What sorta power should i be getting?

[Guest INASNT]

Originally posted by Chris32

bigger is better!

not if u put a 900x600x150 $3500 trust cooler on with a stock turbo, it would be like putting a t88 turbo on a stock rb20det engine

[Chris32]

Would still be better than stock

Stock is shit!

[Guest INASNT]

Originally posted by Chris32

Would still be better than stock

Stock is shit!

rev210 would disagree with that i am 100% sure

[Chris32]

It seems that way

[rev210]

I think we understand each other. Stock is pretty crap. Though the wrong replacement intercooler can take the meaning of crap to new heights and $$$.

The bigger fmic will get you extra top end power.

But, too big and it will take longer to reach the revs it makes that power at.

You will know the fmic is too big when you can't get quicker than a 13.5 on the stock turbo and ecu on a real 1/4mile. Then again if you go circuit racing the effect isn't quite as bad due to reduced heat soak.

A properly sized replacement intercooler will get you a 12sec pass on a stock turbo and ecu, with the usual mods. This would be about 280/290hp at the flywheel with the same response time as the original cooler.

[benm]

Bigger is not always better especially when it comes to turbo's.

Each component of your engine has to much every other component, no point 1 bit being big if the rest can't.

Kinda like a chain is only as strong as the weakest link but in reverse.

[Chris32]

yeah, but there is always exceptions to that rule

It also depends on what your definition of better is

[Sydneykid]

Hi guys, we have run a standard R33 GTST intercooler on the flow bench and until you get to flows around 28 lbs of air per minute they don't show a lot of resistance, less than 2 psi in fact. That's around 280 bhp (160rwkw), so anything less than that is unlikely to benefit from the lower resistance offered by a "better than standard intercooler".

There is an argument that says the lower inlet air temperature provided by a "better than standard intercooler" would result in more horsepower, but that would be dependant on ambient temperature and external airflow factors.

I'm with Rev210, until you get to that level of power output, I would suggest that there is very little benefit in going to a "better than standard intercooler" in a road only or road/drag car. In a circuit race car the additional inlet air cooling would be more relevant.

Hope that adds to the discussion.

[benm]

Quite an interesting fact, thanks Sydneykid.

[rev210]

Sydneykid your a champ!

It's great to have that kind of test info about for others to get at when considering what to spend their hard earned dosh on next.

It's interesting that the peak power figures of some aftermarket intercoolers are quite a bit higher than the factory one on a dyno. I have often thought that since intercoolers (like radiators) rely greatly on airlflow when moving at speed that a dyno comparison overweights the figure in this way.

[Chris32]

What about this then-

Stock 33 intercooler to get 14psi at intake manifold you will have 20psi before intercooler, runnning the turbo out of its efficiency range. My mate went front 14psi with stock intercooler and 140rwkw to 175 rwkw with a aftermarket front mount intercooler and 10psi boost!!!!!!!. You guys thinking that stock intercooler are these fantastic things are only kidding yourself. They are crap, absolute crap! Not to mention that after about 5mins of decent driving will have it heatsoaked beyond belief

STOCK INTERCOOLERS ARE RUBBISH - whats next, I suppose everyone will start to rave about how you only need a decent exhaust once you are over 200rwkw!

[rev210]

Chris32,

I think you are missing the point. No one has said the stock coolers are fantastic. They are 'just adequate' for a stock turbo. You could produce a better one for a front mount but, most people don't size them right (always bigger is better mentality). In additon to this the rather steep cost of a front mount vs the actual 'real world performance' leaves alot to be desired on a street/strip based car. I doubt anyone gets 5 min on full boost on the street and certainly not on the drag strip, if your talking about circuit racing no one is arguing with you.

There is more to life than dyno power readouts. As I said before the peak power figures are only part of the equation. The larger volume of an aftermarket intercooler reduces 'response' even though it allows more airflow at the top end.

I'd like to put my money where my mouth is at this stage and say if you can find a GTST running a FMIC, stock turbo 10psi, stock ecu, street tyres that runs better than 13.4sec 1/4miles (real drag strip) then I'll conceed that a FMIC on a stock turbo is worth the money. Actually you can even include cars with PFC's and as much boost as you want.

I intend to run a nice 12sec pass on my next trip down with the addition of a exhaust cam gear and S-afc. To my knowledge there is no one in this country running that time with similar mods. Any further modification to achieve this time (should I miss out) will NOT include a FMIC.

[Chris32]

Fair enough, but I think you are also missing my point - That your car, although quick, would be quicker again by replacing the stock intercooler!

I respect your goal, but I don't see any sense in keeping the stock cooler.

As for bigger isn't better when it comes to intercoolers - why not. The whole idea of a intercooler is to exchange heat produced by compressing the air - a bigger intercooler will have less pressure drop and more ability to exchange heat - simple. As for drivabilty, I didn't notice any increase in lag or decrease in torque when I put mine on, just more power

Chris

[rev210]

Chris32,

The key to 'making my car quicker again by replacing the stock intercooler' is to replace the stock cooler with one that flows a maximum of about 300HP (motor) at the same time ensuring that the new pipework is short. I'm sure I'd get another 2 tenths with the perfect setup intercooler but, at a cost of $1600+? Thats not good value for money (I have done less than $2k worth to get where I am).

You will never notice 'lag' basically because the turbo comes on boost at 'x' RPM. However the time taken to achieve 'x' rpm is a factor your dyno does not measure and the 1/4mile does.

[Guest Works Auto]

I made 250rwhp with boost , front mount and exhaust system.

I think this is about 170-180 rwkw's .

Make sure you check your timing. JUst advance it until it pings then back it off a bit.

Also r32 gts-t's have the shittiest fuel pump made. Make sure you change it. There crap.

[Chris32]

I would think though that with the reduction of the restriction on the intercooler side would increase the amount of gas ging into and out of the motor, shortening the time to reach 'x' RPM?

this is getting interesting

[Guest Works Auto]

I didnt experience any extra lag with my front mount and it is quite huge. 600 x 300 x 90mm.

I go with the bigger is better. I will disagree with you.

The more heat you can effectively take out of the charge air the denser the air is gonna be going into the engine.

I run some stoopid timing like 35degrees with no pinging evident.

[rev210]

I run 35-40 degrees as well, no pinging.

If bigger is better then you should get an intercooler that replaces your entire bonnet

[Chris32]

I would if they made them that big!

joking of course!

I remember a hot 4's mag once were the whole front of the car was basically a intercooler - no bumper or anything!

[Sydneykid]

Hi guys, I need to emphasise......

If you are running less than 12 psi and 28 lbs of air per minute there is NO real restriction in the standard intercooler. So puting a bigger intercooler on will make NO difference to the maximum power the engine makes.

In a drag car that uses it's power in 13.4 second spurts, there is quite simply not enough time for it to suffer from heatsoak of the standard intercooler. So puting a bigger intercooler on will make NO difference to the maximum power the engine makes.

When you get over 12 psi and/or 28 lbs of air per minute and/or more than13.4 seconds, then a bigger intercooler WILL make a difference to the maximum power the engine makes.

Having killed that off, lets have a shot at response (lag is such a misused term).......

On the run down the 1/4 you are probably going to make 3 gearchanges and therefore you are going to (most likely) take your foot off the throttle 3 times (and the BOV lets all the boost escape). So the amount of time it takes for the boost to recover after the gearchanges is important.

So if I have a standard intercooler and pipework that holds 12 litres of air it will take 9.7 revolutions of the crankshaft to build back to 1 bar of boost at the valve. If I increase the capacity of the intercooler and its pipework to say 30 litres it will take 24 revolutions of the crankshaft to build back to 1 bar.

At say 12,000 crankshaft (average 5,500 rpm) revolutions to do a 13.4 second 1/4, that about 6/10th's of second building boost on the larger intercooler compared to around 2/10th's with the smaller intercooler.

So you could almost guarantee from the above numbers that a standard turbo'ed Skyline at 12 psi would be faster over the 1/4 with the standard intercooler. Dare I say it, but that is a exactly what Rev210 has found in the real world.

Hope that helps with understanding my position on this subject.