13.4 second 1/4 for your 'stockish' R33. (A how to guide).

[rev210]

Ok, I started the same sort of thread on the SDU web site but, lets face it this forum is MUCH better.

OBJECTIVE : Do mid 13's(possibly lower) all day with the standard ecu, intercooler and turbo retained on your R33 gtst.

I used:

A 1995 manual R33 gtst with 93k on the clock.

With the following Modifications:

* K&N panel filter inside stock airbox

* 3inch FGK cat-back exhaust (very quiet and probably more restrictive than some exhausts)

* 3 inch stainless dump pipe off the turbo 'wrapped' with DEI thermal tape to the cat. This dump does not have a sepparate wastegate screamer or feed pipe.

* Diff Cradle kit or 'pineapples' , the Whiteline kit No. KCA349.

* Ogura Lightwieght flywheel 4.8kgs.

* Ceramic puck sprung clutch and stock pressure plate

* Wrapped turbo to intercooler pipe (DEI thermal tape).

* Removed panel behind stock intercooler.

* Timing , see if you can grab a few more degrees over stock.

* disable the carbon canister fume feeds to the intake.

* Turbo smart bleed valve (cheap one) set to 10psi boost

* Simex 205/50 16 inch rear tyres. let them down to 19psi.

* NGK coppers ...6ES gapped to 0.7mm.

Everything else is stock : turbo, intercooler and ecu blah blah blah...

Appart from these modifications there are some don'ts you will find will hamper your attempts to go this quick.

DON'T:

* Use an aftermarket blow off valve. (sorry rice boys)

* Run ultra low profile tyres unless they are wide, 235+

* Run the street inflation in your rear tyres, ie: 36psi.

* Run a pod unless you sheild it and route cold air to it.

* Change gears like a nanna, don't have to flat change tho'

Do this and by all accounts you will get a bunch of mid 13's if you can crack a 2.2 or better launch.

Edited April 10, 2008 by rev210

[rev210]

the time slip. before I get asked again.

http://forums.skylinesdownunder.co.nz/atta...=&postid=189495

[Steve]

So what is acutally wrong with an aftermarket BOV, I noticed less lag on changes with mine fitted -

Signed:

Rice Boy

[GTS-t VSPEC]

rev,

You could start writing a book. It does seem surprising that we are suddenly starting to get to these mid13 times with the stock turbo. I know I have many more mods than you, so what do you think the problem is, the driver? I think that too much power is a disadvantge, too much wheelspin etc.

You recommend pineapples, whereas Osc@r didn't think much of his, did you actually notice an improvment?

Well done on the time again, hope you can keep pushing the stocker a little further.

See'ya:burnout:

[Guest nismogtsx]

Whats the dis advantage of the carbon canistor...

Also what did you do to get around this (disable) is this a legal street requirement to have???

Can it be totally removed legally???

[rev210]

too much power?

Never the problem, sometimes it's a solution in itself, keep throwing horsepower at it till you get the time you want. Know of a few cars that spun the tyres non-stop down the track and done low 11's (sure they would have got low 10's if they got traction but what a great burnout!)

I'll give you an opinion on your car's setup. Here goes...

You have a great efi management in that wolf V4, boost controller, exhaust and an active diff (who wouldn't kill for one).

The pipe work is good too....for a big ass GT30 and not tiny tot stock turbo. Throttle body too big etc.. But hey, your doing the big turbo anyway so I think 13.5 is pretty darn good considering the handicap. I think changing from 2nd to 3rd you are falling just outside the ideal power band rev.

[rev210]

nismogtsx,

My carbon canister looks connected, and is at the fuel tank end, the manifold leak..er pipe side I have blocked and rejoined the pipes so they look factory.

smallish open (to canister) holes to your manifold good for performance?

Nope!

[Guest nismogtsx]

Over kill could be your worse enemy tho.....

I mean 500hp at the wheels on stock gearbox/diff and shit will just be asking for trouble.... BANG.... If ya running 205 tires on 500hp then wheel spin is gonna be an issue...

I mean 205 tires could be rather good if you baby'ed the car off the line and then got in to it.... But ill probably get over excited and spin em... LOL

[Jay95R33]

Great time Rev - congrats.

I've been thinking about a few things (yes, it hurt !!)

Stock tyres on a GTS-t are 225/50/16's. So if your running 205/50/16's the rolling diameter is going to be smaller which will give you better acceleration. Sort of like running a different dif ratio - sort of Well, you know what I mean anyway.... It may not account for much, but it could help.

Also, from what I've read, and expreianced myself, it seems the 1995 GTS-t ECU's seem to handle boost increases etc. better. They don't seem to have as much of a really big dip in power where it retards the timing heaps when your running higher than stock boost (alot of you guys have felt this I bet).

I know of 2 poeple that are around the 190rwkw mark on the stock 1995 ECU with no piggybacks.

I popped the tacho output on my stock ECU (1995 GTS-t), and got a second hand one off of a 1993 model. It runs the car fine, but it is down on power for sure, plus it now has big dips in power when accelerating hard where the 1995 ECU didn't

From looking at them (1995 v 1993 ECU) the 1995 has a newer firmware on the main chip. Maybe they don't run as rich or something??? I'm really not sure....

Soooo, is it possible that a 1995 GTS-t ECU may be a cheap upgrade for people????

Again, great time, well done. If I get a time under the 16 sec mark I'll be happy

J

[rev210]

Jay95R33,

Let me assure you whatever they did to the 1995 ECU, they didn't touch the mixtures or timing graph. The dyno I had done many moons ago showed 189rwhp, I figure I have around 200rwhp at the time of doing 13.4. I feel the dip in power and I've only got 10psi.

Whether people do get 190rwkw on a dyno is not worth anything to you and me because dyno's are just a tuning aid. You can have a car that makes 190rwkw and runs like crap because it isn't tuned right and when tuned the same car makes 500rwkw. Means alot to that guy but not to me.

205/50 16's are factory. If I had wider tyres like 225's I would cut an even better time, even if only slightly, that you can bank on.

Steve,

Aftermarket BOV's do not reduce any lag over stock unless your stock BOV is stuffed, and that does not happen very often when you have less than 20psi of boost. Aftermarket ones actually are rather hard to set up to work properly. For one if you have a factory computer you can expect to be slowed down by mixture problems, as if the map wasn't rich enough already. But hey if you like the 'rice-boy-cop-bait sound' knock yourself out(jokes), just don't think for a minute you have done the performance side any favours.If your stock BOV does stuff up...go buy another one.

[GTS-t VSPEC]

rev,

Thanks for the tips, I'll try and stop shifting like my granny, and yes the piping is currently a little oversize, but with the GT30 it will be just right.

I think it will be an interesting exercise to see you do mods to your car slowly and see the effect they have on your times. If you do one change at a time then it will give us all a good indicator of what potential some mods really have.

See'ya:burnout:

[Steve]

Originally posted by rev210

Steve,  

Aftermarket BOV's do not reduce any lag over stock unless your stock BOV is stuffed, and that does not happen very often when you have less than 20psi of boost. Aftermarket ones actually are rather hard to set up to work properly. For one if you have a factory computer you can expect to be slowed down by mixture problems, as if the map wasn't rich enough already. But hey if you like the 'rice-boy-cop-bait sound' knock yourself out(jokes), just don't think for a minute you have done the performance side any favours.If your stock BOV does stuff up...go buy another one.

Rev210, thanks for your reply,l I noticed a quicker spool up when using an aftermarket bov, which was to replace my stock one as I believed it was stuffed. Also I noticed that i was getting a fair bit of 'flutter' coming out of the intake on lower rev changes, but it just wasn't lifting properly.

How does the running rich on gear change affect mixtures when under power? Does it affect carbon build up on plugs etc?

Cheers

Steve

[whatsisname]

From the factory catalog the stock rear wheel/tyre options on the GTS25t are - 205/55/16 or 225/50/16. So a 205/50/16 combo "may" give a slight improvement in acceleration.

Hey Rev why not go for the bottom of the range GTS non-turbo (RB20E) wheel/tyre option - 185/70/14 :burnout: Don't forget to change to a 4 stud hub

Go stick her on a known local DD dyno mate, just for the hell of it, you know interest sake @ all that See what she makes before you play with the SAFC II. Regardless of the peak rwkw fig' it'd be interesting to see the power, torque & A/FR curves.

[Jay95R33]

Originally posted by whatsisname

From the factory catalog the stock rear wheel/tyre options on the GTS25t are - 205/55/16 or 225/50/16.  So a 205/50/16 combo "may" give a slight improvement in acceleration.    

Cool - I was starting to wonder why my factory Japanese tyre placard was wrong

Yeah, run her up on the dyno just for interests sakes. Then you can say "I could run a 13.4 pass with only XXXrwkw".

That'll get the big boys wondering :uh-huh:

J

[rev210]

Matt,

I've already had a play with the s-afc, without the dyno, and I reckon I've got myself another 15+rwhp. I just couldn't help myself.

Final ratio wise, you don't get much out of the tyre diameter by dropping the profile by 5. If people think that makes a difference you will be barking up the wrong tree. But if someone knows of a low ratio LSD center that will fit the R33 then tell the world!

Steve,

Sounds like the stock one was stuffed. Yep the mixtures are doing you no favours, if you want aftermarket then get a s-afc or aftermarket efi management or swap the BOV for one that also vents back into the intake. At the end of the day that BOV you have makes your car slower (without the other things).

[doxximus]

i'll sticky this along with the low rpm stalling thread, hopefully these are two of the threads that will get their own section on the site with a more detailed information

[Steve]

Rev210, I have a power fc now so I am not too worried. I was just curious and trying to learn something new.

Cheers

Steve

[Jay95R33]

Originally posted by whatsisname

Hey Rev why not go for the bottom of the range GTS non-turbo (RB20E) wheel/tyre option - 185/70/14  :burnout: Don't forget to change to a 4 stud hub

He he he. That would look funny, actually that size has a bigger overall diameter compared to the 205/55/16 !!! But gezz you'd smoke them up good :lol: :lol:

From 205/50/16's to 205/55/16's is a massive 3.35% difference LOL. So your stock final drive of 4.11 would change to 3.97, or is that 4.25 ??? That's if I'm working it out right (brain still in holiday mode) I can never work out which way it goes :confused: :confused: Anyway - that's a bit off topic.

Impressive run no dought.

J

[rev210]

Once again if let the air out of the tyres, what is the diameter?

Forget the tyre diameter acting on the final ratio, it won't make you any quicker and it can cause your brain to swell up and hurt.

[2rismo]

Just my 0.02c re: BOV discussion.

I think that it's a big mistake on anyone's part to say that externally venting BOV's,

"make your car slower"

"are just a wank"

"aren't as good as standard"

"are only an improvement if your stocker leaks"

"are the best things ever made"

"make the chix dig me and my mad styles"

etc etc etc...

Any and all of the above are RIDICULOUS statements when used as a generalisation of every car or even every 'line. If you have a standard R33 for example, and i mean STANDARD, running an aftermarket ext venting BOV will probably NOT help you run quicker times (and that's what we're talking about in this thread) than your standard, in order, factory BOV. Unless your standard valve is leaking, an ext venting BOV is for pose/style/personal preference value.

BUT

If you don't have a standard car, say you've done some mods in particular upped the boost and/or fitted a significantly larger front mounted intercooler, then an argument can be made, and I am, that in most cases the standard-sprung BOV won't perform as well as a after-market valve.

You with me? Then I'll continue.

I'm not for one minute implying that the standard valve isn't doing it's job or that it has 'failed' because of design flaw or missuse. Quite the opposite. As with almost all car components, it was designed with a specific task in mind. In our example's case, to reduce the slowing effect on the turbo by the air that remains pressurised in the system when the throttle butterfly closes AT STANDARD BOOST LEVELS. In some cases, the standard R33 valve (Mitsubishi component in fact), performs adequately at higher levels of manifold pressure. However, when you not only increase the pressure of the air in the system but also the volume, there is an even greater likelyhood of the valve not cutting it.

You see, it now becomes not only a question of, "does the standard valve leak whilst producing positive manifold pressure?", but also of, "what is the limit of flow that the valve can achieve?".

As well as being almost universally more stiffly sprung, (i.e. less prone to on-boost leaking), the aftermarket valves tend to be able to flow a great deal more air, esp. externally venting items.

To illustrate the above, imagine what happens to the volume of air in the system when you add a larger front mount intercooler and associated pipework and up the boost a bit. The turbo works that bit harder innitially to presurise the system, (often noticed as slightly more initial lag compared to the smaller factory item or no cooler at all). When you back off, change gears etc and the throttle butterfly closes, there is a great deal more air in the system than with just a standard cooler/standard boost level. Where does this extra air go? Well in the case of a standard valve, back to the intake side of the turbine to relieve some of the reverse pressure on the comp wheel. How well does it do it? In my experience and that of many others, not particularly well. There is considerably more air trying to get back through the return line and sadly, the standard valve can't flow as much air as is typically desired. An externally venting unit does better in this scenario as it isn't limited by the volume of the system to release pressurised air into.

To qualify the above (as i'm no race car engineer), i would direct anyone who cares to get to the bottom of the argument for and against, to look at the racers of turbo and supercharged vehicles around the world. It would be fair i believe, to cite Kart racing as a fair example of a sport that has many millions of dollars invested in R&D and the brains to make the dollars work! They run, albeit highly advanced, forms of externally venting BOV's!

Too hard-core non-street for ya? Lets see if the guys that race all week at the Pamona Nationals in the states use them. Hmmm.. Some of the fastest 1/4 mile (we're still talking about that here remember) import beasts in the whole world and how many of them DON'T use externally venting BOV's? About none of them i'd reckon.

In short, my problem isn't with standard valves or aftermarket valves or rice-boys etc... It's with people that make blanket statements like, Don't "Use an aftermarket blow off valve. (sorry rice boys)". Yes I read the post, yes I know the cooler was standard for your runs, yes i noticed that you upped the boost.... In your example, as i've said above, the standard valve would have been ample for your excellent times. You can only speak from your experience and I from mine. I beleive that this post was designed to help others achieve what you have and for that we should all be grateful.

Your comment about BOV's wasn't helpful to anyone.

Regards,

Adrian