20V BT low compression!

[Sportmax]

Anyone have any insight on my problem. Im kinda stumped right now.

I just tuned my 20V BT and it came back with disappointing numbers on the dyno. 128WHP and 97WTQ(comparisson, my friend put down 124whp and 104 torque on the same dyno in a MR2 last year. Toally stock engine). I tested the compression it showed 120PSI across the board, no varience between cylinders(maybe 2 psi). This is cranking 4-5 times. First crank shows i think 40 or 50PSI. I did a cylinder leak down test and I have 2% leakage again across the board. All of this was done with a warm engine. Im lost at what is going on. Do i have missed timed cams, to much over lap? somthing does not add up. I did a wet test on 2 cylinders and it did not increase that much.

It ran fine on the stock ecu before I did the AEM and tune. I never checked the compression before. It did have this weird lean condition and not wanting to accelerate when the vvt kicks in, that is Gone now with the EC/tune. It runs great now, pulls decent just does not have the power I was hopping for.

Here is my setup.
20V BT
TRD.8mm head gasket
Tomie Pon Cams
Stock VVT(it does work. i did swap out the actuator at one point with a used one thinking it was bad)
AEM EMS 4. Direct injection and ignition with stock dizzy cam/crank signals
Toyota 1ZZ COP
Open ITB
Cusco header with a very short cat back
540cc Injectors
Tomie FPR
E85

[jondee86]

I tested the compression it showed 120PSI across the board,..

That compression is way low. I suggest you check the cam timing to see if looks reasonable.
Starting point would be factory standard timing, as those cams should install at near enough
to factory timing when set according to the marks on the factory cam pulleys.

There is a post somewhere about an error in the cam pulley mounting instruction in the FSM.
If you have had the pulleys off, that would be worth checking out.

Cheers... jondee86

[yoshimitsuspeed]

Gauges can vary by a huge amount. Elevation also has a big effect. It is extremely unlikely that your motor would be going bad so evenly. The chances of all cylinders dropping that much so evenly is pretty much impossible unless like jondee said your cam timing is off or if you have been running an even amount of dirt through the motor. You say you have open ITBs so I suppose the latter may not be impossible. If it's not killed yet get some filters on that thing before you do wreck it. The first thing I would do is test another motor that is pretty guarenteed to be healthy to use as a baseline.

[Sportmax]

We can forget about this thread. No clue why im low on power for what I was expecting but regardless it runs good.

I took altitude into consideration but that should not cause a almost 100PSI drop. I think my almost brand new Mac Gauge is JUNK. We tested my buddys BT and it came back with almost identical readings. 120-125PSI. So my engine is in Great shape. Oh and my timing belt timing is dead on.

Thanks for looking tho
Kirk

[yoshimitsuspeed]

It's kind of sad but this is common even with high quality gauges. Sounds like the motor is healthy though so that's good.

[Duy-]

the tomei poncams drop the compressiong slightly, not that much.

mr2 has a fwd layout so numbers will be slightly higher due to less drivetrain loss and im just solely assuming you have an ae86 because you mentioned his was an mr2

128 whp is pretty good but id like to see the graph, it'll tell us more about how your engine is running keeping in mind each dyno on each day reads just slightly differently but more than that, please share because it always helps to see what other blacktop owners are getting

[Sportmax]

Sure, ill take a pic of my graph tonight. The MR2 Is totally stock!! No cams, no nothing. I would figure he has less drive train loss then my AE86 but I figured I would gain more then 2 torque over my crappy worn out 16 valve.

Yoshimitsu, I was thinking about buying a cheap parts store gauge and comparing. I used to use a cheap O'riellys guage and that one was spot on and lasted a few years untill it fell apart.

[yoshimitsuspeed]

Sure, ill take a pic of my graph tonight. The MR2 Is totally stock!! No cams, no nothing. I would figure he has less drive train loss then my AE86 but I figured I would gain more then 2 torque over my crappy worn out 16 valve.

If his MR2 was a stock largeport then either that dyno was way off or he had a 25 shot of nitrous in the trunk.
Look at the 4AGE dynos at the bottom of this page to see what your average largeport will do.
http://www.mr2ownersclub.com/mr2records/dyno1.htm
Even the fourth up on the list with mild mods didn't break 110.

a. torque is irrelevant until you associate it with an RPM.
b. the 20 valves are designed to move the VE curve up and therefore the power curve. They are designed to make more power higher in the RPM.

[Sportmax]

OK heres my Dyno Graph. The blue initial run is NO VVT. Then we turned on the VVT and the red run shows that.

[Sportmax]

Sure, ill take a pic of my graph tonight. The MR2 Is totally stock!! No cams, no nothing. I would figure he has less drive train loss then my AE86 but I figured I would gain more then 2 torque over my crappy worn out 16 valve.

If his MR2 was a stock largeport then either that dyno was way off or he had a 25 shot of nitrous in the trunk.
Look at the 4AGE dynos at the bottom of this page to see what your average largeport will do.
http://www.mr2ownersclub.com/mr2records/dyno1.htm
Even the fourth up on the list with mild mods didn't break 110.

a. torque is irrelevant until you associate it with an RPM.
b. the 20 valves are designed to move the VE curve up and therefore the power curve. They are designed to make more power higher in the RPM.

Sorry thats my Mistake. Thought I said it in my OP but I did not. He has a 20V swapped First Gen MR2. I looked at his graph and its based on speed Not rpm so I can not compare the two.
I do need to adjust my Map to turn Off the VVT around 6400 or so. When we did the tune we did not know how to turn it off yet.

[yoshimitsuspeed]

Sure, ill take a pic of my graph tonight. The MR2 Is totally stock!! No cams, no nothing. I would figure he has less drive train loss then my AE86 but I figured I would gain more then 2 torque over my crappy worn out 16 valve.

If his MR2 was a stock largeport then either that dyno was way off or he had a 25 shot of nitrous in the trunk.
Look at the 4AGE dynos at the bottom of this page to see what your average largeport will do.
http://www.mr2ownersclub.com/mr2records/dyno1.htm
Even the fourth up on the list with mild mods didn't break 110.

a. torque is irrelevant until you associate it with an RPM.
b. the 20 valves are designed to move the VE curve up and therefore the power curve. They are designed to make more power higher in the RPM.

Sorry thats my Mistake. Thought I said it in my OP but I did not. He has a 20V swapped First Gen MR2. I looked at his graph and its based on speed Not rpm so I can not compare the two.
I do need to adjust my Map to turn Off the VVT around 6400 or so. When we did the tune we did not know how to turn it off yet.

Ah okay that makes sense.
With the mods you list I would expect you to be a bit higher but it really depends on a lot of things.
How have you tuned it? This is the biggest thing. How have you tuned your fuel and timing maps? Is fuel dialed in?
Have you tried to tune timing for MBT? If so what method did you use?
Honestly I would get filters on your stacks. It's just not worth ruining a motor for looks or 2 extra hp.

Why are you using such big injectors? They should still be small enough to not have a big impact on spray pattern but never the less they are probably double what you need.

Also why does the dyno cut out so bad up top? If the graph is so chopy how are we supposed to trust it's accurate?

[Sportmax]

Laptop, Aem Tuner program on a dyno. I did not tune it. Fuel seemed to be pretty dialed in. Had a pretty close to 13:1 AFR. That is shown on the botton of the dyno sheet. We only had an Hour on the Dyno so could probably get more out of it with more time. We did not mess with timing very much as we only had time to get the fuel and vvt dialed in. The ecu likes to lose connection with the laptop so you have to save the map and reload it after a change, Very time consuming.

Im running E85 so need biger injectors. Ive heard of people running 380CC on E85 but these injectors were what I had at the time(MR2 Turbo).

Not sure why its breaking up at the top. I did notice every couple pulls it would sputter right before it hit rev limit, but be fine up to that point. I have a pull down resistor in my cam signal to ground to eliminate noise. might need a different ohm rating to solve that if that is why its breaking up.

Im thinking about air filters. Its not a DD and barley gets driven on the street.

[yoshimitsuspeed]

I totally missed the E85 part.
That's going to loose you power.
To come close to making as much power as you would on pump gas you would need to throw as much compression at it as possible. Even then in NA form it's hard to make up for the lost energy content of Ethanol.
With the poncams I would probably be aiming for 13:1 or higher.
E85 is great with boost because you can throw a ton more air at the motor and therefore make up for the shortcoming in energy content of the alcohol.
In NA form it's hard to get any performance benefit out of it.
Since you could run your current build on pump gas without any trouble you would make more power on it than you will on E85.

[Sportmax]

So what your telling me is I need to TURBO my car HAHA HEHE

I guess that was my biggest miscalculation. I know E85 has less energy potential then Pump Gas but with all my research people with NA and this engine have run it succesfully. The only variable I forgot to take into consideration is Altitude. 5000 feet above sea level is a lot of air to lose for any NA engine. All the success storys I have read with this engine and other engines on E is probably at Sea Level where there is a lot more air to be squeezed. Might have to spend the money to retune on 91. Damn I like the smell of E85

[yoshimitsuspeed]

So what your telling me is I need to TURBO my car HAHA HEHE

I guess that was my biggest miscalculation. I know E85 has less energy potential then Pump Gas but with all my research people with NA and this engine have run it succesfully. The only variable I forgot to take into consideration is Altitude. 5000 feet above sea level is a lot of air to lose for any NA engine. All the success storys I have read with this engine and other engines on E is probably at Sea Level where there is a lot more air to be squeezed. Might have to spend the money to retune on 91. Damn I like the smell of E85

The altitude doesn't change the rules but it would change the setup slightly.
For example for an optimized build you might be able to run 13.5-14:1 at your altitude on E85 but you may not be able to drive it down to sea level or maybe you could with a conservative enough map and good knock control.
If you were running that kind of compression you would be able to give an 11.5:1 pump gas build a good run for it's money. The only point that an E85 tune becomes the slightest advantage is when the build is too aggressive for pump gas.
You joke about turbo but on E85 with a good tune I bet you could run 10 PSI without breaking a sweat and with a good safe margin for error.
I am at 6500 feet and I am running 7 PSI on my blacktop with stock internals and stock compression on a GZE ECU. With a set of poncams I could run more, with good engine management and better pistons I could run even more. That's on 91 octane because that's all we get up here. On E85 with good pistons, turbo cams and good engine management on 11:1 compression I should be able to make some pretty serious power. That's where E85 becomes a real contender. The difference between you and sea level is a couple PSI. E85 makes it's self valuable when it allows you to run 20 PSI boost on a build that could only run 10 PSI on pump gas.

You say people have run E85 successfully. That doesn't mean they got it to perform superior to pump gas. That takes work and generally boost.

[Sportmax]

I was just reading your Blog on turboing 4AGE's. Think im sold. I have all the supporting mods to run a turbo. Just need the kit. This is not a drag or drift car so I dont need to go Crazzy on power.
Time to start doing side jobs and start saving. In the mean time Ill probably just run my current set up instead of spending more money on tuning for pump and get some Air Filters

[yoshimitsuspeed]

I will tell you high comp turbo 20v is the most enjoyable motor I have ever driven. Not the most powerful by any means but generally speaking especially for a DD and or play car I'd take it over just about anything.

At just 7 PSI it does 0-60 about a second faster than my GZE longblock did on the same turbo at 12 PSI. Beyond that it sounds better, feels better, is more fun and gets 20% better gas mileage.

[Sportmax]

Wow very nice. I bet it handles great on the street since it can spool the turbo so fast. This is my autocross car so fast spooling is Good. The car only weighs 1975 so it does not take much to make it a fast car. I run with 400hp Subarus all day long and usualy hang or beat them autocross racing. What kind of numbers does your car put down? Is it a 2 or 86?

Do you make Intake manifolds? I thought you did but I dont remember. I found the turbo kit I want but the only thing illuding me is the intake. There is a OBX mani out there but since my car is RHD it will need to be Modified to fit around the clutch master!

[yoshimitsuspeed]

Wow very nice. I bet it handles great on the street since it can spool the turbo so fast. This is my autocross car so fast spooling is Good. The car only weighs 1975 so it does not take much to make it a fast car. I run with 400hp Subarus all day long and usualy hang or beat them autocross racing. What kind of numbers does your car put down? Is it a 2 or 86?

Do you make Intake manifolds? I thought you did but I dont remember. I found the turbo kit I want but the only thing illuding me is the intake. There is a OBX mani out there but since my car is RHD it will need to be Modified to fit around the clutch master!

Yeah I can make anything you need.
Here is a 16v mani I made for a turbo race car a while back.
https://www.facebook.com/MatrixGarage/p ... =3&theater
Big short runners and massive plenum. I think they wanted peak power around 9k RPM or something.

Then of course there is my 20v mani I made for my car with an integrated water to air IC.

What turbo kit are you looking at?

I haven't dynoed it yet but up here I'd guess 170ish WHP. At sea level I'd be pretty stoked if I could put down 200 WHP on 93 octane.
I have a MS3 half built for it but since starting my business I haven't had the time or money to finish it or try to push the build further.

[Sportmax]

Yeah I can make anything you need.
Here is a 16v mani I made for a turbo race car a while back.
https://www.facebook.com/MatrixGarage/p ... =3&theater
Big short runners and massive plenum. I think they wanted peak power around 9k RPM or something.

Thats the one I was thinking of that you had built. Thing that sucks when I bought this engine it came with a Intake Mani and a oil pan with a drain already in it. I sold the Intake not thinking I would never turbo it. Kicking my self now. I am running a Greddy oil cooler/filter relocation so I just run the oil feed and drain right from there.

I know its ebay but I have heard decent things about these guys and besides the exhaust mani outer bolts need a trim to fit the 20V it is a direct kit with everything i need for a price my wife may handle She races with me but doesn't spend money like I do lol.

http://www.ebay.com/itm/CXRacing-Coroll ... d7&vxp=mtr

[yoshimitsuspeed]

I don't know much about that turbo but a. I would run a name brand turbo and b. I think you could run a smaller turbo with quicker spool. With your current setup you aren't going to be running 20 PSI or making 350 WHP so the gains from a smaller turbo would outweigh the very marginal benefit of a bigger turbo.
Personally for a high comp autox car I would go dor something in the size of a T25 /13t and aim for 240ish WHP. A step up would be in the range of a T28/14b that would get you into the 300ish range at the cost of a little spool.

I would probably suggest starting with something on the smaller side then you could bump it up later if you want. Just go with a flange format that will give you options to grow. Some turbos have unique flanges and if you want to try something else you would have to change your whole setup.
I am most familiar with and therefore prefer T25 and DSM/MHI turbos. They also have lots of options to size up and down if you want to.
You could probably find a used turbo in decent condition for a decent price. Something like this http://www.ebay.com/itm/Garrett-t25-tur ... 66&vxp=mtr

Or a DSM T25 or something.
http://www.ebay.com/itm/T25-TURBO-2G-DS ... 25&vxp=mtr


I can get CXracing stuff too so if you decide to order let me know and I can get it for you.

[Sportmax]

The CXracing turbo does seem a little big but i just like the kit as it has everything i need to put it together with out searching for parts or peicing it together and fabricating anyting. I know the T3 flange was(or used to be) pretty popular. I haven't been in the turbo game for a Long time. Been NA for Years now and my Skyline was on stock twins.

It will be some time before I can get the funds together to do this even tho I want to do it NOW. Ill definitely hit you up when that time comes. See if we can figure out a Intake or modify a OBX.
Ill be up in Delta in September for a friends wedding.

OBX Intake
http://www.ebay.com/itm/OBX-Intake-Mani ... 15&vxp=mtr

[yoshimitsuspeed]

Sweet, well hit me up if you end up near Carbondale.

Yeah T3 turbos have a pretty good selection. I steer clear of them mainly because I never took the time to get familiar with them and I find there nomenclature and ratings too confusing to bother with trying to get familiar with them.