kpr

Inlet trumpet dyno testing

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so your last test was with out the air box ,so you need a box as big as will fit, plus enough air going into so its the same as no air box  ,thats what i would like to see 

 

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Yep,  so basically simulating open throttles with a cold air feed.

If i ever finish playing with the intake setup, i will go back to  a setup like i ran years ago. Basically sections off the intake side of engine bay.   pics of said setup in below link

https://oldschool.co.nz/index.php?/topic/21725-kprs-kp60/&do=findComment&comment=1624368

 

 

 

 

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2 hours ago, kpr said:

Yep,  so basically simulating open throttles with a cold air feed.

If i ever finish playing with the intake setup, i will go back to  a setup like i ran years ago. Basically sections off the intake side of engine bay.   pics of said setup in below link

https://oldschool.co.nz/index.php?/topic/21725-kprs-kp60/&do=findComment&comment=1624368

I know this is off topic from this thread, but. 

I know you tested the small and larger extractor pipe diameters, but have you had a play around with different lengths at all? 
Or any previous experience with different off the shelf parts or whatever? 

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not really, other than few different things forever ago.     have got a few ideas to try,   just need to figure the most cost effective and least time consuming way to go about it.

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It is interesting that in the Honda world, plenums seem to be par for the course and hardly anyone has ITB?
They all seem to have quite a tiny plenum volume, and do see benefits from changing length of the intake pipe on the front. 
I wonder if this all exists below that theoretical line of where the engines would make power if they had open ITB with fresh air instead.
Or whether small plenum is key to making use of that front pipe. I've definitely seen changes from it.

It's bloody hard to actually figure out how much power some people make when they all post power at the engine, from an at the wheels Dyno.
Which Americans seem to love doing.
Like this dudes saying 242hp which sounds impressive... But then its 180 at the wheels... not so much.
Then fuck me dead they're changing the drivetrain losses numbers with each run
 
https://www.tegiwaimports.com/blog/?p=2443&fbclid=IwAR266P7qfV3gFadKoJUGXyCdNDvf1ZDgb47jYaU5TjK_GKpVJLITCwVSUBU

Bloody Americans

@Hyperblade will show us some proper Honda science soon enough

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Yeah lots of that is just that the stock K20 inlets works real well out of the box. There is like 8 different designs/lengths that move the power around for each application (heavy car gets long runners, type-R gets shorter etc). The aftermarket follows along with so called improvements and makes similar intakes that slam dunk into the factory position so its a easy bolt on type swap. It doesn't mean that is the optimal design, just works well for road cars and you can upgrade manifolds without changing everything else (drive by wire etc etc). The hard core race car or drag stuff still end up with ITB's which end up with a big carbon box feeding air from the front of the car.

People do get gains from larger throttle bodies as they mod K20/4's which are on the end of the plenum so the plenum opening does become a restriction at some point.

There is also the RSP manifold off the FN2 type R which has a larger plenum. From what I have seen it still just moves the power around due to the runner lengths like the others. (hard to find a good photo but I think below someone has polished and fitting thermal gaskets)

intake.jpg

 

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Not picking on Honda people specifically, I remember a really funny case with someone with an MR2. 
They dynoed their car, made some changes, came back. 
The at the wheels horsepower number had gone up, but their "at the engine" calculation had gone down for fuck knows what reason.
So they were disappointed about it... 

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Would be interesting to see the results of having a second plenum halfway down the runners as well as at the ends. I can imagine some dicky dynamics would come into play

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Gen 3 3SGE does that. Has a VSV that can shut off the plenum via throttle plate type things

ssljvy1l.ell.jpg
 

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4 hours ago, Roman said:


Or whether small plenum is key to making use of that front pipe. I've definitely seen changes from it.

 

Was thinking about this the other day.  maybe since the plenum is so small, the pipe attached to the the plenum/throttle body  acts as an extension to the runner. 

Or yeh  as @Spencer says, since there are so many brand name bolt on parts,  most honda guys probably  dont go down the build it yourself and test all  things path.   Then again how many people that put itb's on there engines, actually  go further than wacking them on with some shiny trumpets and call it a day

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5 hours ago, Roman said:

It is interesting that in the Honda world, plenums seem to be par for the course and hardly anyone has ITB?
They all seem to have quite a tiny plenum volume, and do see benefits from changing length of the intake pipe on the front. 
I wonder if this all exists below that theoretical line of where the engines would make power if they had open ITB with fresh air instead.
Or whether small plenum is key to making use of that front pipe. I've definitely seen changes from it.

It's bloody hard to actually figure out how much power some people make when they all post power at the engine, from an at the wheels Dyno.
Which Americans seem to love doing.
Like this dudes saying 242hp which sounds impressive... But then its 180 at the wheels... not so much.
Then fuck me dead they're changing the drivetrain losses numbers with each run
 
https://www.tegiwaimports.com/blog/?p=2443&fbclid=IwAR266P7qfV3gFadKoJUGXyCdNDvf1ZDgb47jYaU5TjK_GKpVJLITCwVSUBU

Bloody Americans

@Hyperblade will show us some proper Honda science soon enough

 

5 hours ago, Spencer said:

Yeah lots of that is just that the stock K20 inlets works real well out of the box. There is like 8 different designs/lengths that move the power around for each application (heavy car gets long runners, type-R gets shorter etc). The aftermarket follows along with so called improvements and makes similar intakes that slam dunk into the factory position so its a easy bolt on type swap. It doesn't mean that is the optimal design, just works well for road cars and you can upgrade manifolds without changing everything else (drive by wire etc etc). The hard core race car or drag stuff still end up with ITB's which end up with a big carbon box feeding air from the front of the car.

People do get gains from larger throttle bodies as they mod K20/4's which are on the end of the plenum so the plenum opening does become a restriction at some point.

There is also the RSP manifold off the FN2 type R which has a larger plenum. From what I have seen it still just moves the power around due to the runner lengths like the others. (hard to find a good photo but I think below someone has polished and fitting thermal gaskets)

 

 

As Spencer said their are so many different designs/lengths for the K20/24 manifolds.

I agree with him that some of this is for different types (weight etc) of cars. I also think a lot of it is packaging in the engine bay. I.e the Euro has a bigger bay so can fit in longer runners. But same manifold won't fit in Integra without a bit of chopping, replacement.

Also Honda doesn't just stick with what they know, they do try and optimise for each engine/car combo. i.e the FD2 has a range of changes just for 5HP.

 

The American market is interesting, a lot of people are really trying to do everything on the cheap, so naturally that means it's cheaper to get a second hand manifold off a different car. So you have these massive debates on which stock manifold is better.

Same with headers, PLM is the greatest for HP (supposedly), but in reality that's only because of the price of it, when in actual fact it's pretty average all round.

They are always after bolt on horsepower, with no tuning, which they get away with because of the factory wideband O2 sensor. They seem to be very reluctant to actually tune a car probably because most don't have aftermarket ECU's or can't afford them.

 

So for Quad Throttles you have the issue they are are fucking expensive for what they are, and they also don't fit in easily with a good air filter (front wheel drive life), so it's a lot harder to justify.

Toyota guys are lucky as they can use the cheap 4AGE ones ($200), but if they were paying $500-$1000 for a set then it becomes a vastly different proposition.

The other side is Honda manifolds are actually really well designed, so it's not a massive gain, plus of course requires an aftermarket computer for ITBs.

So all round it gets to hard/expensive for most of them.

 

I've been trying to find information on Honda K20a Plenum sizing, and have came up with fuck all, I can space my new one out to increase it and maybe? get more HP, but I can't find any data anywhere on how big to go, and the difference it would have on the K20a which is really frustrating.

 

 

 

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Another thing worth mentioning, is big cams on a single throttle setup will run like a bag of shit at low rpm, big plenum making it worse again. But of course with vtec not an issue.  

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There are Honda guys running big vtec eliminator cams and they do see decent gains with a well sorted ITB setup. Which would closely replicate your wild 4age!

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On the Vtec thing, I was thinking back to that Honda guy video earlier in this thread. If you had two sets of injectors, (one set delivering into the trumpet like he did) you could probably use the vtec as the change over from standard position to outboard ones. Then at lower speeds it wouldnt suffer from fuel sticking to the walls etc. 

Even without ITBs, secondary injectors could probably be mounted in the side of an FFP, aiming into internal trumpets within the plenium. 

/semi ling.

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pretty sure old mate @Roman   set his up like  that.  but was still some kind of issue not making it ideal for street use?    
need 8 injector drives  setup as staged, whilst also being able to adjust the injector timing.  so the fuel makes it down the hole at correct time without getting thrown out.
no drama's for ecu's these days. but is still on the spendy end of the scale with most of them

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Yeah you cant just switch between one and the other, or you get a big lean spot.
Every time it switches from inner to outer, the car will bog and turns to shit. It's very unsettling.
Even if you blend it across it still makes engine response suck.
You need to keep running the inners for a few extra cycles, or run outers richer for a few engine cycles at the start for wall wetting to stabilize. 
I think it's a situation similar to ITB installations - the better your injectors are at atomizing the fuel, the more it's fine to keep them right at the ports. 
If your injectors suck, then you'll see bigger advantage of having them further from the head.

Even if you get it all working right, atmospheric conditions change or your manifold temp changes and then it turns to shit again! 
When I went back to just fully port injection the engine was a zillion times punchier. Like night and day difference. 

Maybe with more setup and a bit more experience with tuning these days I could get it working better. 
Might try it again one day.

 

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These are  up next for some testing.  maybe this weekend.      

20200913_145252.jpg.b78092bbd572e0e21421b3d41e558181.jpg

 

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so,

red line - Silver  tape  -  52-70

Blue line   red tape   -   51-62  = best overall to date

20200907_141552.jpg.4cc3be5424a78b64807b1d88d001c639.jpg

2002303014_52-70v51-62.jpg.543057f5c1f5bcf03f87c28aced007ef.jpg
 

some power loss, too big


blue line - same as above
jam the 35mm pipe down the middle as per left in below pic  gain most of power back   - red line
block outer runner with blue plate  -  other red line with gain down low and loss up top

 

20200913_145252.jpg.b78092bbd572e0e21421b3d41e558181.jpg

188665132_innnerouterbdog.jpg.293bf773f8722b248931623775499d8f.jpg

 

 

Looking pretty good,   Haven't decided if its worth the effort to combine the 2 with a variable setup. but pretty close to matching the best trumpet with the double.   it would  make a pretty nice power/torque  curve combing  the 2 positions  together :

1131148737_52-70w35mminnercombined.jpg.d15074212a709b8572a9f4426b4dcbe7.jpg

 

 

 

 

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Bit off topic  but maybe of interest,   every goose  was having a moan asking if i tune the car between my tests.     So this shows how much the power changes with fuel ratio.  also what i keep and eye on when doing the tests.        cbf'd  watching =    13.5 - 11.5  - pretty much same power. into the 10's power starts to  dive.        

Yeh ok,  I just wanted to show off my mangy horse / unicorn photoshop,..  

 

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