ROBO

Has anyone got one fitted and how have they found it?

Mr Footlong

iTrader: (7)

I think that Harj may have some knowledge in this field...


Cheers,


Nicl

ROBO

Come on Harj lets hear what you have to say mate.
Rob

CraigH

I put a BPM dp on my car after having an SS one for about a year.

Although I changed it with the rest of the system, my findings were that low down it was similar, up top it was much less restrictive.

barge

I was going to get a BPM Down pipe but at £400+ I found I could not justify the cost, & am having a Scooby Sport job fitted this comming friday.

Adam M

Harj has no knowledge in this field as he only has a back box.

I have one.

R19Ket has one

Firefox has one,

Bob Rawle has had them.

What do you want to know?

ROBO

I`m getting one fitted along with one of Bob Rawles ecu packages, i just wanted to know how people have found this kind of modification?

Adam M

I posted on this sometime ago.

the downpipe is supposedly 6 db quieter than the ss downpipe. according to those that make it that is.

ss downpipe with bpm mid and bbis damn loud, so dont do that whatever you do.

twin dunp is great
looks nice too.
is hpc coated mild steel, which may explain why quieter as it has different resonance characteristics.

Made a big improvement on my car (22B), but this may be due to the fact that the 2.2 flows more wxhaust gases, and also it has a vf23. Bigger turbos will benefit more from a twin dump. apparently. Have no idea why.

supposed to be worse low down teh rev range, and better higher up!

Havent noticed any loss at bottom, but is much better higher up.

Be warned. is a three inch dp. So mating to a 2.5 mid and back box will generate reflections at the step which is not good.

If it is a smooth transition then it is fine.

many people use the bpm dp and hks hiper mid and bb. Cheaper than super dragger and less restrictive. Meatier too.

You will be well pleased, I am.

Twister backbox is interesting if you want to go for it. Not too loud by any means with bung in it. Sounds awesome with bung removed, but a touch too loud at cruise.

ROBO

good info Adam thanks, i`m fitting the BPM dp to the rest of my standard exhaust system, haven`t a clue if it`s 2.5`` or 3`` any body know?

Adam M

It certainly isnt three inch.

Cant actually remember.
i know the joins are all the same size, I would guess 2.5"

You may not notice any useful gains doing it this way.

There is too much restrictive pipe work after the dp to allow you to reap the benefits. Removing the cat is great, but from then on hmmmmmmmmm.

you have to go for a three inch mid and back box.

this leaves hks as I discussed, available from brd I think? and NITO. Other option worth doing, is scoobymania, which is three inch all the way through. Give mike a call on this one.

Firefox used to have a bpm downpipe with a scoobysport special three inch system.

He also had mrt headers whcih have proved quiet on other peoples cars, but when this set up bas bolted together it was LOUD. Far too loud for me anyway.

Once again, HKS hiper, or scoobymania are the only ways to go, if you are set on the BPM downpipe. and once again you wont be dissapointed.

ROBO

Thanks again, look into the HKS.

ROBO

If i fit a Hiper mid and back box to my BPM dp the car will not pass emissions on an mot any suggestions?

ChristianR

iTrader: (1)

I have a bpm dp, hks racing suction kit, hks hiper mid and bb, and I have found a great improvement otherall - the cars feels much quicker, and hits a ton just like that ! and the sound is awsome - I have it on my wrx sti version iv type-r coupe.

About MOT? no idea about that, I am from Jersey - no such thing on this island!! )

Adam M

ROBO,

if your car is an import, then the mot test is iirelevant as there are no official statistics on what it should be getting as it is not listed in the mot stations records.

If it is a uk car, there are ways of making it pass so dont worry.

Most imprezas on this board will have the same problem as you, it isnt an issue.

ROBO

Well it looks like a Hiper mid and backbox for me, and i`ll take the mot as it comes, be prepared for a cry for help when it doesn`t pass emissions.
Thanks again for the info.

Adam M

ROBO,

It would appear, that a friend of mine thinks I have been unfair telling you, you wont see an appreciable difference from a back box on a standard mid and back box, so to shut him up.

You will still see a difference fitting a BPM dp to a standard mid and back box.

You will still be better off with HKS mid and BB though.

You didnt say if your car is an import or not. Either way you needn't worry as there are twin catted centre sections available for the purposes of mots.

Although I have no idea who would partake in such illegal activities that in no way do I condone!

steve McCulloch

Adam M

I have the full system with Twister BB

The downpipe is certainly a 3inch - it certainly aint a 2.5inch!!

Its about the loudest system out there

Re Mots - crossed fingers!

Re performance - probably not much in it compared to others with twin dumps and free flow 3 inch systems!

If you want something almost identical for less cost ad a bit less noise you'll find the Scoobymania is the one

If you want a noiser one that is only a 2.5 inch system (debatebly more restrictive) then Scoobysport is the one

Then there HKS for a bit more

Then the mother is BPM! (only like it cos of the noise!)

Jza

Just one quick question - what are the merits of 3" vs 2.5" systems.

Is there supposed to be a difference in terms of midrange/Top end?

Jza

ROBO

Keep the replys coming always good to read, and Adam no need to be touchy mate seemed a fair enough reply to me.

Adam M

ROBO, I know it was a fair enough reply, I just dont understand why it has my name at the top???

I thought it was you who was after answers.

PaulMc

Intersting guys....

I am in the process of selling my UK MY97 and replacing it with a P1.

I currently run a ScoobySport BB, so fancy a change... maybe . On the P1, I am thinking of running a Scoobysport DP, SS mid and a BPM mkiii twister bb. I have heard Shaun's car with just this BB on and it sounds great. Anyone else done this or know why it shouldn't be done.

Final point, the BPM bb hangs alittle lower than others. Anyone had any trouble with grounding out?

Adam M

why is this aimed at me?

I know everything you have said here!

I was trying to help someone else steve, this isnt my thread!

Adam M

Paul MC, dont do it, unless you are prepared for it to be very very loud.

Nothing wrong with ss, but ss upstream of bpm, is ridiculous.

Couldnt handle it, was way too loud.

BPM full system made things quieter, included central cat, and dp is supposed to be 6 db quieter, than what I have no idea, and where that figure came from, again just manufacturers claims!

Certainly is much quieter with full system than mixed and matched.

Apparently, 2.5 inch is supposed to yield better low down torque due to slightly more back pressure, where as 3 inch yileds more power up the top end of the rev range.

Since fitting the full bpm twister mark 3, I have noticed no drop in low down torque but a substantial improvement in the mid to top range. It seems to breatha better, and continues pulling to the red line.

It is possible it has less low down torque, but the 2.2 has so much on offer anyway, that I noticed no drop.

Incidentally, running on the standard ecu, it doesnt appear to be running too lean, although is dipping below top green light on full boost, which it did not used to do.

this leaner running on boost suggests there has been a power increase.

Ken E

ROBO

If you're going to get the Hyper, and you need to use a twincat centre for the mot then it may be worth checking the centre will fit with the hyper backbox before you pay out. I have a HKS Super Drager on my car and the centre section and back box are different lengths to the original one, but overall length of the two is about the same.

Ken

NDT

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Adam M:
<B>Apparently, 2.5 inch is supposed to yield better low down torque due to slightly more back pressure, where as 3 inch yileds more power up the top end of the rev range.
[/quote]

Narrower diameter pipe will have higher gas velocity -
makes it more restrictive at high gas flows (i.e. top end) but may help flow at low/mid flows due to inertial scavenging - assuming that gas flow through the turbo is still pulsed.

Nick

PaulMc

Thanks for the info Adam. I have read all your other posts and follow what you are saying. However, how loud is LOUD, say compared to a full SS system? I just like the sound of the BMP twister BB, and don't want to fork out huge sums of money for a BPM DP when I know and rate the SS DP.

Adam M

Okay, let me put it this way.

I liked the theory of the bpm twister, so I decided to buy it. I wanted a twin dunp and liked the idea of mild steel (quieter resonance) with hpc coating (maintains high temp in gas- which increases speed at which pressure waves will travel).

these details are unimportant.

basically, changing the whole system takes time and I was impatient, so I did just the back box for three days then fitted rest afterwards.

This meant I had standard 22B, running standard ecu, standard turbo, standard headers (k+N induction kit but forget that , essentially standard car, running scoobysport dp and mid, plus twister bb.

Was damn loud, is all I can say. Twister back box, has a corkscrew type bung which goes in tail pipe to make things quieter, with this in place, with ss dp and mid, it was still uncomfortable, on removing it, it sounded like a racing car.

this was witnessed by R19KET, Moray Mackenzie and Pat, two of whom are considered to know their stuff, and certainly have a lot of experience of different exhaust setups. All agreed it was too loud. This can be tolerated but it was particularly bad at cruise, making it very tiresome to drive.

I was concerned about thisvolume but once the high flow cat bpm mid, and twin dump downpipe were in place, it became much quieter, almost to the level of the full ss system and I was happy again.

Bung can still be removed for that extra noise if you are in the mood. Takes seconds.

If you arent buying a full system, there is no way, EVER that I would live with a ss BPM hybrid. Have heard them both ways round (albeit one off 3 inch SS mid and BB) and they both sound appaling.

SS is great on its own, or with magnex, but just doesnt mix with BPM.

Its your choice, You could always try, BPM BB and Scoobymania DP and Mid, all are three inch. But I have no experience of how that would sound.

If in doubt, stick with SS, it does sound great all together.

PaulMc

Nicely explained, Thanks Adam. Now then decisions, full SS or full BPM? Hmmmmm.

Adam M

Oh and one more thing, BPM back box does sit lower. Have exited one steep ramp which caused it to scrape on floor, just after I got it.

After a closer look, it turned out to have scratched on the screw which held the bung in as this protrudes the most. That was a relief as it is replacable.

RobJenks

I have recently had fitted to my complete BPM exhaust - including the twin dump -a VF22.
Greg of BPM recommends the fitting of
" a minimla separator for the downpipe between the wastegate and turbop exit."

Can anybody explain what this is?