Right guys lets have some feed back on this one. As there seems to be a lot of conflicting opinions out there.

 

280BHP

With regards to power increases we all know that we first need to improve the breathing.

290 - 310BHP

This can be done by fitting better flowing air filters or an induction to get the air in,

310 - 330BHP

An after market exhaust to get the air out.

330 - 340BHP

We then know that to allow slightly quicker spool up times we decat, this may or may not give us a little more BHP as well

340 - 370BHP

Then it's time to up the boost, but this is were it starts getting interesting.

The stock chip seems to be ok for about 11 - 12 psi of boost without detting.

370 - 400BHP

After this we get an aftermarket chip in to increase the fuelling.

Then we up the boost to 14 - 15 psi

What's next ?

How much boost can we run on stock internals, stock injectors, stock Intercoolers and stock turbo's.

 

Now to run higher boost you need to keep the turbo's cooler so I would think that bigger IC's are next ?

 

But when do the injectors max out ?

When do the stock turbo's peak ?

 

Lets just say we get T28's or Smithy hybrids on there, some bigger intercoolers and 555 injectors ?

 

Now how far can we go ?. How much psi/BHP can we push before we need to get forged pistons or solid lifters ?

 

How much BHP can each stock cylinder provide ?

 

I think this would make a fairly good debate so lets have your view on this one.

Good idea Stu - and I'd say those BHP figures are pretty accurate. This could go in the FAQ section ;)

Stu,

 

I can't really comment on the latter part of your post, that needs someone with far more expertise/knowledge than me :D. But, I can't believe that by doing zorst, induction and de-cat, you could realistically expect up to 60 bhp over standard.

 

IMO, from what I've read, I'd be surprised if you'd liberate more than another 20 with all this done, taking power to approx 300bhp.

 

I do however, think that another 70 with the right fuelling and boost increase should be achievable.

 

There, that's a start ... ;)

 

CheerZ,

JB.

Originally posted by pete shrimp

Good idea Stu - and I'd say those BHP figures are pretty accurate. This could go in the FAQ section ;)

 

Not according to the RR day we had there not

http://www.netcomuk.co.uk/~webster/gio/graphics/90-95_300zxtwinturbo.pdf

 

http://www.twinturbo.net/ttnetfaq/appendixz.aspx#Stages

 

HTH - Gio

Originally posted by bagins

Not according to the RR day we had there not

 

That's what I was thinking. Some people had all those mods inc chip + boost controller & still only got just over 320BHP.

 

Could it have been because the I.C.'s weren't being cooled?

Originally Said by Bob & pete @ SE

This rolling road is notorious for reading low

Originally posted by shaunmac

That's what I was thinking. Some people had all those mods inc chip + boost controller & still only got just over 320BHP.

 

Could it have been because the I.C.'s weren't being cooled?

 

I have larger IC's so I don't think so and also it was only a single run so the IC's should not have been that hot anyway

Will be intreresting to see what figures people get at the next RR session(Ajay any update on this;) )results will be better i think:) ;)

Originally posted by bagins

Not according to the RR day we had there not

 

Gotta agree with you there, mine has an Induction kit and only made 256. I think manufacturers figures are optimistic at best, bit like the mpg figures.

 

I think quoting bhp figures is a bit of a pi$$ing contest, but I would say that with my 256BHP :D:D:D

 

Mike

Originally posted by Herman Munster

Gotta agree with you there, mine has an Induction kit and only made 256. I think manufacturers figures are optimistic at best, bit like the mpg figures.

 

I think quoting bhp figures is a bit of a pi$$ing contest, but I would say that with my 256BHP :D:D:D

 

Mike

 

And of course with your height mike you should be able to pi$$ further than the rest of us :D

Ok the figures I put up were rough guide lines based on my car. When I first got my car it had been RR'd previously to me buying it and all it had was zorst and decat. They RR's it at 315 BHP. I then fitted an induction and just before the RR I had head and piston work which meant my car was now 100% or there abouts on every cylinder.

At the RR I got 334 so whether these are accurate is not the point. Different zorst, induction and chips will have different effects. There's no point on running up'd boost if your engine is not at 100%. I say get the engine sorted first. You can’t tell me that all the people on this forum that hit the RR did a conzult diag and a compression test on each of their cylinder before they went on.

 

I know my engines power is at 100% or there abouts because I did have compression test. Conzult diag and many other test before I went on. This is why I beieve I got quite a good BHP reading and nothing else.

 

Anyway the main point of topic is not really the BHP results we got on the RR as this seems to be a little touchy for some people and is probably best left alone, only when we have another RR on different rollers we can speculate.

 

I'm more interested in how much we can push out of a stock engine and at what stage we need to start changing bits to gain more power.

 

Thanks Gio for the links. It seems as though the TT.net stuff has no reference to forged pistons, but if my calulations are correct Steve Millan is basically saying the pistons are good for about 600 - 650 HP. In terms of calulating that to BHP flywheel ?. Fook knows !!!

Steve Millan also give the opinion that stock injectors are only good for up to 16 psi and the stock turbo's are only good for 17 psi.

 

So from that do we have any other views ?

 

Zorst/ induction/decat/chip = 14 - 15 psi / 380 - 400 bhp

Intercoolers = 15 - 16 psi / 400 - 420 bhp

555 Injectors = 17 psi / 420 - 440 bhp

New Turbo's = 18+ psi / up to 550 BHP

Forged pistons = 550 BHP+

That's what I was thinking. Some people had all those mods inc chip + boost controller & still only got just over 320BHP.

 

Could also be less than optimum compression pressure or a bit of ring/bore wear giving leak down.

 

Watched the video wiv me anorak on;) I noticed a few were belching the odd puff of smoke out the zorsts at full whack. Wondered is this normal or a sign of breathers chucking oil vapour into the inlet or what else causes it?

 

You see cases on here with upped boost etc then a few weeks later they're dropping more smoke than the Red Arrows and wondering if a new pcv will cure it!

Dont forget that the car is not moving.

 

The cars intercooers are a lot cooler while moving and their is more air being forced into the car. You should have a huge fan or 2 blowing on the front of the car to do 2 things, try make a situation as close to the car moving on the road as possible and to help cool the car down. I didnt see any fans on the video.

dont forget though that if you put decals on each side of your car, ie, blitz, apexi, sparco and various others, oyu gain an extra 5bhp per sticker.

not sure how this works, but apparently it does!!!!!!!!!!:tongue: :tongue:

Originally posted by mikegsi

dont forget though that if you put decals on each side of your car, ie, blitz, apexi, sparco and various others, oyu gain an extra 5bhp per sticker.

not sure how this works, but apparently it does!!!!!!!!!!:tongue: :tongue:

 

:rolleyes:

Originally posted by SMW1

How much boost can we run on stock internals, stock injectors, stock Intercoolers and stock turbo's.

 

Turbos are 15-16 psi with a reduced lifespan!

Stock Injectors 16-17 psi, with stock turbos!

Stock Intercoolers just suck anyway!

 

 

Now to run higher boost you need to keep the turbo's cooler so I would think that bigger IC's are next ? Good Idea

 

But when do the injectors max out ? See above

When do the stock turbo's peak ? See above

 

Lets just say we get T28's or Smithy hybrids on there, some bigger intercoolers and 555 injectors ? And do what with them?

 

Now how far can we go ?. How much psi/BHP can we push before we need to get forged pistons or solid lifters ?

 

There too many variables out there to give a straightforward answer! Some companies say that the lands between the pistons go, when PSI above 17 is applied. When some people say that piston land breakdown is due to the ignition timing not being retarded enough during full boost, due to incorrect mapping! Some people say you can run 6-700BHP on a stock bottom end!

 

How much BHP can each stock cylinder provide? Have a look at the Zed with the most bhp on stock cylinders and divide by 6:D

 

I think this would make a fairly good debate so lets have your view on this one.

Originally posted by mikegsi

dont forget though that if you put decals on each side of your car, ie, blitz, apexi, sparco and various others, oyu gain an extra 5bhp per sticker.

not sure how this works, but apparently it does!!!!!!!!!!:tongue: :tongue:

 

Only works on Mitsi-whales & hot hatches Mike. ;):D

Originally posted by bagins

And of course with your height mike you should be able to pi$$ further than the rest of us :D

 

That'll be my 'height' perfomance upgrade! :D:D:D

 

Mike

:rofl: :D

Another point of discussion would be….

Where do solid lifters, cams, Re-bore, light weight pully(s), velours, port and polish, Metal Head gaskets etc fit into this ???

Are these just a case of added HP or are the necessary at some stage.

 

Obviously higher boost = higher HP but would be good if we could colate all this info and get a graph in place with various points.

Originally posted by SMW1

Another point of discussion would be….

Where do solid lifters, cams, Re-bore, light weight pully(s), velours, port and polish, Metal Head gaskets etc fit into this ???

Are these just a case of added HP or are the necessary at some stage.

 

Obviously higher boost = higher HP but would be good if we could colate all this info and get a graph in place with various points.

 

Solid lifters, I think they good hand in hand with some of the harsher cam applications! Someone please correct me if I am wrong!

 

Cams, can make the idle very lumpy and believed to be only of real application above 600BHP! Can be timed using vernier pulleys to reduce lag or top end power depending on what you want to use the car for!

 

Rebore, practically useless in gaining any real power! Only 1 in 3 blocks are meant to have thick enough cylinders to take the 3.1 rebore, can be strengthened using epoxy though and the top edge of the bore can be strengthened as well! These can be tested by ultrasounding to check cylinder thickness, one cylinder modification is to knock out the core plugs and clear away the old water channel flashings around no.4,5, and especially 6 cylinders!

 

Port and Polish/three or five angle valve job, meant to reduce lag and increase BHP got mine done along with the heads skimmed and valves lapped in at CTM in Ilford for £400 cash all in super price! Might as well be done if you have heads off!

 

Metal head gaskets, can be used in various thicknesses to reduce compression ratio for higher boost! Meant to be tougher than stock although many people doubt this!!!

 

Lightweight pulleys great if they are harmonically dampened and of the original diameter of the stock item, the only one like this is made by Fischer! If they are not dampened then the resulting resonation can damage the crank and give unpleasant reverberations in the engine bay!

Underdrive pulleys are a reduced diameter pulley for race apllications where it is believed the high rpms you are subjecting the ancillaries to wear them out, in a stock car this means your alternator is doing more work and your water pump is not moving water as designed so a higher engine temp can result!

 

 

I thought Stillen already had one of these charts done!

Originally posted by SRRAE

Dont forget that the car is not moving.

 

The cars intercooers are a lot cooler while moving and their is more air being forced into the car. You should have a huge fan or 2 blowing on the front of the car to do 2 things, try make a situation as close to the car moving on the road as possible and to help cool the car down. I didnt see any fans on the video.

 

Very good point, I must say that on all the articles I have seen on RR sessions they have had these whacking great fans blowing in front of the car.

There was a fan, it was just to narrow to put any air into the intercoolers.

 

Mike