rpm_pwr

If you've seen this before then your insight would be appreciated, otherwise, just sit back and have a chuckle.

Model australian-spec 1994 (series 2) FD
Factory rated power 177kW (236hp)
Mods: None. original engine. 140,000km's

Boost pattern:
2500rpm: 12psi
3000rpm: 13psi
4000rpm: 10psi
4500rpm: 9psi
5000rpm: 10psi
5500-6000rpm: steady decline to 7psi
6000rpm-redline: 7psi

We threw this car on a dyno. Now bear in mind normal oz-spec FD's push around 190rwhp on this (dyno dynamics electro-mechanical brake) dyno. They generally read 10% lower than US dynojets for the same car.
My car: 216rwhp @ 5000rpm-7500rpm (flat line at the top)

Just to prove a point, we lined the car up with an E36 M3 (euro-spec) that is definitely good for mid 13's and the FD beat it convincingly. Twice It shredded 255 Toyo Proxes T1-S all the way through first and second. Remember this is a stock car that on paper should struggle to run a mid-14 on a drag strip with a new engine and a good driver (I'm not).

I've seen that boost pattern once on an FD that had the wastegate and pre-control connectors swapped around, but nobody had ever seen a stock FD throw down so much power at such low revs!

-pete

Engberg

Funny how a boost problem can add extra horses until BOOOOOOM! If it is stock, I suggest you stop running it like that and get your boost in check.

rpm_pwr

Mixtures and EGT's are fine, and it's been running like this for at least a year. Possibly more. Regardless of that, I'm switching to manual pre-control and wastegate when I replace the exhaust.

-pete

HEns

im not saying im an expert but im pretty sure a stock fd can hit low 14's, high 13's

rpm_pwr

Find me one person who has done it in an oz-pec FD. Best I ever saw was 14.5. Wheels even got a 15.0 in 1993.

-pete

skunks

egt gauge=crap, get true wideband

in ancyase, that is the same exact boost curve i was getting like a week ago

i fixed it by redoing my vaccum hoses (i pretty much hook everything up to stock, my secondary bov was tied in to my primary for some weird *** reason)

rpm_pwr

I had a $3000 wideband AND an EGT probe They belonged to the dyno guys.

It's funny you mention the secondary BOV (CRV). I pulled it from the airbox and it's not venting air during pre-spool (even though it's open at idle). Yet, I have the best changeover I've ever seen - the gauge just twitches momentarily. In fourth it doesnt move.

-pete

rx7raca

since when is an fd slower than 13.9 in the 1/4? pple have gotten 13.5-13.7 with good drivers...
am i missing something? im little confused.

rpm_pwr

Since mazda made FD's for RHD countries as well. Australia and the UK got FD's with a precat that bends around the steering column. It narrows down drastically to get past. Japanese FD's dont have the pre-cat but the stock dump pipe still gets so narrow you can only *just* get your fingers through the gap. I'va had both types of FD.

....in america. See above.

re your earlier boost comment (that has disappeared). The wastegate duty is a fixed amount is not related to feedback from the MAP sensor. As such, if there is a problem, the ECU wont compensate. For example I might have the wrong restrictor in the line.

How do I know the ports are normal? I have every service reciept since the car was picked up in 1994. Unless the engine builders at mazda had a crack at a bit of porting one day, I can safely say everything is normal.

-pete

911GT2

Woah woah, slow down there tiger. US spec FD's have a pre-cat too. And ours is damn restrictive. US spec cars gain 5-10 hp on a duno by throwing on a downpipe. Not sure about oz-spec cars, but our pre-cat sucks.

rpm_pwr

I know US cars have cats, but you don't have a steering column to contend with do you? Put it this way, just a downpipe on an australian FD is good for 15rwkW (20HP). I've seen US pre-cats and they dont have the nasty bottleneck RHD countries get.

Dont believe me? US spec FD's were rated at 255HP new. Australian-spec FD's were rated 20HP less. Why do you think that is?

-pete

johnchabin

iTrader: (2)

I think he's saying the exhaust takes a different route to the back of the car...? I have no idea if this is true.

911GT2

I understand that you RHD guys have the steering column right in the damn way of the exhaust, but aren't the dp's the same? Anyone with more knowledge care to interject?

Either way, nice job smoking that M3. I've seen them at the dragstrip here running mid 13's, so the FD must be putting down good power.

HEns

i thought oz-spec ones where just jap-spec ones that where australian delivered, maybe detuned slightly for 95ron fuel

saxyman990

I'm just curious as to where you are getting the numbers for the rated power output? I know US spec cars were rated at 255Hp, but I've never seen any documents pertaining to the power rating of any other spec cars. As a matter of fact, I could have sworn Mazda rated the power output at 255Hp (190kW) for every country they sold the car to (I guess that was a bad assumption). Could you point me to a website or another document that displays this information for non-US spec cars?

Thanks,
Rob

DigDug

I'd be willing to bet you have a vacuum leak. It is likely turbo precontrol or charge control (if it were wastegate control, you wouldn't be seeing boost that high) - look around the intake manifold, where some of the lines go "through" the manifold (if you look, you'll see what I mean). Kinda vague, but I have seen similar, ending up being a vacuum leak in that area. Maybe it has something to do with increased heat nearer to the motor, and how it effects the vacuum lines? Either way, might as well go silicone!

rpm_pwr

Nope I've got a dump pipe sitting at home for my current FD and I had one custom made for my original FD. They get just as narrow as the stock pipe (about 1.25"), but they get very wide to keep the same cross-sectional area as a 3" pipe. There is no easy way past the steering column for us. A few single turbo setups move the turbo up and out creating a path next to the manifold, but the stock twins are fundamentally flawed in their positioning.

There are hundreds of differences. I've owned a 92 JDM Efini RX-7 and now own a 94 oz-spec rx-7. All JDM cars have no pre-cat. oz-spec cars redline at 7k not 8k like the JDM cars, EGR etc etc etc

It's mazda's official figure for oz-delivered rx-7's. (actually 176kW it turns out). Do a google search for rx-7 specs and put site:au on the end. You'll see the quoted power is 176kW for 1992-1998 oz-delivered cars. I have a brochure at home and theres one floating around the net but I cant find it today.

It was partly. We fixed a vacuum leak and now I get 10-9-10 trailing off to about 8.5 by redline. I'd say the trail off is just the old cats. I'm going to give it one last run at an rx-8 dyno day and then it's upgrade time...

-pete

HEns

oh ok, thnx for that rpm pwr pretty interesting stuff