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Hi Guys..

I got my front mount intercooler installed last week, and i am a bit dubious about the dyno reading - in that its too high..

I have had two dyno readings - both done with the same settings on the same dyno in the same place - all in shootout mode.....please keep in mind these dyno runs are done just so i know where i stand with the car - im not after dyno output figures only tuning, as this car's objective is the 1/4 mile...

1st dyno run: 166RWKW (HKS super-dragger exhaust, front dump pipe, HKS air pod) - This is about what i expected, which is fine..

Installed GTR front mount intercooler - 120 bend from plenum, 2.5 aluminium pipes all round, cut front bar, plumb back BOV (turbosmart)

2nd Dyno Run: 196RWKW/199RWKW/203RWKW - wtf ?? On the sheet, the first run (done about a month ago) was overlayed, and the difference is all mid range/top end. Additionally, the a/f ratio leaned out a tad, which is also what i expected..

However, i wouldnt expect more than about 10RWKW with this mod, due to the decreased resistence in boost.

Boost is stock, as is the turbo - i was paranoid and all the way home checked the boost gauge (stock) to see if something was amiss to count for the extra power - didnt go over 3.5.. (7psi...ish)

The car as since done about 200kms, so im pretty sure everything that has to be connected is. The feel is that the car is most improved top end about 5,000rpm...

Im after any plausible explanations for this - i dont care about the figures, moreso the huge jump.

Thanks,

Matt

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Perhaps the dyno is a little bit overzealous... my car with full zorst and air pod managed 149.2rwkw on a cold day with a tank of Ultimate, in shootout... car was tiptop, no other issues... and a @40rwkw gain from an FMIC sounds huge...

Either the dyno is out, or there's something in your car that you don't know about. :D

Hi Matt, this is a mixture of comments and questions....

A standard R33 GTST puts out 120-125 rwkw on our dyno, we have had about 20 of them now and that's about the average (and applies to over 80% of the time). With RAWS compliancing we are seeing more and more stock standard cars.

Your car had

just a HKS super-dragger exhaust, front dump pipe, HKS air pod
and made 166 rwkw (ie; 41-46 rwkw more). Based on my experiences, I don't think so! :headspin:

More like 146 rwkw I would say.

Then

GTR front mount intercooler - 120 bend from plenum, 2.5 aluminium pipes all round, cut front bar, plumb back BOV
makes another 37 rwkw (up to 203 rwkw).

The best I have seen out of that upgrade is 25 rwkw accompanied by a small increase in boost, about 1-2 psi. So when you say stock boost? Where is that measured? On what gauge?

Final comment is, I have yet to see an R33 RB25DET make 200 + rwkw without some form of A/F ratio correction (SAFC or PFC etc) and a boost increase, with 10 to 12 psi being the normal level. For your upgrade level I would expect 170 to 175 rwkw. The A/F ratio correction usually yields around 10 to 15 rwkw and the boost increase a similar 10 to 15 rwkw increase. Thus 200 rwkw is a common goal with a standard turbo whilst maintaining some life. :freak:

It would help a great deal if you could post the dyno graphs, there are generally a lot of clues contained therein. :aroused:

Hope that all makes some sense

Guest Robo's
Interesting... generally the anecdotal evidence is the other way around, bigger gains for gears than the FMIC... weird. :D

Its quite common knowledge that the exhaust cam gear on a R33 yields about 5rwkw. Going by the seat of the pants feel, thats as most as i got too. With the FMIC, i could feel a noticeable gain.

Guest Robo's
Well, if it's common knowledge, there's a lot of people out there who have it wrong.

Well i have been reading these forums for about a year now and its quite common knowledge. Maybe your getting mixed up with the GTR in which they get around 20rwkw with both inlet and exhaust cam gears adjustments.

Hey Guys - thanks for the interesting posts.....

Hi Sciby - im sure the dyno is reading high - im more interested in the RWKW difference (which is about 40RWKW) than the actual figure. im using this diagnosis as a tuning tool, nothing more - as i wish to get this beast out on the 1/4 mile to prove its worth..

Generally - no cam gears (yet - soon, though) - and running stock boost (7psi) and stock turbo

Hi Knore - hard to say in regards to SOTP feel. Im sure it feels better, but its hard to say 40RWKW better. Im sure this mod would pickup boost increase by default (due to less restriction), however this should be about .5-1 psi i wouldve thought...

Hey SydneyKid - stock boost is as it states - i havent touched the turbo or boost in any way, shape or form on this car. The boost is measured on the stock gauge for the moment (bad, i know) - and this is based on the fact that at 5k RPM the boost gauge is not going much past 3.0...this tells me that as inaccurate as the gauge is, the car is not running over 10psi (being generous)...ill try and scan the dyno sheet...

Hey Nathan....it was a dyno dynamics dyno, in shootout mode - same settings for both runs..

Cheers,

Matt

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