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Greddy VPL Intercooler and Polished Modified Inlet Manifold


supRo
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Intercoolers don't give any performance gain.

 

40% of what?

 

 

I thought as an intercooler reduces the intake tempreture therfore more power? I maybe talking crap here :stickpoke

 

The ported manifold is 40% increase in inside volume over stock manifold

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Thanks Paul, perhaps you can put me straight on this. I didn't think lowering the charge temp actually gives any more power. As I understand it, cooling the charge allows you to run higher boost more safely.

Obviously it doesn't actually increase the boost, so they're a supporting mod rather than one that increases power. Is that right?

 

supRo,

Are you running a single turbo or stock J-spec ones, or what? I was under the impression that you needed to be making big power before a modded intake was really beneficial.

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I'll have a stab at this.

 

If you reduce the temp of the inlet charge you get a more dense charge therefore better volumetric efficiency, thats why some people report the car as being a little bit more responsive on a cold winters morning rather than in summer.

 

Is that right?

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Lowing the charge temperatures does increase power, as the air is denser and therefore contains more oxygen. Have you ever felt how much quicker your car feels in the winter compared to a hot summers day. I'm sure I must get at least a 10% increase in power on the coldest days in HK (8C) compared to the hottest days (38C.) This is also why people report a loss in power after fitting a cone filter, as the engine is taking in hotter air from the engine bay.

 

Saying this fitting an intercooler will only give a small power increase, which you will probably hardly notice. As Jake says the main benefit is that you can run higher boost more safely.

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I'll have a stab at this.

 

If you reduce the temp of the inlet charge you get a more dense charge therefore better volumetric efficiency, thats why some people report the car as being a little bit more responsive on a cold winters morning rather than in summer.

 

Is that right?

:thanks: and as any of us ex calibra turbo owners know a crap intercooler equals no power on hot days.

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Hello,

I've just ordered the above...

Can anyone tell me of the performance gains on the above? Is that a decent intercooler?

Apparantly the manifold is 40% increase over stock.

 

Cheers

The intercooler will give you nothing unless you change the fueling to take advantage, or up your boost as has been said above.

 

Likewise, I suspect that the polished intake manifold will give you absolutely nothing on WOT and maybe a little weeny bit off boost. Intake manifold tuning isn't anywhere near as much of an issue on forced induction cars as it is on NAs. Even then is more down to runer lengths than plenum volume.

 

40% performance increase for just opening up and polishing the manifold internals is a crazy claim (IMHO of course).

 

I'm prepared to be shot down with a "before and after" dyno test, though.

 

I don't want to p*ss anyone off here, but I think the claims being made about this product are way out of left field.

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Thanks Paul, perhaps you can put me straight on this. I didn't think lowering the charge temp actually gives any more power. As I understand it, cooling the charge allows you to run higher boost more safely.

Obviously it doesn't actually increase the boost, so they're a supporting mod rather than one that increases power. Is that right?

 

The wastegate system attempts to maintain pressure at one level, e.g. 1.2bar of boost. If the intake air charge is made colder, by it being a colder day, a bigger turbo, or a more efficient intercooler, the air contracts (opposite to it expanding when it heats up etc etc). Pressure therefore goes down (again, opposite to heating). So the wastegate system lets the turbos spin faster until the desired boost level is reached. So although the boost pressure remains the same, the amount of air reaching the engine (and therefore burnable oxygen) is increased.

 

This would actually be problematic if the ECU didn't know what the air temp was, but the J-spec has an air temp sensor in the intake plenum (the shiny bit in this post :D ) so the ECU can compensate with more fuel due to lower intake temps.

 

I think the MAF based cars use a temp sensor in the MAF sensor itself, but how that takes into account the turbo and intercooler I don't know, maybe it also has the plenum temp sensor but then why have one in the MAF...? Anyway.

 

Upshot of this is, lowering the intake temps is a *very* good way of increasing power, providing the ECU can compensate for the drop in temps. This is interesting with a BPU car as anything over 1bar = 100% duty cycle, so if it needs more fuel due to colder temperatures, it can't be supplied.

 

People may think that airflow signal mapping could be tripped up by this as you can't adjust the fuelling depending on temperature, but in my experience the stock ECU's compensation for air temps translate across to the airflow map and bigger injectors nicely :thumbs:

 

-Ian

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This would actually be problematic if the ECU didn't know what the air temp was, but the J-spec has an air temp sensor in the intake plenum (the shiny bit in this post :D ) so the ECU can compensate with more fuel due to lower intake temps.

 

I think the MAF based cars use a temp sensor in the MAF sensor itself, but how that takes into account the turbo and intercooler I don't know, maybe it also has the plenum temp sensor but then why have one in the MAF...? Anyway.

 

-Ian

Dude,

 

What's important is mass airflow. The mass of air on the atmospheric side and the pressurised side will always be the same, so the MAF meter will always report the correct amount of air entering the engine.

 

I think the temp sensors in hot-wire MAF meters are there for some sort of internal compensation.

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Does anyone have the VPL Intercooler fitted? What do you think of it?

 

And ported Inlet Manifold - can anyone tell me of the difference it has made to theirs?

 

Cheers

Speak to dude regarding the manifold mate - he has one fitted to his car.

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The VPL is the cheap 2 row FMIC with e 2.5in piping thats been on ebay a lot lately for £500, right?

I can't comment on that one but I did notice a reasonable performance increase at high rpm (5.5k+) after changing to a Greddy 3-row FMIC. It dyno'd 387bhp with a knackered stock IC, using the 'seat of pants' dyno I would guess the FMIC made this up to 400bhp.

 

Not that I'm an expert but I can't see how that intake manifold would increase bhp, possibly the only benefit would be to increase the power off boost or while the turbo is spooling (more air available before positive boost is reached). Probably someone more technical will be able to explain this better!

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