4722 replies to this topic

[ChrisS1]

All very interesting stuff. Looking forward to seeing the outcome.

[smiley]

Maybe I over reacted a bit, but I simply don't have any IAT issues, either during spirited driving or flat out endurance tests.

 

 

Where is the sensor in your car Nev? (i'm not into turbo's so don't know)

In the manifold, or in the intake pipe? (ie is the sensor measuring compressed air, or intake air?)

 

 

[Nev]

I have a thermo-couple installed just after the inter-cooler, with a digital readout on my dashboard. So the IAT temps I am talking about are the temps of boosted and intercooled air.

 

I think what is happening is that the supercharged owners just assume that because they get IAT issues then I must have them as well. There are several good reasons why my IATs are low, which I think most people are unaware of or don't understand.

 

Edited by Nev, 25 November 2016 - 07:33 AM.

[Arno]

Honda uses an interesting passive approach in their OEM TypeR silencers.

 

A sping-loaded flap on the input pipe inside the silencer housing gets pushed open by the exhaust gasses at high load and bypasses a lot of the chambers:

 

 

 

 

 

Bye, Arno.

[Nev]

Thanks for posting that Arno, that was not something that I was aware of or had even thought about. It looks like a nice simple solution and I guess they must have done some R&D on making a spring (though I can't see it) that either isn't affected by the heat or is calibrated for when it is hot.

 

It's rewarding to know some OEMs have taken the same pressure release approach as me.

 

 

 

 

 

and as I said, all OEM implementations have a different approach.

 

 

*Please take note.  

Edited by Nev, 25 November 2016 - 09:40 AM.

[The Batman]

I have a thermo-couple installed just after the inter-cooler, with a digital readout on my dashboard. So the IAT temps I am talking about are the temps of boosted and intercooled air.   I think what is happening is that the supercharged owners just assume that because they get IAT issues then I must have them as well. There are several good reasons why my IATs are low, which I think most people are unaware of or don't understand.  

Would be very silly for sc owners to compare there figures to a tubby, completely different chargecooler system and heat issues.

[Nev]

Sheesh, this exhaust is time consuming, no wonder Simpsons wanted so much money to do it.

 

Spent about 4 hours in the garage and built an end cap and drilled the hole for the tailpipe stub: https://sites.google...gn/05-build-log

 

I'm off to a table tennis match (Bristol league) now and I feel as knackered as if I've done a days work !

Edited by Nev, 25 November 2016 - 06:10 PM.

[Nev]

I've really struggled to find a place to get my perforated sheet steel rolled into 3.5" tubes, but by luck a friend of mine has just bought some long rollers (which need some repairing) in order to make some sheeting for his bespoke VX220 roof. So I've decided to wait a few weeks for them to be repaired so I can do the job myself. I will stick the old exhaust on in the mean time so I can go on a few drives if the weather permits.

 

I bought some fully synth 20w60 for the car. Up to now I've been using pure mineral oil in order to "run it in" for the last 12,000 miles and avoid the bore glaze that I had previously. Vacuum on coast down has improved slowly over time by about 2 inches/hg at 2000 RPM, indicating that the piston rings have bedded in better, hence the swap to the more expensive stuff. I am hoping this will help reduce engine wear as my magnetic sump plug usually showed about 1 to 1.5mm of fur on it at each oil change (every 1200 miles) when using the mineral oil. It probably sounds a bit thick to some people, but I find the 60 thickness oil important for the car, particularly in summer.

 

 

Edited by Nev, 30 November 2016 - 03:30 PM.

[fezzasus]

It probably sounds a bit thick to some people, but I find the 60 thickness oil important for the car, particularly in summer.

 

 

 

Nope.

 

Absolutely no link between viscosity grade and wear within an additive technology or across additive technologies. 

[tibby]

Something for U ? https://www.facebook...0488180/?type=3 https://video-bru2-1...91a&oe=583F2904

[Nev]

Thanks Tibby, looks like amazing welding, I think you sent me pics of it before. It sounds a bit noisy to me, though it's hard to tell with videos I'm sure.

 

At least with my own design, I can keep changing it and testing it until it becomes quiet enough. Even though the project is taking loads of time (as usual !) it is quite satisfying. I just really enjoy developing and R&D'ing my own stuff for some reason. Even if someone offered to build me a super quiet exhaust for just £500 I would probably still want to build my own, just so I learn and understand.

 

 

 

 

Edited by Nev, 30 November 2016 - 07:26 PM.

[Nev]

Did a bit of initial noise testing today which reveals how little my old exhaust box was doing: https://sites.google...6-noise-results

 

What's really noticeable (now that I am actually trying to measure it), is the pulsing of the exhaust. I hope my long lengths of perforated pipes will allow these pulses to get "split" into hundreds of smaller pulses all at different exit times (freq) due to the length of the internal perforated pipe and due to variance in refraction distance off the walls before the gas exits the tail pipes.

 

I am beginning to think (hope!) just design #2 is likely to suffice to get the noise down to 100 dB at idle, which will avoid the complexity and risk of installing the butterfly valve.

 

We shall see.

Edited by Nev, 01 December 2016 - 12:37 PM.

[chris_uk]

100dB at idle! 

 

your not going on many track days then... oh wait ...

[Nev]

your not going on many track days then... oh wait ...

 

I don't know why you have to keep chipping away... that's twice now recently in this thread alone.

 

Surely you should keep your fingers off the keyboard instead of giving your company a bad reputation by presuming to infer that I (or maybe you mean the car) is either unwilling or incapable of driving round a track?

 

Please don't bother ringing me up next time you have a problem with a VXT and can't understand how to fix it.

Edited by Nev, 01 December 2016 - 01:10 PM.

[The Batman]

[smiley]

[Nev]

Bad minion !

[Nev]

Managed to find an engineering firm to bend my sheet into tubes this afternoon, it took about 8 calls to find someone, quite a lot harder than I expected.

[smiley]

Every time i watch wheeler dealers, it makes me think the UK is a cool place with small engineering shops at every corner.

It's probably not like that, and closer to what Nev is describing

[leevx2.2]

Every time i watch wheeler dealers, it makes me think the UK is a cool place with small engineering shops at every corner.

It's probably not like that, and closer to what Nev is describing

There is to be fare most industrial sites have an Engineering  unit  a lot have closed but they are still there  ;-)