Dyno Proof!

[QRI05E]

Hey guys, here is the specs of my car:

'96 R33 GTS-t

Stock ECU

Stock Turbo

Stock intercooler

Stock Exhaust (2")

(3" front pipe which came on the car)

Stock Dump pipe

Stock CAT

Stock Boost

We put it on the dyno and produced 144.3rw/kw...

We then took it back to the work shop and fitted a single 3" dump, CATCO 702cfm CAT, 3" mandrel bend exhaust with 6" cannon...

We went back on the dyno to have increased to 154.6rw/kw (10rw/kw gain)

Back on the hoist and got the boys to custom build a split dump with a 40cm waist-gate pipe and sperating tounge as similar specs to the one made by C.E.S...

We went back on the dyno to have increased to 164.6rw/kw (another 10rw/kw gain)

As results may vary from car to car... However the dyno proves that the split dump pipe is worth every cent!!!! The increase in power is VERY noticable when driving... and can be felt through out the rev range...

Here is the dyno for proof!

Regards,

Sarkis

Edited December 20, 2005 by QRI05E

[tezflow]

I just installed one on my R33 last week i didn't know that the spilt pipes were that much better but after seeing your results im glad i didn't go cheap and by a single dump and front pipe.

[jnr32r]

very interesting...

I would have never thought the spit dump would actually make any difference at all...

How long down the dump is the split?

[Cubes]

Its hard to tell if the split dump is really better in this case as the usual 3" open mouth dump wasn't tested, just the stock item.

On another note... Thats quite a nice looking little R33 you have there QRI05E. Nothing more do I like than the smooth lines of the R33 with a nice set of wheels. Body kits ruin it in my opinion.

Now do one more test.

Remove the 2 stage boost and still run the stock higher level boost just not the 2stage that steps up.

And post another dyno graph.

It would be interesting to see how much more of a difference the removal of the 2 stage boost makes.

Then you have a mild mod power guide.

Edited December 20, 2005 by Cubes

[R33_Series2Lover]

In regards to the cat. Is it safe and ok to be running such a hi flowing cat converter on a otherwise stock car or doesnt it matter?? Just someone said these kinds of cats are used with high HP applications only and better to get just a smaller 3 inch hi flo cat if using it on a stocker.

[SimonR32]

have u got a photo of the 3 inch dump?

this may be true for small power ups but when the flow is really maximised i would imagine that a 3" would make more power as the lack of total flow of the split dump would create a resitriction

[SimonR32]

actually u can see what i mean at the very top end of the graph... the split dump curve falls over well before the other 2, this may be exagerated with more mods and power

[Sweetleaf]

Ive found open mouth dumps better than split.

[QRI05E]

Just a reply to a few of your quires:

jnr32r: The wastegate split was made 40cm long.

Cubes: If you read the dyno graph the single 3" Dump was tested compared to the split dump. I appretiate your compliments on my car, thats how i love my cars too... simple yet eye catching... classy yet sleek...

R33_Series2Lover: The higher flow of the CAT the better especially for turbos! my car didnt run rich or lean... the flow was perfect.

Cerbera: sorry i dont have a pic of the split.. its a replica of the C.E.S Split... and No, the single 3" dump is not better for performance than the split... on the dyno the single 3" dump lost 2kw on bottom end! From experiance the split works wonders, other wise all major racing exhaust manufacturers wouldn't swear by it!

Im just sharing my experiance with you guys hoping to help you out.. and the split dump really works! the Dyno graph is the proof! When driving revs pick up MUCH faster then the single 3" dump... acceleration is GREATLY improved... you feel the car just want to pickup and go! Feel free to ask me any questions..

Regards,

Sarkis

[raz0r$harP.UK]

Thanks for that.. power opens up nicely up top with the split..

[rev210]

It's not just the 10kw gain, it's the fact that the gain is across the power band. Very good comparison indeed. Such an increase in average power delivery would make the car alot quicker.

[Cubes]

Cubes: If you read the dyno graph the single 3" Dump was tested compared to the split dump. I appretiate your compliments on my car, thats how i love my cars too... simple yet eye catching... classy yet sleek...

<{POST_SNAPBACK}>

Ahh you did indeed.. Sorry buddy.

It was a long day at work. lol.

[Evan_R33]

i agree, split dumps the way to go. I have just installed a C.E.S split dump/front pipe on my 33 and the difference is noticable without getting on the dyno.

The idea i guess for those who are a little in the dark about what a split dump does, is that it provides a much clearer path away from the turbo and then re joining the exhaust flow further down.. instead of swirling around directly behind your watstegate then having to flow downwards then back out the dump. So you are most likely to notice the difference when the wastegate is open.... just a little info for ya's

[The Mafia]

or you can get a custom one made up like my mate made me....

[jnr32r]

how much these custom made ones going for at exhaust shops?

[BHDave]

You are saying that you gained 20rwkw with a dump pipe, a front pipe and an otherwise stock exhaust? Because you'd be aware that a 20rwkw gain by installing a full exhaust is considered to be pretty good.

Also the way that the power is really starting to dive at the top end isn't a good sign (i'm assuming that the throttle wasn't eased off). I'd be interested to see what happens once a higher flowing exhaust is fitted as it is the biggest restriction in the system at the moment and may explain the drop off. It should also net some significant power gains.

Is your split dump a bolt on piece between the turbo and front pipe or have you created a new dump/front with the collector merging smoothly in the same way that mafia's does as shown above?

[Cubes]

Looking at the design of the dump wher the wastegate joins......

I would have thought it would be best to place the joining in of the wastegate either on the straight or the inside of a bend to prevent turbulence.

Definitely not on the outside as they seem to do??

[Evan_R33]

these are some pics of the C.E.S type. they quote a 25kw gain. I also got it HPC coated. looks awesome...

Edited December 21, 2005 by Evan_R33

[Bass Junky]

The drop off at the top is probably not so much the exhaust running out of flow, but the cams coming off song and the general characteristicts of the power curve coming through.

[Cubes]

Especially considering the motor is now making more power with basically the same airflow?!?

Can only make so much power out of a given airflow.