1JZ VVTI conversion
- Thread starter Howie
- Start date
Ric said:
I know you have homer in the avatar. Think about what you are saying here. The topic of VVTi is about the valve train, not rods in a particular motor. And I am thinking that there are as many bozos for this engine as there are 7M's.
Nick M said:
Installing VVT-i is not worth it, and yes, that's my opinion. It's cost per HP man. It's not an old school mindset, it's about money and being worth while.
Superior design? If it were really so superior other than stock, it would be retained in high HP drag cars. You read features of mustangs that run sub 10 1/4 mile times with Sequential EFI, AND old school tech. On the other hand, show me where a high HP true VVT-i engine is used to achieve the same result in any magazine. Superior to what? A non-VVT-i engine? Stock perhaps, but not when it comes to potential that 600+whp non-VVT-i engines can make with no internal mods.
Before someone says they aren't making a drag car, or a stock VVT-i powertrain is good enough for their daily, know that my opinion is based on using VVT-i as a tool to reach the potential of the cheaper and more install friendly non-VVT-i motors (JZ) which have proven themselves already. VVT-i as a mod itself isn't worth it for the money, IMNSHO. Valvetrain only or not.
You need to read about rules of racing before commenting on why a Mustang uses a particular setup. I'm not trying to piss you off. Variable cam timing is a holy grail of tuning. Ever see a big lopey cam in a car, and how shitty it idles? What if you could change that duration at idle? I don't understand why you wouldn't want the torque of an RV cam, and the pull of a 3/4 cam on the same engine.
If it is about the budget, get a different car. Or nitrous.
If it is about the budget, get a different car. Or nitrous.
Nick M said:
We all want great response down low, and good top end power. I simply do not believe VVT-i can give it to you in stock (valvetrain) form much past 400whp even if the internals are swapped. Consider VVT-i was made for stock twins to further flatten out the torque curve. VVT-i works under full boost, and the stock twins spool up so fast, VVT-i has TIME to work with the cams down low, and change it up on top and is matched with the flow of the twins down low and on top. Larger single turbos full boost come on at a higher RPM, say 4,000-7,000 rpms for example, flow rates have changed. To make peak power, all you need is a cam that will give you max power in that range. A lot cheaper to just buy a set of cams, than to have special ones ordered for VVT-i and then tune the VVT-i with another piggy back, or standalone.
VTEC cams are thrown out the window after 10PSI. Yeah, they are NA profiles, but they get rid of VTEC, because it's not worth spending all the money on the cams for boost in VTEC form. Single profile wins.
You can say good things all day long about VVT-i, and I'll agree with you the concept is great.
It's not budget... It's price per HP gained, and considering if the mod is worth it compared to other modifications.
I don't start racing at 2500rpms anyway. My turbos don't get full until after 4,000rpms.
they'd get full sooner than 4000rpms with a VVT-I motor. knocking on VVTI 'cause it "doesn't make cost sense" is really not cool. It IS just as backwards as people bitching about fuel injection on mustangs, or bitching the the '97 camaro (the first LS1) was "the catfish car" because of the headlights.
can you put a price on a better running engine? if ALL your car does is run straight down the track, even then there's still lots of use for variable valve timing. but applications for daily drivers are where the real incredible gains are.
I understand price/performance, and I'm not even gonna just go "get a different car" 'cause a mk3 CAN be made stupid fast for stupid cheap. and no, this isn't necessarily how to do it. But to have a stupid fast daily driver that still runs and idles nice and isn't a headache to drive in bumper to bumper traffic..... that's not as cheap. but it's still a beautifull thing.
can you put a price on a better running engine? if ALL your car does is run straight down the track, even then there's still lots of use for variable valve timing. but applications for daily drivers are where the real incredible gains are.
I understand price/performance, and I'm not even gonna just go "get a different car" 'cause a mk3 CAN be made stupid fast for stupid cheap. and no, this isn't necessarily how to do it. But to have a stupid fast daily driver that still runs and idles nice and isn't a headache to drive in bumper to bumper traffic..... that's not as cheap. but it's still a beautifull thing.
VVT-I is a good thing, period. HKS is selling VVT-I conversion kits for GTR RB26s now and the results are outstanding. The large singles are spooling around 2k rpm sooner on the 2.6 liter. Power FCs for VVT-I cars can have the VVT curve tuned by the FC software too, which is an added bonus. Just because the 1J VVT motors have weaker rods from factory (I'm not sure if this is true or legend) is no reason to knock the cam setup.
In NHRA top fuel dragsters, they use the worst ignition control made. It is mandated to slow the machine down.
In NASCAR, they use fucking carburetors, to slow the machine down.
In NASCAR, they use fucking carburetors, to slow the machine down.
Id personally love to have a VVTI 1jz.. I'll be working on one in about a month, ill let u guys know how it is.
mabru said:
Maybe good if it came on the car, but installing it afterwards as a "mod"? Not really the best "good" thing to do.
I wasn't aware VVT-i was offered on nissan engines, unless nissan has their own cam timing control. If you want to pay for an HKS version of VVT-i, that's awesome, it's just not cheap. For a flatter torque curve it might be worth it for your application. VVT-i seems most practical in traffic, in stock trim which I've already said before. Any racing you do whether you do auto cross or drag, or whatever, you're going to keep the motor in a certain RPM range best suited for the mods you have.
Toyota intentionally designed all VVT-i engines with smaller rods.
junior said:
As far as the turbo's spooling faster due to VVT-i I want to know how many of you have actually looked at dynos of a single VVT-i setup, and saw what gains it had with X turbo compared to a non-VVT-i motor with a single profile cam suited for the same turbo.
Price on a better running engine? It depends on whether you use your car recreationally, or race it all the time, or keep it stock... Pro racers have an incredible ability to build "better running engines" and none I hear about use VVT-i, rather, VVT-i gets thrown out.
Oh and knocking on VVT-i is as cool as Honda guys knocking on VTEC after it limits their HP too.
Nick M said:
Most high HP 2J-GE owners use fucking non-VVT-i platforms, to go faster.
In stock form, VVT-i is great. WOT, 2,500 rpms full boost and full torque? Sounds like someone in Japan driving in traffic alright. Internal combustion engines are most efficient at WOT, and low RPM WOT means better fuel ecomomy. Great in stock trim, not developed (yet) for racing. I google'd "HKS VVTi" and found squat for performance products.
Like I said VVTI is better technology give better power curves & haves more posssibilty to tune!
But when you have a 7-800+ hp engine who cares about mpg you run on race gas anyway and go after power to dyno and brag about.
By the way i know a lot about VVTI i have an all motor dual VVTI engine in a 1700lb 1969 opel gt base power is 210 i plan to tune it to 275 like this guy did and with a 6 speed and 275 whp in a 1700lb car i should get a 10-11 in quater.
Researched from here also tells you how to tune dual vvti one of the best toyota engines ever made! http://www.billzilla.org/fraser.htm
http://www.fraser.co.nz/
http://www.billzilla.org/carindex.htm
http://www.billzilla.org/fraserrev1.wmv
http://www.billzilla.org/fraserrev2.wmv
how vvti works in detail! http://www.billzilla.org/vvtvtec.htm
http://www.billzilla.org/links.htm#Motor
http://www.billzilla.org/engvariable.html how to tune duel vvti
But when you have a 7-800+ hp engine who cares about mpg you run on race gas anyway and go after power to dyno and brag about.
By the way i know a lot about VVTI i have an all motor dual VVTI engine in a 1700lb 1969 opel gt base power is 210 i plan to tune it to 275 like this guy did and with a 6 speed and 275 whp in a 1700lb car i should get a 10-11 in quater.
Researched from here also tells you how to tune dual vvti one of the best toyota engines ever made! http://www.billzilla.org/fraser.htm
http://www.fraser.co.nz/
http://www.billzilla.org/carindex.htm
http://www.billzilla.org/fraserrev1.wmv
http://www.billzilla.org/fraserrev2.wmv
how vvti works in detail! http://www.billzilla.org/vvtvtec.htm
http://www.billzilla.org/links.htm#Motor
http://www.billzilla.org/engvariable.html how to tune duel vvti
Like I said before, VVT-i is great with the stock turbos and as EE1.3 has posted, great with NA. Try it past 400whp with a larger single, and try to tune it! Let us know how much it costs, then come back and let us know if it's really worth it!
"Con's to having VVT-i vs. without- You are pretty much stuck with limited modifications to the engine, eg, air filters, extractors, etc, to get more power. The reason for this is the very system that give the engine all that extra power - The cams & VVT/V-TEC. You can of course use larger cams to get more power, but this defeats the purpose of having the VVT/V-TEC in the first place. You'll most likely lose power at low revs, and not gain a great deal at high revs. (The VVT will gain proportionally more than the V-TEC, however, as the V-TEC head is optimised - well, compromised - for the 'big' cam & 'small' cam and so using a larger cam may not help much at all).
So, if you want an engine with power like a racing engine, then you're better off building a straight race engine right from the start. Or maybe a turbo engine ...
The other concern I have is the longevity of these sorts of engines. I believe that the VVT system would be largely trouble free for the life of the engine provided that you keep the oil clean and change it regularly. Even more so with the V-TEC, as with all it's little bits & pieces in close formation in the head I'd hate to think what would happen if some of those little locking pins didn't engage properly at 6000rpm+."
From http://www.billzilla.org/vvtvtec.htm
The above is for N/A only, the author even says if you want power, built a race motor with the right cams, or turbo it (meaning without VVT-i). Even the dynos for the 3S engine above, don't come turbo with VVT-i. LOL, even the Skunk 2.4L Honda engine had the VTEC removed. It's an ALL MOTOR N/A monster, that took the tube frame car into the 9's in the quartermile. If VTEC was so great, why get rid of it? It limited the motor's potential, as it does with 90% of all high HP engines. As soon as you have a turbo that will get you into 500whp on your 1J with VVT-i, I seriously doubt VVT-i will show any gains vs. the same turbo on a non VVT-i equipped car.
"Con's to having VVT-i vs. without- You are pretty much stuck with limited modifications to the engine, eg, air filters, extractors, etc, to get more power. The reason for this is the very system that give the engine all that extra power - The cams & VVT/V-TEC. You can of course use larger cams to get more power, but this defeats the purpose of having the VVT/V-TEC in the first place. You'll most likely lose power at low revs, and not gain a great deal at high revs. (The VVT will gain proportionally more than the V-TEC, however, as the V-TEC head is optimised - well, compromised - for the 'big' cam & 'small' cam and so using a larger cam may not help much at all).
So, if you want an engine with power like a racing engine, then you're better off building a straight race engine right from the start. Or maybe a turbo engine ...
The other concern I have is the longevity of these sorts of engines. I believe that the VVT system would be largely trouble free for the life of the engine provided that you keep the oil clean and change it regularly. Even more so with the V-TEC, as with all it's little bits & pieces in close formation in the head I'd hate to think what would happen if some of those little locking pins didn't engage properly at 6000rpm+."
From http://www.billzilla.org/vvtvtec.htm
The above is for N/A only, the author even says if you want power, built a race motor with the right cams, or turbo it (meaning without VVT-i). Even the dynos for the 3S engine above, don't come turbo with VVT-i. LOL, even the Skunk 2.4L Honda engine had the VTEC removed. It's an ALL MOTOR N/A monster, that took the tube frame car into the 9's in the quartermile. If VTEC was so great, why get rid of it? It limited the motor's potential, as it does with 90% of all high HP engines. As soon as you have a turbo that will get you into 500whp on your 1J with VVT-i, I seriously doubt VVT-i will show any gains vs. the same turbo on a non VVT-i equipped car.
I would love to have VVTI on the exhaust cam. I currently retard my exhaust cam by 2.5 degrees for quicker spool and flater powerband.
If that could be controlled by computer, woooohoo that would be bad ass!
Oh wait, thats been done...
If that could be controlled by computer, woooohoo that would be bad ass!
Oh wait, thats been done...
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Do it Ric, then start bragging. No one's brought any evidence of a turbo VVT-i motor showing the substantial gains. Jay's 1JZ makes more power than that RB with the variable cam timing. Hell, there are less expensive 2JZ-GE engines making more power for less money. Price per HP, wow, what a concept. You might get 10 extra HP for $3000 or so it would cost to get VVT-i going right tuned after you bought everything you needed to control it, standalone, harness, what have you. Mad money. Someone already said you can't put a price on a better tuned engine, but you can if it's a waste of money on a motor you've already spend thousands on for no gain.
Dialing in cams is part of the game, and it will not be replaced by VVT-i, VTEC or anything similar on any engine making more than 400WHP FOR THE MONEY with those above technological valvetrains. Use VVT-i, and you won't really be able to tell a difference unless you put it on a stock engine with stock turbos. Keep it stock.
Dialing in cams is part of the game, and it will not be replaced by VVT-i, VTEC or anything similar on any engine making more than 400WHP FOR THE MONEY with those above technological valvetrains. Use VVT-i, and you won't really be able to tell a difference unless you put it on a stock engine with stock turbos. Keep it stock.
RB's with aftermarket control on the VVTI show noticeable gain in HP under the curve with correct tuning. Retarded EX cam at low RPMs to promote spooling, and back to "zero" at higher rpms for power up there. Nissan had it right from the start, and the power curves they make show it. Now as far as total power output.. yeah RB's suck nuts compared to a 1JZ, but peak HP doesn't mean anything. We all seen the 1000hp 2JZGTE's get spanked by 700hp 2JZ's due to the fact of a larger power band. Thats why 1JZGTE's are so fun. We spool turbo's the same as a 2JZGTE, but we pull the power almost 2000 more rpms.
It's hard to show these results on that billzilla site, because theres major differences in NA and boosted cars when it comes to cams.
It's hard to show these results on that billzilla site, because theres major differences in NA and boosted cars when it comes to cams.
What? I've seen tons more powerful RB26s than 1Js.Ric said:
I'd like to see proof of these 700hp Supras beating 1000hp Supras. Where? the drag strip? Put a competent driver behind the wheel of a 700hp Supra and a 1000hp Supra. Do you really think the 700hp car is going to make up a 300hp deficit? :stickpoke
1Js spool turbos at the same time? Make up your mind, dude. Which is it? Is it the same or a few hundred RPM later?:icon_conf
Ric said:
Higher redline? Sure, I guess so... 2Js rev to 7k+ RPM as well. RPM is cool but if you don't have the cam for it, what does it matter? Can your 1J rev out to 8000+? Congratulations. Not like you're making anything extra up there without support cams? 2Js are known to be commonly be in that rev renge as well.
Ric said:
Try it with a 1J Ric, then tell me if it worked how you wanted it to. Nissan did it right making their valve timing for Turbo cars, see if you can apply the same to Toyota JZ with VVT-i. Toyota pussed out in the HP department with their VVT-i cam profiles (even on the 1J-GTE).
Ric, who told you this thread was about peak HP vs. larger power band? Neither one of the above used VVT-i. It doesn't matter about 500rpm faster spool the RB gets from the exhaust cam timing control. It matters about putting VVT-i on a non-VVT-i engine, or swapping the internals out JUST TO HAVE VVT-I as a MOD. You get a turbo that goes full from 4,000 to 7,000 rpms, or whatever you want to race from, and get the cams to match. This isn't difficult to comprehend. I seriously think Nissan did it better with the RB26, no one will argue that, I'm not arguing that. We are talking about how much it costs for VVT-i on a Toyota, and the 10HP or so you can gain from it.
Price per HP, VVT-i loses, unless you keep the engine stock, because that's what VVT-i was made for, more low end grunt for the traffic commuter.
Ric said:
O'RLY?
Ric said:I would love to have VVTI on the exhaust cam. I currently retard my exhaust cam by 2.5 degrees for quicker spool and flater powerband.
If that could be controlled by computer, woooohoo that would be bad ass!
Oh wait, thats been done...
The button on the RB exhaust cam is the cam/crank angle sensor. I have seen one example of an RB26 that ran dual VVTI and that was insane. I can only imagine how much he paid to have that exhaust setup done.
As for Nissan engines coming with it from factory, later Black top SR20DETs and all RB25DETs came VVTI from Nissan.
