Davies Craig EWP - Opinions?

[psychofox]

I've been pondering putting one of the new Davies Craig EWPs on my 4AG 20V I have in my AE86. I have seen alot very polar opinions on the net about them from "yeah they are really great" to "they suck big time", etc. there seems to be a lot of opinion and less real life experience (including the thread in the old forums).

Does anyone has had any real experience with them? Can anyone quantify things like Power gains? Reliability? Cooling Capcaity?

My application - a small capacity NA motor - seems to be the best from a power gain perspective (stock water pump drag relative to total engine output), and I suppose this is one of the major factors in my interest.

Thanks,

Fletcher

[takai]

A lot of the stuff ive heard is when the temperature controller isnt used alongside the EWP. But like you Ive heard both really bad and really good regarding it. One of the R34 track cars we built last year had a pair of EWPs and that worked really well. But then one of the Clubmans i know blew an engine due to an EWP failing 2 months after installation.

I think vibration is an important part with the EWP failure, a lot of the ones ive seen fail havnt been vibration dampened.

Ben Wilson on this forum has one in his MR2 as well.

[CrUZida]

Mechanical energy converted to Electrical energy converted back into Mechanical energy will always be less efficient than straight mechanical energy.

This is assuming the original mechanical energy is efficient.

ie, your 20V waterpump will be very efficient (relatively speaking), where as a 1970's SBC V8 waterpump will be no where near as efficient.



In short, don't use one.

[69 sprinter]

Only used one and was not that impressed.With the temp controller fitted I found that it really struggled to keep a constant water temp(it would go quite hot before come on and then dropped the water temp very low). The temp change was very dramatic.

[4agte]

i suppose you could use an aftermarket ecu to controll the temp using the water temp sensor and settting the values for the relay to turn the pump on and off?

[CrUZida]

I tihnk you'd need a dedicated spare PWM output from the ecu.
Not many ecu's will have this.

[takai]

That and its not a simple on/off setup, its more like a gradual increase/decrease in speed.

[mrshin]

Kind of what CrUZida already said... Just buy a Motec, and these sorts of things just don't prove to be problems!

[Dimitri]

ive taken notice on other forums. from what i can gather, theyre ok, but shouldnt be solid mounted as this seams to make them fail.

mr2drift has one on his pink track 86, i also noticed he had a spare in the boot of the cenetury.

[oldcorollas]

a few years back, i spoke at length with a guy with a heavily modded jag V12.. not known for it's good cooling systems (british and all..)

anyways, he had excellent results.. drove the car around australia, drag runs, circuit days and never had an issue...

compared to some guy with a commondore that had one " professionally fitted" had endless problems and the big dollar motor ended up being rooted because of it...

i think with proper instalation and sensible design, there is no reason they will not work.

if you want something better (and have a JZ motor so you an buy a bolt on) then Mezierre?? (poor sp ) makes much better pumps...

i think the noeticable difference would be negligible.. the main benefit is higher flow at idle speeds, and slower flow at high rpm, ie no covitation, and optimum speed rates...
adjusting the rate of flow can make a large difference.. if the temp varies too wildly, the rate is too high, or needs more restriction... or the thermostat was left in

but yeah, approach with caution if you are not cluey about cooling systems...

[Ben Wilson]

I sitll haven't road tested mine, but it seems to bring the engine to normal operating temperatures very quickly (2-3 minutes from dead cold), and hold very steady.

[ToySprinta]

Had big problems with mine when i first installed it. Firstly it varied widely between, 60-110C then would stay at 110C when driving. The controller then died, triggering the failsafe, making the pump run full on all the time.
Second controller under warranty came, put a resistor in line from the temperature sensor to make the controller think its hotter then it actually is. Had to fiddle with the control setting to get it right, but now sits between 65-80C normal drivng and get to just over 90 when track driving.
Although, its slowly starting to run cooler, so i think that constant adjustment will be needed
This is on a 4agze running 10psi and 120rwkw
Its a bit of a stuff around, but i think its starting to pay off.

[Selk]

how much do one of these go for? .........say its for a 4age

[ToySprinta]

price is around $200 each depending on where u look

[Ben Wilson]

VPW have them cheaper than anywhere else I've found.