2871R goes rather nicely...

[karlblues2]

Sooo. What does that mean Mr Paul? Is that good or bad?
Am I better off ditching it and going the 2871 or 3071?
All help appreciated
Cheers
Karl
Oz

[S2central.net]

Well - let me do some quick lunchtime turbology

Of course - this is just one K27 comp map - it may or may not accurate basis for yours.... I'll try to call up the manufactures today and see what info they can divulge.
Assuming its a 3" housing on yours we are at least in the right ball park.

[urS6Tom]

Paul - what IC are you using on this S4, and how did you manage to fit it under the bumper.

I like the sound of this 2871R setup for my urS6 (combined with your multimap ECU), but am struggling to come up with an IC and stock bumper solution.

cheers,
Tom

[S2central.net]

Looking good so far.... will snatch some more time later and post some theoretical plots...

[S2central.net]

1st rough pass with a few options... PDF attached... Just realised all these calcs done with 95% duty cycle which is a bit high. Hard to say how realistic this is for real world MD147 but its a starting point. On paper at least it is capable of ~1.7bar at 3500rpm and of hitting nominal max boost of 1.9bar at 4000rpm... Could probably boost her higher but hey.

[karlblues2]

Hi Paul
Thanks for that. If I'm reading the plot correctly, none will spool up any quicker below 4000rpm by the looks of it which is where I thought the 2871 would. I thought max boost on 2871 was claimed to be at 3300 rpm, ditto 3071, so I'm confused now. Also, plot shows MD147 lasting longer than 2871 through the rev range. Is that true?
Thanks in advance matey
Cheers
Karl
Oz

[S2central.net]

The 2871 does perform better than what is shown there - I was able to make it boost a little harder than the surge line would have us believe... There is some margin there - the compressor maps have to be very conservative.

Again - this K27 map is just a guideline - it may have nothing to do with the MD147... However it makes sense as ATD have used it in 400bhp installations according to their bumf.

I know DJones absolutely raves about his MD357 - I am quite confident the MD147 can be made to perform well... Maybe needs a beefy WG spring to help it low down. It won't hit max boost at 3000rpm - but it will be blowing hard and needn't feel particularly laggy - it comes with the territory though if you want to get towards 400bhp at the top end.

[A80Avant]

when you are giving all those rpm figures, what gear are you referring to?
if it is 3d gear, i can get the 3071R to give me 2bar @ 3680rpm and 3300 on 4th. (lower than that on higher gears)

so it seems that the 2871 should perform sooner than that

[S2central.net]

I'm not talking about any specific gear - or using anything special for that on those estimate plots...

Also the 2871 setup I am talking about had stock internals so no way to find limits on boost on torque - it was making around 1.2bar below 3500 on 4th gear pulls and pulling very nicely... especially beyond 4000rpm. We played it safe to the redline as well - ensuring we stayed on high efficiency part of the map.

Was not attempting to approach 2bar levels in mid range on that setup. Got a feeling the MD147 could just stretch to those levels - but I wouldn't want to play in that territory first before getting some baseline of how it performs on lower levels of boost.

[S2central.net]

My advice for Karl - whatever setup you plan to try - get some instrumentation by way of AFR and EGT... I'd recommend Zeitronix ZT2 but others exist of course. Thats $US400 but a mighty piece of kit that will collect lots of data for you.

Also - get a variable FPR and pressure guage in the engine bay so that if I do get into some chip options for you that you can trim off the correct fuel pressure to get good mixture at WOT - and adaptation will sort the rest out - saves me trying to perfect that on chips from 6000miles away - LOL.

I'd like to try a setup on the MD147 that boosts well low down but runs to fuelling limit on the RS2 injectors you have first of all - circa 370bhp... Can talk you thru how to change some chips as we go for more aggressive boost. Bit of trial and error here so might be a bit frustrating but I reckon I can get something strong and reliable quite quickly.

[Rocco]

Paul you will have more market with the 3B owners.......


dont forget it and make something for this lower cars

[karlblues2]

My advice for Karl - whatever setup you plan to try - get some instrumentation by way of AFR and EGT... I'd recommend Zeitronix ZT2 but others exist of course. Thats $US400 but a mighty piece of kit that will collect lots of data for you.

Also - get a variable FPR and pressure guage in the engine bay so that if I do get into some chip options for you that you can trim off the correct fuel pressure to get good mixture at WOT - and adaptation will sort the rest out - saves me trying to perfect that on chips from 6000miles away - LOL.

I'd like to try a setup on the MD147 that boosts well low down but runs to fuelling limit on the RS2 injectors you have first of all - circa 370bhp... Can talk you thru how to change some chips as we go for more aggressive boost. Bit of trial and error here so might be a bit frustrating but I reckon I can get something strong and reliable quite quickly.

Thanks Paul
Happy to work with you and get whatever I need this end to facilitate!
Cheers for your efforts. Appreciated
Karl
Oz

[urS6Tom]

Paul - what IC are you using on this S4, and how did you manage to fit it under the bumper.

I like the sound of this 2871R setup for my urS6 (combined with your multimap ECU), but am struggling to come up with an IC and stock bumper solution.

cheers,
Tom

Hi - any info on the IC you're using with this setup and how you got it to fit?

Would be very interested in hearing about what you used.

Also, are there and pics of this car?

thanks,
Tom

[Jamo]

Car belongs to Diesel Des so be best asking him

[urS6Tom]

Car belongs to Diesel Des so be best asking him

Ah right. Sorry!