How much BHP improvement will I see fitting a better exhaust than stock to my NA? If that was the ONLY thing I did. I do not want a massive loud rude exhaust. I like four exit, just a bit bigger- not HUGE (and not too loud). Anyone recommend one?

The Mongoose is owned by a number of forum members, it's good value (around £500) and is of all stainless steel construction.

It is not too loud, even on de-catted twin turbos.

However, I have not heard one on a NA- which are even louder than TT's.

Good luck

Dave

Mongoose wont make it really loud. It rumbles really deep at about 2000rpm which sounds cool. Idle sounds lovely and on the motorway the exhaust sound is virtually gone.

 

Exhausts are said to add anywhere between 3%-5% extra power.

I put a longlife on my NA, a couple of the TT boys have them as well, handbuilt from t304 stainless, lifetime guarantee. Best part is you can choose your sound, I have a very loud pipe (which is probably not what you are looking for) but Cybernet has a quieter version (you can still hear it but not obtrusive at all ) Look at http://www.exhausts.uk.com

 

HTH

Exhaust design makes a big difference with NA's. NA design depends on tuning exhaust pulses so that each pulse of exhaust gas coming as the valves open helps to pull gas out of the next cylinder as the valve opens. This helps the engine breath better at the designers chosen rev range torque band. Get the design wrong and you can have great power at max revs but lousy torque at low revs.

 

This is not the case with turbos. With turbos you just want to let the exhaust out as fast as possible without worrying about tuning for pulse effects. The energy is used driving the turbo.

 

The power gains wont be as much as with turbos because of this.

 

 

That is a picture of my mongoose, there is another tailpipe on the other side ;) thats just the best photo I have.

Thanks for this info. So I should make sure I get the right exhaust. Who can 'tune' the exhaust right then? Any performance fitter? or should I go to someone who knows zeds well?

 

I like the look of the Mongoose, from what I can tell on their web site there is a choice of tailpipes. I am looking for something modest- not too huge. I do like that pic of the mongoose though.

 

I do not want to LOOSE torque. I want as much low down torque as possible. My TT soarer picks up and shoots off when the turbos get going about 3000/3500 revs- the NA 300 has been a bit disappointing in it's acceleration although when it gets up enough steam it goes well.

 

So the car is standard and has about 222bhp, with the right exhaust tuned right (although I don't know how they tune it to 'pulse' when the valves open) it could make about 230ish?

The exhaust that you are looking at is from the cats back and whilst the rear boxes are restrictive , you will only see a slight improve ment , possible mid range improvement ,,,but if you remove the cats from the exhaust system by getting new down pipes then things get more interresting and with a good induction kit should give the engine a bit more bhp ,where you will notice it ,,,but the car is quite heavy so the N/A engines never seem that quick , unless your on the motorways etc,,,,as for tuning the exhaust , thats done by the diameter of the pipe and manifold shape , its some thing you buy when given a choice and there is limited if not no choice of N/A exhaust manifolds so i would not worry about that aspect of tuning , buy from the shelf so to speak ,,,check out the guyz in the states in there forums as well for ideas etc ,,,:cool: good luck:cool:

I had Predator do me some exhausts - excellent.

Geoff.

'300ZX Non-Turbo Headers

 

The single most significant power modification for a non-turbo z car (Short of nitrous). Expect an increase in horsepower throughout the RPM range with the greatest gains at higher rpm. Expect up to 16 rear wheel hp.'

 

Is this a worthwhile mod? I got the product details off strictlyz.com. Would that have to be done in combination with a new exhaust? Please don't kill me for asking a stupid question- is a header an exhaust manifold? This sounds like a nice upgrade- is it a big job?

Here are a few pics showing the Mongoose exhaust a little better.

 

 

 

Lovely looking exhaust

Pick my scorpion up next week, £250 brand new ..... bargain!!!;)

 

Dont know what it will look or sound like though!!!:D

is a header an exhaust manifold? This sounds like a nice upgrade- is it a big job?

 

A header is the US expression for an exhaust manifold. The normal manifolds are cast iron. A fabricated tubular steel multi branch (bananabunch) is the optimum for tuned gas flow.

 

But could be an expensive extra few bhp.

 

They're in the Stillen catalogue as well with Stillens estimate of power gains.

Check out Borla (http://www.borla.com). I have them for quite a while (8 yrs) and still look the business. they also come with a million miles warranty. Anyway any exhaust you choose make sure it is of the 304 stainless steel otherwise there life will be limited.

Originally posted by WillieO

 

...could be an expensive extra few bhp.

 

They're in the Stillen catalogue as well with Stillens estimate of power gains.

 

16BHP at the wheels. That sounds a decent gain for an NA. Only is it a pure pig to fit them?

 

Someone on here posted pictures of a wine red NA just like mine, but with a few mods- exhaust (and Recaros inside). Whoever it was had a nice exhaust on that car. I like the mongoose above, but maybe want the tails just a little bigger.

Originally posted by Rich

I do not want to LOOSE torque. I want as much low down torque as possible. My TT soarer picks up and shoots off when the turbos get going about 3000/3500 revs- the NA 300 has been a bit disappointing in it's acceleration although when it gets up enough steam it goes well.

 

I might be passing you ovoid objects for elderly relatives to ingest here, but...

 

You gotta drive an NA and a TT differently.

 

You need to rev the tits off the NA to get performance, as you've found - they are (traditionally) designed for high power not high torque - which means high wheel torque at high revs in a low gear. (It's a bit more complicated since all these weird and wonderful valve timing designs since the late 80s, which mean NAs do deliver torque low down ... but I'm ignoring that.) It's really worth going right to the redline in 1st and 2nd to take advantage of the gearing.

 

Lots of gear changes to stay in the power band...

 

In a TT it's all about boost, and staying on boost - a gear change costs you lag. Therefore it's not always worth changing down a gear, better to just stay on boost and wait for 3500 revs to arrive. Engine speed makes much less difference, it's all about boost.

 

So no gear changes unless you're WAY down the rev range!

 

I like getting in different cars and figuring out what to do differently to get the best... it's all part of the fun. Just look at it that way - much cheaper than trying to give an NA engine a TT torque curve!

ovoid objects...oh yes, I see. click click click whirrr.

 

No- not at all- this is exactly the advice I was looking for.

 

I am not experienced in driving higher power cars, and in fact I am a totally shit driver. I just press the pedals and go. I should like an auto then, but I don't. I like the feeling of control I get from a manual. Even if I am too thick to drive it properly. 'Ha ha, I am in complete control. I will cock up gear changes WHENEVER I want.'

 

So I should let the engine rev past 5000, or even to 6000 or beyond? I have a REAL problem revving it in 1st like that. It's a real mental block. it sounds like it shouldn't be done.This is not something I am used to doing in my previous cars. Will this damage the engine, or is it designed for this? Even in first and second?? I used to be in fourth in my previous cars well before I am in my zed, but in third at about 30 to 40 mph I can feel the power, and it's this feeling I am looking for through the gears

 

You said...

'I like getting in different cars and figuring out what to do differently to get the best... it's all part of the fun. Just look at it that way - much cheaper than trying to give an NA engine a TT torque curve!'

 

I agree with this totally. This is why I got the soarer. It does feel very different. And it sounds different too!!! However, having driven the cars I think I will move onto a 300 TT as soon as I can. The Soarer has had the turbos redone and I think there is more lag than on the standard turbos. This means it accelerates and then there is a sudden burst at 3500. I like the drive, but the engine gives a little buzz rather than a roar, which I understand a lot of people on here wouldn't like.

 

So what difference does vvti make? Or is that just like trying to explain calculus to a nursery child?

Ive been looking into the exhaust thing for a while and it seems to me that the best exhausts system to go for is B&B (cat back). They are a bit pricy but look the *****cks, life time guarentee aswell! Not heard one my self but they supposedly give the car a V8 kinda sound. Im gonna be fitting one after christmas, ill let u know what its like.

If your cars pre '92 get a de-cat pipe. (stillen) If its not, get a d-cat pipe! Just dont tell anyone!

Stillen manifolds, again look good, but dont buy until you've got the intake sorted out and had it chipped! (so i hear)

I've got single zorst HKS super dragger, with no cat, and sounds really great.

From memory I think the japanese performance car mag listed this mod as giving between 15 to 20 bhp increase.

 

And yes due to variable valve timing it really does need to be thrashed to get to the max. powerband above 5k, but sounds lovely.

 

at normal revs still sounds deep and and burbly and quite load comparedto normal cars.

I have another question about revving the engine...

 

I'm going at about 50/60 onto the motorway and I've just shifted into 5th but I haven't got enough grunt to overtake the Laguna in front, if I drop to 4th and the revs jump will it knacker the engine? What rpms should/would it jump to? I know this is really a basic driving question, but this is all stuff I just 'did' in any other car. I wasn't worried about the performance really.

At 50, drop into third! Wont damage the engine, they're designed for it.

3rd will do 100mph

...but you're way past peak torque at 100mph in 3rd, you should have changed to 4th to get on up to 130!

 

:dance: