Mythbuster: continuing project thread of my 1303 '75

[Steve C]

Hi Wally

Thanks for that I will get one now, I think a fixed mount so that the correct aiming can be setup would make for repeatable results.

Steve

[Sandeep]

Nice tour of the 'ring' Walter !

What size of injectors are you now using ? How is the duty cycle ?
I have 600cc/ min injectors currently but am looking to upgrade to 850cc units. Are you using low or high impedence injectors with the s60 pro. ?

Thanks

Sandeep

[Wally]

Originally Posted by Sandeep

What size of injectors are you now using ? How is the duty cycle ?
I have 600cc/ min injectors currently but am looking to upgrade to 850cc units. Are you using low or high impedence injectors with the s60 pro. ?

Thanks
Sandeep

I was using 660cc Siemens, but was seeing 96% IDC when experimenting with a little over 16 psi and 6,5K rpm... and I already bumped the fuel press to 4 bar before that..
So I got myself a set of ID1000's. They are Bosch but made for Injector Dynamics. VERY good injector. Highly recommendable if you get past 660cc as they made the car start even sooner and have great idle also.

Just get these, trust me, you won't be diappointed and they don't cost more than lesser injectors (=pretty much everything else's injector, but thats just my limited experienced take on it).

Always high impedance of course

[Xellex]

Wally, I was wondering, what car is your tacho from? Now that I have a 911 tach in front of me, I realised yours looks more like a 911 unit than 914. I also found this website about the 914 tachometers, and yours doesnt seem to fit in that description:
http://www.p914.com/p914_gauges_tachs.htm
I'm curious if I could fit the 6cylinder tach on the 4cylinder engine (and make it show the real RPM).

[Wally]

Originally Posted by Xellex

Wally, I was wondering, what car is your tacho from? Now that I have a 911 tach in front of me, I realised yours looks more like a 911 unit than 914. I also found this website about the 914 tachometers, and yours doesnt seem to fit in that description:
http://www.p914.com/p914_gauges_tachs.htm
I'm curious if I could fit the 6cylinder tach on the 4cylinder engine (and make it show the real RPM).

Good eye mate!
Its indeed a 911 6-cyl tach that has been converted to 4-cyl. The car doesn't get its name from nowhere you know "You cannot use a 6-cyl. tach" Hehe, yes you can

[Xellex]

So, how did you do it? I'd like to be able to use the 911 tachometer also.

[Wally]

Originally Posted by Xellex

Excellent! Like it a LOT

So, how did you do it? I'd like to be able to use the 911 tachometer also.

It was handles by a specialised shop locally. I am not that handy with electronics
There is a gauge specialist in germany also (Peter Fett, Fett-electroniks.de or s/th) that surely can do it.

Last week I started something I am thinking about for a long time. So, just did it and went to fabricate a rough shape out of cardboard and when it was somewhat ok-ish, made a better one out of 5.5mm plywood.

Its a 'splitter' and turned out like this (in primer now, will be painted black):



I have no idea if it will work as I think it could be, but only one way to find out huh?

[volkdent]

Great minds!!! I did mine out of ABS plastic, heavy but durable, that I would make a mold of and make from CF/Kevlar if I like it. I'm worried that in normal daily driving it is going to be too beat up.



The front leading lip is an extra I purchased years ago for my E36 M3. I think its funny that my bug is as wide as the almighty M3 now!

Jason

[chug_A_bug]

very nice wally
I have been thinking the same and even doing a whole underbody just to try to smooth out the air flow under the car..
just need the time and $$ to do something that big tho... lol
can't wait to see it done and on the car
Chris

[judgie]

when i put the splitter under the front of the race, same as you used 10mm ply board for mine and about the same shape.it made huge differance in high speed turn in. did have raise my static ride hight abit to allow for reduction in high speed ride hieght. with that and the f3 lola rear wing i run i was getting about 25mm lower ride hight above 75mph so it was doing somthing.

[Wally]

Thanks for the encouragements guys!

Originally Posted by judgie

when i put the splitter under the front of the race, same as you used 10mm ply board for mine and about the same shape.it made huge differance in high speed turn in. did have raise my static ride hight abit to allow for reduction in high speed ride hieght. with that and the f3 lola rear wing i run i was getting about 25mm lower ride hight above 75mph so it was doing somthing.

Thanks for sharing your experience Rob!
So, I guess it will probably do 'something' huh? 25mm lower ride height at 75mph
Lets see, I run around 130 mph at some parts of the track, so I better make some extra reinforcements... especially since its only 5,5mm thick, not 10mm
I just painted it black, now drying out

Oh, the carbon front disks finally seem to work ok, so I hope they stay like this.
Hopefully coming weekend I can make a pic of the tray under the car. I may you guys help on how the ends should look like as the ends are much wider than the Kamai.

[judgie]

the first mounts i made for it out of 5mm alloy broke after about 10 miles of use i had to seruiosly beef them up. in the end i ran 8mm alloy mounts from the front bumper mount down and then a 25x25x5 alloy angle running the full width at the front. I could stand on it in with the new mounts
first pic is what i had and the second is what i run now. I'm going to put a splitter on the new one as it worked so well on the old one.

[evilC]

Rob, if you're getting a 25mm compression @ 75mph that equates to 260lb of downforce at your spring rates! That's very impressive for a bug.

One suggestion though - put a couple of castors under the splitter to stop it bottoming out. lol.

Clive

[judgie]

it really suprised me how much it was going down. when i ran with no areo stuff on it to when i ran with the big rear wing and the front splitter, i didn't change anything on the suspension and i was getting rubbing on the front splitter and exhaust at speed. had to raise it up approx 25mm all round to stop it. the early pic's of the car at speed show the front lifting a lot, like 30/40mm which ment it wouldn't turn in at speed lol. with the big rear wing and splitter it made 6 seconds differance up prescott!
want to try a proper rear defuser as well for next year to try and clean up the rear air flow from around the engine gearbox. shoiuld be ok with this as i dont do any runs that are longer than 1.5 mile so the heat build up is not to bad. when i ran a rear defuser before on the road i noticed a marked increase in oil temps.

[Wally]

I got the plate painted black and made all the brackets for support, so trial-fit time. You can also see the alu profiles I used for added stifness of the plate.
Just need to think of something for the end pieces. Was thinking of an sloping upward piece for added downforce. Any ideas?
The ends will be connected to the bumper ends with a bar afterwards.