How restrictive is the stock 1UZ inlet manifold ?

[XR8tt]

Imo atleast port inlet so it has the same diameter all the way to head ??
This is what I intend to do... I'll talk to my welder. We may have a go at making a sheet metal inlet ?? Copied off some of the Chevy / Ford modular turbo / centrifical motors..


I don't like the angle of the port before head on std manifold.. It's strange that some of these turbo pushrod engines use high performance carb manifolds converted to EFI and reach high rpm power levels with some loss in low rpm torque....



A 1UZ manifold would be much compact...

 

[ed_ma61]

Have a look at the 1UZ inlet? They tapper down around manifold / head gasket.. I assume to increase torque ?? To pull heavy vehicles..
With this restriction, it would cause resonance big time..

The new XR6T has a MUCH shorter inlet manifold..
On most converted turbo engines you gain better power etc by shortening inlet by about 20%

im not sure youre understanding the concepts of intake flow and tuning

 

[ed_ma61]

more reading:

http://www.v-eight.com/tech_forum/viewtopic.php?f=4&t=563

http://www.v-eight.com/tech_forum/viewtopic.php?f=4&t=138

 

[XR8tt]

im not sure your understanding the concepts of intake flow and tuning

Well I can only compare to what works on other manifolds..
My Ford will rev to 7500+ rpm if I let it with Trick Flow heads and induction..Big long ports for a 5.4 pushrods which has the same stroke as the 1UZ..
The 1UZ with multi cams, ports etc should pull MUCH harder in rpm range.. I don't see too many GOOD manifolds where there SEEMS to be a restriction 2/3 's the way through inlet port..
All the good manifolds seem to tapper down slightly and continuously..

But we need to figure inlets with stout engine to compare!!
Boosting a near std engine with std cams and valve springs
is like running a marathon with gumboots on !!!

 

[ed_ma61]

yeah, sure, but you need to understand why it works on other manifolds, or more to the point, why the 1uz manifold sucks wang

i agree stock cams and springs is dumb, no argument. but even with stock cams and springs, if the springs can hold say 15psi, a new manifold will get you perhaps 1000rpm shift in rpm band, and thats a 20% increase in power straight away

 

[XR8tt]

Exactly it seems in this case its all three working [or not working] together.. More so than most other engines.. Seems Mr Toyota did a good job all round of making this engine pull at low rpm and limiting max rpm for reliability endurance...
Being that 15 Lb is a restriction of flow!!!
Then I assume if power increases ?? There must be a restriction in the inlet manifold!!
A restriction caused buy resonance etc not necessary smaller in size type of restriction.. Sheesh putting this to writting is harder than straight up talking about it...

 

[Fasteddie]

...discussed the inlet issue with my engine builder....first we will go with the stock manifold + stock cams and take 500+ rwhp as a goal...
Next we will upgrade the inlet into something similair to this:

...after that we will get the appropriate cams...

Today we also looked at the 3UZ inlet manifold...off course it doesn't fit the 1UZ but it sure is a nice design compared to the rather old 1UZ design...