Whoop_ass

iTrader: (7)

For all the big turbo guys that are running 35r and bigger, I just wanted to know.

What sort of timing do you guys run on peak torque and at redline on 93 OCTANE.

Now I am looking more for figures of the evo 9 as I know they run a little less timing than the EVO 8

reason I ask is that i think my tuner is being a bit to conservative and leaving lots of power on the table.
I am seeing intake temps of about 113 deg, this reading is taken from intake mani.

Surely with bigger turbo cars you can run more timing due to them being more efficient.

Mellon maybe you can chime in as you do lots of tuning.
comments are welcome

lemmonhead

search the "show me your timing map" thread. tons of maps in there.

crcain

113F isn't too bad. I am in 85F weather and my intake temps are normally around there. Here in the Caribbean, our fuel is worse than 93, so I can't answer your question.

But if a tuner knows what he is doing, he will map your car for a TON of boost on pump. Like 30-34 psi. That doesn't mean you will run that boost, but at least the car is mapped for it.

At a total guess I'd bet a T3 sized turbo on a well setup evo at 30 psi on 93 would be anywhere between 1-5 degrees advance at peak boost (~30 psi). Then adding a degree or two more every 500 rpm.

It all depends on the car and the key is knowing how to monitor the engine properly for det. Whether it be by a stock ECU knock control, det cans, or ECU knock voltage.

Ph3n1x

iTrader: (12)

8* Peak Tq.
14* Redline

Pump gas @ 26PSI

Mellon Racing

iTrader: (38)

everything affects the timing you can run...head/cams/fmic/compression/boost/turbo/octane etc...don't get hung up on the number, just give the car what it likes.

Chabada15

iTrader: (2)

my method was add timing till i encountered knock...always got me great torque numbers on a dyno and a great butt dyno feel, i run my fuel conservative for what its worth

fid

iTrader: (18)

If you are on a dyno then there is no need to keep adding timing untill the car knocks because by the time the engine knocks you are most likely far past MBT and the ragged edge for pump fuel. If you let the car cooldown and recover inbetween pulls (meaning all pulls are on the same playing field) all you really need to do is watch your torque curve. Once the torque curve starts to fall off or flattens out you have approximately found MBT for the fuel and boost you are aiming for. Pull a degree or two and you should have yourself a nice, safe street tune. Shoving timing down a cars throat untill it knocks is poor practice no matter what car you are tuning. Timing needs to optimized via the torque curve and then use boost to obtain the overall power curve you are looking for. Of course this is simplified and there is always more then one way to skin a cat. Excessive timing + Pump Gas + Overfueling to try and compensate for it = Underpowered, dangerous tune. No offense to you, nothing personal but just my 2 cents.

kouzman

iTrader: (6)

Around 4 degrees at peak boost and around 12 after 7000-7200rpm and that's with anywhere from 23-26 psi on 93 shell... Always 0 knock... That's on a gt30 based turbo (3065) and I would say that it is a conservative map especially on ~23psi... Afrs always less than 11.5....

Mellon gave the correct answer... Give the car what it likes... Every car is different...

crcain

Have you ever tested the above theory in practice?

It's my understanding a high powered evo on crappy pump fuel will keep making power then knock as you add timing. Not stop making power, then knock. In a recent thread on the MLR John Banks who from my understanding is a very good tuner, said the car will knock slightly, and keep making power.

I believe the theory you suggest above, of seeing power fall off on the dyno, before the car begins to knock, doesn't actually exist on pump gas turbo charged applications. It will knock/det before power can be seen to falloff.

Also keep in mind, many top, top very experienced tuners are more than happy to map a car on the road. I asked my tuner Mark Shead when he flew here to tune my car and others, "how much more power would you get out of the cars if we had a dyno?"... he replied matter of factly, "none"

That is coming from someone who maps cars on engine dyno, chassis dyno, etc

kouzman

iTrader: (6)

you have a good tuner mate!!!

M.A.Developments have built some of the fastest cars in the UK...

wreckleford

iTrader: (2)

I agree, but then again I am used to 90 Octane crap gas.

fid

iTrader: (18)

To answer your question I have practiced this "theory" for many years myself. But it isn't my theory but what has been passed down from guys like Ben Strader (EFI University) and Bob Norwood before my ***** even dropped . Its not exactly a odd/off the wall practice to optimize a tune following a torque curve rather then waiting for it to knock and reacting from there. Especially when the motor is octane limited. This is the way your most average, everyday combustion engine operates. There are of course are exceptions such as rotaries and high revving Honda motors are a few that react a bit different. And I have absolutely no clue what you are trying to say about road tuning a car, care to expand on that alittle?

I think you are missing what I am saying or maybe I sucked at explaining my point of practice. Yes engines, like such you mentioned, will keep making power(horsepower) into there knock threshold. But it doesn't mean that that is thing to do OR what the motor wants or even the safe thing to do. They are knocking because they are octane limited with to much lead time. Everything I said was in reference to a motor being tuned on pump gas (my assumption is 93 octane). What I have found in a normal, everyday street motor (not meaning radical compression, huge cam, etc) on pump gas will respond much better to a more conservative timing figure and a slightly more aggressive boost curve/limit. By using a dyno as what it was intended for, a tuning tool, on pump gas you will see alot of different engines torque fall/leveloff once it reaches "its fill" of timing once it reaches MBT. I do agree, and I have seen personally, horsepower keep climbing even after MBT has been reached. It was only untill I started using det cans and actual knock devices, us evo guys take for granted , that the my car was actually knocking even though I was making more hp. Every motor I have ever seen on pump gas the torque curve would fall off before it ever started knocking. But I have only truly tuned high horsepower street cars/drag cars nothing extremely radical.

Everyone has there own way of tuning a car. Its just my experience and preference not to shove timing down a motors throat even if it is making more power but knocking. Like I said, just my 2 cents .

l2r99gst

iTrader: (2)

How was knock being monitored in these examples? Usually, on pump gas, you are octane limited, which means that you will encounter knock before reaching MBT.

If what you were saying were true, we would never have to use high octane racing fuels to achieve maximum power.

fid

iTrader: (18)

From as primitive as det cans to a knock link. I shouldn't say torque has fallen off always or even the majority of the time. But more torque leveled off are only gained slightly (2-4ft.lbs) from previous runs. What I am saying is I have always reached minimum best timing,then a maxiumum best timing before I have reached knock. I would always see just a slight increase in overall torque gain from minimum to maximum best timing and then knock. My idea is to optimize a timing map that isn't on the ragged edge, dancing along the knock line especially on pump gas and then that is it. And that is what I was replying too.

jid2

iTrader: (62)

You can continue to make more power while losing torque, that why it's important to tune off the torque curve.

Horsepower is work/time, thus influenced by time, torque is a more "pure" indicator of engine output.