What will the following gain?

Hi,

I have a question regarding possible gains by doing the following,

Current setup - Two Brother VALE Slip on, PC III, O2 eliminated

Proposed setup - Above + BMC air filter + de flapper + Stock header +remove the cat.

I know the previous owner (the one who put in two brother + pc3) did a Dyno.

With above setup after a redyno, any idea on what I should expect?

Thanks.

 

not sure about the gains as i have yet to dyno mine. you should throw in a de-snorkel while your at it. as far as gutting the cat on the stock header, i would stay away from this. with the small primaries of the catted headers this doesnt seem worthwhile. besides creating a large echo chamber where the two cats used to reside would create unwanted turbulance. i think it would just add noise and stench with no gains and possible losses in power. i would go with a motad header(steve larson is a great guy and a pleasure to work with) or atleast a stock 98-99 header that has larger primaries and no cats.

 

The Motads are costly. Ok will stay away from the cat. So de-snorkel, flapper mod and removed velocity stacks. Then because of this you rounded off entries to the throttle bodies and smoothed out the bottom of the air box right?

And I guess rounding of entries and smoothing out the air box will only make sense once I open her up and see for myself right ?

 

yeah the motads are kinda pricey. about 500 flat if you talk to the right person... but the going rate for the 98-99' is about 250 plus shipping and they're 10 atleast ten years old. then there is the sandys and delvics or something like that on ebay, and the quality is really hit or miss on the reviews... that seems really risky to me. believe me i weighed all the options for about 3 months till last week. hopefully ill get my motad soon.

anyways on the intake side... ive seen the dyno before and afters for the flapper mod(not sure if the snorkel was done in conjunction with) and it made 1 to 2 hp through most of the powerband and didnt really loose any anywhere. the BMC should only help this... but after i put the BMC in i noticed it is much thicker than the stocker and practically rests on top of the velocity stacks. so i took them out for some trial and error and she ran great. i just couldnt imagine the velocity stacks doing any good with out any room ,so i left them out. someone on here went on and on to explain how an open flange flowed much less than a rounded off one. he had air acceleration figures and blah blah blah... so after i was sure that i didnt need the stacks i went to town with a dremel on the bottom of the box. i rounded the entries off a good deal ,to where they almost appear to be velocity stacks sitting flush with the bottom.

on a side note we have 36mm throttle bodies. you figure conservatly those stacks are 1mm thick. they rest about an inch into the inside of the throttle bodies. they are essentially turning 36mm throttle bodies into 34mm throttle bodies.

i dont think all this work has really added much to my bike yet. but i figure after a full exhaust and a good tune its going to be pretty up there. hopefully atleast another 5hp above your everyday slip on and tune vfr...

 

I have the following mods: BMC filter, De-snorkel/flapper, Delkevic headers, PCIII (using Tinyminds map), 2 Bros VALE exhaust. I don't know how much you gain with gutting the stock exhaust for the reasons listed in a previous post. The headers did make a noticeable difference, especially in conjunction with a good PCIII map. Where you really see a difference is how fast the motor will spin up. The cat must cause a good bit of restriction. You can also feel a greater deference in performance between maps. With Cozey’s map the bike runs fine and I get the same mileage (aprox 40). With Tinyminds map it drops to around 36, but man does it ever run sweet. Mid to upper RPM’s have much more pull and the bike feels more aggressive. Sound is a lot nicer too, not much louder but much deeper.

A quick word on Delkevic headers, the quality of the materials is good. I had to do some alignment of the tubes to get everything to fit. I also had to grind out a little excess metal on the collectors. That being said, at $275 to my door, they are still a good deal IF you don’t mind a little work to get them to fit. See my post on them for more info.

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Delkevic Headers on 5th Gen

Just put a set on my 5th generation and agreed. They take a little work to fit but be patient and you will be satisfied. Especially considering the $$$$. Had the same problem of getting rear pipe to seal with collector but a little perserverence won out. Look is great compared to old pipes. Just the "style" points alone are worth it!:biggrin: Since mine is a 98 it didn't have cats or O2 sensors. Guys at Delkevic were great to work with, would recommend them to all. Total cost with gaskets $325.