OFFICIAL: NicoClub's Rally 240SX, by Finnish Fury Rallysport

[mechanicalmoron]

Don't take me seriously, you obviously know way better, but.....

This would look a bit funny, but you could put a pretty big scoop over that airbox on the hood, face off the fender side of the box, and make it large enough that you could put two of the stock style filters side by side diagonally, and if you think that wouldn't stop enough water if it rained or something, a further catch or second filter in the airbox.

If you faced off the back of the airbox you might even get a ram-air effect. But maybe it'd get too wet or something.

As far as hood holes, you just need a ramp shaped part on the rear side, such that you could drive a toy car out of the engine bay through the hole, and strait up towards the windshield. (didn't see a picture of this hole)

It's a race car, cut them funky vents......

[FlatBlackIan]

Don't take me seriously, you obviously know way better, but.....

This would look a bit funny, but you could put a pretty big scoop over that airbox on the hood, face off the fender side of the box, and make it large enough that you could put two of the stock style filters side by side diagonally, and if you think that wouldn't stop enough water if it rained or something, a further catch or second filter in the airbox.

If you faced off the back of the airbox you might even get a ram-air effect. But maybe it'd get too wet or something.

As far as hood holes, you just need a ramp shaped part on the rear side, such that you could drive a toy car out of the engine bay through the hole, and strait up towards the windshield. (didn't see a picture of this hole)

It's a race car, cut them funky vents......

In all reality, I know next to nothing, I just get lucky a lot, and I surround myself with smart people. Can't complain though lol, it seems to be working.

As for the big scoop with a panel filter, Broc suggested the same thing. I contemplated it for a few days, and rolled ideas around my head, but it just didn't seem like a good solution. It would allow for ample airflow, with the possibility of pressure increase, but, and this is a big but, executing it properly would take more skill and time then I have. I also worry about clogging the filters with mud if they are out front. A lot of mud gets thrown forward and up from the front tires.

As for the "ramp", we are way ahead of you. See following pictures.

Started by building a front lip for the vent.



Then we bent up a downward facing lip for the back side. We decided a cool design was in order.



Getting there.



Painted and installed.



This should hopefully lower the pressure inside the engine bay, allowing more air through the radiator.



In other news, I finished the air box structure, sealed the cracks with fiberflass, and then bed lined it. I figure the truck bed liner will help insulate the airbox, as well as cut down on engine resonance.



It still needs another coat.



Also picked up some material for new larger mud flaps, sealed the radiator to its support, and ordered up some random odds and ends.

[mechanicalmoron]

Sweet vent, I might do that, just for funsies.

As for a scoop, if you pointed it backwards I don't THINK it would have negative pressure, and you wouldn't get mud in it? It would still have cold air. And it wouldn't be hard fab stuff, you can get a cheap bolt-on cowl at auto-zone (usually bought for the inherent HP increase associated putting a scoop on a honda civic) thaw would pop right on....

Anyway, really neat looking stuff.

[FlatBlackIan]

Airbox is finished. I am very happy with how it turned out.



Fitment is tight, but it does not rub even under full throttle.



Took the first drive with both the new header, and the airbox. I did not notice any increase in power, but the sound is changed significantly. The car is much quiter, both the intake and the exhaust. The header also cleared out the remaining rasp that the car had. Sounds clean all the way to redline.

Between the two things, the tune needed to be changed significantly. Strangely, I need to add more fuel from about 4000 to redline, while at the same time I ahd to take fuel away from part throttle midrange and cruising. Amazing how a few parts can so significantly change the airflow properties of an engine. Just over a week left the sort everything. Can't wait for Ojibwe.

[gmac708]

I usually don't say much because I really don't have much to contribute to this thread. But I must say that this car is looking amazing. Great job guys. Always look forward to your updates.
Gord

[DeXteR]

Good work on getting that vent more flow friendly.

Give Broc and internet high-5 for me.

[FlatBlackIan]

Good work on getting that vent more flow friendly.

Give Broc and internet high-5 for me.

Many high fives have been given.

I will give a little update, sans pictures.

Spent some time working over the tune last night. In doing so I have discovered 2 worrying new problems. One will need to be rectified before competing in the car, the second can wait.

First off, braking issues. Due to the lack of a plenum post throttle body, there is no place to pull a 1/2 inch line for the power brake booster. To rectify this, I T'd off all 4 throttle bodies, and linked to the booster. For normal driving, this worked perfectly. They wouldn't build vacuum in the booster as fast as a stock system, but with the check valve I didn't notice any issues. Once I started opening the throttle hard, and alternating onto the brakes, like I would while transitioning between turns, I would loose boost very quickly. This is a major problem. Time to get fancy.

The ideal way to solve this issue, would be to convert to manual brakes, which is the plan. There just isn't time before OFR. Let the Finn rigging begin.

The second problem. With the tune coming together, the car was pulling harder and harder. Everything was fine and dandy until one of my warning lights began to illuminate. Second and Third gear, around a hundred RPM before the shift light turns on (6500), I get an orange warning. I preset that light to activate when injector duty cycle hits 90%. Checking the laptop revealed that at 7000 RPM, I was getting to 92% duty cycle.

What to do? Well, I am not happy about that kind of DC. Extended time spent at 90+ can and will shorten the injectors life. If I were to swap to a hotter set of cams, I might very well push to 100%. I may experiment with mixtures of E85 and high octane, or I could just swap to race fuel, all though I don't want to. I am blown away that This motor is sucking enough air to nearly max out 565 cc injectors.

On high octane, these injectors allow an STI to make 300ish WHP. This means, with the 30ish% increase due to E85, maxing out these injectors should put me over 200 horsepower to the rear wheels. These are just armchair calculations, but I know I am in the neighborhood. I can't wait to get it on the Dyno after OFR to find out for real.

Dave, are you ready to duke it out for highest HP NA KA on pump gas? E85 comes from a pump right?

Either way, the car pulls silly hard on gravel now. Its whole different animal then ever before. She scares me a little.

[PapaSmurf2k3]

This is awesome.
I was going to say "well, you can calculate rough HP based on your MAF", and then I remembered what thread I was reading.
What do your AFRs look like?

You could always add an additional injector of your fuel choice (methanol perhaps? Although I doubt you need it) to just after the filter, sort of a "throttle body injection" type setup, you know, if you had a throttle there. Trigger it to come on only above 4,000 RPM or something, otherwise airflow wouldn't be high enough to sustain turbulence/atomization. Even though you don't have the throttle plate located there, it should still work.
What fuel pressure are you running? You could try bumping that up a little bit too just to squeak by.

[Razi]

Pretty impressive that you're maxing them out on an N/A setup.
I was hitting 93% at 6200 RPM with my 370ccs, that convinced me to switch to a bigger size.

Smurf, how do you calculate rough HP with MAF readings? Do you put in the MAF size + the voltage reading to get a rough estimate?

[Ajax]

I can't wait to get it on the Dyno after OFR to find out for real.

Dave, are you ready to duke it out for highest HP NA KA on pump gas? E85 comes from a pump right?

Sure we can do that, but I pick the location. Hmm, where is E85 not available?..

[PapaSmurf2k3]

Pretty impressive that you're maxing them out on an N/A setup.
I was hitting 93% at 6200 RPM with my 370ccs, that convinced me to switch to a bigger size.

Smurf, how do you calculate rough HP with MAF readings? Do you put in the MAF size + the voltage reading to get a rough estimate?

You basically go by what the MAF is known to max out at (so like an N62 300zx TT MAF maxes out around 530whp @ 5 volts). From there you just use a ratio of voltage to horsepower. @ 3 volts you should be about 318 to the wheels. Its rough, but not bad.

[mechanicalmoron]

Pure-awesome.

Are you controlling it with megasquirt? Or somethin' more fancy-like?

[Razi]

Pretty impressive that you're maxing them out on an N/A setup.
I was hitting 93% at 6200 RPM with my 370ccs, that convinced me to switch to a bigger size.

Smurf, how do you calculate rough HP with MAF readings? Do you put in the MAF size + the voltage reading to get a rough estimate?

You basically go by what the MAF is known to max out at (so like an N62 300zx TT MAF maxes out around 530whp @ 5 volts). From there you just use a ratio of voltage to horsepower. @ 3 volts you should be about 318 to the wheels. Its rough, but not bad.

Sweet. Pretty cool!

[DeXteR]

Tell Chris not to soil the seat this weekend...

[FlatBlackIan]

This is awesome.
I was going to say "well, you can calculate rough HP based on your MAF", and then I remembered what thread I was reading.
What do your AFRs look like?

You could always add an additional injector of your fuel choice (methanol perhaps? Although I doubt you need it) to just after the filter, sort of a "throttle body injection" type setup, you know, if you had a throttle there. Trigger it to come on only above 4,000 RPM or something, otherwise airflow wouldn't be high enough to sustain turbulence/atomization. Even though you don't have the throttle plate located there, it should still work.
What fuel pressure are you running? You could try bumping that up a little bit too just to squeak by.

AFR's are in the 13s until 4500 then I pulled it down to the mid 12s. Conservative is the name of the game. I am still also reletively light on timing in the top end. Once it gets a big boy tune, I fear the injectors will be too small.

Meth is out of the question, only water can be injected into the intake tract save for normal fuel. The ITBs do have ports for top feel injectors, but they are before the silicone couplers, so I would be worried about melting them.

I have thought about a Nismo FPR so I can bump the pressure, but we will see. I tweaked my duty cycle warning light to trigger at 95%. If I see it come on again, then I will have to back off, but I figure I'll be alright.

Pretty impressive that you're maxing them out on an N/A setup.
I was hitting 93% at 6200 RPM with my 370ccs, that convinced me to switch to a bigger size.

Smurf, how do you calculate rough HP with MAF readings? Do you put in the MAF size + the voltage reading to get a rough estimate?

What did you switch to? I never thought the 565s would be too small, so I haven't looked at much else.

Sure we can do that, but I pick the location. Hmm, where is E85 not available?..

If I am towing the car, then nowhere lol. Too bad you will win the driveability challenge. For some reason giant throttle bodies, and tons of compression do not lend themselves to streetability. The step from no throttle to part throttle is huge.

Pure-awesome.

Are you controlling it with megasquirt? Or somethin' more fancy-like?

Link G2 full standalone.

Tell Chris not to soil the seat this weekend...

He will probably read that before the weekend lol.

I almost had an accident while testing. Transitioning from a very fast left into a tight right, I went for the binders, and got a pedal like a brick wall. It's been a long time since I've clenched that hard lol.

In other news I took her into work today to redo the alignment. Driving it on the street felt weird. It pulls more like a stock SR20 then a KA.

[Razi]

Pretty impressive that you're maxing them out on an N/A setup.
I was hitting 93% at 6200 RPM with my 370ccs, that convinced me to switch to a bigger size.

Smurf, how do you calculate rough HP with MAF readings? Do you put in the MAF size + the voltage reading to get a rough estimate?

What did you switch to? I never thought the 565s would be too small, so I haven't looked at much else.

Nismo 740cc.

Some trucks have vacuum pumps right? I think diesel trucks come with them.
I guess you could ghetto rig one to the booster if you're in a bind.

[FlatBlackIan]

"The time has come," the Driver said,
"To talk of many things:
Of brakes--and arms--and CV axles--
Of scratches--and dings--
And why the body is so dented--
And whether the engine sings."

"New suspension," the Walrus said,
"Is what we chiefly need:
Hoods and bumpers besides
Are very good indeed--
Now if you're ready, Navi dear,
We can begin to speed."

And so begins my final post in this build thread. It is with a heavy heart that I write this. This build is, for all intents and purposes, over.

Due to a miscalculation on my part, the rally 240SX left the stage road of Special Stage 2 of the Ojibwe Forest Rally while traveling at a high rate of speed. We contacted a tree with the right rear corner of the car, then spun into the woods hitting more tree's with the front of the car. We attempted to continue racing, but were forced to withdraw when damage done to the drivetrain, braking, and suspension systems made the car unsafe to drive.

The co-driver and I did not sustain any serious injuries, but the car is heavily damaged.

This is my first DNF, and the first major damage done to the car. So this it seems is the logical closure point of the build thread. In a few days, I will begin to repair the car. It will no longer be a build, but a re-build. So, I believe a new thread is in order.

I will end things with a picture of how she looked before that fateful day.

You can find pictures of the carnage and the rebuild thread here: Rising from the ashes. The rally 240SX rebuild thread



Thank you to everyone who has followed us over the past 3 years, and I hope you continue to follow as we move onward and upward. I really enjoy all the feedback.

[NismoZRS]

Hey, i have a question for you.. What did you do to have idle air?? i'm in the middle of building itb's and i haven't found a good way to create idle air yet..

Edit: I'm also not going the route of map sensor or megasquirt.. I'm building an airbox plenum that in inducted from a MAF and filter intake.. and tuned with SAFC 2

[FlatBlackIan]

Hey, i have a question for you.. What did you do to have idle air?? i'm in the middle of building itb's and i haven't found a good way to create idle air yet..

Edit: I'm also not going the route of map sensor or megasquirt.. I'm building an airbox plenum that in inducted from a MAF and filter intake.. and tuned with SAFC 2

Nothing, just adjusted the throttle stop screw. Its really really cranky when cold, and someone has to sit in the car for a minute or two to keep it running. This isn't really an issue though, because its not a daily driver.

If you are maintaining a factory ecu, I would take the OE IACV off the intake plenum and add a flange to it, then Tee it into each runner seperately.

The Hyabusa ITBs come with a throttle up cable, that will bump the throttle up a little for warm up. I thouht about extending that into the cabin, but never followed through on it.