Messages

1

Forced Induction / GReddy Plenum vs Modified Factory Plenum

« on: January 13, 2007, 12:43:39 PM »

The lenth of the runners on an efi application is to do with pulse interference from other cylinders. It has the largest impact on light throttle and cruise fuel mixtures when talking forced induction.Once the boost pressure is above '0' then short runners = better. So considering torque is actually highest under boost, a long runner setup isn't going to win any prize against a well designed short runner setup.

An issue with Rb250/25's is the length and volume and restrictive bends in pipework when a FMIC is part of the equation. The response of the motor is down but, by having a forward facing plenum you can get alot of that back and then some.

The Greddy plenum isn't the best design out there if you consider that it lacks 'bell mouths' inside the plenum chamber (it's only cast). This certainly helps off boost response to have them in.As a middle of the road solution Plazamaman makes a very good bolt on unit that retains the longish bottom half factory runners, for improved ecconomy  and adds a good volume well designed plenum chamber with bell mouths for improved top end.

There are a number of greddy 'knock off' plenums around and it's too easy to make one given the greddy is only a cast thing with no real attention to machining. They must make huge profit on those things. Number 6 piston is still an issue with the greddy as well. Not a big deal just have your injectors flow tested and slap the biggest flow unit at the back in No 6 position.

2

Forced Induction / R34 gtr v spec turbos info plz

« on: October 18, 2006, 01:09:35 AM »

r34 gtr turbo's still have ceramic exhaust wheels. They are ballbearing core though. the N1 R34 GTR turbo's are the real upgrades, V-specs still have the standard r34 gtr turbos.

3

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 08, 2006, 09:35:45 PM »

economical or good. Choose one.

Considering what gains the right intercooler give you over a 'bolt on boy' one it's better to wait and save your pennies. Learn that lesson and you are half way tp having a standout car performance wise.

4

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 08, 2006, 03:55:44 PM »

Remember you can always sell the intercooler pretty easy and get one thats a perfect match made up. There really isn't any point trying to make an engine package fit a cheap intercooler, do it the other way round and you will never look back. An intercooler is one of the things worth getting right I mean really right. Even a T3/4 hybrid size turbo isn't going to be big enough to justify that core size. Have a look at this site http://www.are.com.au, I've used these guys to make custom sized stuff based on my airflow and cooling requirements. They have plenty of good info on the site as well.

5

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 08, 2006, 06:29:30 AM »

the fan shrouds are usually needed when you have low speed situations and the fans are trying to draw the air through efficiently. If you don't have efficiency/shroud you can always substitute power/big fans.

6

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 08, 2006, 02:42:10 AM »

gtsr,

right you are about ducting. It's all about getting the air to go the path you want it. Sometimes some glued in high density rubber foam can do the trick if there isn't much space in the gaps and you don't have a mate who can weld some sheets of metal up for you. Air loves to wash over radiators and intercoolers if there are nice big gaps around them providing the low pressure carrot. It's the same thing for retaining a good radiator shroud for your fan. Lots of people turf the shroud when fitting electric fans and can sometimes wind up with heat issues. Having a shroud around the new electric fan is well worth the hassle of making one.

7

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 08, 2006, 12:08:40 AM »

But on the dragstrip the car is moving fast enough to suck in heaps of outside air easily out-flowing the air generated by a crappy dyno fan..

Im sure the air coming into the larger fmic's would increase the turbo's efficiency especially above 140ish kph

You are right about the air moving differently and in different volumes on the road. This is actually the same reason why a final tune/run on the car ought to be done with the bonnet down. Air never escapes the engine bay that way on the road and the air paths with the bonnet down including the high and low pressure areas are decently replicated using the dyno fan.

Most dyno fans are pretty decent actually. If you consider that some cars that NEED the cooling to be tip top, like oh I don't know 800rwhp  car as a popular example. Thats 800rwhp worth of heat to be getting rid of using the good old air heat exchange of the radiator (albeit a big ass one) and intercooler. Those fans are actually half decent, at least good enough for a little 200rwkw job.

On a street car it's hood down for the final tune on the rollers for me. Then a road/track tune with a wideband for the ideal finish off. It makes a difference, think about it.

8

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 07, 2006, 11:56:23 PM »

Thanks for your comments but i disagree with um everything you have said it comes down to traction and practic. As this was only my 2nd time to the track

My dyno was done with bonnet up. and the intercooler is a ok size for my current mods and the boost im running

And you guys in oz have a much better track than we have in NZ ours sucks sh!t

It's your 2nd time to the track. I've been drag racing for a little while , I'm just trying to help you understand some things.Your going to get alot of 'do this do that..' playstation-mechanic-bolt-on-boy-advice.

NZ tracks may not be real flash, I've raced on poor preped tracks plenty of times, BUT, when we are talking about slow ass street cars that aren't pulling 130+ mph terminals then you need to understand the track 'isn't' your problem yet. Ask RIPS he's a local, with a fair whack of experience drag racing in NZ and doesn't winge while he cuts respectable times. 'Dedicated' drag cars find those tracks tricky due to the surface not being as flat as they would like, it makes it harder to keep the car from going into the wall. Again there are some good times being set regardless due to drivers with balls of steel and the better ambient air that often blesses the tracks in NZ.

2.3 60ft that you have. Thats not great, you can improve that pretty easy. That's not the track at all, it's all you and the car's setup period, good news really.

Working on the launch tecnique helps a great deal to lop some time off but, getting hold of rear cradle pineapples (about $100 to buy) will set the car up with a good 'squat' weight transfer for launch. Taller profile tyres for the back can help as can reducing the tyre pressure to provide more surface area to contact the road on launch. If you are really adventure bound then a set of BFG drag radials will lop big chunks off the times.

Now the intercooler business...

Ok? I don't think so. It's 'poor'. Looks nice though I'm sure.

You know the core that size you have if it's actually half decent is the right size for airflow in the range of well over 300kw. By having it on a car with a shortfall of over 100kw from it's optimum means you lose precious time getting the air to the inlet valves. Yes the intercooler works. It doesn't work as well as the stock one for drag racing when using the stock turbo though. The stock intercooler isn't real flash as far as core quality goes but, it's nice and small. A good upgrade core size would be a tad larger than the stock one. As a comparison a bar and plate core size of around 460x300x75 would be right for about 285kw.

The 13.8s I ran were with ambient temps in the high 30deg range. on the same night other r33 owners with the same ever popular 600x300x75 kits struggled to make it to low 14s even with the same 60ft's. Later on the car with S-afc II and a light weight flywheel ran very easy low 13's with a mph good enough to break 12's. A number of guys since have ran 12's at various tracks following the same basic setup give or take. However there are ten times that number of GTST owners who take the sheep approach and end up staying in 14s till they upgrade the turbo.

food for thought?

good luck and have fun.

9

Australia / Any Old school SDU People still around here?

« on: October 07, 2006, 09:02:39 PM »

moved to SAU. look here on the odd occasion but, there's not much left. All forums get crappy after a while, quite normal.

10

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 07, 2006, 08:59:10 PM »

hang on I did have rear cradle bushes in too (aka pineapples) helps with the traction a tad.

11

General Performance / What do you think of my Drag slip. 14.78sec ET

« on: October 07, 2006, 08:55:47 PM »

The terminal speed tells me you are not exactly oozing power.

As a comparison my old R33 gtst with an exhaust only ran easy 13.8's at 101-102 mph. Thats a stock ecu , intercooler and turbo.

An un-shielded pod filter? Do your dyno run with the bonnet 'up' instead of down. That intercooler is way too big for a stock turbo by the way, it's not doing you any favours.

12

General Skyline Discussion / 1/4 mile times

« on: October 07, 2006, 08:49:58 PM »

R33 gtst about 170rwkw .
stock turbo (10psi) & intercooler. S-afc II . exhaust. BP98 fuel. 205 tyres.

13.3@106mph 2.3 sec 60ft. Kwinanna Motorplex Perth WA.

13

General Performance / GTR R33 intercooler Vs BAR & PLATE?

« on: August 15, 2006, 02:58:43 AM »

i think your talking ****..  theres no way that one of these coolers would decrease performance, over the ****ty EXTREMELY restictive stock cooler. its just not possible, providing the piping etc was half decent.

another fact, all the trademe intercooler are the same. there is nothing differerent between them, as theyre made in the same place , some just being rebranded. hell, even racepro stuff is made by the same company..

Although the example mentioned might have other factors, an 8kw difference may have something to do with the conditions at the time, the fact is that you can very easily go backwards in performance if the intercooler is a miss match.

The response of the china core 300x600x75 on a small factory turbo is a step down in terms of raw accelleration, even against the less than mighty factory intercooler. That core size is way too big for the factory turbo. The cores are usually half decent the question is the size being right for the application.

The right intercooler match is like everything else. Cams,turbo's,compression etc.

14

General Performance / GTR R33 intercooler Vs BAR & PLATE?

« on: August 12, 2006, 12:44:01 PM »

read this and you will know a bit more about the intercooler thing.

http://www.are.com.au/feat/techtalk/...tm#Turbo%20Lag

15

General Skyline Discussion / WRX vs SKYLINE?

« on: August 10, 2006, 09:54:49 PM »

205? sure thats not a typo?

no.

nothing like the feeling of ice skating, without the ice