1player2nv1

Okay so I have stock jdm GSR intake manifold and I was wondering if there was away to keep my secondary’s opened all the time, I heard by taking off a vacuum line and plugging it up? Anyone have experience with testing this out?

I Havent heard of the greatest results, would you need to chip your ecu? what else is needed to make this happen without throwing a code and such?? Lemmme know what's up PPL... thanks

oneslowstd

ok the reason why Honda decided to put secondary butterflies on this manifold is to create greater ft-lb numbers in lower RPM's. They succeeded lol, The best way to go about this is to remove the manifold from the head and then remove the butterflies individually. I did this on my 96 gsr and I could tell a big difference. It flows much better on the top end with the sacrifice of lower end tourqe. It wont hurt anything by removing them. No tune needed, but I would recomend it along with a hondata intake manifold gaskit since you have the mani off. Good luck

SleeperGSR

to the OP. Do you search before you post? Stock mani, leave it alone. Besides the fact that you won't get any power out of just a mani, you'll need to get cams, otherwise you'll be sucking the same amount of air. There are many more reasons this isn't a good idea. but you can search to find thoes out. GL

OH_1fstgsr

iTrader: (2)

If you remove the vacuum line they will remain open.
But like ONESLOWSTD said you will lose power in the low end and midrange, top end will not change. If you remove the plate you basically shorten the runners by about 3/4" and will see a small change in the top end, but still lose some power in the low end and midrange. You would need a tune to get the most out of these changes.
Why do you want to do this?

1player2nv1

I spent only 20 mins on a search and I was reading conflicting stories...I just wanted to get some great opinions straight up. it seems as if it isnt worth doing, might as well get an R manifold, some cams and a chip. Thanks for the answers

efsedan209

What vacuum line is it I wana try it I been reading bout it. If anyone can show me a pic or something would be great and btw I thought type r Mani don't fit a Gsr head and skunk2 works better

PatrickGSR94

iTrader: (1)

Correct, the Skunk2 manifold as basically an ITR manifold made to fit a GS-R head. You're really better off going that route.

There's really no point in keeping the secondaries open all the time. They're open anyway at higher RPM, and with them open at lower RPM I think the car will fall flat on its face. So just keep it like it is and let it operate as designed.

MyFreakGSR

with them open at low rpm, you just sacrifice a little bit of pick-up is all. The car will run fine but you may lose 1mpg city driving....no reason to unplug it.

Buy a skunk 2 pro series manifold and you'll be good.

OH_1fstgsr

iTrader: (2)

I am going to have to disagree with these statements. The graph below is a GSR manifold BLUE vs a Performer X RED, similar to a Skunk2 on my car.
There is nothing good about this. Overall it lost power. I don't drive between 7200-8200 all that much either.

sebTeggy

wow, Stock butterflies for the win!!

dntnedvtec

Wasn't this the GSR manifold that was ported? AND still have the secondarys in place?

OH_1fstgsr

iTrader: (2)

Secondarys still in place. The runners are just polished to a mirror finish, this added more mid-range power only.

dntnedvtec

Okay, I was just making sure. Thanks! Looks like the GSR manifold was there for a reason....

dk=gsr

wow, this is surprising.
wouldn't think that the gsr manifold would make that much power just by doing so little to it compare to skunk2's and victor x's.

PatrickGSR94

iTrader: (1)

To get gains with a Skunk2 manifold on a GS-R you have to have it tuned, and it's also better with larger cams, such as ITR or aftermarket.

So no, you didn't really disagree with me. I totally agree that slapping a Skunk2 manifold will result in LOST power without the supporting mods and work. And I also disagree with the other statement you quoted, just was too lazy to post anything.

01tegsr

I have plugged the line in my stock gsr just to see. and no difference on the butt dyno. If your into free mods I guess go for it lol. If your worried about the torque being effected you have the wrong engine lol

OH_1fstgsr

iTrader: (2)

The dyno I posted is fully tuned. The car is running ITR cams and has many other supporting mods.
The car was also retuned again. My tuner wasn't happy with the results and wanted another try at his expense. 4hrs later it was a better tune but still showed losses across the power band in certain areas. The cam gears are set so far off that at idle the car actually is a bit lopey, or rough.
I am actually in the process of redesigning the interior air flow pattern of a GSR manifold to outflow a Skunk2 and Px, with the IAB active of course. Some solid modeling and CFD analysis is all it takes.

Blue is the new tune with the Px, Red is the GSR manifold tune. You can see between 3-5.5k the GSR is a bit better. This is how the car is driven right now.

PatrickGSR94

iTrader: (1)

I have a hard time believing a fully built and tuned B18C1 with stock manifold makes more power in most of the powerband than with a Skunk2 IM with proper tune. I'm not familiar with this Px manifold, but from what I understand the Skunk2 is identical to the ITR IM just with the different mount flange.

This is all pretty off topic from the OP tho.

94VTEC2TONE

your talking about some mad research and design man, and ill bet that the stock manifold will outflow midrange due to that design and all the work you have put into it. In reality question is is the OP looking do drag race, stay in the higher rpms or like you stay in the midrange and daily drive. Me purposely ill sacrifice a little midrang for a good topend because i like to drag race.

Whats in your motor besides itr cams?

OH_1fstgsr

iTrader: (2)

I use a very good solid modeling program every day as well as the add-on FEA program. This shouldn't take me to long, CFD isn’t that overly complicated.
Plus I have been reading up and studying different manifold designs for over a year now, and not just Hondas.
True, it is ultimately up to the OP, I'm just try to see if I can find away to have the big top end gains and keep my midrange. Very close now.

stancati

"VTEC, as most of us know, was a way to attack the compromise of low end power vs. high end power. It was pretty much impossible to make an engine with high output in the upper RPM range without sacrificing drivability in the lower RPM range. The physics of it work in a way such that a slower moving engine cycle responds better to low lifting valves with almost no overlap. However as the engine cycle speeds up and demand for air increases, the engine will need higher lifting valves with more overlap to meet the demand.

If you have high lift/overlapping valves at slow engine speed, the engine won't be able to expel waste gases fast enough before it breathes in again. So instead of the nice breath of combustible oxygen air your engine was expecting to get, it gets a load of its already burnt carbon monoxide gas. You'll notice this happening with a loss in low end torque as well as shaking, sputtering, and crackling when the engine is at idle.

On the other side, if you run low lift valves you'll get your nice idle and smooth response in the beginning. However as the engine spins faster, it can't circulate the air quick enough and the valves end up closing before the engine has completed breathing in all the air it needed. You'll notice this when your engine is pushed harder, and your acceleration seems to get weaker rather than stronger.

Every cam has only a single RPM in which the engine speed perfectly match with the cam lobe profile. You can usually tell how a cam was designed by looking at where the engine's torque peak occurs. The solution to that was to change the valve lift and timing on the fly, giving the driver excellent response at both ends of the RPM spectrum. Honda's solution was VTEC. An acronym that loosely stands for Variable valve Timing and lift with Electronic Control. Yeah I know they missed some letters, but VTEC just sounds cool so I guess they just picked the letters they felt like using for marketing sake

Coupled with VTEC, the GS-R engine has three stages of operation. Stage 1 (0-4400 RPM): Low-lift cam lobe and long intake runners. Stage 2 (4400-5800 RPM): High-lift cam lobe and long intake runners (Vtec). Stage 3 (5800+ RPM): High-lift cam lobe and short intake runners. This three stage system is how the GS-R is able to keep a flat torque curve. Changing to a single-stage intake manifold such as the Skunk2 would amplify the cam lobe change and you would see a double hump curve similar to the Type R. Increasing the high end torque while receiving a slight decrease on the overall curve."

lots of good info on the difference between the GSR's IM and the Type-R's IM on this page ... including pictures of the torque and horsepower curves



http://www.team-integra.net/forum/14...uestion-2.html