Real world effects on performance
#1
Real world effects on performance - Racing Beat mod.
I'm posting this information on behalf of Wildcard, who recently transferred to a remote part of this country where there are no speed limits on the open road. Wildcard has limited internet acces, and agreed for me to tell his story.
Before he left for "the territory", there were a couple of mods done to his car. Firstly it had a custom made exhaust: Headers, highflow cat, midpipe etc. All mandrel bent, all custom made from exhaust ports to tips.
The supercharger was removed before the trip, as we knew it wasn't quite ready, and also to the remoteness of Wildcard's posting along with the regions high ambient air temps.
But something else was fitted prior to the trip. We put on a Racing Beat Ram Air Duct.
Apart from all that, and a K&N Panel Filter, everything else was stock.
Wildcard has reported earlier about his problems on the trip - bad fuel economy, serious overheating problems, lack of top end speed. It got that bad that he seriously considered swapping the RX-8 for some Chevy powered V8 muscle.
His top speed he could achieve was only 215km/h or 134MPH.
I had some long serious discussions with him about it. I suggested taking the ram air duct off, and putting the factory VFAD back in. The next thing I know, I got a short email saying "I'm keeping the car!", along with the following picture as an attachment:
Wildcard had infact taken the ram air duct out and put the VFAD back in. The immediate result was his top speed increased by 20km/h to 235km/h or 146MPH.
But one problem remained: the engine wouldn't rev past 7250 RPM. VDI perhaps? Yep, he checked the DVI valve, and the vacuum hose had come off somehow. (VDI being the valve that connects the two long runners "together" for the "variable dynamic intake"). The result: Revved like he remembered it always did, right to redline. Plus he picked up another 5km/h top end speed.
As far as I know, this information has been supplied back to Racing Beat via the sales channels it went through to get here.
I hope you all find this interesting.
Thanks once again to our fearless test pilot!
Cheers,
Hymee.
PS - Fuel consumption had also returned to expected levels.
edit: Removed reference to overheating issue in relation to back to back tests. Overheating was earlier a problem in 40+ deg C ambient temps, but these were not encountered at the time of the test, or since.
Before he left for "the territory", there were a couple of mods done to his car. Firstly it had a custom made exhaust: Headers, highflow cat, midpipe etc. All mandrel bent, all custom made from exhaust ports to tips.
The supercharger was removed before the trip, as we knew it wasn't quite ready, and also to the remoteness of Wildcard's posting along with the regions high ambient air temps.
But something else was fitted prior to the trip. We put on a Racing Beat Ram Air Duct.
Apart from all that, and a K&N Panel Filter, everything else was stock.
Wildcard has reported earlier about his problems on the trip - bad fuel economy, serious overheating problems, lack of top end speed. It got that bad that he seriously considered swapping the RX-8 for some Chevy powered V8 muscle.
His top speed he could achieve was only 215km/h or 134MPH.
I had some long serious discussions with him about it. I suggested taking the ram air duct off, and putting the factory VFAD back in. The next thing I know, I got a short email saying "I'm keeping the car!", along with the following picture as an attachment:
Wildcard had infact taken the ram air duct out and put the VFAD back in. The immediate result was his top speed increased by 20km/h to 235km/h or 146MPH.
But one problem remained: the engine wouldn't rev past 7250 RPM. VDI perhaps? Yep, he checked the DVI valve, and the vacuum hose had come off somehow. (VDI being the valve that connects the two long runners "together" for the "variable dynamic intake"). The result: Revved like he remembered it always did, right to redline. Plus he picked up another 5km/h top end speed.
As far as I know, this information has been supplied back to Racing Beat via the sales channels it went through to get here.
I hope you all find this interesting.
Thanks once again to our fearless test pilot!
Cheers,
Hymee.
PS - Fuel consumption had also returned to expected levels.
edit: Removed reference to overheating issue in relation to back to back tests. Overheating was earlier a problem in 40+ deg C ambient temps, but these were not encountered at the time of the test, or since.
Last edited by Hymee; 03-03-2006 at 02:49 PM. Reason: Removed overheating reference - not an issue during back to back tests.
#2
M0D Squad -charter member
Join Date: Jan 2003
Location: Alabama
Posts: 1,498
Likes: 0
Received 0 Likes
on
0 Posts
I am to assume the RB Ram Air was not fitted with the RevI Intake?
This is an interesting observation. During normal daily driving, my RevI & Ram Air combo nets me ~ .5 mpg better than stock. It appears to have a detrimental effect at autobahn speeds.
This is an interesting observation. During normal daily driving, my RevI & Ram Air combo nets me ~ .5 mpg better than stock. It appears to have a detrimental effect at autobahn speeds.
#8
Originally Posted by Nemesis8
Was the VDI vac line off the whole time until he saw it was loose? Also, I think the larger REVi intake would have helped. The panel filter drop in does not have the same surface area.
#11
Shifty Bastard.
Join Date: Feb 2004
Location: Melbourne, Australia.
Posts: 4,835
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by WantedTwo
Kinda hard to see out the wind shield with the hood up.
That ain't the hood.
It's the inner rim of the steering wheel.
#13
Originally Posted by Gomez
Average daytime temp in that neck of the woods exceeds 30Deg C.
About 90F for those blokes using funny numbers
Cheers,
Hymee.
#14
Since the size of the panel filter in the RX8 is about 30% bigger than that found in 5.7 Chevy LS1, I have never believed they presented a restriction. Unless they are dirty of course.
Also, when you look at the maths relating to rolling resistance, wind resistance etc, top speed is more or less releated to power in a "cubed" relationship. I.e. A small gain in power is only going to give tiny speed gain, but a large gain in top speed means a substantial power gain has been found. A good read can be found here: http://www.pumaracing.co.uk/topspeed.htm
Cheers,
Hymee.
Also, when you look at the maths relating to rolling resistance, wind resistance etc, top speed is more or less releated to power in a "cubed" relationship. I.e. A small gain in power is only going to give tiny speed gain, but a large gain in top speed means a substantial power gain has been found. A good read can be found here: http://www.pumaracing.co.uk/topspeed.htm
Cheers,
Hymee.
#15
Shifty Bastard.
Join Date: Feb 2004
Location: Melbourne, Australia.
Posts: 4,835
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Hymee
About 90F for those blokes using funny numbers
Mostly I provide conversions for them, but sometimes I like to make them work for it, Hymee....
We never see the Yanks post anything on this forum in metric!!!
#18
Originally Posted by QBallz
All this really shows is that the VDI is important, which Dyno's have been showing for awhile.
In some ways I am really amazed at the responses to this post.
Cheers,
Hymee.
#19
Shifty Bastard.
Join Date: Feb 2004
Location: Melbourne, Australia.
Posts: 4,835
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Hymee
In some ways I am really amazed at the responses to this post.
A fair amount of air reaches the radiator via the lower opening sub-bumper level though. The overheating that Wildcard experienced could possibly be explained by the fact that the duct is located at the high pressure area on the front of the car. It's at this point that the air splits and goes either under the car, or over the top.
It seems apparent that the opening behind the grille becomes increasingly important to cooling as speeds rise.
Gomez.
#22
Int'l Man of Mystery
Join Date: Jan 2004
Location: Central Florida
Posts: 3,651
Likes: 0
Received 0 Likes
on
0 Posts
Aww Hymee... you can't just say that and not let know what was posted or point us towards the post.
Temps... they could be a factor or the factor. VDI and SDAIS control... hmm. I wonder what would happen with the stock box and no VFAD or RB Ram air -OR- RB intake and no VFAD or RB Ram air. I'd like to see those results as well...
Temps... they could be a factor or the factor. VDI and SDAIS control... hmm. I wonder what would happen with the stock box and no VFAD or RB Ram air -OR- RB intake and no VFAD or RB Ram air. I'd like to see those results as well...
#23
Originally Posted by Japan8
Aww Hymee... you can't just say that and not let know what was posted or point us towards the post.
Temps... they could be a factor or the factor. VDI and SDAIS control... hmm. I wonder what would happen with the stock box and no VFAD or RB Ram air -OR- RB intake and no VFAD or RB Ram air. I'd like to see those results as well...
Temps... they could be a factor or the factor. VDI and SDAIS control... hmm. I wonder what would happen with the stock box and no VFAD or RB Ram air -OR- RB intake and no VFAD or RB Ram air. I'd like to see those results as well...
Here is what I eluded to:
https://www.rx8club.com/showpost.php...8&postcount=27
As for the temps being a factor - he re-tested in the same locality. I even posted the weather details for that month so you can see how stable it is.
Cheers,
Hymee.
#25
Originally Posted by Nemesis8
For more air entering the front grill, why not hollow out the OEM grill diamonds then. I think the wall of plastic is there to only cover up the bumper brace, right?
Cheers,
Hymee.