PD Supercharger & heat issues.

[Usdrothek]

I'm looking at getting PD blower (Harrop TVS) and have been talking to a few workshops about it. I think my VE needs the instant response down low in the revs.

While all of them said they will fit any supercharger I like, some have given me their honest opinions and spoken of their dislike of the topmount PD blowers for VE's. They told me that, even with an OTR and intercooler, the intake temperatures get rather high (90 degrees) and lead to a reduction in performance. Something about every 3 degrees above a certain temp = a loss of 1HP. Also that the replacing of the L98 plastic manifold with a metal blower causes faster heat soak and more heat problems.

Their summary is: although the PD blowers work, the 'bang for your buck' is not as big as you may expect. A dyno run from a cold engine may be great, but once the engine is hot, they don't perform optimally. These Harrop superchargers ain't cheap and I want to know what I'd be in for, before dropping that much cash on one.

Is this true? Anyone with a educated opinion on this?

[Evman]

For starters, forget Harrop and just get the Magnuson one. With regards to heat, they certainly warm up but 90 degrees is a crock. If you get your temps to 90 degrees then your intercooler water pump has failed. Having said that, on boiling hot days in traffic mine (albeit a VY but still an L98) will hover around 60 degrees, if not even a little bit more. On a cool night like tonight here in Perth whilst cruising along a 60km/h road it'll be sub-40deg (ie in the 30s). Water to air intercoolers are simply not as efficient with the volume of airflow these suck in. Remember that the heat exchangers that matter the most are between the blower and the heads. There's not much room in there for a heat exchanger!

Overall given the chance I'd supercharge my car again. If I bought a new car the first thing I'd do is supercharge it, it makes that much difference even with it showing 60deg intake temps. The lowest mine has dynoed was on a Mainline on a stinking hot day with a stinking hot engine and a stinking hot blower, and it still reeled off 495rwhp.

[heavyduty1340]

Evmans on the money

They are awesome Bang for Buck, and Id do it again without hesitation!!

And as Ev said - grad a Maggie, you cant go wrong .

[Usdrothek]

Why Magnuson over Harrop?

[heavyduty1340]

Same performance at much less $

Internal rotors are identical IIRC

[Usdrothek]

Thanks.

Are they equally quiet? Stealth is important for me.

[heavyduty1340]

Certainly are

Both have a whine to a small extent, but its not too in your face.

[CALDIR]

Same performance at much less $

Internal rotors are identical IIRC

Hi

Even though I wish the above comment were true but wouldn't it be more appropriate to say: similar performance at much less $$..."
I thought the Harrop kit's were a little more refined over the other Magnuson kits.

regards,

Richard
HRTSEN

[Usdrothek]

I thought the inlets were slightly different.

Thanks for the replies everyone.

I do wonder then, why the performance shop told me about this supposed heat problem. They sell all kinds of superchargers including Harrop, Magnuson, Vortech and procharger, so I doubt they are trying to sell one brand over another. The shop owner did say he didn't care, but this was their assessment from their testing and none of them liked the PD chargers.

[Evman]

Hi

Even though I wish the above comment were true but wouldn't it be more appropriate to say: similar performance at much less $$..."
I thought the Harrop kit's were a little more refined over the other Magnuson kits.

regards,

Richard
HRTSEN

I've asked for proof a thousand times and never received any. The only thing that will make a difference that is even half noticeable is the heat exchangers under the blower. If Harrop somehow managed to squeeze exchangers that were twice as large as the Magnuson ones then I'd believe their advertised improvements. This simply isn't the case though. The big R&D is in the rotors and they both have the same pair. Harrop without a doubt have some fantastic engineering capabilities, but it's not like they're the world leaders in supercharger design. Magnuson design and produce a far larger range of blower kits than Harrop do so it's not like Magnuson are some backyard company just throwing the kits together. Couple that with the fact that Harrop charge us a pretty hefty premium when compared to the same kits they sell to the US and opinions start changing pretty quickly.

Fact of the matter is, if the Harrop kit was noticeably more efficient it would have been measured, documented and advertised loudly to gain a market advantage. They may well be more efficient, but it's obviously not by much if they are.


Usdrithek, they do heat up but like I said before mine still pulled just shy of 500rwhp on a stinking hot day. Side mount blowers simply wont have the same heat soak but they also have a different power delivery. The choice is entirely yours, but I'd be more than happy to go a PD blower again. If you want complete stealth then (I'm sorry to say) a TT kit is what you need. They will net more power and they're a lot better hidden, but they're not without their own problems.

[1BEAST2NV]

magnusun MP1900, 570rwhp, still has good street manners and power on tap, would def do it again.

[jimco]

Hi.
I had a Harrop HTV 1900 fitted to my VY LS1 5.7 about two years ago. At the time my tuner was surprised at the lower intake temps this unit produced,some 20 degrees lower than other forms of FI he had tuned.But ls1's seem to produce high under bonnet temps and heat soak is the problem. I can cruise mine for hours,stop and flip the bonnet and the blower is cool too the touch but in heavy stop start traffic it certainly heats up and gets as hot as the rest of the engine. I have an OBD2 scan guage fitted that shows intake temps and cruising shows intakes as low as 40 degrees all the way up to around 90 degrees on a hot day in heavy traffic. Heat robs power but once you start to move temps drop rather quickly,besides what good is all that HP in traffic anyway!.Regardless if it's an air to air or water to air intercooler it only works at it's best if you are moving. 470rwhp/850 rwnm.
Regards.

[Evman]

Wow jimco I'm really amazed you see up to 90deg IATs in traffic. 90deg is roughly what the coolant temp will be unless the aircon is on on a hot day, in which case it can rise to over 100deg quite quickly. The IATs should only reach the same temp as the coolant (ie 100% heat soak) when the [intercooler] coolant pump has failed and there's no flow through your intercooler system. Any ideas what your engine water temps were at the time?

[jimco]

Wow jimco I'm really amazed you see up to 90deg IATs in traffic. 90deg is roughly what the coolant temp will be unless the aircon is on on a hot day, in which case it can rise to over 100deg quite quickly. The IATs should only reach the same temp as the coolant (ie 100% heat soak) when the [intercooler] coolant pump has failed and there's no flow through your intercooler system. Any ideas what your engine water temps were at the time?

Hi Evman.
Yep up to 90 degrees in Sydney traffic,engine temps usally around 90 degrees to tops of 102 degrees before fans kick in. I usally monitor both coolant temps as well as intake temps on the one gauge and in heavy traffic the difference can be as little as a couple of degrees. Remember sitting still or crawling the intercooler pump is just circulating ever increasing hot water until you begin moving at a resonable pace or your engine temps trigger your fans. But that's an extreme example given a cool day and cruising can see 50 degree differences in intake / engine temps. A recent early morning trip from Sydney to Goulburn saw engine temps of 88 degrees and intake temps of 35 degrees with an outside ambient temp of 14 degrees. But even after 2 years it still brings a smile to my face when you bury your foot, lots of power /torque and 9.41 ltr/100k when cruising.
Regards.

[Evman]

My fans kick in at 90deg, which must be where the main difference there is. I think I've seen 70deg intake temps once on a 40deg day here in Perth after driving the car for half an hour, parking it for half an hour then driving it again. It didn't really want to get below 60deg for most of the drive home.