Zorsts and cats

[Nick_Walczak]

I have a 98 car so there is no chance of getting rid of the cat. Also I am not willing to risk invalidating my insurance.

This being so, is it worth getting a large bore exhaust? Or is the cat just going to be a bottleneck?

[Tom_S14]

Hi,
When I had my exhaust done at tube-torque I had a chat with them about this. They reckon there's not much to be gained on a modern japanese car. They reckoned they design them much better than they used to. I've come to the conclusion it's probably not worth the bother.
When you say bigger bore, how big do you need to go ? You can ditch the standard back boxes and go for a more efficient exhaust without increasing the bore.
While I was at this place, there was another guy there with an S14a (mines S14) - the newer ones have two cats - an extra one in the down-pipe, but mine only has the one.

Tom

[Nick_Walczak]

Thanks Tom. I was hoping this was the case. I don't want to spend huge amounts of money on the car. I probably won't exceed 15psi in my mods so the standard exhaust is probably a large enough bore.

If it rots away, I might replace it with a stainless mandrel bent item. Any suggestions?

So my shopping list at the moment is:
* Boost gauge
* Bleed valve - hopefully can be adjusted in the car
* Induction kit
* bigger Intercooler

[JohnD76]

I have recently had a Blitz Nur Spec R fitted and an SUS airfilter, (and dump valve :rolleyes http://300zx.co.uk/200sx/ubb/smile.gif. The performance increase is very noticable and so is the sound!!! It also makes the car a little different.

My insurance company are aware of the exhaust and filter. My mileage has dropped too, so with the saving on mileage and the non standard bits, my insurance company gave me £34 back! Result.

[Nick_Walczak]

John, doe your exhaust include:
a) your original cat
b) no cat
c) a new cat
...?

[Dark S14]

I'd agree with john. I've recently had a HKS cat back system fitted and it does make a difference. It also looks and sounds sweet. When you look at the orginal system it does look very restrictive, with a couple of very tight narrow bends, i cannot imagine it promotes the free flow of gases. I think the exhaust will also come into its own alongside other mods such as boost upgrades and a more efficient intercooler.

[JohnD76]

Originally posted by Nick_Walczak:
John, doe your exhaust include:
a) your original cat
b) no cat
c) a new cat
...?

Nick,

The exhaust is still using both factory fitted cats, and there is definately a noticable increase in power http://300zx.co.uk/200sx/ubb/biggrin.gif. It looks a lot better, sounds a lot better and also is made from Stainless steel.

Most insurance companies refer to these are non-standard exhausts. Going on that addage, they could say that a cheap replacement from KwickFit is also a non-standard exhaust, which literally it is. Extreme example ok, but they could be buggers if they wanted to be.



------------------
John (S14a)
Blitz Nur Spec R, SUS, MSTT, Dump Valve, and other tit bits..
222.8hp @ 6062 RPM
206.2lb ft @ 4755 RRM
http://mysmilies.com/cgi-bin/r.cgi?cwm/cwm

[JohnD76]

Originally posted by Nick_Walczak:

....If it rots away, I might replace it with a stainless mandrel bent item. Any suggestions?

So my shopping list at the moment is:
* Boost gauge
* Bleed valve - hopefully can be adjusted in the car
* Induction kit
* bigger Intercooler

Nick,

I really like the Blitz stuff, but the HKS bits are good too. I went for the Blitz air filter, and thought, well might as well go for the other blitz bits too. Haven't looked back either, an very very VERY happy. Blitz also do really nice boost gauges, indigo I think they are called. They have a blue face and are backlit blue too http://300zx.co.uk/200sx/ubb/biggrin.gif.

PS If you fon't want to spend too much money on your car, I suggest you forget about this forum completey and never come back. It has a habit of making you smitten with the modifying bug.$£$££$£$£$£$£$£$£$£ http://300zx.co.uk/200sx/ubb/biggrin.gif

------------------
John (S14a)
Blitz Nur Spec R, SUS, MSTT, Dump Valve, and other tit bits..
222.8hp @ 6062 RPM
206.2lb ft @ 4755 RRM
http://mysmilies.com/cgi-bin/r.cgi?cwm/cwm

[This message has been edited by JohnD76 (edited 03-08-2001).]

[Nick_Walczak]

John, thanks for the info.

BTW: looking at your sig I see you've been on a dyno... are those figures @ the wheels??

And what is a SUS and a MSTT?

[This message has been edited by Nick_Walczak (edited 03-08-2001).]

[Daniel san]

SUS is the Blitz stainless steel mesh air induction kit.

MSTT = Multi speed turbo timer. The thing that lets your car idle for a set time period after you've switched the ignition off, so as to allow the turbo time to cool off. The MSTT also measures 0-60 and 1/4 mile times.

As you can see by my sig, I quite like the blitz stuff. Yeah it's not cheap, but the quality is unsurpassed.

------------------
Dan
www.puresx.co.uk

'98 Saphire Blue S14 (manual of course)
Blitz Induction
Blitz Dump valve
Blitz Exhaust
Blitz MSTT
No CAT
30mm Drop
Skyline style front spoiler
18" Kosie Snipers
Racelogic Adjustable Traction Control
Launch Control
Full Throttle Shift
Clear Indicators
Several MELTED Spark Plugs, resulting in
HKS Forged Pistons
HKS 1.2mm Metal Head Gasket
Trust Iridium Spark Plugs
Done me 1000 miles, now just waiting for Abbey to give me the go ahead before I drop the hammer again!
Credit cards would be more popular if you didn't have to pay the bill every month!
Do not take offence to anything I might say, I am completely mad. So jus chill de feck oooot, ok!

[Nick_Walczak]

This place: https://www.needforspeed.co.uk/index.asp
says that cat back exhausts improve power by 4-5 hp.

[Tom_S14]

Hi,
I wasn't very clear with my original reply ! What I meant to say was the CAT doesn't make much difference - rather than the exhaust ! Sorry about that, it came out a bit misleading.
I'd definitely agree the std. exhaust is restrictive, my car is a fair bit quicker (and a hell of a lot louder) with the tube-torque cat back on it. Found an air filter made quite a bit of difference too - particularly to the acceleration figures in 1st - strangely enough. Perhaps it is rate of change of airflow related ?
Power output increase quotes can be misleading. Worth bearing in mind that anything that can improve breathing at higher revs or let the engine rev higher will result in a higher bhp figure since bhp is proportional to revs for constant torque !
This is how superchips do it on NA cars ! Half of it is moving the redline up to enable them to quote higher power. (my personal opinion, disclaimer disclaimer)
I'd be happier to believe there's a percentage torque increase distributed somehow over the torque band by adding an exhaust / filter / other modification.
5 bhp increase on a 100bhp car might give 10bhp increase on a 200bhp car all things being equal - but it's all pretty daft. The other dumb thing is the notion that all these numbers are somehow additive ! People start totting up the x bhp increase they get from each thing they bolt onto the car which is obviously total nonsense.

God, I've gone off on one there - sorry about that http://300zx.co.uk/200sx/ubb/smile.gif

tom

[JohnD76]

As Dan said:

"Yeah it's not cheap, but the quality is unsurpassed."

I can't wait to drive my car this evening! http://300zx.co.uk/200sx/ubb/biggrin.gif Gonna be looking for GT4's http://300zx.co.uk/200sx/ubb/biggrin.gif

------------------
John (S14a)
Blitz Nur Spec R, SUS, MSTT, Dump Valve, and other tit bits..
222.8hp @ 6062 RPM
206.2lb ft @ 4755 RRM
http://mysmilies.com/cgi-bin/r.cgi?cwm/cwm

[Daniel san]

Obviously if you wanna know how much bhp increase you get from a mod, RR it before and after.

I found there to be a bloody good increase in performance by adding the Induction Kit and Zorst, as well as removing the CAT. The CAT was the first mod I did to mine and found a noticable improvement straight away, you could here it sucking up more and whistling nicely. When the Indution kit was added and then the zorst the car felt quicker due to it sucking and blowing much easier, which also spins the turbo up quicker. I reckon I've got about 40bhp increase, but I'll know for sure when Abbey give me the go ahead to start caning it again and I'll get it RR'd. Will obviously let everyone know when I've done that. http://300zx.co.uk/200sx/ubb/smile.gif



------------------
Dan
www.puresx.co.uk

'98 Saphire Blue S14 (manual of course)
Blitz Induction
Blitz Dump valve
Blitz Exhaust
Blitz MSTT
No CAT
30mm Drop
Skyline style front spoiler
18" Kosie Snipers
Racelogic Adjustable Traction Control
Launch Control
Full Throttle Shift
Clear Indicators
Several MELTED Spark Plugs, resulting in
HKS Forged Pistons
HKS 1.2mm Metal Head Gasket
Trust Iridium Spark Plugs
Done me 1000 miles, now just waiting for Abbey to give me the go ahead before I drop the hammer again!
Credit cards would be more popular if you didn't have to pay the bill every month!
Do not take offence to anything I might say, I am completely mad. So jus chill de feck oooot, ok!

[Tom_S14]

Well, yes, but really you want to see the torque curve. One of the reasons turbo charged cars tend to perform better than NA cars with the same peak BHP in 0-100, 1/4 mile tests etc is because they develop more torque throughout the rev range. There is no real physical relationship between bhp and accleration - it's a single figure designed to compare engine power output. It's torque which really matters. However, it's torque at high revs which is really the key becuase it allows a lower gear to be used. Losses in the gearbox aside, it's nearly always better to be in a lower gear.
Amyway, I'm boring myself here let alone the rest of you http://300zx.co.uk/200sx/ubb/smile.gif
Tom

[Actual_Ben_Taylor]

I got rid of both the cats on my 98 and fitted a full 3" turbo back system (tube torque front/blitz back). There is a huge difference in performance. The turbo spools up much quicker and it pulls a lot harder, my only other mod is the SUS filter. I know a few people on this board are running similar exhaust/filter combos, so why don't we all go to the rolling road day in October and see what kind of different figures we get? Might be interesting...

Ben

------------------
http://forums.evilnet.net/ubb/smilies/pc1.gif
Black '98 S14

[Tom_S14]

Ben
How much did tube torque do the front pipe for ? I've been thinking about getting one put on. They said it was almost identical to an RS Turbo http://300zx.co.uk/200sx/ubb/frown.gif - about 160 quid for 2.5"
I've heard you can gain a bit my matching up the flanges on the turbo and the downpipe ? Did they do this too ?
I'm definitely going to try to make it to the rolling road day. My accelerometer gadget reckons I'm about 180bhp at the wheels.
Tom

[Actual_Ben_Taylor]

Tom, front pipe was 140 fitted (for cash). What exactly do you mean with the turbo flanges? There is a funny triangular shaped flange that comes off the cast turbo elbow (for want of a better description), obviously he used the same size flange on the exhaust....

Ben

------------------
http://forums.evilnet.net/ubb/smilies/pc1.gif
Black '98 S14

[Nick_Walczak]

I hope you are right about the exhaust because I want an easy bolt on power upgrade. I want to see some rolling road figures! http://300zx.co.uk/200sx/ubb/smile.gif

[Tom_S14]

Ben,
140 quid cash ? And that's for 3" ? I'll have to see if I can knock him down a bit.
The flange matching thing... the exit port of the turbo isn't circular in cross section, and I'm pretty sure you can improve gas flow my matching the cross section of the downpipe - ie.. it's not circular at the top. Any sudden steps in the pipe caused create turbulence (same as in an intake manifold or something).

tom