really isn't that huge of a deal.

But i will say that the TRD reflash is probably a little overly conservative. Either way, we have dynos of stock ecu unmodified on cars with SC & turbo. Time to reflash an ecu, as it comes as part of the SC package and see what happens. anyone thrown a EGT gauge on these cars. put it 1in off the exhaust flange and that would be an easy way to tell if timing is being thrown at the engine.

again, I don't care how hot someone's engine bay is, with a good heat exchanger and a high flow pump, the water can keep the intercooler cold enough. unless they are wrapping the header with the water hoses, then it shoudln't change things too mcuh. Either way, get out a thing of wrap and wrap them, solution found. its just talk as of now, as no one has any specs on it.

 

The stage 0 car was dyno'd with an emanage, 550's, and a FMIC and therefore cannot be compared. Technically, all of the cars are on the "stock ecu". When you manipulate them, it changes everything.

Not to mention, if the turbo kit on the stock injectors puts you in an 11.8 afr under boost and the s/c with the upgraded injectors is running rich, lets say a 10.8:1afr then im sure the cars would be comparable if they were truely both on the stock ecu and stock injectors. There are to many variences right now to even consider comparing them.

My car was running 27 degrees peak timing on 6 psi and 27 degrees peak timing on 14 psi. The car was seeing well over 1300 degree's at the bottom of the downpipe which im sure puts it in the 1400's in the manifold. IMO, this is just to hot for a car that is going to be driven, and in most cases beaten on daily. Especially when its already been proven that these cars have weak ringlands. Plus, if I understand the system correctly, (its possible that I don't) the VVT-i on the cam gear is not even controlled by the computer. Its simply a basket, with different weight clutches in it that sits on the end of the intake cam and adjust timing according to rpm. There are no electric devices that attach to it at all. I can include pics if anyone insists. The VVTL-i that is found on the Celica's is a completely different system. Im trying to gather as much information as I can on this, but its vague at best.


THIS IS A QUOTE!
The tC appearently uses the "old style" VVT-i because that basket is full of just that. Little gears, springs, and splines.

In either event, I think its safe to say that most NA cars that are converted to FI need some sort of timing alteration/control to last. Sure, on a honda with a map sensor, you can throw on an FMU and set it to 8 or so lbs and call it a day. Unfortunatly its not that easy with these cars. They are to smart for their own good and they require something extra for the car to last more then 10,000 miles. Just my .02 cents.

Charles

 

if you are getting 1300 degrees in the downpipe, i bet you are over 1500 degrees in the manifold. Pistons melt at 1600degree mark. I kept my EGTs to 1400-1450 on my honduh, but then again, it had forged internals. The temps would die off as the rpm band increased due to the cooling effect of the injectors, and lack of timing.

but a MAF based car can easily get far beyond its boundaries. As for the VVT-i being driven off gears and ____, that's just crazy. I read about the camcon VVT-i controller and just assumed that the scion's VVT-i was driven by the ecu. if not, that scares the ____ out of of, as with a log manifold you definately need to compensate duration & overlap to prevent EGR reflux from the increased backpressure.

for all those that say a turbo is the most reliable, i'd start checking in with all the original turbo kit people and see how many miles they have on the car and check out leakdown & compression numbers.

I would think the TRD SC is by far the most reliable setup, because Toyota themselves have given it a warranty. that means they assume that people will buy it, ***** the car 100% and they will cover stupid stuff.

 

What car are you talking about that's 3200lbs?


I don't think anyone is claiming that the turbo is more reliable than the S/C. I was merely trying to understand why people bought it for the warranty, and now talk about upgrading the pulley to make more power. From my understanding the S/C comes with a tamper proof cap for the pulley, so naturally wouldn't you void the warranty on it if you changed it?

And if you want to talk to someone with a time tested Stage 0, talk to ScionDad. I'm sure his daughters Automatic Stage 0 TC has somewhere near 4k miles on the turbo with no problems (don't know, last time I checked, the car had 2k+ miles on the turbo).

 

The VVT-i is controlled by the ECU, even more so with the inclusion of the tC's electronic thorttle control.

As for the tC's VVT-i controller being a "box of gears", that is just wrong. The tC uses a four vane, oil-pressured controlled system to advance and retard timing.

As for how it is used....

 

i bet the automatic cars run less timing than the other cars. Just from seeing other manufactures, the auto cars tend to run less timing on the ecu, as they are not as performance oriented as manual ones.

I assume that the cars are 3200lbs, i know they are 2000lb cars like i'm used to.

 

The curb weight of the tC is slightly over 2,900lbs.

 

For me specifically the warranty issue is not specifically why I am willing to shell out more money for less gains initially. I live in California and my TC is going to be my project car for 6 years or so. This means I'm going to need to pass smog which I can do with a SC even modded without needing to really remove anything to pass the visual.

Also boosting my car with a SC also lends some protection against police harassment as the TRD sticker is a very good deterrant. I'm not a stop light racer but I do occassionally punch it when I need to...

Resale value will also be a lot easier back to a dealership if I decide not to part out the engine. Most of the time the dealer will ask you to part out the turbo but a TRD badge keeps them from saying much and probably adds incentive for resale for a niche group.

Also when I autox and track it, it's generally easier for ME personally to drive a more linear car. [although with the rite piping for a turbo i'm sure that could be taken care of]

There are a couple reasons why someone would choose sc vs turbo and I'm glad zpi is putting out the option for both.

 

A lot of auto's also pull timing at the shift points to help the life of the tranny by lowering torque. Its a trick that a lot of auto Supra owners use to keep their trans from blowing spraige(sp) gears inbetween shifts.

Charles