Tweaks Re-build thread

[Advancedynamix]

I need to come out and get one or two of those clean bodies.

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I will help as much as I can if your serious.

[gergorian]

EFI systems(Italy) Euro4. Much better system than the M4.

How much do they run? I was thinking about going MS in the future because of the features and pricing.

[Advancedynamix]

The EFI Euro 4 is not really comparable to MS. I have chosen this system because of it's superior traction control features, as well as it's extremely effective auto-tune. This is the system used on many of the British Touring Car championship, World Touring Car, and s2000 world rally car front runners. It is also the system used by Lotus, and Lamborghini on their purpose built track cars. I have been tuning EFI systems controllers for almost a decade with great results. They are one of the more pricey systems available, but offer OEM quality construction and reliability. I've had my Euro4 for about 4 years and have used it to control a 500hp m10 powered BMW E30.

[moz]

500hp m10 powered e30... Dreeeewwwl....

[gergorian]

The EFI Euro 4 is not really comparable to MS. I have chosen this system because of it's superior traction control features, as well as it's extremely effective auto-tune. This is the system used on many of the British Touring Car championship, World Touring Car, and s2000 world rally car front runners. It is also the system used by Lotus, and Lamborghini on their purpose built track cars. I have been tuning EFI systems controllers for almost a decade with great results. They are one of the more pricey systems available, but offer OEM quality construction and reliability. I've had my Euro4 for about 4 years and have used it to control a 500hp m10 powered BMW E30.

Ok. What about the Euro2? I looked at both and I really don't need some of the features of the 4. Also, I could not find any pricing whatsoever on either units but I assume the 4 is in the thousands of dollars range.

[defprun]

I guess if your comparing it with a Motec the price range is correct...maybe a Megasquirt PNP would be more suitable?

[bhearts]

Charlie. Would you have any more pictures of that front lower support. I know it's secret, but I'd like to copy it. I'm interested to see how you mounted your cross member to it. And what percent under drive was your alternator pulley

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[sketchman]

Gomez has nice pics of his and specs too.

[nitrofarm]

Gomez has nice pics of his and specs too.

X2 Gomez spelled it out in Black and White very nicely,no secrets.

[Icedawg]

Hey Charlie, I am joining this conversation late, sorry. To re-affirm, that is a beautifully clean engine and engine bay, and very interesting ideas on where the chassis twist comes from and how to strengthen it. I have debated that with friends who ice race these chassis many times, as to how best to improve the front suspension.
But I have a question, in the video you re-posted. There is a segment with the Miata following you where you go into a fast, wide sweeper, I think it might be the end of the front straight, but I could not tell for sure. The video shows at least 2, if not 3, sequences of the rear end starting to come out, you catching it, maybe getting a touch of understeer, then the rear comes out again to start the cycle a second, and maybe even a third time.
The same cycle happens to me ice racing in the fast sweepers, enter, apex, then understeer-oversteer-correct, oversteer-correct two or three times. It is not so pronounced in other chassis I have raced so I put it down to the short wheel base. But are there things you have done to the spring rates and shocks specifically to reduce this effect. At least, things you are willing to talk about?
With the ice racer, the suspension still needs to be soft, though stiffer than stock, as the rear stock spring rate is scary low when racing, it just bounces and oscillates way too much. (I put Festi fronts in the rear to stiffen it a bit) Anyhow, my point is, the actual rates are not going to be the same as yours, but the front to back ratio, or the corner weight ratios might be similar, to reduce the effect.
Of course, better driving is always indicated, but any chassis tips in this regard are very welcome.

[bhearts]

My next roadrace setup will have a tubular front end with trailing links and no front sway bar. I'd like to put 250 ft.lbs to the ground with an open diff.

so youre telling us that the limited slip differential is only needed in cars that have absurd chassis flex. in your theory, no lsd is needed if you can get both your tires to stay on the ground an equal amount?

[nitrofarm]

so youre telling us that the limited slip differential is only needed in cars that have absurd chassis flex. in your theory, no lsd is needed if you can get both your tires to stay on the ground an equal amount?

I think what he saying is he is hoping that he will be able to get enough traction with the contact patch he is running. LSD's really don't work well in high speed corners,you get bad over steer.But Charlie will fill us in in I'm sure.

[Advancedynamix]

Hey Charlie, I am joining this conversation late, sorry. To re-affirm, that is a beautifully clean engine and engine bay, and very interesting ideas on where the chassis twist comes from and how to strengthen it. I have debated that with friends who ice race these chassis many times, as to how best to improve the front suspension.
But I have a question, in the video you re-posted. There is a segment with the Miata following you where you go into a fast, wide sweeper, I think it might be the end of the front straight, but I could not tell for sure. The video shows at least 2, if not 3, sequences of the rear end starting to come out, you catching it, maybe getting a touch of understeer, then the rear comes out again to start the cycle a second, and maybe even a third time.
The same cycle happens to me ice racing in the fast sweepers, enter, apex, then understeer-oversteer-correct, oversteer-correct two or three times. It is not so pronounced in other chassis I have raced so I put it down to the short wheel base. But are there things you have done to the spring rates and shocks specifically to reduce this effect. At least, things you are willing to talk about?
With the ice racer, the suspension still needs to be soft, though stiffer than stock, as the rear stock spring rate is scary low when racing, it just bounces and oscillates way too much. (I put Festi fronts in the rear to stiffen it a bit) Anyhow, my point is, the actual rates are not going to be the same as yours, but the front to back ratio, or the corner weight ratios might be similar, to reduce the effect.
Of course, better driving is always indicated, but any chassis tips in this regard are very welcome.

Sorry, I missed this question. The multiple mid corner pivots are caused by throttle input and lift. To tune this, you shouldn't use spring rate, but instead the shock valving. That wide high speed carousel is tricky because I've got the valving set up to work well in the tighter sections of the track so I've got to dance it a little on the high speed stuff. It blows my mind how easy this car is to control on the edge. I bet they are a lot of fun on the ice tracks.

[Advancedynamix]

so youre telling us that the limited slip differential is only needed in cars that have absurd chassis flex. in your theory, no lsd is needed if you can get both your tires to stay on the ground an equal amount?

LSD is a good way to cover up improperly set up chassis. I prefer to set up a car with an open diff, until it's perfect, then add an LSD if I feel it's beneficial. Sometimes it isn't. With 180hp, the Festiva doesn't gain anything from an LSD on a road coarse if it's set up well. I believe an LSD would have actually hurt my lap times in this car. I often intentionally spin the inside tire to get the car into the power before settling the chassis ( similar to slipping the clutch on a motocross bike). Additionally, like Nitrofarm said, certain limited slip differentials become a hindrance in corners.

Also, a side note. Not all chassis flex is bad. In fact, most chassis flex helps a car to maintain traction. Bad chassis flex is the kind that points the wheels in the wrong direction or destroys the car. The Festiva has just the right amount of good flex.

[Damkid]

To add my little bit of experience towards LSD in a festiva, my festiva sucks under WOT around a corner and was easier to handle with the open diff, however my straight line traction was improved with the LSD