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Discussion Starter #1
After fixing a few issues with the original config of my Link G4 Storm we ran the car on the dyno this week. With some tuning the results were 193 Bhp at Crank and 145lb/ft at Crank. I am happy with this as the engine, although rebuilt with ARP and uprated parts, is essentially stock performance wise.



What is confusing me is that after 7,000 RPM the power and torque drop away pretty quickly and I would have expected a flatter curve until 8,000rpm or so. I have lift engaging at 5,600rpm.

Any thoughts on why this might be, or should I stop over analysing this :D ?

My suspicions are that the main offender may be my exhaust, this is a solution built from a Toyosport header, the cat removed and a Blitz rear silencer.



I appreciate your time to offer any ideas.
 

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What are you tuning with? Looks like a crappy tune to me. Power and Torque should be smoother especially around the cam change over
 

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I actually would be prett happy with those numbers and curves. It is dropping off before redline but you are getting a nice horsepower peak right in the meat of that torque plateau. Seems like if you are running it hard you should be able to keep it in lift and playing in that sweet zone.

What ECU or EMU are you using?
 

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Discussion Starter #4
What are you tuning with? Looks like a crappy tune to me. Power and Torque should be smoother especially around the cam change over
:D

The engine is running a Link G4 ECU as mentioned. No 2ZZ maps were available so we are starting from zero and basing things on what I can find. The engine pulls cleanly and AFR's are constant, its just the post 7K issue that I find curious. Also look at the scale, its not "that" lumpy

Thanks
 

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Discussion Starter #5
I actually would be prett happy with those numbers and curves. It is dropping off before redline but you are getting a nice horsepower peak right in the meat of that torque plateau. Seems like if you are running it hard you should be able to keep it in lift and playing in that sweet zone.

What ECU or EMU are you using?
Yeah as mentioned I am happy with the the power as it's basicaly a stock engine updated for reliability, its the odd fall off at 7K I am confused by. The ECU is a Link G4 Storm.

Thanks
 

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:D

The engine is running a Link G4 ECU as mentioned. No 2ZZ maps were available so we are starting from zero and basing things on what I can find. The engine pulls cleanly and AFR's are constant, its just the post 7K issue that I find curious. Also look at the scale, its not "that" lumpy

Thanks
I am talking about your two dips, the one at the cam change over, which I am sure makes the car sound real cool, and the power dive at 7K. I did notice that it starts to come back up. Makes me wonder how old the motor is. An older used motor could be inducing some noise and making the knock sensor activate a knock ignition retard map. It could be a hundred different things though. With out seeing a log file who knows
 

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8uijn vc
 

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I appreciate your time to offer any ideas.
Your Sick.. the Shop is too Clean.. :)

I would look at the Exhaust.. that is a good clue..
It does start to rise at the end.. little strange.. I would like to see some logging of the MAF sig and Knock Value.. might show something..

Thanks for Posting..

Cap
 

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It almost looks like the operator lifted his foot off the pedal after 7k. Exhaust won't cause that much of a drastic drop, timing can though.

Just curious why are there 2 oxygen sensor bungs on the headers anyway?
 

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Dip then rise appears to be a vvt issue. Cam angle is probably out of whack at 7.2k rpm

The Link G4 storm says it can control VVT, I don't have any experience with it but was your tuner able to adjust the VVT?
 

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Discussion Starter #12 (Edited)
It almost looks like the operator lifted his foot off the pedal after 7k. Exhaust won't cause that much of a drastic drop, timing can though.

Just curious why are there 2 oxygen sensor bungs on the headers anyway?
Interesting thought.

Not sure, thats how it came, they are un-used. I use a single wide band later in the system. I plan to buy/have built a 4-1 solution soon anyway. The PPE system I like but shipping to the UK for such a large item is obscene at the moment! :D

Thanks
 

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Discussion Starter #13 (Edited)
Dip then rise appears to be a vvt issue. Cam angle is probably out of whack at 7.2k rpm

The Link G4 storm says it can control VVT, I don't have any experience with it but was your tuner able to adjust the VVT?
Yes we had a little play with the VVT table but mostly concentrated on fuel and timing. No 2ZZ-GE tables for VVT were available so I wrote my own based on what I can find on the internet and by converting some PFC ones a couple of the guys on here were kind enough to send.

This is inlet cam advance, so for comparing to PFC tables use 55-my number. Hope that makes sense :) I am somewhat starting from scratch, so as this is the first session I am encouraged. If we can smooth out some of the curve a little and recover the power later on I will be very happy.

Thanks.



I was reading your forum and Arthur's car is what got me thinking :) Some nice work on your cars. Aslo one of your inlets might help I think, can you send them to the UK ;)
 

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Discussion Starter #14
Your Sick.. the Shop is too Clean.. :)

I would look at the Exhaust.. that is a good clue..
It does start to rise at the end.. little strange.. I would like to see some logging of the MAF sig and Knock Value.. might show something..

Thanks for Posting..

Cap
Not mine, thats Rogue Motorsport UK. They built and installed the engine. I am just an amateur playing around here. Their shop and the tuner they use are a bit too far from my home for regular visits, hence me working on this in the interim.

Thanks for the hints, the Link has a good logging facility so I will try to grab some.
 

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Are you using MAF or MAP? Why is the VVTI scaling based against TP%. That wouldnt be my ideal setup especially if you have a stand alone setup
 

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How do you like the EMS?.. is it easy to work with.. Cost?..

AND.. are you going to share your Map?..

Cap
 

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If you have the time and don't mind a bit of redundant wiring, the way I would normally approach something complex like VVT tuning on a new platform would be to first wire in the standalone as a logging box (don't let it control spark or fuel) and log what the stock ECU does.

But it looks like you're past that point. As you are running a real ECU, do some logging.
In particular, log MAF voltage, load and RPM (and AFR) and have a go at tinkering with the cam angles in between runs. Bascially, you want to find the angle at each load/rpm point that maximizes MAF voltage.

If you want to go nuts and have 3 spare inputs on the G4, slap in a cheap 3-axis accelerometer. It's like having your own private street dyno. :)
 

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Discussion Starter #18
Are you using MAF or MAP? Why is the VVTI scaling based against TP%. That wouldnt be my ideal setup especially if you have a stand alone setup
The Fuel and Ignition tables are using MAP. The VVT table is TP because that's how it came to me :) I can convert it to MAP fairly easily. In fact having them all consistent might be better.

Thanks for the replies.
 

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Discussion Starter #19
How do you like the EMS?.. is it easy to work with.. Cost?..

AND.. are you going to share your Map?..

Cap
It is very easy to work with and has some powerful features. The cost is a bit high but cheaper than a Motec which was my original choice.

If anyone wants my map they are welcome to it, just PM me. It might be better to wait a few weeks until I am closer to a final version.
 

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Discussion Starter #20
If you have the time and don't mind a bit of redundant wiring, the way I would normally approach something complex like VVT tuning on a new platform would be to first wire in the standalone as a logging box (don't let it control spark or fuel) and log what the stock ECU does.

But it looks like you're past that point. As you are running a real ECU, do some logging.
In particular, log MAF voltage, load and RPM (and AFR) and have a go at tinkering with the cam angles in between runs. Bascially, you want to find the angle at each load/rpm point that maximizes MAF voltage.

If you want to go nuts and have 3 spare inputs on the G4, slap in a cheap 3-axis accelerometer. It's like having your own private street dyno. :)
Great ideas there sir! I never had a 2ZZ Toyota ECU and went straight for the Link.

I don't have a MAF connected to the Link, it uses it own internal MAP sensor. The 1ZZ ECU is still there so I guess the MAF is still powered and might be useable. I am trying to get back on the dyno in the next 7-10 days and to focus on the cam timing table now that I am happier that I am close on ignition and fuel.

Thanks
 
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