Watermeth

[rerb]

I've just bought the AEM watermeth kit after giving up on an intercooler setup. Might be a little fancy, but I've always wanted one. Borg's intake temp calculator says my intake temps are close to 230f, and after a long pull the plenum will actually burn my legs, so I believe it. I think heat is a big reason I only gained 4 hp on the dyno going from 10 psi to 15. (Sub 200hp) as the engine is in perfect condition (just tore it down).

The plan is to progressively spray a 50/50 mix of water and meth into the charge pipe after the pilot tube starting at 8 psi, adjusting the "full" spray point depending on my AFRs. I don't want to be lower than 11. 

An electrical engineering buddy of mine is going to help me code an afr/boost logger on an arduino for dirt cheap to help tune it.

The challenge now is just mounting everything up, I'm thinking using the passenger footpeg brackett for the tank. Once it's all together I'll head to the dyno and do some experiments with the MAP/IAT I'm buying from ignitech.

Anyone else gone this route before?

 

 

 

[denisd]

See this where I bow to superior knowledge, what language is that? 

Fair dues to all you turbo nerds. 

[Gixer1460]

If heat is a problem at such a low boost number, I don't think water injection will make a significant difference - it's a fundamental turbo efficiency problem as it's being pushed beyond its 'happy place'.

[Joseph]

6 hours ago, denisd said:

See this where I bow to superior knowledge, what language is that? 

Fair dues to all you turbo nerds. 

Yep this definitely wouldn't go through google translate with much success 

[rerb]

8 hours ago, Gixer1460 said:

If heat is a problem at such a low boost number, I don't think water injection will make a significant difference - it's a fundamental turbo efficiency problem as it's being pushed beyond its 'happy place'.

This too crossed my mind, going by the compressor map (and rough estimation) I think I'm dangerously close to the surge line, as the 16g should be fine for 400 cfm. Assuming 200-250hp high revving I should only be around 200 cfm(?) If this is right I highly doubt I'm overspinning it (unless my turbo is complete junk), but rather not being able to spin it fast enough. 

 

My solution? Skimming the heads. I'm going to drop a mm off the cylinders before reinstall, and see if that helps bump things up a bit.

[Gixer1460]

Ooooh that'll be a bit controversial - raising comp plus high inlet temps = recipe for detonation!

[rerb]

3 hours ago, Gixer1460 said:

Ooooh that'll be a bit controversial - raising comp plus high inlet temps = recipe for detonation!

Haha, once together I'll do some test runs on wastegate (8 psi) with meth enabled, while logging IATs from the sensor. If all is well I plan to slowly push more, making sure temps and afrs still good. I'll keep doing that until I see 250 wheel!

 

It's worth mentioning the sub 200hp runs were on the old turbo with a bad seal, after putting the new one on at 18 psi is when heat became the real issue

Edited September 10, 2022 by rerb

[Gixer1460]

I must be missing something here as my 1st turbo build - a suck through Garrett T2 and S&S carb made 205whp @ 10psi boost. No intercooling obviously but I doubt not a lot more boost would have made 250 but it was Max'd out at 10 lbs. Yours is more sophisticated so I would have expected better numbers?

[rerb]

4 hours ago, Gixer1460 said:

I must be missing something here as my 1st turbo build - a suck through Garrett T2 and S&S carb made 205whp @ 10psi boost. No intercooling obviously but I doubt not a lot more boost would have made 250 but it was Max'd out at 10 lbs. Yours is more sophisticated so I would have expected better numbers?

That's what I've been fighting, I'm also replacing the carb boots and adding more clamps to the intake incase for whatever reason boost in the plenum isn't reaching the carbs. I had issues where boost would blow the lip of the silicone connector just a tad off the carbs, I added some plenum supports but I'm not sure that fixed it at max boost. I tuned my AFRs to be more on the safe side (12 - 11.5) so it's not the most efficient, but I agree I should be seeing more power than I am. Could also be Eblag turbo bs.

I guess we'll see if it's gotten better next dyno day

Edited September 11, 2022 by rerb