Changing the VVL (lift) point - don't bother. [Archive]

monkeywrench

12-01-2003, 04:08 PM

Using the PFC, we fully tuned the 2ZZ in using ONLY the small cam, then ONLY the large. Then we overlaid the graphs. Drum roll please... the crossover occurred at about 6300 RPM. We got our best results during tuning the switchover by changing over at 6000 or slightly after because of the time the VVTi actuator takes to react.

See results at:

http://monkeywrenchracing.com/mwr_celica_gts.html

Why did we do this? To get people to FINALLY stop requesting a way to change over to the large cam earlier. You'll lose power, and here is the proof. We successfully did change the VVL point with the stock ECU over a year ago, the results were poor though. The reason is that the big cam dosen't offer an advantage until after 6000 RPM. Plus, if you're using the stock ECU, you can't get tune the VVL to work with the earlier VVT.

With the addition of a turbo this changes. More on that later :)

Note: Honda switches to the large cam profile later than optimal for whatever reason, which is why VTEC controllers help those engines. Toyota did not make the same choice in their tuning.

TeeAREdee

12-01-2003, 04:12 PM

:thumbup: monkeywrench

:thumbdown toyota

MicaCeli

12-01-2003, 04:21 PM

that would be why Honda has such a nice power curve.

shyvpboi

12-01-2003, 04:22 PM

1) Is the redline extended also?

2) So when are the pre-tuned PFC ready for sale?

Black_TRD

12-01-2003, 04:26 PM

:angry:

monkeywrench

12-01-2003, 04:27 PM

Originally posted by TeeAREdee
:thumbup: monkeywrench

:thumbdown toyota

This means that Toyota did things right.

I am not particularly fond of their choice in cam profiles though, which is most likely the cause of the hole at 6k. It's nothing we can't overcome.

Blue Bomber

12-01-2003, 04:44 PM

Finally, proof! :applaud:

celico_man

12-01-2003, 04:51 PM

Great job monkeywrenck, keep up the good work...

All_MTR_GTS

12-01-2003, 06:27 PM

i know you can set the rev limit to anywhere you want it but what would be the ideal cut off point! i mean you can only make power to a certain rpm.

LilRocketSpyder

12-01-2003, 06:47 PM

Great job Matt. We need more lift on the small cam. Think it could be done with a slightly redesigned rocker arm?

APRoMeO637

12-01-2003, 06:52 PM

its good to see you guys are having fun doing this also... so cams for the GTS would be extremely helpful! too bad we got none..

-Mike

vvtlikick

12-01-2003, 06:55 PM

No 5000rpm lift :(

monkeywrench

12-01-2003, 07:16 PM

Originally posted by All_MTR_GTS
i know you can set the rev limit to anywhere you want it but what would be the ideal cut off point! i mean you can only make power to a certain rpm.

We've revved it "pretty high" during testing, but as you can see the power peak is before 8000 RPM. On an autocross course you might want to rev it pretty high to avoid an upshift at the end of a straight. For drag racing you'd probably want to shift out of 1st at 8600 or so, and at 8300 or so for the other gears. There is no one right answer.

We'll see what happens to this number as more mods are added.

aznleo28

12-01-2003, 07:19 PM

so what do u mean all that changes if you have a turbo? I have the xs turbo kit with the pfc.

QWKsilvr808

12-01-2003, 09:06 PM

wow, great info! :thumbup: Thanks for all the hard work!!

All_MTR_GTS

12-01-2003, 09:19 PM

Originally posted by monkeywrench
We've revved it "pretty high" during testing, but as you can see the power peak is before 8000 RPM. On an autocross course you might want to rev it pretty high to avoid an upshift at the end of a straight. For drag racing you'd probably want to shift out of 1st at 8600 or so, and at 8300 or so for the other gears. There is no one right answer.

We'll see what happens to this number as more mods are added.

awesome!! i dont think it needs to be any higher then 8500 anyways but good stuff man keep up the good work!! :thumbup:

Bimbleuk

12-01-2003, 11:32 PM

You don't need very wild cams for forced induction cars in fact some of the best turbo cars retain standard NA cam profiles. Also a lot of valve overlap on a forced induction is bad as the turbo just ends up blowing air/fuel out the exhaust valves. So up to 96 degrees overlap on the VVTLi may actually reduce the potential from a turbo install.

I'd certainly like to see the effects from reducing the overlap on the VVTLi or even from stopping the switch to high lift completely. On my supercharged Celica the switch from low to high lift is hardly noticeable except the boost goes from 7PSI to 6PSI when the switch happens. Is that due to better the VE of the engine or because the effective compression is reduced due to the overlap?

Keep up the good work by the way. Good to see a proper analytical approach for a change backed up by before and after graphs!

Keyshawn

12-02-2003, 06:15 AM

Great work. Now if we could get some cams for this engine, the n/a guys would have some great power potential.

monkeywrench

12-02-2003, 11:26 AM

Originally posted by aznleo28
so what do u mean all that changes if you have a turbo? I have the xs turbo kit with the pfc.

The tuning needs to be very different. Hopefully we'll get to do another turbo car soon so I can do similar testing to optimize it. We've done it in the past, but before the Datalogit so we couldn't save maps.

marc

12-02-2003, 12:48 PM

SO would it be beneficial to engage lift earlier on a supercharged car?

monkeywrench

12-02-2003, 01:44 PM

Originally posted by marc
SO would it be beneficial to engage lift earlier on a supercharged car?

Only the all-knowing dyno can answer that.

cool2miketlu

12-02-2003, 02:06 PM

XS-Engineering already said this about 6 month ago when they played with the GT-S before installing the turbo.
Neways good to see the dyno sheet to give further proof :)
XS-Engineering also showed that there is not that much HP to be gained (without going dangerously too lean) from further tuning on NA GT-S to make PowerFC to be worth buying, however for boosting application it is a great device.

marc

12-02-2003, 06:18 PM

Originally posted by monkeywrench
Only the all-knowing dyno can answer that.

I just wish it weren't so expensive to find out!

Jesse IL

12-02-2003, 06:22 PM

Originally posted by monkeywrench
The tuning needs to be very different. Hopefully we'll get to do another turbo car soon so I can do similar testing to optimize it. We've done it in the past, but before the Datalogit so we couldn't save maps.

I might be able to offer you up my car for this. I am thinking seriously about a turbo setup. What type of timeframe are you looking at?

monkeywrench

12-02-2003, 07:07 PM

Originally posted by Jesse IL
I might be able to offer you up my car for this. I am thinking seriously about a turbo setup. What type of timeframe are you looking at?

Tomorrow good for you?

Rave669

12-02-2003, 07:08 PM

nice dyno's man, but the key is labeled as every color being the small cam, looking at the chart, I figured it out though, it wasn't that hard. Just thought I'd let you know.

It looks as though you may benifit by moving changeover up to about 6500 RPM, but I suppose by that point, torque would've fallen off too much, so the toyota guys apparently did a bang-up job at tuning the ECu from the factory. Guess I'll scrap my OCV controller for a while.

Apparently the guys at lotus did figure out a way to do it though, you may want to look into it. Issac posted this in the EC.com forums... Check this out:
http://homepage.interaccess.com/~wcsi/pics/1862378574-screen.jpg

So I suppose another possibility will be to perform a lotus ECU swap, or wait for toyota to adopt this new tuning. Maybe you can call some people and find out how they smoothed out the changeover.

Keyshawn

12-02-2003, 08:12 PM

Originally posted by marc
SO would it be beneficial to engage lift earlier on a supercharged car?

Engaging lift earlier in a supercharged Prelude helps quite a bit, as shown by this dyno (notice the improvement in the HP and torque curves in the midrange area):
http://www.jacksonracing.com/pages/details/detailjr/images/99prelude_vpac.gif
http://www.jacksonracing.com/pages/details/detailjr/99prelude_vpac.html

It's possible our car might see similar gains. However, we'd probably have to change our lift bolts every week if our changeover was lowered to 3000 rpms like this Prelude's was.;)

http://www.jacksonracing.com/index.html
http://www.jacksonracing.com/pages/hondapps/vpac.html

bagodoosh

12-02-2003, 10:16 PM

regarding the prelude..
Originally posted by monkeywrench
Note: Honda switches to the large cam profile later than optimal for whatever reason, which is why VTEC controllers help those engines. Toyota did not make the same choice in their tuning.

Keyshawn

12-02-2003, 10:21 PM

Originally posted by bagodoosh
regarding the prelude..

I think that the supercharger has more to do with it than Honda's tuning in that particular case. An n/a Prelude would probably run like crap with a 3000 rpm VTEC switchover.

bagodoosh

12-02-2003, 11:16 PM

oops. i forgot conversation moved to F/I. :gap:

t2000gts

12-03-2003, 05:53 AM

that's a sign that the big cam on our engines is quite aggressive. :thumbup: to toyota. similar power curve to the B18C5 (ITR).

t2000gts

12-03-2003, 05:54 AM

Originally posted by Keyshawn
Engaging lift earlier in a supercharged Prelude helps quite a bit, as shown by this dyno (notice the improvement in the HP and torque curves in the midrange area):
http://www.jacksonracing.com/pages/details/detailjr/images/99prelude_vpac.gif
http://www.jacksonracing.com/pages/details/detailjr/99prelude_vpac.html

It's possible our car might see similar gains. However, we'd probably have to change our lift bolts every week if our changeover was lowered to 3000 rpms like this Prelude's was.;)

http://www.jacksonracing.com/index.html
http://www.jacksonracing.com/pages/hondapps/vpac.html

aren't the lift bolts always under a little wear at all times to begin with? just hitting lift more shouldn't make it that bad

CIN

12-03-2003, 08:16 AM

I really think that with some nice headwork the stock cams should still be making power above 8k. This can also be seen from various dyno sheets with only bolt ons.

The problem we have is the low lift cam.

CIN

12-03-2003, 08:21 AM

I would like to see a dyno of the lotus tuned 2ZZ to see the difference in the torque curves. As for the mech changes. Only the in/ex manifolds are changed and I do not know if the intake is that much different. The difference is probably in the TB/surgetank as the piping seems the same as the celica.

OH and Toyota has already 2 different intake manifolds. One with the straight TB inlet and one where the TB is at an angle.

Look

2002 engine

http://www.spydermagazine.com/files/MRS2ZZthrottle.JPG

Engine from japan(dont know year)

http://www.spydermagazine.com/files/2zzmanifold1.JPG

And one pic of the engine on my car :D

http://www.spydermagazine.com/files/MRS2ZZcomplete8.JPG

Keyshawn

12-03-2003, 08:31 AM

Originally posted by t2000gts
aren't the lift bolts always under a little wear at all times to begin with? just hitting lift more shouldn't make it that bad

That last comment was an exaggeration, hence the ;). However, you do bring up an interesting question. I also wonder exactly how much lowering the changeover (and thus hitting lift more often) affects the life of the lift bolts and other components in our VVL systems (engagement pin, etc.).

vvtlikick

12-03-2003, 09:56 AM

CIN mentions the intake manifold with the angled inlet. I expect that's just change made for fitment on the Matrix/Vibe/Corrola, since the intake tract runs "backwards", compared to the Celica.

I expect most of the Elise intake/exhaust manifold changes are for fitment, and maybe a little for performance :) But we'll have to wait and see.

As for lowered lift engagement increasing wear, It wouldn't be a problem with the way I drive, unless the lift engagement threshold is moved into the normal, boring rpm, ie. below 5000rpm.

Lowering the lift disengagement point could prevent wear for the same reasons, by keeping you from falling out of lift. :)

Jesse IL

12-03-2003, 11:24 AM

Originally posted by monkeywrench
Tomorrow good for you?

hahaha...I wish. Give me a number to call any a contact person and we'll talk about this more. Thanks.

afghan

12-04-2003, 06:35 AM

Originally posted by TeeAREdee
:thumbup: monkeywrench

:thumbdown toyota

That has to be one of the funniest Signatures I have ever seen!

:gap: :gap: :gap: :gap:

Ditto

12-04-2003, 10:40 AM

Cin, I have both types of intake now. Which do you think would be better for the Spyder application? Can you see any issues with fitment of the angled one ( I see the straight fits:) ). Do you think their is any advantage to one over the other?

CIN

12-04-2003, 02:13 PM

I think that photo was from you??? :)

I think that with the angled one you would be better off if you want to use the stock intake since the stock 1ZZ has an angled TB. Actually mine with the straight TB is a bit tight in there since the piping is a bit too low.

You can use whatever you want but I suggest you use the straight one and make a straight intake pipe to the vent. I have one on order from PPE. Should make a nice power up. :D

how did you get both??? Two engines??

Ditto

12-04-2003, 03:38 PM

Yeah two engines, I bought the one in the pic first. Then I got a pretty good deal on an engine, tranny, and ecu. Got all the wiring and stuff too. I'm waiting on my shaft from LR, then install LSD, Cryo tranny, finally the install of engine and tranny.

I'll pobably hit you up for some of the wiring info around the first of the year if thats ok.

The intake, is it like the Spyder one their selling? What if anything did they change? Will they make it available for us engine swap jobs (if it's different from the Spyder ones)?

LilRocketSpyder

12-04-2003, 05:12 PM

I doubt anyone will make an intake for engine swaps. I have an injen for the celica. It is a larger diameter than the spyder's. It makes about more 10 h/p on the celicas IIRC. Going down to the spyder's intake is no doubt losing probably 5-10 h/p plus the stock ecu won't like it.

I intend to cut up and route the celica injen like injen did their intake for the spyder.

Ditto

12-04-2003, 05:53 PM

The intakes are .25 in. different inside diameter, right? I was just wondering if Cin had talked them into one of their design with a larger diameter pipe.

CIN

12-04-2003, 06:57 PM

Ditto Paul is making one specifically for me so when that is ready(next week or so)I am sure he can replicate it again. :)

LRs route will be much cheaper for him than buying one. ;)

You can email me anytime. Same goes for LR obviously :)

I do not have much time to do the write up I promissed...sorry :(

LilRocketSpyder

12-04-2003, 09:54 PM

S'ok I am taking vacation in January to do my install. I have at least 2 spyderchatters that are going to lend a hand. On is coming from South Carolina. Should be a fun week. I will write it up then.

CIN

12-05-2003, 01:39 AM

Thanks David.

If you need anything let me know.

I will try and make a small summary before then with what you need. :)

Celicasaur

09-11-2007, 04:10 PM

Nearly 4 years on and we have seen that it IS possible to lower the VVL point AND make power. Just to do with tinkering with VVT.

Or have I lost the point somewhere in translation...?

Jesse IL

09-11-2007, 05:40 PM

You haven't missed anything. MWR was wrong. Changing the VVL point AND making power is tricky, which is why at first glance it would appear that it doesn't work.

Boosted2.0

09-11-2007, 10:35 PM

You haven't missed anything. MWR was wrong. Changing the VVL point AND making power is tricky, which is why at first glance it would appear that it doesn't work.

+1

You can lower lift point sucessfully below 6K and make power but it requires VVTi and AF tuning to work right as Jesse says.

MWR does a lot of cool stuff, but Matt is human too - hes no more omnicient or infalliable than any of the rest of us.

Jesse IL

09-12-2007, 06:55 AM

+1

A big factor is that tuning the VVT system was very new to everyone with this motor. There are still many, many shops/tuners that completely ignore it while tuning, either assuming that its good enough, not realizing its even there or avoiding it entirely because they just didn't understand it. When we were tuning Smaay's car, a couple of the guys there seemed completely mystified by it. I explained that it was simply a programmable adjustable cam gear, but I still don't think they were making the connection without having an actual adjustable cam gear that they could physically touch and adjust. To be fair to Matt, this thread is four years old, and the PFC was a very new thing at that time. I've been working with the PFC for three years and am still learning new tricks or better ways to do things.

Celicasaur

09-14-2007, 06:20 AM

Yeah I agree with you guys.

Just a shame that being able to adjust cam timing as easily as this, is not something more and more tuners are able to grasp...

monkeywrench

09-17-2007, 10:34 AM

Unless I've missed something this still holds true. With heavily modified engines (stroker, high compression, long tube header) we can get the optimized point as low as 5500 but for your conventional 2zz you still want to be switching at 5900-6000. Sure, you can make the point as low as you want but it will hurt acceleration. The original point of this post was to address the phone calls we used to get every day from people asking us how to change the VVL point on their stock engines to 3500rpm. Those calls have let up over the years so I think it did its job.

It's not a matter of a tuner being "able to grasp" VVT in our case. When the optimized (VVT, ign, fuel) torque curves for the small and large cams cross at 6k it's just not common sense to to switch at 5k.

Obviously aftermarket cams and turbo/supercharger systems change things completely. In fact I'd bet we're hitting the big cam much lower than anyone on earth with our race car right now because of its unique setup. On a stock-ish NA car though we still end up near 6k.

Jesse IL

09-17-2007, 11:22 AM

Redliner9k

09-17-2007, 12:58 PM

Matt, with proper VVT tuning, many people have found very sizeable gains on a stock 2ZZ engine by setting the lift transition at 5600 rpm. There are several dyno graphs which prove this. Turbo engines seem to vary setup-by-setup as to what the ideal point is.
+999999999

I've been one of those persons able to lower Lift as low as 5500rpm on a stock 2zz and as low as 5200rpm with a custom long tube header. I've achieved this tuning both PFC and Hydra. All of them with mayor gains in the powerband.

mitsumania

10-31-2007, 12:54 AM

(sorry new guy here has uh dumb question) PFC is a performance chip rght?

zuoom

10-31-2007, 02:01 AM

you guys managed to tune a SC 2zz? hearsay the lotus 2zz does the cam changeover at around 4000rpm.

Genomaxter

10-31-2007, 07:07 AM

PFC is a stand alone unit. Chips suck.

I have never heard the SC Exige has lift at 4000. Its at the same spot as all stock 2zz's.

Jesse IL

11-01-2007, 03:00 PM

oleg

11-21-2007, 04:24 PM

danGTS

11-21-2007, 08:33 PM

Here's a dyno showing that this works.

This is a car with a map that was not even tuned for his car and no additional tuning to try and correct the dip at the lift transition.

http://www.newcelica.org/photopost/data/500/medium/10934PFC_Dyno.jpg

Nice dip at 5.5k! (I am just saying this tuning i snot optimal)

i havent been able to go as low as some guys here but 5.8k went well and smooth with mine (with proper vvt and AF adjustment). 5.6k did not work ,a dip at transition no matter which vvt (with AF adjsutment). 5.7k might have worked but I did not bother. Might be because of my injen .. (unless someone claims it was done with injen)

nikos

11-27-2007, 11:23 AM

C:\Documents and Settings\Gates\Desktop\NIKOS MUSIC\PHOTOS\ΚΑΣΤΟΡΙΑ 2007\20070916\17082007256
This my dyno sheet with tony map 04

nikos

11-27-2007, 11:25 AM

Sorry this trully wrong but I don't know how to post dyno photo as above.Any help?

zero2toy

11-27-2007, 01:22 PM

post the picture on a photo share site, ie photobucket, they will give you the code to put the pic up on this board.

Jesse IL

11-29-2007, 06:48 AM

He emailed me the pictures and I tried looking at them, but they were almost impossible to see and didn't show anything conclusive at all. Basically, there was still a huge torque dip at the lift transition and I can't believe the car was making very good power, because the ignition timing is pretty retarded on the map he's using. It was only a base map and needed significant additional tuning at both the lift transition and with timing/fueling/VVT.

danGTS

11-29-2007, 10:10 AM

Jesse IL

11-29-2007, 11:21 AM

I can't believe the car was making very good power, because the ignition timing is pretty retarded on the map he's using.

Not saying the opposite since that's very likely, a good tuner is hard to find for us but ..

Lemme still guess, injen intake again?

I have no idea what he was running intake-wise, but he was running an older revision of a base map unmodified. I'm going to assume the AFR was fine, but VVT is rough at best and I can tell you for a fact that ignition timing was retarded. Its impossible for his car to make good power using that map.

zuoom

12-26-2007, 06:57 AM

you guys managed to tune a SC 2zz? hearsay the lotus 2zz does the cam changeover at around 4000rpm.

http://www.seriouswheels.com/cars/top-2006-Lotus-Exige-Cup.htm

The supercharged and intercooled engine in the Lotus Exige Cup 240 has a maximum power output of 247 PS (243 hp / 181 kW) at 8000 rpm and a torque figure of 236 Nm at 7000 rpm. This vast amount of extra power and torque now available means that the cam change between the low-speed cam and the high-speed cam now takes place at around 4000 rpm giving a smooth and linear surge of power from 4000 rpm all the way to the maximum 8300 rpm.