4AGE budget cam install and tuning

[FossMan]

vashy - Just noticed you are in Bristol too. Whereabouts? I Don't suppose you fancy lending me a hand with my cams sometime?

[vashy]

yeah sure. send me a pm.

[vashy]

Hey Jeremy, I have a couple more questions for you; I might as well ask them on here (:

Would it be ok to tweak fuelling by modifying the intake air sensor signal? (I know you said it's not ok to modify the coolant temp signal as this affects ignition timing also).

I dug out your articles and they suggest air intake temp can adjust fuelling by +/-9%. Is it possible to work out how much effect this would have on AFRs? Are these formulas correct:

my current AFR 12.5
say 1250 units of air, 100 units of fuel
1250 / 100 = 12.5 AFR
fuelling +9%
1250 / 109 = 11.47 AFR
fuelling -9%
1250 / 91 = 13.74 AFR
so roughly +/-1 AFR

Also... do you think the pot could be triggered with a relay connected to TPS throttle fully closed signal or TVIS signal so you could control fuelling at idle or high rpm respectively?

Also... if it's possible, I'm hoping to try your mod again on a Corolla ECU at some point

[34atm85]

Hey Jeremy, I have a couple more questions for you; I might as well ask them on here (:

Would it be ok to tweak fuelling by modifying the intake air sensor signal?

(I know you said it's not ok to modify the coolant temp signal as this affects ignition timing also).

Hi Vashy

All my tuning work brought me to one solid result, we don't need more fuel with the cams we are using. I have an FPR and Wideband and EGT installed, I can say the richer I made the car, the worse it became.

Please check the link. http://forum.miata.net/vb/archive/index ... 97626.html

I really don't think you need more fuel. I have more compression than you have and still AFR's are OK. What we need is more RPM for more HP. The map sensor works fine and ECU provides enough fuel at WOT by means of MAP. I tried so many times, the AFR never goes below 12.7 and EGTs are OK. AFRs play around 12,3 - 12.5 at WOT, 4th gear 5th gear 6800 - 7200 rpm. If you need more power you need more lift with the cam and more revving engine. I am not sure if we are reaching 95% IDC's (I am trying to find a logger) but what I know is, with the cams (264/256) we are using we do not need that much fuel. If you really think it is needed than you can use a decent FPR, dial it for more pressured fuel, and play with the afr screw next to the map sensor for low RPM tuning (it has no effect after 3500rpm), at wot leave it to the ECU and check the numbers. I am not sure you are going to get additional HP but will loose decent amount of fuel

Jeremy, please correct me if I am thinking wrong.

Map reads the vacuum and sends the information to ECU
ECU reads TPS info, intake temp, water coolant temp, map and some additional data and than decides the amount of fuel needed at that rpm with that load. fuel injectors opened to provide enough amount fuel for a certain amount of time according to the map in the ECU. So if the map is reading correctly because we are not sucking to much air into the cylinder because we have mild cams, the ECU can provide enough amount of fuel. This is what I have seen by using Wideband and EGT sensors. When I changed the FPR it did not add more power and torque but it stole some due to the richness.

May be I am totally wrong but this is what the AEM WB and EGT says

[vashy]

Hi Erin

I think you are right, I don't need more fuel!

I was actually wondering whether a pot on the air temp sensor might be useful for future mods.

I was thinking if it could work for 20v throttles! (after doing some reading it looks like ITBs really mess up the MAP sensor readings, and a pot wouldn't be enough, I would need some form of addon fuelling computer or standalone.)

In my post above I used my current AFR as an example, so I can see how it might have looked like I wanted to change my AFRs.

Thanks for the link though, it's very interesting. So, 12.5 all the way to redline without dropping off is an excellent result!

Your last paragraph sounds right to me. I wonder if the ECU overfuels at high rpm for safety, and our cams can make use of this extra fuel so the fuelling is closer to optimal..?

Hey I have a link for you, I think you might find it interesting (:
http://www.modified.com/projectcars/scc ... index.html

I think the next stage for my tuning project is to get some cam gears and try to set them up...

[LimeyMk1]

I was thinking if it could work for 20v throttles! (after doing some reading it looks like ITBs really mess up the MAP sensor readings, and a pot wouldn't be enough, I would need some form of addon fuelling computer or standalone.)

Vash the Honda bods use one of these to even out their MAP signal with ITBs.

http://www.goldeneaglemfg.com/index.php ... 3f6ud1tba7

[Gad]

I was going to suggest something similar, you can get them from techno toy tuning along with an adapter for any 20v ITBs you might come across...
Mine's a fetching shade of black.
And cost $9 more than that, dammit.
*edit*
That said, their shippings ridiculous...

[Gad]

Doh, double post.

[vashy]

the corolla boys just use a spare 4AGE fuel rail

anyway, you buggers, you're giving me ideas

If you happen to spot any 20v ITBs come up, don't let me know

[cartledge_uk]

the corolla boys just use a spare 4AGE fuel rail

anyway, you buggers, you're giving me ideas

If you happen to spot any 20v ITBs come up, don't let me know

I know where some are

[Gad]

If you need an adapter for a big port engine, I have one, turns out mine's had a conversion to a small port.
Note to self; stop making assumptions!

[Bender Unit]

You will need an adaptor regardless of big port of small port to get 20v ITB's to fit the 16v.

FYI John there is a set of ITB's on driftworks for reasonable money.

I just wish I could get around to getting my OER/SK Sanyo bodies fitted - as they look utterly badass!

[Gad]

I know, it's just the adapters are bigport/smallport specific, assuming I had just got a 4AGE from an early Corolla I picked up a bigport. More fool me!

[aw11rally]

I've got some 20v ITBs and an Omex 500 and a loom. I'm not using any of them.

Oh I've got an adaptor plate and modified cylinder head water outlet so it all just bolts on.

I also knocked up a vacuum canister to stabilise the map signal and feed the brake servo.

It's here if you're interested.

[vashy]

FYI John there is a set of ITB's on driftworks for reasonable money.

Smokin' cakes, they've gone already. For that kind of money though, I think it might be worth getting a set, have a play and see if I can sort the fuelling...

.....aw11rally, YHPM!

[34atm85]

FYI John there is a set of ITB's on driftworks for reasonable money.

Smokin' cakes, they've gone already. For that kind of money though, I think it might be worth getting a set, have a play and see if I can sort the fuelling...

.....aw11rally, YHPM!

Hi Vashy

I have to warn you, without a decent tune with a standalone your low revs will not be good and you may feel that you lost a lot of power at low revs. I think it is better you ask it to people who uses ITB's for a daily drive. Your fuel consumption will be higher and up to a certain rpm the torque will not be there. Like the tvis plates

Just my thinking.

[Bender Unit]

Its all in the mapping - a AE101 AE111 Corolla running a stock 20v on open stacks performs very nicley.

When ever you start to look at performance tuning on a 4age you have to accept that your going to have to make a scrifice in terms of drivability or low down grunt; however all of that means nothing if it performs well at the top end in its power band.

The sound from ITB's is worth the few HP you may loose lower down in the power band.

[cartledge_uk]

.....aw11rally, YHPM!

I did tell you he had a set

[34atm85]

Its all in the mapping - a AE101 AE111 Corolla running a stock 20v on open stacks performs very nicley.

When ever you start to look at performance tuning on a 4age you have to accept that your going to have to make a scrifice in terms of drivability or low down grunt; however all of that means nothing if it performs well at the top end in its power band.

The sound from ITB's is worth the few HP you may loose lower down in the power band.

this is what I am saying. Without a standalone or mappable ecu it is not logical to move to ITB's. May be I am wrong thinking that Vashy is looking for a car which is responsive with good power / torque ratio at drivable RPM's. I just wanted to express that without a standalone it will a waste of money and time and power

[vashy]

good discussion guys

It sounds like ITBs on the stock ECU really isn't going to work.

anyway... talking of low/high end power...

the next stage of my tuning project is... ... cam timing! I may have found a cheap set of adjustable cam gears. So I can see if I can squeeze any more out of the 264/256s. I know I have plenty of fuel everywhere so I should be able to shift the powerband whereever I like.

I've been looking on the net and in my tuning book for information on what happens when you change the cam timing on the 4AGE engine and there really isn't that much information out there. Not only that, the information out there is not only inconsistent but sometimes completely contradictory! Also, some of my google searches for info find my own thread! So I guess I'm going to have to try it out and post up the results (:

So, it's looking like the cam gears will let me do something like this.

retarding (or maybe advancing, who knows!) the intake cam will shift peak power up (or down) the rpm band.

advancing (or possibly retarding!) the exhaust cam will increase low/mid range torque, while sacrificing a little peak power.

And then because it is a twin cam we can adjust the overlap. Increasing overlap should improves high rpm performance. The exhaust gasses flowing out the nearly closed exhaust valve help suck in fresh fuel/air. But too much and at low rpm you lose power and economy because some of the fuel/air charge goes straight out the exhaust while both sets of valves are open at once.

Also, changing the exhaust cam affects the ignition timing, because the dizzy gear is on it. So I will just reset it to stock setting 10DBTDC each time.

so... we will see what happens...