just to get this straight the origional cat and silencer were used?

 

That's the way I read it.....

 

it was so hot that no one was able to get on the ground and check out the setup....
maybe next time..

 

Yes I saw it. That's my trailer they used in that flick. They wrecked it too, wound up paying me for it. It's a little poetic licence if you noticed it is suppossed to be carrying a Camero, It's built for a Formula Atlantic car. So they used it for carrying spare tires and the like. The lack of weight caused it to bounce and flex across the country, cracking all the siding and some structure. Which the butcher with some on the road repairs.

So I got it back along with enough money to build a new one. A freind of mine signed on as a driver for the shoot, and wrecked a Daytona in a freeway chase.
They paid out a bunch of money to the two Cobra owners also. Yes, they had two, just in case one wasn't running when they needed it. I saw them at the wrap party sitting on one with drinks on the hood.

That's how they treat your stuff in Hollywood. Don't rent it to them if you love it. Goes for your girlfreinds too.

 

hahah, that's my name, Sung Hoon !!
but you are the one with all the crazy overtaking moves

 

you better start preying Missy..

 

yeah, and you are living up to it....

at least i didnt overtake on double un-broken lines

 

hope mr. joystick will turn up that day for you to preying on

 

who's talking about cars.... i was referring to the personality.... inner beauty thingo....
gees.....

 

my typo...

umm, your yumyum emoticon..

 

Kunz told us that on the day as well. There's no smoke n' mirrors here.
It's the stock cat. All that has been changed is the muffler (Hymee) and the straight bit of pipe that comes AFTER the cat connecting to the Hymee exhaust.

That's why it was no louder than any of the other (numerous!) Hymee exhausted attendees on the weekend.

Dyno's are so finicky! Personally I don't think you can get much better than 4 hours apart on the same dyno by the same operator. I thought it was a good effort anyway, always keen for people to dyno before and after, part by part. Looking forward to seeing what happens with the intake Kunz!

(Don't post figures if power increases tho )

 

Thanks for confirming that Muzz. Now I need someone to explain this hp improvement to me.....

 

That's a gain of 9rwhp. I've been searching for high flow cat and I have seen dyno figures approaching 200rwhp. I think it was an RP supercat and Greddy SP2 catback combo. I think a high flow cat would give higher gain. The combo claims a 21 hp increase (28kW).

See the dyno:
http://www.rx7.com/RPGReddyRX8exhaus...reddy_dyno.gif

 

Astro, I think your conversions are **** about. 21kW is 28HP

Kunz got 12kW which is 16 HP. Use Google to search for "12kW in HP" http://www.google.com/search?hl=en&lr=&q=12kW+in+HP

I suspected it was the "intermediate" pipe that was replaced, rather then the mid pipe. But I can't see it making any difference - the stock one is mandrel bent 2.5" and basically restrictionless.

Good on Kunz for sticking his neck out and posting his results. Although it is a different result to my own testing (on a Mild Steel system), who am I to argue? This test was done on the same day by an independant operator with nothing to gain by cooking the figures. And guess what? The very first time I "modded" a modern car, it was an exhaust, and I had a before and after done in the one (independant) shop, just like Kunz. Ahh - the memories.

There are LOTS of variables though, but you cant do much more than what Kunz has done. Congratulations to you for going the extra mile to keep track of what has done what to your car. I don't expect you are that keen to re-do the tests with the cat-back on, then swap back to stock and do another few runs, hey? Hehehe.

Cheers,
Hymee.

 

I agree. You think it's possible he's gained 16hp by fitting your mufflers alone?

I'd be interested to know more about this midpipe......

 

From what I understand, and what Muzz said, he didn't replace the midpipe - that was just a terminology mixup.

Do I think it is possible? Well it sounds a lot, and it might raise an eyebrow or two. I'm not in much of a position to argue with the dyno results - you can't do much more than what Kunz did to find out, hey?

Cheers,
Hymee.

 

A couple of thoughts:

1. Hymee, according to the dyno chart, your car was around 135rwKw after installing the exhaust, which is around the same as Kunz

2. Before fitting the exhaust, Kunz's car was putting out 123rwKw. This is around about the same stock dyno reading as I have seen for a number of cars. One I remember is MissyK's at AutoSalon recently.

3. Of all the Hymee instals I have read, Hymee himself is the only one who never mentioned the Jesus clamp

So, my thought is that it is perhaps not so much the exhaust as the removal of the restriction of that clamp??

 

The Jesus clamp isn't really reducing the pipe diameter much....it'd only be an 1/8 of an inch or so.....if that even??

 

Yeah, I couldn't imagine it myself....but??

 

I just realised something, but it's effect is unknown...

My dyno results are on the Aluminised mild steel version, with the "press bent" tail pipes.

The first few stainless systems uses similar press-bent tail pipes, but when we made the first export versions, we went to mandrel bent tail pipes. All the rest have been made like that, and to my knowledge, Kunz is the first to test and publish his findings with this "design".

Cheers,
Hymee.

 

i dont think anyone is disputing the factory reading, low 120s to mid 120s is about what the 8 would put out.....
kall's 120.8kw on the autosalon dyno was with the exhaust... so thats about 15kw less than what Kunz's got...