Engineering the TOY

[Toy77]

G'day all,

thought i'd put up some problems, solutions and testing i did whilst engineering my celica with 1ggte.

I had already engineered the engine (stock), gearbox, brakes (corona/pug).

i have now added the volvo diff, aftermarket seats, 17in volks, a sidepipe exhaust system, a fuel system (surgecan,filter and 2 pump) where the muffler normally sits on a 28, exposed front mount cooler, battery where the back seat was.

to get the seats where i wanted them required the cutting of the floor (the raised rail the seat bolts to). so the engineer was contacted to check legalities of what he would require to pass this. He said it was fine as long as metal was welded back in to keep rigidity.

The side pipe stays on drivers side of car, never crossing the centre of the car. it has seperate wastegate pipe down past gear box, where both pipes are flanged for romoval. the pipes then join just before cat, then a speedway muffler (3inch thick muffler, allowingmuffler under centre of floor), then out the side in front of rear wheel. The engineer was contacted before this was done too, saying the pipe had to exit behind the last passenger door and behind last opening window - the rear 28 window is fixed so this is ok.

the rest off the mods were pretty straight forward.... so off i go to engineer.

SURPRISE - the car failed....... the major things passed, seats, diff, wheels (17x7 and 17x8) and the exhaust location.

Failed -

1. he wanted a shield around the fuel system, as it is exposed to the rear wheel (this was on the plans anyway so no biggie)

2. the battery in the back was secured with a strap, although it was secured inside the box, he wanted a mechanical system anyway (a bit of a pain due to chassis rail and suspesion box being below the battery - but got one in anyway)

3. i had wheel spacers under back rims, cos i like the look, but they fit without no dramas, so this was easy fix.

now the 2 big problems

4. The exhaust was too low, the tip was close 95mm (legal is 100mm) but the muffler was bout 85mm.

5. The exhaust was too loud! i read 102.5 dB (legal for my car being 96) so i was way over, which was a surprise because it wasn't that loud.



Well the height i thought i could fix - i jacked the exhaust till it touched the floor of car, then wired the mounts there. this got muffler to 95mm, tip was well over.
i pumped the tyres up too 50psi.... this gave me 98mm. though the engineer noticed it was not quite 100mm he let it through, saved me changing to stock springs.

The noise was a different problem. the exhaust pic show the location of the flange. i decided to make a plate to place between the flange that would restrict the flow.

i borrowed a calibrated noise meter from work.
before i started i did a noise test at home as it was.
the testing positon for noise is - 45 dgree angle from exhaust flow, 550mm away, 150mm above ground.

Before - the noise meter gave following reading with no changes

Idle - 90 dB
3000rpm - 100 dB
3800rpm (where engineer wanted to test) - 106 dB

no i believe this is higher than when engineer tested it simply due to location-proximity of my house, trees etc.

The Cross sectiona area of a 3in pipe is approx 44 square cm.
the first restrictor plate i made (plate1 in the pics) has 11 10mm holes in it - a cross sectional area of around 8 square cm. I though this may be too restrictive not allowing the car to rev, but it was somewhere to start.....

Testing plate 1 -
idle - 95 dB
3000rpm - 102 dB
3800rpm - 105 dB

this was quite dissapointing. i tried a few other things now, including jamming this plate up end of pipe (in case it was a muffler resonance prob, not flow), taping a rag over pipe etc...... none had any decent effect... so i went back to original plan and made a new plate.

plate 2(plate2 in pics) has 11 6mm holes (i havent worked out area.... but is stuff all)
results-
idle- 90dB
3000rpm - 94dB
3800rpm - 96 dB

the car is that restricted that it doesnt make boost now (1-2psi)

but it did pass engineering - tested by him at 93dB he did coment that the harder i reved it, the quieter it was getting, being loudest at 1500rpm, once spiking to 98dB but the test is done at 2/3 of max horsepower rpm so he ignored that.


Sorry for the long post, but thought someone may find it interesting

Cheers
Stew

[ra_28]

I hope the plates are comming back out.

And that really pisses me off because I got done by the police for for my exhaust not exiting the rear of the car i was also under the impression that the exhaust had to end only passed the rear most opening door, because my ended about where yours was. So the police calasifed the boot as an opening door if it was a ra23 I would have no troble because the boot is not part of the interior but because the boot had no partition I had no leg to stand on.

Alex

[Toy77]

the law states it has to exit behind last opening PASSENGER door. but yeah coppers are crap like that at times, some are good though, i was let off the other night.
i did remove the lock from the boot, so no opening door....

there is a year limit on side pipes, drivers and passenger side up until 88 i think, but passenger side is legal up till current models i think.

was your exhaust engineered?

edit - i just noticed you are in qld, possibly different rules. and yeah plates are coming out today..... hehe


Cheers
Stew

[CrUZida]

Did you put that plate right at the bottom of the dump pipe?

Did you try putting it just before the muffler?

[ra_28]

No the exhaust was no engineered but the dept of transport states that the exhaust has to end 29 inches past the rear most opening door. That how I understood it anyways.

[Toy77]

heya,

unfortunately my camra is broken, and my phone doesnt want to photogragh under the car for some reason....

the plate was about 8in infront of the cat. the cat is welded to the muffler....

i know its not the best for flow, but space constraints under the celica dictate the terms.
plus i have a race system with no mufflers or cats and a screamer pipe....

as for distance for side pipe, nsw used to state 30cm behind last opening passenger door, but this has been changed. to simply, behind the door...

Cheers
Stew

[hypo23]

just a little side note on on the engineering of the seats, any one wanting to buy aftermarket buckets, and have them mounted to the actual floor of the car, dont bother, get the standard seats reabolsted and trimmed


in all seriousness mate its good too see that it is REALLY fully engineered

[Dom-AE71]

just a little side note on on the engineering of the seats, any one wanting to buy aftermarket buckets, and have them mounted to the actual floor of the car, dont bother, get the standard seats reabolsted and trimmed

can you please explain what you mean here? are you talking about welding the seats to the car so they are non removable?

becasue AFAIK your allowed to make custom rails and mount them so you can remove them ect so long as the welding is safe and strong, unless the rules have changed?

[Toy77]

yeah dom, what you are saying is correct....

Steve (hypo23) helped me fit the seats, actually, he did most the work, all the welding.
there was alot of hassle and mucking around to get em right.
but he did an awesome job, they came up perfect..... but took us a month.....
mind you beer and lack of motovation stretched the timeframe....

Cheeers
Stew