Blacktop 20valve or GZE in my race car?

[Icsunonove]

Yep, I met these guys at JAE this year. Had a good chat to them. Very reasonable prices.

[waynestoyotamr2]

Thats a fair bit cheaper than the 1350 +vat that fensport charge

Spend a few hundred extra and you'd get yourself a whole SC from Jap auctions for that kind of money!!!

[tim_chick]

I guess you have seen:

www.billzilla.org

Everything I have read seems to suggest 140bhp for 20v silver top, and
145 for blacktop, rather than the figures Toyota claim. Does anyone have dyno results for the 20v?

Tim

[Lauren]

I guess you have seen:

www.billzilla.org

Everything I have read seems to suggest 140bhp for 20v silver top, and
145 for blacktop, rather than the figures Toyota claim. Does anyone have dyno results for the 20v?

Tim

Well yes, i've heard that too... but i think the 20v is restricted by the stock cams as it has a lot of potential.

Trouble is i haven't seen any proof that this is the case IYSWIM... I never believe HP figures on US sites tbh, mainly because they measure it in a totally different way.

[PsychomIKE]

Thats a fair bit cheaper than the 1350 +vat that fensport charge

Spend a few hundred extra and you'd get yourself a whole SC from Jap auctions for that kind of money!!!

I think the main advantage are that these are later MAP sensored units and come standard with 20 + bhp more than the mk1s 4AGZEs rather measily 140 ish bhp. Also be mighty surprised if you can get an imported SC'r for a couple of grand plus VAT but there you go

Everything I have read seems to suggest 140bhp for 20v silver top, and
145 for blacktop, rather than the figures Toyota claim. Does anyone have dyno results for the 20v?

The general consensus seems to agree with you on those figures but that it could be possible to really open it up with after market engine management and a set of cams. This is from the club4ag boards, those guys know their stuff...

The biggest gain your going to get out of your 20v is via a standalone. Why? because the stock 20v computers run VERY conservative ignition mapping. On some parts of my ignition map, you can see that the total timing is 42 degrees and I never ran it lean/detonated/pinged ever. Though the car was tuned slightly conservative with these ignition maps (12.5:1 vs a normal 13:1 A/F) I really like the megasquirt units, I also have my maps on the internet that you can load up right into your unit, and then you really wont have a need to tune it. I can also supply these units with upgraded resistors and a CNCed case for around $280 shipped in the USA. ( email me [email protected] )

So who knows what is possible with it. Unfortunately when the guys in the US want big power from these engines, the only place i think these swaps can be considered at all common, they nearly always turbo/supercharge them so it really is hard to find out how much is possible whilst keeping it naturally aspirated.

The thing for me with considering those 20valves was the lack of weight added to the car, especially at the rear. Imagine just 170 or 180 bhp at the crank with no extra weight... *drools*

Mike

[Lauren]

Agree with you Mike... I think the 20v has the potential to be a fantastic engine with a stratospheric rev limit... fensport were telling me they had one up to 9300rpm no probs!

Cams and management are definately the way to go as with everything else specced so highly (ie 20v and throttle bodies etc), i too have spent some time on club4ag (i'm 86 obsessed). I've also heard that you may as well throw away the VVti stuff... think this is pretty pointless anyways as soon as you fit lairy cams.

It would be an absolute corker if you could get a set of cams that peak at say 8000rpm...

[tim_chick]

But I thought Mat J couldn't change the cams?

Anyhow, it appears I was a little hard on the 20v - 145 and 150(black)

See UK site, with rolling road:
http://www.thewinchesterclub.co.uk/spec.htm

The stock cams are longer duration and higher lift than the stock 16V
engines I think.

I believe the reason for the move to 20V was to meet emmision standards rather than performance - which probably explains the conservative ECU.

Also people seem to believe the 16V is capable of more power when tuned, N/A of course. Apparently the 5 valve configuration does not
allow for the most effecient combustion and breathing, which is why the
F1 teams and performance motorcycles do not use it any more.

If we are just lusting over engines - how about the 2l V8 made from
2 x 1000cc Yamaha R1 engines. Mmmm 300bhp@10,000rpm without tuning or stressing the engine. Made by cyclone they cost 14 grand + VAT though

[Lauren]

You are right Matt, can't change the cams, but i was just talking about how you can tune the 20v.

It maybe so that power outputs between the 16v and 20v are fairly minimal, but the great thing about the 20v is its got all the right bits and so much potential to start with.

For a start much higher compression, it has throttle bodies as standard plus its AE101 spec so with a bit of balancing a redline of 9500rpm is easily achievable.

The thing is to get the 16v to out power the 20v you need fit most of the parts that are already on the 20v! Hence why a 20v is a better starting point.

[luthor1]

FYI, balancing does not increase the rev-limit on an engine.... unless it removes a bothersome frequency, and even then only by 50 or so rpm. If you balance it and then set 9300rpm limit, that's fine, but it would have done 9200 MINIMUM before the balancing anyway.

(reference: David Vizard: Tuning BL's A series engine, chapter on general theory about engine balancing)

Grinding the crank lobes thinner to reduce the centripetal force on the oil preventing it "flinging" off at high rpm is a better idea. Oh obviously don't go too mad otherwise you will reduce the strength of the engine.

[PsychomIKE]

FYI, balancing does not increase the rev-limit on an engine.... unless it removes a bothersome frequency, and even then only by 50 or so rpm. If you balance it and then set 9300rpm limit, that's fine, but it would have done 9200 MINIMUM before the balancing anyway.

Well I think what Lauren meant was having the balancing done will help, even if only slightly, and then the ECU rev limit would be moved from its conservative 8k rpm (or whatever it may be) to a still safe 9.5k.

You obviously know your stuff though Luthor1. Have you any experience on working with 20 valve 4AGE's?

Mike

[luthor1]

I am not a mechanic, but "back in the day" I read a lot of theory about tuning, mostly generic, when I built my Mini. I know things have moved on since then, and I am trying to quickly read up and learn about the toyota engines. There is so much potential in the Mk1 NA it's untrue, but it seems like the engines are extremely sensitive to the fine details. You could get the same ingredients and build it differently and see 15bhp difference. Important things like making sure the intake manifold to gasket to cylinder head is a smooth transition is *worth* doing, and at high specific outputs are very sensitive to the exhaust manifold.

At extreme output, there seems little to choose between the 20v and 16v, but at low to mid output the 20v has the edge it seems.

Basically, I love talking about over-tuned engines (over 100bhp per litre). Looks like Honda has the torch at the moment with the S2000, 247bhp out of a 2 litre and they have (afaik) no failures!

Can someone shoe-horn that into a Mk1?

[Lauren]

FYI, balancing does not increase the rev-limit on an engine.... unless it removes a bothersome frequency, and even then only by 50 or so rpm. If you balance it and then set 9300rpm limit, that's fine, but it would have done 9200 MINIMUM before the balancing anyway.

(reference: David Vizard: Tuning BL's A series engine, chapter on general theory about engine balancing)

Grinding the crank lobes thinner to reduce the centripetal force on the oil preventing it "flinging" off at high rpm is a better idea. Oh obviously don't go too mad otherwise you will reduce the strength of the engine.

Stock crank on AE101 is reputedly good for 10,000rpm. What i meant by balancing is that by balancing the rotating assembly to much finer tolerances will certainly help if you are revving the engine higher. So my point is that it will take it anyway, but it is always good to practice to lighten and balance.

[luthor1]

I totally agree that lightening and balancing is the cornerstone to proper internals rebuild, especially if you are running new pistons/rods/flywheel and are intending to rev it hard.

However, if it is balanced to run 7800rpm (standard) then it is balanced to run 9500rpm. Further balancing of one that is good for 7800 will *not* make it good for 10k. What you may find is that balancing allows it to run "longer" at high revs due to less internal friction, which is a good point. Lightening and balancing will improve POWER, ACCELLERATION and MPG for free basically. Power and MPG due to less internal friction.

The failure (if you revved a 1.6 to internals failure) would probably be a broken con-rod, or lack of lubrication to the main bearings.

[JMR_AW11]

I totally agree that lightening and balancing is the cornerstone to proper internals rebuild, especially if you are running new pistons/rods/flywheel and are intending to rev it hard.

However, if it is balanced to run 7800rpm (standard) then it is balanced to run 9500rpm. Further balancing of one that is good for 7800 will *not* make it good for 10k. What you may find is that balancing allows it to run "longer" at high revs due to less internal friction, which is a good point. Lightening and balancing will improve POWER, ACCELLERATION and MPG for free basically. Power and MPG due to less internal friction.

The failure (if you revved a 1.6 to internals failure) would probably be a broken con-rod, or lack of lubrication to the main bearings.

I turned up the rev limiter in my reprogrammable 4A-GE ECU and let the engine rev past 8000rpm. I've done this twice now. Both times in second gear. The engine goes eerily smooth at 8000rpm but it sounds like it is revving much higher as it really screams. (I bet it would sound amazing with a sportier exhaust note!) It also showed no signs of wanting to stop revving higher. My car is mapped to remove the overfuelling above 6000rpm and the power curve on a roling road keeps climbing past 7200rpm. I didn't dare take it higher than about 8200rpm.

I've heard reports the stock engine can take well over 9000rpm in short bursts. I don't think I'm going to volunteer to test this on my engine...

[MartG]

I've heard reports the stock engine can take well over 9000rpm in short bursts. I don't think I'm going to volunteer to test this on my engine...

Pity the engine someone ( Paul Woods ? ) recently 'tested to destruction' didn't have one of your ECUs on it to see at what revs it went pop

[Lauren]

I turned up the rev limiter in my reprogrammable 4A-GE ECU and let the engine rev past 8000rpm. I've done this twice now. Both times in second gear. The engine goes eerily smooth at 8000rpm but it sounds like it is revving much higher as it really screams. It also showed no signs of wanting to stop revving higher. My car is mapped to remove the overfuelling above 6000rpm and the power curve on a dyno keeps climbing past 7200rpm. I didn't dare take it higher than about 8200rpm.

I've heard reports the stock engine can take well over 9000rpm in short bursts. I don't think I'm going to volunteer to test this on my engine...

The later AE101 engine has a better crank and is essentially stronger, so thats the reason why it can go a bit higher than the earlier versions of the 4AGE.

[luthor1]

8500rpm should be a realistic limit tbh. If you have cams that are providing a power band up at 9000+ then it will be fairly narrow to say the least, and you will find that standard gearing is not optimal, or at least starts to drift off optimal. At 8500, the next gear is still likely to hit the powerband.

Integra TypeR is a good example, the gears are really close and it rev-limits at 8650 (on the dyno, 9250 on the tacho). I have access to a 211bhp (flywheel) tuned one. It is nuts-o.

My point is, select your power-band based on the gearing and optimise the cams etc for that. the higher you rev the engine the further away 2nd gear revs are from 1st gear.
Eg...
if 40mph is 7800rpm in 1st and 6000rpm in 2nd (guessing) then 9000rpm in first is 46.2 and 46.2mph in 2nd is 6930.

1st example the powerband needs to be 1800rpm wide, 2nd example the powerband needs to be at least 2070 wide. As you move the powerband up with cams and tuning, the chances are you will narrow the powerband not broaden it, so the standard gearing starts to work against you.

Oh I am boring myself now, sorry

[JMR_AW11]

Thats a fair bit cheaper than the 1350 +vat that fensport charge

Spend a few hundred extra and you'd get yourself a whole SC from Jap auctions for that kind of money!!!

I think the main advantage are that these are later MAP sensored units and come standard with 20 + bhp more than the mk1s 4AGZEs rather measily 140 ish bhp. Also be mighty surprised if you can get an imported SC'r for a couple of grand plus VAT but there you go

Everything I have read seems to suggest 140bhp for 20v silver top, and
145 for blacktop, rather than the figures Toyota claim. Does anyone have dyno results for the 20v?

The general consensus seems to agree with you on those figures but that it could be possible to really open it up with after market engine management and a set of cams. This is from the club4ag boards, those guys know their stuff...

The biggest gain your going to get out of your 20v is via a standalone. Why? because the stock 20v computers run VERY conservative ignition mapping. On some parts of my ignition map, you can see that the total timing is 42 degrees and I never ran it lean/detonated/pinged ever. Though the car was tuned slightly conservative with these ignition maps (12.5:1 vs a normal 13:1 A/F) I really like the megasquirt units, I also have my maps on the internet that you can load up right into your unit, and then you really wont have a need to tune it. I can also supply these units with upgraded resistors and a CNCed case for around $280 shipped in the USA. ( email me [email protected] )

So who knows what is possible with it. Unfortunately when the guys in the US want big power from these engines, the only place i think these swaps can be considered at all common, they nearly always turbo/supercharge them so it really is hard to find out how much is possible whilst keeping it naturally aspirated.

The thing for me with considering those 20valves was the lack of weight added to the car, especially at the rear. Imagine just 170 or 180 bhp at the crank with no extra weight... *drools*

Mike

If anyone could get me a 20V ECU I could probably dump out the ROM from it and publish the stock 3d ignition map.

[JMR_AW11]

I've heard reports the stock engine can take well over 9000rpm in short bursts. I don't think I'm going to volunteer to test this on my engine...

Pity the engine someone ( Paul Woods ? ) recently 'tested to destruction' didn't have one of your ECUs on it to see at what revs it went pop

I'd like to test the engine for its ability to withstand abusive mapping. i.e how much warning the engine gives the operator if you start doing daft things with the timing and mixture. One engine tuner I know uses a long hose pipe and doctor's stethoscope as a way of listening to the engine whilst it is being mapped.

On my stock mk1b (89661-17140 ECU) there are places in the stock 3d ignition map where the engine pinks! He could hear this via the stethoscope but I couldn't. I had to back off the timing in a few places as he wasn't happy to leave the timing like that (even though we were actually optimising the fuel mapping at the time)

Sitting in the passenger seat of a mk1 MR2 on a rolling road with the engine howling in 4th gear whilst tuning the mapping on a laptop is quite a thrilling experience! It's noisy too so ear defenders are mandatory!

[PsychomIKE]

If anyone could get me a 20V ECU I could probably dump out the ROM from it and publish the stock 3d ignition map.

I know less than nothing when it comes to stuff like this. If you were to publish the ignition map what could be feasibly possible, and for what sort of money?

Mike