Toyosports exhaust manifold

[trooper99]

Sounds like it! What gets me is that a relatively modern motor is so under-powered: 138 Bhp from 1800cc isn't too good, even adding 10 Bhp or 7% isn't winning any awards!
The 2ZZ is the same size yet giving a not bad 190 bhp, only just over the 100 bhp/litre 'decent output' that most tuned engines give.
The best thing about the Roadster is Power to Weight Ratio, which is pretty good, so even a small bhp increase will have a bigger effect than in other cars.
I reckon the intake and exhaust valves must be tiny on the 1ZZ, that would explain the poor tuning potential.

[secla]

1zz is variable valve timing only 2zz has variable valve and lift
thats where a big chunk of the power comes from

[1979scotte]

1zz is an economy engine.
2zz is a performance engine designed by Yamaha.

[Alex Knight]

2zz is a performance engine designed by Yamaha.

Yamaha only designed the cylinder head, as with the 3S-GTE.

[Carolyn]

Back to the 'Toyosport' theme:

Jon brought his rebuilt PFL by yesterday and I had a drive in it.  Very smooth, the engine was quiet and responsive but.

There is a noticeable difference in initial pick-up between his car and my MR S.  The MR S is much better.  Once they are both spinning, the power seems very much the same, but mine definitely has a much better initial response.

There are two differences between the cars.  Jon's has a standard de-catted exhaust manifold, mine has a wrapped Toyosport.  Mine also has a JDM  MR S ECU and Jon has a standard Euro spec ECU.

My feeling is that the manifold is making the difference. not the ECU, but can't be sure.

Has anyone swapped a de-catted stock manifold out for a Toyosport and noticed a difference in low-end performance?

[shnazzle]

I wrote about this when I decatted my manifold. Nobody believed me  s:) s:)  
Although, I had the opposite!

Initial pull increased a tiiiiny bit, but it introduced a clear flat spot at full load higher rev.

My logic (perhaps very wrong) was that the removal of the pre-cats allowed a better flow at pick up, but then at high load the exhaust gets backed up in the empty chambers where the pre-cats were and causes too much back pressure.

The toyosport removes this.
This is why I said I regret gutting mine and not just spending 90 quid replacing the manifold.

Sent from my SM-N9005 using Tapatalk

[Anonymous]

Logically the toyo one would have less turbulence and make it a more flowing exhaust to a decatted stock manifold

[lamcote]

Carolyn, I noticed EXACTLY the same difference you are describing between your MR S and my standard FL that still has precats.

I wondered if the MR S has different gear ratios? If not the Toyosport seems a likely explanation.

[Carolyn]

The JDM does has slightly different ratios - but higher up the box.

Shame the Toyosports are unavailable right now.  Hopefully they'll produce some more soon.

that's several votes for the exhaust, then.

[trooper99]

Thanks again everyone! My mate who owns a Toyota independant garage (we worked together at a Toyota dealer years ago, I left in 1986, when he was foreman: talk about his years of experience!) and he knocks out pre-cats on lots of vehicles, as they clog and reduce power. I did the same on my Isuzu Trooper 3.0 TD 16V DOHC, it really made a big difference and fools the MOT man as it looks standard   s:wink: :wink: s:wink:  
The toyo manifold does indeed have the same 2 sensor fitting holes, so they are a straight swap, and the pipes that replace the pre-cats are the same diameter as the rest of the manifold which should allow smooth gas transfer.
Yamaha still make Toyota engine blocks, the 2 firms linked up to carry out cylinder head development work around 1978, so its been a long term job! Yamaha were the firm that made most jap engine blocks back than.
My real passion is classic jap bikes, mainly the XS650 inline twin, I've rebuilt 2 full bikes and a few engines, Toyota designed the combustion chambers in these rather slow and lazy motors, they are said to be similar to the first toyota 18RG head/chambers, its amazing what can be found with a little effort.
QUIZ!
do you know where Mr Toyoda (yes, Toyoda) got the money to start building cars?   s:shock: :shock: s:shock:    s:shock: :shock: s:shock:

[Essex2Visuvesi]

He found it down the back of his futon?

[trooper99]

Er..nope!
I live in Oldham, an important town for Mr T