EVOIV

500rpm less lag is definitely worth it, especially seeing that cam gears aren't too expensive.

If you only want less than 200rwkw (I say only, cos although it's still damn fast...lotsa people on this forum are well over 200rwkw) I would stick with the SR20 engine. The SR20 is a very responsive engine. Just need to pick a correctly sized turbo, and for around the 200rwkw mark I would go for something like a GT2530 or something. Should be able to hit the mark on a bit over 1bar, and not much laggier than standard. For a bit more power, but more lag...go the GT2835 which is supposed to be damn nice for the SR20. Any larger and I reckon you won't like it as it's too laggy. Also, the TD06 can be a nice equivalent too.

Just throw on a T88 and away you go!!! Have a look around the forums as there are good posts on people getting great results from various turbos. No need to buy an HKS turbo if you're short on cash, a Garrett one in my opinion is almost as good and is BB based so will not be so laggy as an equivalent sized normal bearing turbo. But then it costs more, but it's worth it. You can always hi-flow the stock turbo but if you really want more power it's better to get a bigger turbo in the long run. It's not cheap to hi-flow turbos either.

I'd say it'll be close, but I'm only guessing cos I dunno how much the Audi puts out and how heavy it is. Sounds like it's pretty decent though. The new GTA type Alfas look pretty nice too, got some go in that thing. Turbo european cars, guess that's the Japanese influence

I'd go the silver one with bodykit and modifications. It also looks as if it's got a decent FMIC there too. You should probably drive the cars first to see how they all feel. The insurance is going to be a pain though, and the extra mods will make it more expensive to insure. I'm not too keen on red cars, unless it's a Ferrari. I think black or white looks the best personally. Silver is good too, but it's a common colour. I guess you can always get the car resprayed.

Hello, I was just wondering what brand and grade of gearbox oil you people use in your cars? I need to do an oil change. Do most use 75W90 grade? 75W80 grade? In the morning, when it's cold, I have great difficulty in getting the car into reverse (or first). I would like to try a different oil to get the gearbox running smoother in the morning. Once the car warms up, the gearbox is fine...although it can be a little notchy at times. I have heard that RedLine is very good, but I can't find any. Does anyone know where I can get some here in Adelaide? I don't mind paying for it (cos I know it costs a lot), I just want to try it out. Cheers.

I heard that running a little too rich can be just as dangerous as running a little too lean? Is that true? Anyone had experience?

That's a nice car. Big turbo, nice piping, larger plenum...nice and clean. Is that an RB25 or RB20 sitting in there? What sized turbo is it?

rob77: I wouldn't expect the 20G to be much laggier than a GT3037S if at all. The 25G may be laggier, but the 20G is a smaller turbo. Plus, you seem to be getting great results out of the TRUST turbo. Go the T88, now that's a lag monster

Steve: What's happening to Trent's 180? As I last heard from Chris (who now works at JMS) that they are going to put on a GT2835 as they found the GT3037S too laggy for their purpose, which I think is street and drift. They used a 0.87A/R on theirs I believe? If you're planning on running high boost (1.5bar), it may be wiser to go with a slightly larger exhaust housing so it's more free flowing at higher boost. I think you should be fine with a 0.73 or 0.87. For boost around 2bar, it'll probably be worth the 1.01A/R.

It's up to Steve, but also depends on me when/if I can get my turbo repaired. If not, why not keep the 1.01A/R RS500? Probably too laggy? But it's gonna hit like hell

Yeah that could be true, probably reaching the rev limit there. There's no torque curve on my graph, just power and AFR (which I think was a little lean). When it was on it felt pretty sluggish off boost, but was really good once boost kicked in. Never lost traction through the gears though, I am not sure if this was due to the AWD or loss of torque? It was run at 19psi. I think you will need to increase your boost to see how it responds. Then you can tell whether or not you want a larger exhaust housing or not.

Comparing your dyno graph to mine, it does look quite similar until your car reaches full boost. On mine, at 60km/hr the car produces 60rwkw, then at 100km/hr it's at 206rwkw. So there is a steep curve, just like on your graph at a similar range. Only difference is that your graph keeps going up from then on whereas mine doesn't. It would have been good if they took a torque curve on my dyno chart too. So they're probably equally as aggressive as one another, only thing is that mine is AWD so I rarely had traction problems. One thing I did notice was that the car seemed to lack low down torque with the larger turbo, yours might be different.

Steve: I have had a look at your dyno graph but I can't really tell when things go wild? Can you explain? I guess my chart is a lot smoother and progressive with it's power, but of course doesn't make as much power as yours My chart also seems to produce power a lot sooner than your chart, but then I can't remember what gear my car was run in. Yours was done in 4th right? I would have assumed the same? Or maybe mine was done in 3rd? Anyone know what's the norm when tuning cars? My car was tuned by Shaun (who used to work at MORPOWA, then RPM...now???). Done at Turbo Tune's dyno. [i've attached my dyno chart on another thread somewhere, called "Apart from Tilbrook..." or something like that]

Nice work! You're using the RB25 right? I get confused about the T04R too. But I am pretty sure you are talking about the big HKS one right? I don't believe it is BB, or is it? How does the T04R compare to the T51 series turbo? I've always liked that turbo, I reckon it's a great turbo for the RB26 or RB25. Which is bigger?

RS500: Sweet! I'll have to get my turbo repaired and have a better think about it now. Just wondering, why do you have the exhaust housing? Do you have another turbo to match? Have you decided what you're going to do next to ur car?

Not so sure if boost is going to come on more smoothly with a 0.73 compared to a 0.61? I was under the impression that the larger the turbo (and larger exhaust housing) the bigger *thump* when the turbo hits boost? Or maybe it's just an increase in lag?

Steve: As you know, I have a GT3037S in bits at the moment. Compressor and Turbine housing, and core. The exhaust housing is a 0.73A/R. I am still not sure what I am going to do with this turbo. I do want to get it repaired eventually, if I can get my lazy ass into gear Also, not sure if it can be fixed - it will have to go to GCG or Garrett first for an inspection. But hopefully it can be as I think the turbine wheel is the only damaged part. If it does get fixed, I may opt to put on a larger turbine housing (sourced from where I don't know?). So then the 0.73A/R might be up for grabs. Maybe I should buy the 1.01A/R of RS500?

Well, I don't know too much about dynos or how they work. I just read in a magazine that they were the results. Maybe once a car gets so powerful, there is a larger discrepancy between results?

As I said in another post, the type of dyno used does matter. I read in a Fast Fours that the JUN s15 in Perth pumped out around 700hp (???) at the wheels on one dyno, only to produce a comparitively measly 550hp (or thereabouts) on another dyno. Well, actually it's still damn impressive but not so much when compared to the 700hp figure Best is to have a dyno day shootout for comparisons sake.

Depends on the tuner, dyno used, temperature of air on the day, mods...etc. But still, great results by all!!

Steve: Do you know what are the differences between an HKS turbo and a Garrett turbo? I heard that the cores and turbine trims are the same. The only difference are the compressor housings and compressor trims. Are the exhaust housings also different? Or is it in size where they are different? Example: I know the GT3037S can have a 0.73A/R exhaust housing, and I don't think the Garrett GT30 has the same size? The reason I ask is because I have a broken GT3037S turbo. It has a damaged turbine wheel and I am going to try get someone to repair it - either GCG or Garrett in Sydney. If the turbine wheel is replaced with a Garrett turbine wheel, could my repaired turbo still be classified as an HKS one? Meaning that the turbine wheels are the same for both Garrett and HKS GT30 cored turbos?

I think most companies use the Dyno Dynamics dyno (?). Very nice results, will be interesting to see how the turbo fares as the boost is increased. It does seem to produce more power than Steve's HKS one, but it also seems to have more turbo lag. Maybe there is a noticeable difference between the Garrett and HKS turbos afterall? Once you guys start increasing the boost, then we should be able to see what happens. I've heard that HKS turbos are more efficient at a higher boost level (eg 1.5bar), and that they spool up faster. I've heard that Garrett turbos are more efficient at lower boost (eg 1.0bar). Guess time will tell...keep up the good work!!!

Yes, that's also true.

Great results GTS-t VSPEC!! Wow, it really seems that the GT30 turbos are responding well on the RB25s. 270kW@wheels on 13psi is a $#!T load!! Sure you'll be having traction problems. The only problem I see with comparing dyno figures is that they can vary from dyno to dyno. Also depends on the air temperature of the day. For example, the JUN s15 equipped with T88 (in Perth I think) produced something like 700rwhp on one dyno, only to get 550rwhp on another dyno. Something like that anyway, I read it in a Fast Fours mag. Anyway, point being that there is a difference between all dynos. To compare two cars you really need to dyno both on the same dyno on the same day. In the end, it's really how fast you run the 1/4 mile which is going to judge how quick your car is. Still, very impressive figures to both!