P2R Throttle Body Spacer FAQ's

[BTRobertson]

So does anyone know if the spacer will work on a larger volume TB, like the Skunk2 68mm or 70mm? They fit directly to our intake so I would imagine the bolt points are identical, just the intake inlet is larger. Just curious because I'm considering the S2 TB before I strap on the TBS and TBG.

[bizzybearfigiblue]

i mentioned earlier that these spacers only come in one size... and if I were to put a larger TB on, then i would have to bore the spacer out as well... just to be sure...

[KSE]

yezzir ^^^

[sikassdrummer]

I love the p2r spacer and their plastic gaskets I can really tell a differance and It sounds kick ass . Way to go p2r

[OrdnanceMarine]

Originally Posted by bizzybearfigiblue

i mentioned earlier that these spacers only come in one size... and if I were to put a larger TB on, then i would have to bore the spacer out as well... just to be sure...

[Adlh29]

Just installed my spacer and gaskets today. Install went nice and easy. I do have a slight whistling noise like that mentioned in the FAQ.

[JKinATL]

I saw that there are issues with the TSB and CAI or SRI intakes in the Si engine... what about the R18 engine? The throttle body is in the back of the engine instead of the front, but there's that darn radiator hose right there to the left of the intake. Anyone?

[OrdnanceMarine]

Originally Posted by JKinATL

I saw that there are issues with the TSB and CAI or SRI intakes in the Si engine... what about the R18 engine? The throttle body is in the back of the engine instead of the front, but there's that darn radiator hose right there to the left of the intake. Anyone?

Get one of those corrugated flexible radiator hoses. Do a search and you'll find info on them.

[BTRobertson]

Have mine installed now and yep, nice little whistle and a tad more response in throttle. But, could be the placebo effect.

[JKinATL]

So, as a generalization, it seems like a TBS tends to add power across the entire range of RPMs, even low-end, whereas mods such as SRIs and CAIs detract from power in low-RPM situations and add in high-RPMs. I'm interested to know if anyone else agrees with these generalizations?

Also, I read elsewhere that the TBS may not exactly be good for the engine in the longer-run because the spacer, and its gaskets, don't allow the intake to absorb and disperse heat from the manifold... thus reducing the life and durability of the manifold. Any thoughts on that?

[BTRobertson]

Originally Posted by JKinATL

So, as a generalization, it seems like a TBS tends to add power across the entire range of RPMs, even low-end, whereas mods such as SRIs and CAIs detract from power in low-RPM situations and add in high-RPMs. I'm interested to know if anyone else agrees with these generalizations?

No, that's not altogether true, though it depends mostly on the brand and type of intake. My Fujita F5 SRI made power throughout the powerband - low to high. I have dynos. The TBS adds a trivial amount of power, but the main benefit is that it prevents heat soak - this is answered below...

Also, I read elsewhere that the TBS may not exactly be good for the engine in the longer-run because the spacer, and its gaskets, don't allow the intake to absorb and disperse heat from the manifold... thus reducing the life and durability of the manifold. Any thoughts on that?

First things first - heat soak is bad all the way around. Yes, heat has to disperse from the block, but if heat soaks into the manifold and then into the intake, there's no water channels or any other method of heat dispersal in those places, so the engine compartment heats up and heat is never removed except by the air around it or coming in through the front of the car at higher speeds.

The intake manifold gasket is something one would consider when doing the spacer, which keeps the heat from soaking TOO much into the manifold. Now, I say too much because it doesn't 100% PREVENT heat soak from occurring, just keeps it from happening too much. The water/coolant system works harder to keep the heat away from the block as a result because less heat is soaking into the manifold, hence less heat is soaking into the intake.

The result is a cooler charge of air entering the manifold and then the combustion chamber = more power/torque across the RPM band. The consequence? Keeping heat where it's supposed to be - where the water/coolant system can get to it and disperse a lot more effectively than the air can. And again, not ALL the heat is at the block, just a bit more than usual because the heat soak is prevented. Trust me, keeping heat where it can be dispersed more effectively is probably the best policy - the IM and TB don't have cooling capabilities at all, so why would it best to have heat soaking into those metal components when they're not built for dispersal?

That's my two cents, anyway; an engineer may prove me wrong.

[OrdnanceMarine]

Originally Posted by BTRobertson

No, that's not altogether true, though it depends mostly on the brand and type of intake. My Fujita F5 SRI made power throughout the powerband - low to high. I have dynos. The TBS adds a trivial amount of power, but the main benefit is that it prevents heat soak - this is answered below...



First things first - heat soak is bad all the way around. Yes, heat has to disperse from the block, but if heat soaks into the manifold and then into the intake, there's no water channels or any other method of heat dispersal in those places, so the engine compartment heats up and heat is never removed except by the air around it or coming in through the front of the car at higher speeds.

The intake manifold gasket is something one would consider when doing the spacer, which keeps the heat from soaking TOO much into the manifold. Now, I say too much because it doesn't 100% PREVENT heat soak from occurring, just keeps it from happening too much. The water/coolant system works harder to keep the heat away from the block as a result because less heat is soaking into the manifold, hence less heat is soaking into the intake.

The result is a cooler charge of air entering the manifold and then the combustion chamber = more power/torque across the RPM band. The consequence? Keeping heat where it's supposed to be - where the water/coolant system can get to it and disperse a lot more effectively than the air can. And again, not ALL the heat is at the block, just a bit more than usual because the heat soak is prevented. Trust me, keeping heat where it can be dispersed more effectively is probably the best policy - the IM and TB don't have cooling capabilities at all, so why would it best to have heat soaking into those metal components when they're not built for dispersal?

That's my two cents, anyway; an engineer may prove me wrong.

Your explanation looks good to me! One little tidbit that doesn't really matter to our application but I'll include anyway: Getting a cooler (more dense), more energetic (since more fuel is added to match the extra air) charge burning inside each cylinder produces a corresponding amount of extra heat. The cooling capacity of our engine is more than adequate to handle this small amount of extra heat but if you were to add a lot more air/fuel (i.e. turbocharge, etc.) you could bump up against this limit. I intend to find it this summer with a drive to Death Valley in early July (hottest time of year).

The reason the intake manifold doesn't make a lick of difference in dissipating excess heat is that it takes way too long for the heat to move into the manifold. Any signifigant rise in cylinder temps during a hard run would transfer to the coolant long before it had a chance to make it to the intake manifold.

Now, if you've shut down and want to cool off your engine enough to work on it and you've raised the hood and maybe put a box fan in front of it, the engine with the intake manifold gasket WOULD NOT dissipate the heat as quickly as the stock setup, meaning you'd have to drink an extra beer or two while you wait for it to cool down or you get drunk enough that you don't feel/care about getting burned.

[JKinATL]

Originally Posted by OrdnanceMarine

Your explanation looks good to me! One little tidbit that doesn't really matter to our application but I'll include anyway: Getting a cooler (more dense), more energetic (since more fuel is added to match the extra air) charge burning inside each cylinder produces a corresponding amount of extra heat. The cooling capacity of our engine is more than adequate to handle this small amount of extra heat but if you were to add a lot more air/fuel (i.e. turbocharge, etc.) you could bump up against this limit. I intend to find it this summer with a drive to Death Valley in early July (hottest time of year).

The reason the intake manifold doesn't make a lick of difference in dissipating excess heat is that it takes way too long for the heat to move into the manifold. Any signifigant rise in cylinder temps during a hard run would transfer to the coolant long before it had a chance to make it to the intake manifold.

Now, if you've shut down and want to cool off your engine enough to work on it and you've raised the hood and maybe put a box fan in front of it, the engine with the intake manifold gasket WOULD NOT dissipate the heat as quickly as the stock setup, meaning you'd have to drink an extra beer or two while you wait for it to cool down or you get drunk enough that you don't feel/care about getting burned.

Thanks. I appreciate the static cool-down scenario. Nothing quite like automobile mechanical mods that drives a man to drink.

[JKinATL]

Originally Posted by BTRobertson

No, that's not altogether true, though it depends mostly on the brand and type of intake. My Fujita F5 SRI made power throughout the powerband - low to high. I have dynos. The TBS adds a trivial amount of power, but the main benefit is that it prevents heat soak - this is answered below...

I'm interested in your dynos! As I said, most dynos that I've seen have shown the HP drop compared to stock when under about 6k RPM. I wonder why yours show an increase across the board.

One of the side-effects of these forums is that you have a whole lot of people with numbers, stories, and experiences that weren't in controlled situations, so its not that scientific and you have wildly varying results.

I wish the following:
1. I could speak Japanese
2. I could call up a Honda engineer and get the word from their multi-million dollar R&D department on all of the above and more.

[Adlh29]

I'm really liking this thread. I have found a lot of great info from some knowledgeable people in here. Thanks guys.

[bizzybearfigiblue]

Originally Posted by JKinATL

I'm interested in your dynos! As I said, most dynos that I've seen have shown the HP drop compared to stock when under about 6k RPM. I wonder why yours show an increase across the board.

One of the side-effects of these forums is that you have a whole lot of people with numbers, stories, and experiences that weren't in controlled situations, so its not that scientific and you have wildly varying results.

i'm sorry but i could pull up a few dyno's that show an increase throughout the entire powerband... not just above

here's one keeping track ... mods + dyno numbers
and another P2R TB Spacer Dyno

[JKinATL]

I was speaking of the dynos for his Fujita SRI because most that I've seen for SRIs and CAIs show loss until 6,000.

Conversely, the TSB dynos, such as yours, seem to show an increase across the band, as I mentioned earlier.

[bizzybearfigiblue]

Originally Posted by JKinATL

I was speaking of the dynos for his Fujita SRI because most that I've seen for SRIs and CAIs show loss until 6,000.

Conversely, the TSB dynos, such as yours, seem to show an increase across the band, as I mentioned earlier.

whoops... i knew that

[BTRobertson]

Originally Posted by JKinATL

I was speaking of the dynos for his Fujita SRI because most that I've seen for SRIs and CAIs show loss until 6,000.

Well, if someone is showing losses before 6,000, something else is wrong in my opinion, especially with a CAI at the very least because a CAI is known to produce more low-mid range hp and tq. The AFR is crucial when understanding air flow (header, intake, exhaust, etc.). With the F5 on my car, it produced noticeable power in the low and mid-range right after I installed it; very easy to feel it. Below is a picture of my dyno - blue line is stock, F5 installed is green. For some reason the peak graph didn't display correctly, but the number is there for you to see.



The only way I could see someone losing power before 6,000 RPM is if they messed with their car and messed up the AFR. Proof? They took the filter off my F5 for a run (not documented in my files) with a velocity stack, which is essentially nothing but a plastic cone that speeds up the air as it enters the intake. I actually LOST power at peak, but gained in the mid-range easily. More air doesn't always mean gains, but it doesn't always mean overall losses either. I've not heard of anyone losing power throughout the pre-VTEC kick-in, but perhaps I'm not looking hard enough. The F5 kept my AFR at a consistent 13.97 at peak and just over 14 right above VTEC kick-in, which to me is damn near perfect. Notice the blue line is way below the green one for AFR at peak - it's almost a .4 difference in AFR at that point. That screenshot is also below. The main point here is that you can see the difference in the two lines - the green is above the blue at every single point in the run, never below. I can also get other dynos from bone stock Sis from my speed shop that shows their numbers all below mine throughout the band. Again, key point is that it differs per car so this ultimately means nothing for everyone here - I'm okay with that. The F5 worked for me perfectly, but it won't work for everyone. Just gotta try different things to see what your car likes best.

[bizzybearfigiblue]

omgosh bro... ur running super lean... my car has never dyno'd that lean... i'm around 10-11 AFR in higher rpms... that's rich i know but that's stock too