4AGE budget cam install and tuning

[Lauren]

Hi John,

Fair enough about the Honda's, was hoping it would stay on thread rathe than a discussion about whether the dyno is accurate or not(!).

Well, you'd think the 4-1 would push the power band more towards the top end. But, yes, I'm sure I could more the torque by adjusting the exhaust pulley.

The rev limit isn't lower on AE86's. I'm not sure what you mean there as you can see on the graph it ran to 7718rpm (rev limit should be 7599rpm).

I actually watched the RPM when it buzzed the limiter and it was at around 7700 and that was on the stock ECU.

[pk_090]

Are there any differances in ECU between the AE86 and the mr2? I know its the same engine usually!
Alex

[Lauren]

AE86 had the early ECU. The early MR2s shared the same engine and ECU as the AE86. Though, there are different part numbers for early ECU's and obviously JDM and UK ECU's differ.

The later MR2's, '87 on had the later engine and later ECU. Rev limits are the same on all at 7599rpm.

Earlier ECU's had more aggressive mapping and opened the TVIS slightly later. They were also mapped right through to the rev limiter, whereas later ECU's just dumped loads of fuel in at high revs.

I'm sure Jeremy can give you the intimate details on it.

[elbon50]

3 types of ECU have been used in the UKDM spec Mk1 MR2

89661-17030 Small case Mk1a
89661-17070 Bigger case Crossover 1b
89661-17140 Case as 070 Later 1b

Peter

[pk_090]

so by that then the early ECu would be best, just plug and play?

[PW@Woodsport]

No, early engines have no injector resistor pack, late engines do, so if you plug an early into a late or vice versa bad things will happen.

[jimi]

Earlier ECU's had more aggressive mapping and opened the TVIS slightly later.

It's the other way round operating points for T-VIS are
MK1a it comes in at 4350rpm and stays in until the revs fall back below 3950rpm.
MK1b it comes in at 4650rpm and stays in until the revs fall back below 4250rpm

[jimi]

3 types of ECU have been used in the Mk1 MR2

89661-17030 Small case Mk1a
89661-17070 Bigger case Crossover 1b
89661-17140 Case as 070 Later 1b

Peter

That's just for the UK, there's actually a lot more than 3

89661-17020- :01 :8412-8608 :COMPUTER, ENGINE CONTROL :AW11..MTM

89661-17021- :01 :8608-8708 :COMPUTER, ENGINE CONTROL :AW11..MTM

89661-17030 Nov 1984 to Aug 1986 UK MTM

89661-17050- :01 :8508-8608 :COMPUTER, ENGINE CONTROL :AW11..ATM

89661-17051- :01 :8608-8708 :COMPUTER, ENGINE CONTROL :AW11..ATM

89661-17070 Aug 1986 to Aug 1987 UK MTM

89661-17201- :01 :8708-8712 :COMPUTER, ENGINE CONTROL :AW11..GT..USA CALIFORNIA SPEC

89661-17130- :01 :8708-8803 :COMPUTER, ENGINE CONTROL :AW11..SPC..USA CALIFORNIA SPEC

89661-17140 Aug 1987 to Dec 1989 UK MTM

JDM

89661-17010- :01 :8406-8608 :COMPUTER, ENGINE CONTROL :AW11

89661-17090- :01 :8608-8702 :COMPUTER, ENGINE CONTROL :AW11..SPC
(SUBS) : :89661-17091- :01 : : :

89661-17060- :01 :8608-8709 :COMPUTER, ENGINE CONTROL :AW11..TWC

89661-17091- :01 :8702-8709 :COMPUTER, ENGINE CONTROL :AW11..SPC
(SUBS) : :89661-17180- :01 : : :
:
89661-17180- :01 :8709-8805 :COMPUTER, ENGINE CONTROL :AW11..SPC
(IRRG)

89661-17160- :01 :8709-8809 :COMPUTER, ENGINE CONTROL :AW11..TWC
(SUBS) : :89661-17161- :01 : : :

89661-17161- :01 :8809-8810 :COMPUTER, ENGINE CONTROL :AW11..TWC
(SUBS) :89661-17162- :01 : : :

89661-17161- :01 :8810-8904 :COMPUTER, ENGINE CONTROL :AW11..MTM..TWC
(SUBS) :89661-17162- :01 : : :

89661-17210- :01 :8810-8904 :COMPUTER, ENGINE CONTROL :AW11..ATM..TWC
SUBS) :89661-17211- :01 : : :
:
89661-17220- :01 :8805-8912 :COMPUTER, ENGINE CONTROL :AW11..ATM..SPC
:
89661-17230- :01 :8805-8912 :COMPUTER, ENGINE CONTROL :AW11..MTM..SPC

89661-17162- :01 :8904-8912 :COMPUTER, ENGINE CONTROL :AW11..MTM..TWC

89661-17211- :01 :8904-8912 :COMPUTER, ENGINE CONTROL :AW11..ATM..TWC

General
89661-17040- :01 :8411-8608 :COMPUTER, ENGINE CONTROL :AW11..GEN

89661-17080- :01 :8608-8708 :COMPUTER, ENGINE CONTROL :AW11..GEN
:
89661-17100- :01 :8608-8708 :COMPUTER, ENGINE CONTROL :AW11..FRG

89661-17190- :01 :8708-8803 :COMPUTER, ENGINE CONTROL :AW11..ARL
(SUBS) : :89661-17191- :01

89661-17140- :01 :8708-8912 :COMPUTER, ENGINE CONTROL :AW11..EUG

89661-17150- :01 :8708-8912 :COMPUTER, ENGINE CONTROL :AW11..GEN

89661-17170- :01 :8708-8912 :COMPUTER, ENGINE CONTROL :AW11..FRG

89661-17140- :01 :8803-8912 :COMPUTER, ENGINE CONTROL :AW11..RHD..GEN SINGAPORE SPEC

89661-17191- :01 :8803-8912 :COMPUTER, ENGINE CONTROL :AW11..ARL



Abbreviations
TWC = Twin cam (the NA)
SPC = Supercharged
ATM = Automatic Transmission
MTM = Manual Transmission
EUG = Europe General
ARL = Australia Spec
FRG += Federal Republic of Germany Spec

[vashy]

Lauren - my dyno on page 2 goes to 8000

tottacrolla, Lauren - did you notice any drivability changes with your modified ECUs?

so, looking at Lauren's dynos, it looks like they they add fuel (and possibly back off ignition advance I wonder) so you lose power with stock or mild cams...

[vashy]

Also...

It's definitely worth addressing the overfuelling.

A few years ago I had my stock mk1b remapped by Rich Benton at Powerstation Tewkesbury and he removed the stock overfuelling whilst remapping the fuelling and it does help hold onto power past the peak. My car delivered a fatter torque curve and produced smoother power at high rpm.

After mapping I'm not sure the car was realistically any faster but it was the sweetest 4AGE engine I'd ever driven when being driven hard although it was a fairly good one anyway.

almost missed this post!

really interesting!

was your remap just fueling or did he get the det cans out and remap timing too?

I'm just wondering how much margin there is in the stock ECU ignition timing map, for running hot cams. Although since seeing how rich it runs even with the cams on my dyno (and excess fuel should help prevent det) I've been running my engine on 95 (super just for trackdays). It hasn't blown up yet lol.

[JMR_AW11]

He had the det cans on but just did the fuelling although he did trim part of the ignition table at part load at around 4000rpm to remove some detonation sounds.

It was about 6 years ago (scary how time flies) and I sat alongside him whilst we did the mapping.

I did mean to go back the following week to get the ignition mapped but never got round to booking it in.

[vashy]

so at the weekend I went to the dyno to try out my latest cam timing (in -5, ex -7) and get my apexi SAFC set up properly.



my work here is done

[cartledge_uk]

Nice work

So whats next on the list of mods?

[FossMan]

I was hoping you would update this thread!

I got to go out in Vashy aka Emmett Brown's car on Saturday and it certainly is a lot of fun. Really revs all the way to the red line.

Thanks to him I have also joined the HKS crew, so I'm hoping for a rolling road session of my own soon.

[Lauren]

Great result, John, well done!

[vashy]

Nice work

thanks!

So whats next on the list of mods?

a shift light

I got to go out in Vashy aka Emmett Brown's car on Saturday and it certainly is a lot of fun. Really revs all the way to the red line.

hahahaha!! actually I reckon I can get a flux capacitor hooked up to the 4AG with some old japanese fuelling computers and some bits of hose, and it does get up to 88mph pretty quickly now!

Thanks to him I have also joined the HKS crew, so I'm hoping for a rolling road session of my own soon.

cool and let me know when you´re on the dyno; if I´m free I´ll come down and bring my timing light and a mirror on a stick I reckon getting the exhaust cam timing set right for those long secondaries on your janspeed should make some good torque

Great result, John, well done!

cheers Lauren!

[elbon50]

Hi Vashy,

I have a pair of HKS 264 8.35 cams which I bought from Chris (Oukie) a while ago

Hoping to get around to fitting them soon

Will the clearances change very much with the "new" cams in

Shall I be able to borrow the shim bank & Tool

Do you have the bank @ the mo ?

Ahhhh questions questions

Peter

[Lauren]

Hmm, quite tempted to set my cam timing the same as your's John.

IIRC think I've got -3 and -4.

Obviously I don't have an SAFC.

Just out of interest, do you think it's worth doing John?

Would take under 20 mins to do as getting to my cams is a POP.

[vashy]

some stuff about clearances

After fitting new HKS cams to my engine, the clearances were very close to what they were before and all still within spec. I´ve seen HKS cams installed in another engine that had clearances all within spec afterwards. Proper japanese cams made, I expect, to some pretty tight tolerances. Someone else has the shim bank, I bumped the thread recently, please bump it again to keep it on the first page!

Just out of interest, do you think it's worth doing John?

go nuts

note that the ideal exhaust cam timing will be different with different exhaust manifold lengths, and, according to my tuning book, will be peakier with your 4-1, which means it will be easier to tune, because it will be easier to feel where the peak is.

[LimeyMk1]

Someone else has the shim bank, I bumped the thread recently, please bump it again to keep it on the first page!

I think I should sticky that thread.