I don't think I've ever read/seen a single piece of evidence that supports itb+turbo having an advantage over a nice plenum+turbo.

All I see for itb+turbo is 4 points of restriction vs. 1 point of restriction.

 

And I've heard that when Nissan moved to ITB + turbo they got better response than a plenum. Evolution of the GT-R video.

 

How much better are we talking? "They" as in Nissan, right? Was anyone else able to confirm it besides them?

 

It was a documentary. They certainly didn't go down pages of technical specifications of every change from generation to generation of that car or I'd still be watching it.

Look up information. I've given you what I have. Do with it what you will.

 

Honest question: who here has a motor/setup badass enough for THAT to be the "restriction" if you will? LOL

 

Hell if I know. A Q45/big LSx throttle will move a lot of air.

A stock throttle body is a slight restriction at even tuned N/A power levels, so I've heard.

They weren't looking for power, but for response. This was the GT-R in the days of the '276 hp gentleman's agreement' of Japanese car makers. Feeling good/better control can be just as much reason to do something as more power, depending on what you want.

 

This is true, but then look at soviets plot, the torque his car makes, the topend power it makes, and all the reports from everyone that's driven it saying it feels like a gt2554 car and response being crazy.


.....on a stock tb and 99 mani...

..and suddenly I wonder if a irtb setup is worth the effort

 

If the stock turbo EVO guys have taught us anything, it's that you can make insane amounts of power working around a restriction...

...or racing series that have throttle restriction plates, or F1 that only has 1.5 liters, the list is endless.

Good engineering works around issues, much like how much power we can make with an 80's economy car engine head.

 

Yeah, nissan did it with the rb26. And the sr20 in the pulsar gtir. I know some crazy aftermarket guys change the rb26 to a big single TB, but that might be for ease of tuning or because they are running massive turbos and its too hard to modify the stock plenum to make the most of it.

Its not really a practical thing to do when it comes to cash, and its a bit of a ****. But just in theory...

Here's another one. Exposed TB with appropriate length trumpet vs inlet manifold? Im hijacking this thread a bit, but I dont give a hoot.

 

I hear what you guys are saying, but IRTB is kinda like putting Gold Bond on your *** before wiping it: it probably helps, but there are MUCH more pressing matters to be addressed before its a necessity.

Like our heads. And cams. And valvetrains. And.....

I am not by any means talking you out of it, but for goodness' sake please make sure you upgrade the much more pressing areas of our engines/setups before you take on IRTB in addition to turbo.

 

Give us a little bit of trust. Next you'll be warning us that the 1.6 rear end and five speed, the bottom end might not handle 300whp...

For outright power per dollar, it's nonsense.

Of course, for power per dollar, a cheap turbo on a cheap engine built cheaply is the only way to go, and some might consider anything else a '****.' Some people prefer different feelings over outright power, though.

 

If you look at the top running FI drag cars (turbos and centrifigals) you never see ITBs on them any more. They all have one throttle body and and plenum intakes. We all know how much power they are making. However, there is only one throttle position during the entire race in drag racing

However, in driving an ITB car and turbo, single throttle body car, there is a huge difference in how much sooner the car starts moving with the ITB set up. Not that it would win the race overall.

I think that in an on and off the throttle race with two cars of identical set ups, the ITB car would have an advantage. All out horsepower drag race? Not so much.

 

I certainly agree about the 1.6 diff. It will not take much abuse and a big power increase will end its life quickly.. I am not totally sure I would take the path I took if I knew what I know now.. But maybe.. The fun factor is definately better than stock. But I did spend quite a bit to get to this point, and if I was going to add the cost and complexity of IRTB, and turbo together, I think I would have to choose the V8 swap. The cost difference would start to get small enough that it would be hard to resist..