how much does HP really cost

[Jared]

So I was thinking of making a list of things I would like to do to my car as a hobby and was thinking about the engine performance parts and how much they cost vs how much the gain would be.
The aim is 150 to 160 bhp with a little bit of weight loss as well.
Caps MAF mod (better that an piggyback so I've been told) £120 6bhp
Alt under pully and belt £90 3bhp
Markiii pipe (fitted) £30 1bhp
Better air filter (blitz or Piper) £30 1bhp
new exhaust 200 cell cat £500 6bhp
Total £770 15BHP that's £51.33 per HP
Then I thought how much would an engine swap cost (not that I'm going to go that far)
2ZZ engine cheapest on ebay £1300 plus all the things needed and fitting £3000 50bhp gain
That's £60 per HP
So is getting more HP out a 1zz expensive? well I'm sure you wont get as much power as a swap but the 2zz is heavier and all the gains are right at the top of the rev range so getting extra power that starts lower in the rev range even if its not quite as much for less £££ per HP does not seem quite so bad for a street car.
 

[Ardent]

Turbo option for the low down grunt?

[Jared]

Turbo option for the low down grunt?

Ok so how much for all the bits to turbo and how much gain. that's the question isn't it

[Alex Knight]

If you tune a 1ZZ, you are making it less reliable.

If you keep a 2ZZ stock, it will be more reliable than if tuned.

It's all well and good looking at the immediate gains, but will it last - going forwards?

I know what I prefer.

[Carolyn]

A 200 cell cat will struggle at MOT.

I  think your BHP gains are very optimistic. 

[JB21]

Strip the shite out of it for free hp (power to weight) gains.

[Call the midlife!]

The basic mods you list won't necessarily give you the results you expect, especially with a tired old engine, they're also won't necessarily add the hp in the tiers you're imagining.
A filter and MAF mod together won't necessarily give you the individual gains you're looking at but will combine to give an average 
Your prices might be a bit on the conservative side too, a genuine Markiii pipe if you're desperate for one will be anywhere around £80, a length of silicone etc will be nearer your £30 with some decent hose clips.
Speaking from experience there are WAY more cost effective routes for hp gains than trying to squeeze them out of bolt ons to the 1zz.
Having said that, it's a fun way to throw money down the road 😃

[Topdownman]

You probably need a V6.

If only we knew of someone who was selling one......

[Jared]

The basic mods you list won't necessarily give you the results you expect, especially with a tired old engine, they're also won't necessarily add the hp in the tiers you're imagining.
A filter and MAF mod together won't necessarily give you the individual gains you're looking at but will combine to give an average
Your prices might be a bit on the conservative side too, a genuine Markiii pipe if you're desperate for one will be anywhere around £80, a length of silicone etc will be nearer your £30 with some decent hose clips.
Speaking from experience there are WAY more cost effective routes for hp gains than trying to squeeze them out of bolt ons to the 1zz.
Having said that, it's a fun way to throw money down the road 😃

I've seem someone selling a markiii pipe on ebay for £70 and he will except  offers and the silicone tune I have was £30 (same job) but I also said the under pulley was £90 with a new belt.
From what I've seen you can buy it for £53 and don't necessarily need a new belt.
So I'm sure there's a bit of back and forth there but the concept remains.

[Jared]

Strip the shite out of it for free hp (power to weight) gains.

I'm all for weight loss, even the driver is on a diet, that's what i love about exhaust upgrade it's more free flowing and lower weight than factory.
I have got the manifold so need to invest in mid pipe and back box next

[Ardent]

Ok so how much for all the bits to turbo and how much gain. that's the question isn't it

The gains are known and documented, tte kit as a benchmark for example.
How much to buy? That is indeed the question.

[Call the midlife!]

Ok so how much for all the bits to turbo and how much gain. that's the question isn't it

At least £2500 to do it properly using the 1zz and limit it to around 10/12psi at 250hp for engine safety sake.
There's a bloke who's developed a full bolt in kit for the 1.8 20v turbo Audi engine that goes way better than that but no long term reviews etc.

[Iain]

What tyres are you using or planning to use? One of the best performances gain you'll get is a set of quality rubber.

In the MR2 Championship we have to stick to certain regs with performance mods but the big ones that are free are intake and exhaust. Average bhp is in the high 140s. But the biggest gain in performance you'll get is the weight loss.

[shnazzle]

I think you can feel the overall sense of "don't waste your money", coming from a place of been-there-done-that.

You won't notice 10hp over stock.

What you will notice is throttle response, liveliness of the engine and ability of the engine to stretch its legs. That's what makes it "fast".
Unhappy engines with mods thrown at it tend to feel a bit sluggish,loud and flat.

I can almost 100% guarantee you that spending the (little) money on sorting out your valve clearance, timing chain tensioner, top quality oil, correctly gapped and fresh spark plugs, a good strong battery, fresh good quality air filter, fresh MT-90 gearbox oil, cleaned MAF and fresh engine mounts or a head-steady and you'll feel more gains than bolting all of the above on an aged engine.
A compression test also worth doing to check whether your rings are alright, and running good quality fuel like vpower, ultimate or Esso 99 will help keep things clean.

Checking your VVTi valve operation also helps, to make sure it is operating at its best.

For mods my next port of call would be a decent exhaust manifold and good quality cat (a good 400cell is better than cheap 200cell).

- valve job: 70gbp for gasket and bits/bobs
- timing chain tensioner and viton gasket: 30
- oil: 45-50 for Miller's or Fuchs Titan race pro
- filter: 10gbp
- sparks: 25
- air filter: 15
- mt-90: 50
- battery: 80

There's a much much much bigger chance that the above 200gbp will unleash 10+ hp your engine has lost than any of the mods.
Then save a bit more for a good manifold and cat.

[Petrus]

with the 1ZZ it is about marginal gains.

That said the 2 - 1 flexi in the cat pipe is a serious restriction. Freeing that one up will introduce restrictions in the rest of the flow chain.
Yes is it good vfm to make it free flowing.

Next there are gains in reducing the temp. in the engine bay. This lowers intake air temp = increases power.

Going the whole hog with these two will be about 15 hp. and the MAF mod will see the injectors less stressed about it.

For the rest it is all about weight reduction.
Reducing rotating mass on the engine will see you more hp on the Dyno and more accelleration but is not more BMEP; not more hp on a brake.

As observed, deleting things is free weight reduction. Go for it!
Read Southern Belle´s thread.

and last; forget about kg / buck or hp per ditto; look at the FÚN per money.  This little car is extraordinarily responsive to changes.

[Petrus]

Markiii pipe (fitted) £30 1bhp
Better are filter (blitz or Piper) £30 1bhp
new exhaust 200 cell cat £500 6bhp

It does not work like that.
Best to think of the engine as an air pump and intake to exhaust as a single flow, as a chain of air passages.
Reducing the reduction of pressure, of flow, at óne pint makes the rest of the tract more critical.
In other words; there maý be a handful of hp to be theoretically gained at one reduction but that will only be realised if the max air it can then flow actually passes through the whole of the tract.
Best seen by freeing up the inlet only making sense if the exhaust allows it to flow oút and vv.

Also remember that the ambient air pressure is the one and only feed of air. It starts at the side entry. Any drop over a flow reduction equals loss of BMEP.  Same applies to increase in charge temp.