Tech Spam thread - because 1/4" BSP gets 5 hand spans to the jiggawatt

[cletus 30,345]

Dunno, I think I'd need to run it up the other way so the pipes work, and the inner guards taper in at the bottom so theres not as much room for bends etc  

[Testament 8,208]

I have a pumped system on the fiat but it's general other shit running issues precluded seeing any benefit from it to date, will have to see if sequential injection solves the other issues and report back. That said it depends how its tuned. if you tune it so its fine without the water injection then no big worries. also put a low level switch/warning ideally.

basically the WI should lower the IAT so the ecu should know to retard timing/reduce boost etc. when IAT = too high

another option with WI for simplicity is using an air atomising nozzle and boost pressurised tank so theres no pump to fail. you bleed boost off the compressor to push the water out of the tank, and in the nozzle a second supply of air bleed is used to atomise the liquid which is then injected upstream of the compressor - this makes the air denser and increases the mass flow rate of the compressor so you can use a slightly smaller compressor wheel for a given flowrate/power level.

Air to air is certainly the least fuss to live with but none of the issues with WI are thaaaaat big of a deal if it's actually put together well. You can have the same kind of issues with your main fuel injectors or fuel pump blocking up or stoping working.

 

[mjrstar 2,590]

If you want to go faster at the drags and have limited intercooler sizing something like this co2 spray kit would be an option to consider. (or better still build your own) 

https://designengineering.com/intercooler-sprayer-kit/

As mentioned above if you rely on water meth injection and tune to capacity you run the risk of a meltdown.. 

 

[h4nd 5,019]

On 20/11/2019 at 16:15, Spencer said:

... new stack of risk as you are reliant on another active fuel system to be working correctly at all times...

Interesting point, well stated.

@cletus does however already have available a high pressure supply of a volatile substance which will evaporate and cool the Air. It's the petrol. Try extra injector(s) upstream, simplify EFI / mix / AFR setups? Just run hella rich momentarily, safer on the pistons too, right?

[Spencer 19,467]

I think the setup is blow though carb so the tune is baked in.

[RUNAMUCK 21,325]

Yes but with the extra heat wicked out of the charge, there will be greater density. So more power will be extracted from the same volume* of air/fuel for any given tune.

*greater density for that volume/more atoms.

[kpr 5,174]

Personally i wouldn't bother with the water/ meth. For the more shit to go wrong and blow up your engine reasons.  Have played with injecting water alone and isn't  much to be gained. Meth yes, but if system fails all bad.

Run an intercooler even if its small. Pulling some heat out is better than nothing. Just make sure it flows enough for the engine.  If flows across  the width make sure has plenty of height and thickness, so isn't  a restriction. 

Tune on pump gas for best  boost/ timing compromise.   If want to go fast at the drags of the likes  throw in some race gas and wind up the boost.   Still goin to take the hit on the iat's / lower air density.  But higher octane will deal with knock. 

As im sure everyone already knows, its just a big ballancing act with compression, fuel quality, heat and how much air your trying to jam in there.

 

[SOHC 7,836]

what the fuck is up with the Volvo water pumps and that seal to the cylinder head? my home made seal lasted well but it was too compressed to use with the new pump, I have a new one I made tonight from a sway bar link rubber, the factory seal needs to be flat on top and not domed and hollow.

[SOHC 7,836]

I have had this problem before, I fitted a new Dayco timing belt and a GMB tensioner pulley, and at about 2000 2500 RPM it makes a funny screaming howling noise, and this is with or without fan belts.

Last time I got worried and changed the tensioner and it went away but this time I changed it and its still doing it, I set the belt tension by letting the spring pressure push it tight and turn the motor over by hand then lock up the main nut on the stud.

I was reading new belts can make a noise for a little wile?

[kws 3,242]

If anyone is after a cost effective Dial Gauge, I picked one of these up today and its shockingly decent for the price. Has a certificate of NZ calibration, and has a decent heft to it, doesnt look or feel cheap. https://www.saecowilson.co.nz/#/Product/info/M339A

Same with the magnetic base, better built than the price lets on https://www.saecowilson.co.nz/#/Product/info/M329

[kws 3,242]

Im redoing the carpet in the TVR myself, and have a source for the carpet but im stuck on the underlay. The company that supplies the carpet (Basis) has "underfelt" but its made of pressed wool and is not water resistant. Being a glorified swimming pool, I would like an underlay that wont absorb water if it does get wet. I would need a few meters of it. Anyone got any ideas? Im guessing im looking at a foam or something. The Pararubber site doesn't seem to have quite what I think i need, but i could be wrong.

[NickJ 3,101]

3 minutes ago, kws said:

Im redoing the carpet in the TVR myself, and have a source for the carpet but im stuck on the underlay. The company that supplies the carpet (Basis) has "underfelt" but its made of pressed wool and is not water resistant. Being a glorified swimming pool, I would like an underlay that wont absorb water if it does get wet. I would need a few meters of it. Anyone got any ideas? Im guessing im looking at a foam or something. The Pararubber site doesn't seem to have quite what I think i need, but i could be wrong.

Get underlay from modern cars and trim to size was the advice given to me

[Mof 10,286]

Gents

Where might I find a new one of these? 

It's the solenoid for my mig

I don't know if this is the right thread...

[Bling 16,233]

Quick google of the model number shows ~$100US 2nd hand, shipped. Not sure if after a local source though.

[UTERUS 15,262]

Gas solenoid? 

I usually start with the supplier of the machine, if they can't help then Google.

[Mof 10,286]

Yeah I was right pissed off with it and wasn't in the mood for Google 

It's an old cigweld, I might drop it in to Denis Cunningham, they'll have a laugh, and sell me a new one 

[NickJ 3,101]

Its just a 3 phase contactor no? any electrical wholesaler will have something of similar abilities 

[UTERUS 15,262]

Yea is it solenoid or contactor?

If it's contactor, then any wholesaler will get you one.

[Mof 10,286]

I tried to take it apart to see if I could clean the contacts, but I wasn't sure if it was serviceable. And I still had welding to do. 

The issue is sometimes when the trigger is pulled, it trips the breaker for the wall socket. About 50/50 weld/breaker.

What do you guys think? 

[UTERUS 15,262]

If you just pull the trigger and not weld, does it trip the breaker?