modified downpipes...do they work????

Here are pics of the original race pipes ( hopefully )

I forget who made them but I seem to think it was about £180 to mod your standard units. I'll try and search for them in a min.

I believe both pipes are needed to overcome the deficiencies as standard

This was the caption to go with the pics

Hi all. Just bought this from MHP and wanted to know what your thoughts where on it. The discription that came with it was as follows.

"Here we have an MHP modified OE manifold for an Aprilia RSVR 99 - 02 single sided systems. The enhancements enable the system to improve performance by 15 bhp across the midrange and by upto 3 bhp at the top end, but the benefit is the spread of power across the whole rev range. This manifold was used in the MRO Aprilia Challenge so this enabeled a single silencer to match the capacity of a twin Akropovic system."


I believe the guy to see is CHEESY as he was active on this thread

Here we go, follow this link to MHP in Stevenage :thumbup

http://200mhp.co.uk/default.aspx

nice one...thats so much clearer ,think i'll buy some headers and modify them then just swap them over.

Can i use any headers from 98-03...i.e. all single pipe headers i have a 2000 mille ?

Ok

Now I am getting all antsy again!!

Does anyone have conclusive proof of gains etc, claims of 15bhp through the mid-range seem a little ........................ well you know!!

I have the titanium EVO headers which weight 1.8 kgs less than the OEM dumps, however would offer no more gain than perhaps that of weight loss

I would not even hesitate to modify and put the old steel dumps back if I thought such gains (or even another 5bhp) would be possible.

ANYONE out there trialled and had success with evidence??

Cheers Pete

Must admit it seems a bit optimistic to me as well :dunno

However, I found this info on AF1's forum and several of the guys who did the mod posted back with glowing reports. Never saw +15 bhp on any dyno curves posted tho.

I'd post a link to some of the threads,just not sure if you're supposed to direct people to rival forums :dunno

Bollocks! Why not,it's all relevent.

http://www.apriliaforum.com/forums/showthread.php?t=138578

There is more,not sure if it's on the Tuono section

And the other

http://www.apriliaforum.com/forums/showthread.php?t=141552

IanG said:

Must admit it seems a bit optimistic to me as well :dunno

However, I found this info on AF1's forum and several of the guys who did the mod posted back with glowing reports. Never saw +15 bhp on any dyno curves posted tho.

I'd post a link to some of the threads,just not sure if you're supposed to direct people to rival forums :dunno

Bollocks! Why not,it's all relevent.

http://www.apriliaforum.com/forums/showthread.php?t=138578

There is more,not sure if it's on the Tuono section

Click to expand...

Thanks IANG

Now its starting to sound like a worth while mod, is there any chane we can get GRIFF to get some input on this :devious

Cheers Pete

IanG said:

Here are pics of the original race pipes ( hopefully )

I forget who made them but I seem to think it was about £180 to mod your standard units. I'll try and search for them in a min.

I believe both pipes are needed to overcome the deficiencies as standard

Click to expand...

WTF

I just pulled my original dumps from the shed only to find that the design of my headers is different to the ones in the pics :dunno

Has anyone else got this, were there an early design for the 98-00 of mine which has been changed to the pics for the 01-03??? My titanium evo headers are the same in the pics though.

dont know whats happening here, will post some pics as now I dont know how to mod the originals on mine??

Pete

Pete
It seems there was an earlier version check here http://www.apriliaforum.com/forums/showthread.php?t=141552&page=4

this is probably what you have. 2nd down?

It seems the object was to give the single can MRO series racers some sort of parity with the later twin can models. I think the more exotic systems used similar balance pipes as standard so probably nothing to be gained if you already have one of them.

Agreed, any input from Griff would be welcome.

Ian

I've had to send my Scorpion Carbon can back (hopefully under warranty) due to blowing joints.

Having just put the bazooka back on has got me seriously thinking about exhaust mods again, may have to canibalise the spare SV system and do this mod.

any body got pics of early headers modded...all the pics i've seen are of 2001-2003 pipes..i'd say space would be tighter with the earlier pipes as the design of the pipes leaves less space for the front link pipe mod the oil tank may get in the way ..the rear mod is not a problem.

failing that are 2001-2003 headers a straight swap?

going by the other forum answers the bike pulls hard from 5000 and gives you a real kick in the pants,not sure if it gives extra bhp but the torque gained is worth the effort

Some Hardly Davidsons and the like have link pipes between the headers, but only 1.
LIKE THE ONE IN THIS PICTURE
So the mod must be worthwhile.

I found this info about the crossover pipe -


In the case of 4 stroke motorcycle engines, the reason for a cross over is this...

After a cylindar fires and the piston cycles “up” - exhausts gas vents through the Exhaust valves, along with the remainder of the “explosion”, exiting the cylinder into the exhaust system.

This explosion creates 2 pulse waves… a Sonic Pulse - and a Thermal Pulse.

When the faster Sonic Pulse leaves the exhaust it has created a vacuum in the pipe behind it, which air pressure will enter the pipe to fill the vacuum. This air will collide with the Thermal Pulse and cause it to reverse. The timing of this event causes exhausted gases to be returned to the cylinder while the exhaust valve is still open therein not allowing all the spent gas to escape and also polluting the environment for your next stroke cycle with fresh air/fuel mix.

This “Event” is call Reversion and seriously degrades performance and lifetime of valves and cylinder heads.

The Cylinders fire opposite of each other – or nearly so on a Harley. So when One side is firing, the other side is idle. Having the cross over pipe allows the pulses to dissipate back and forth between the tubes instead of - or before exiting the exhaust and therein greatly diminishing the effects of reversion and so improve performance and engine life.

Yes - you see a lot of bikes with duels and no cross over. These are usually "Tuned Pipes".. meaning their length and size are tuned to work with the S/T Pulse in such a way that reversion can not return to the engine before the exhaust cycle has ended.
:dunno

IanG said:

Pete
It seems there was an earlier version check here http://www.apriliaforum.com/forums/showthread.php?t=141552&page=4

this is probably what you have. 2nd down?

It seems the object was to give the single can MRO series racers some sort of parity with the later twin can models. I think the more exotic systems used similar balance pipes as standard so probably nothing to be gained if you already have one of them.

Agreed, any input from Griff would be welcome.

Ian

Click to expand...

Ian

You are spot on mate, where they show the 2 different headers side by side, mine is the odd one on the left. Now this looks harder to modify, wonder if anyone has done this at all??

Or do I try to find the other type and fit them on??

As for your Scorpion, hope they fix it up under warranty for yer mate.

Cheers Pete

Mark sent me this when i asked how much !? :eatcorn


I can re-work the original pipework, it consists of two modificatios.

Mod 1-
The loop underneath, between the two downpipes.
This will restore the midrange powerloss at 5,000rpm, that has been caused by use of non-origonal silencer.
Cost £80.

Mod 2-
The balance pipe of the rear downpipe to exit pipe.
This is designed to spread the width of power at the top end.
Designed for race track use, well that’s the main benefit.
Cost £90


There will be an extra charge of £15 for dirty pipework.


Return postage via DHL, £16

Hope that answers most of your questions.

Regards Mark Hill



:thumbup

that's just cleared up any questions i had about this mod! i'm gonna call in a few favours with mates and reckon i can get this done for about 40 squid all in. happy days!
marks prices seem very resonable for the gains tho!

i know too many welders to see £185 in it, but then he knows all the bores,lengths etc..

Incidentally do 01-03 pipes fit 98-00 bikes as the earlier pipes look a little hard to mod due to the design.