Thank you though pizzaman for your enthustasic opinion, hopefully one day I'm at the level of your car.

 

Not intended to be smart. This is what I was told when I wanted to get a huge tb and 3in ic piping. I thought bigger, better.

 

Im just looking for actual hard data not what someone was told by there builder/tuner/cousin

 

So you want me to post? I have posted that there was an 8whp gain at 700whp going from the following-

4" Garrett core FMIC
2.5" piping
MIL.SPEC 65mm

to
5" Garrett core
3" UICP
Boomba 75mm

Both runs were the same boost (41psi) on Q16.

I will look for the dyno sheet right now.

Aaron

 

My bad, it was 13 peak and some across the powerband-



Dyno MAP sensor was offline, I only have the log of the 708 on my computer but it was 40+psi to get the gains and even then it was only over 6k.

If dollar per hp isnt important to you I would say go for it. If you dont want to spend $100/hp (and that was on the hookup) then probably should stick with the more proven combo.

aaron

 

john, thank you for posting and actually puting some hard data up there to answer my question

 

In the next 2 weeks I'm testing the following on my Evo X in stages on the dyno:

1) Larger Plenum Intake Manifold with stock TB and 2.5" cold side piping

2) Larger Plenum Intake Manifold with 75mm TB and 2.5" cold side piping

3) Larger Plenum Intake Manifold with 75mm TB and 3.0" cold side piping

The Intake Manifold in stages 2 and 3 will be a second one that I'm having a 75mm inlet and flange welded onto.

We'll see once and for all if these upgrades will make any difference on a 550-650 crank HP setup. Possibly I might test 2.75" cold side piping since a ~70mm pipe probably flows similar to a 75mm TB when you consider the TB shaft going through the middle.

 

Which reflects an improvement of <2%, which more or less lies along the threshold of variation between different dyno runs.

This isn't surprising, as no matter how much air density (boost) we're throwing at it, we're still dealing with the volumetric demands of a tiny 2.0L engine, and factors like ideal TB and IC tubing diameter logically seem to be a function of volumetric consumption (cfm) more so than power.

I suspect much of what improvement can be realized from larger TBs in this case result from reduced turbulence (e.g. reducing or eliminating the step).

Just my $0.02.

 

I have said it many times over. It seems to just be a big waste of time and money. I have no problem testing it though and will. Should be interesting to see the gains and losses.


-Em

 

Which you can see in that plot as well, it does smooth out some for sure.

 

Not to seem like I am backtracking but it did add 20whp right where I had it selected from smoothing it seems. Thats why peak numbers dont always matter, sometimes its average increase. Even then 20whp on a 695whp total setup is a small gain for $1500.

 

Aaron was that Jessee's car?

For the money I would stick to the 65mm MilSpec. I may be going to a 4.5" FMIC and 3" UICP and 70-75mm throttle body in the future but I'm not looking for much of a gain honestly. I would be happy with 10whp. My goal is to make the most power on the lowest boost.

Mikey

 

Aaron, thanks for the comparison data on our TB vs. a larger unit.

IIRC, on Lucas' maxed-out E98 Evo (and I stress maxed-out), he didn't show any gains on the dyno with our TB. BUT, he showed the car going leaner and once he took it to the track, he gained a few MPH in the 1/4 mile (3-4MPH I think it was).

The benefits of a MIL.SPEC 65mm ported TB are increased power (~8-10 whp, sometimes more, depending on mods) AND increased throttle response.

 

So of the stock throttle body ported is the best bet what would then be the perfect intake manifold to compliment it and give the best results for a DD that sees the drag strip every now and then?

 

It depends on what you're looking for. "The Best" depends on what you're looking to do. Some people don't like the lag an intake manifold with a larger plenum will induce. Some people don't mind. Some people with stock turbos don't feel the need to do anything but port the OEM intake manifold.

There is no "perfect" or "best" answer. It depends on what you're looking to do. For some, a larger than OEM aftermarket throttle body may be the better option.