habu2

Have you looked at an LS1 FD? Have you looked at an LS1 engine?

The weight is lower in the engine bay with an LS1. Aluminum heads and composite intake on top, and the steel crankshaft/flywheel/clutch (the majority of the weight of an LSx) is lower than the rotary centerline. The engine does go over the rack but it also goes back to the firewall. The weight (and height of that weight) of the transmissions is different as well. The swapped cars corner balance out the same as a non-swapped rotary, and the overall CG of the car is actually lower with an LSx/T56 than with the stock rotary setup.

I don't want to turn this into an LS bashing thread, but you are wrong on the points you mentioned. This variable has no influence on the choice or performance of coilovers or spring rates.

t-von

iTrader: (8)

Corner weighing will tell you nothing about how HIGH the weight is in the chassis. Higher weight will make the chassis lean more in turns than necessary because your center of gravity is also higher. Also corner weighing wont tell you how quickly a vehicle will respond to change of direction.

Here's an experiment. Take a go cart and add weights to make it perfectly balanced 50/50 front and rear. Then add about 50lbs of weight at the very front and 50 more lbs at the very rear. We still got perfect corner balancing right? Now go out and start doing some quick transition turns left and right and tell me how responsive the cart has become. Your not gonna like it because the response will be worse. OMG the cart should still handle great right because we still have the 50/50 balance! Not necessarily because the 50/50 argument is only half the storey. To regain the steering response, you would have to move that weight closer to the center of the car's rotating center line. This is the exact reason Mazda has always engineered the Rx7/Rx8 chassis to keep the engines as low and as far back as possible. Unless your hacking the firewall and doing V8 swaps that place the engine as low and as far back as the rotary, your response to steering inputs will NOT be the same. Scientifically speaking it can't if the engine is higher and further forward. I know that everyone I've seen sits over the factory rack and not behind it. On my own 20b swap I took the long road and moved it back because I refuse to do anything that will effect my vehicles center of gravity and handling response as I chose to keep with Mazda's design and engineering philosophy. My rear rotor housing section sits under the firewall and so low that I will have to make a new oil pan to keep it from sitting the ground. So I can honestly say my chassis configuration is actually better than stock.

Like I said earlier with the V8 swap, the difference isn't noticeable enough to cause a huge debate about it on this thread because most that do the swap only care about reliable hi hp and not handling.

t-von

iTrader: (8)

I understand that most of the weights are in the bottom end of these engine however, you still have considerable amount of weight forward over the rack. You take the total length of a LS1 tranny combo vs a 13brew combo, more weight will sit forward of the center line with the v8 combo unless you seriously hack the fire wall to move everything back behind the rack. I've seen numerious V8 swaps and hacking the firwall isn't something they are doing.

Brent Dalton

iTrader: (31)

I'm familiar with vehicle dynamics. I tell you what, I'm moving to TX in April. Why don't you bring your perfect supsension 20b FD out to the road course of your choice and I'll bring my V8 FD(only 330rwhp) out and we'll see who has a better handling car? You want to keep talking theory and what you read in a book or are you ready for a practical application?

Brent Dalton

iTrader: (31)

Yeah... tons of weight... *sarcasm*

t-von

iTrader: (8)

My perfect suspension??? I thought we were discussing engine placement? Nevermind because this thread is going too far off topic. Dude your getting all but hurt over this. Handling numbers and handling feel are two totally different things. Look at the Rx8 for example. Numbers wise it's numbers are poor when compared to the Fd however, from behind the wheel the handling feel is far superior because that chassis configuration / engine placement is far superior to the Fd's. Stock for stock the Rx8 handles better than the Fd but the numbers don't show it. It only lacks in power. Like I said for the 3RD TIME:


That engine does sit nice and low however it does still sit forward due to length. That's not theory that's a fact. If you didn't hack the firewall, YOU have more weight further away from the center line so even if your engine weighed exactly the same as the 13b it's still further forward. It doesn't take rocket science to break out the ruler. Even if your engine was scraping the ground, you would still have more weight away from the center line.


I'm done with this discussion!

Josh18_2k

iTrader: (3)

ever notice how far an M3 engine sits over the front axle? ever notice they happen to still kick ***, despite ancient suspension?
maybe all this engine placement business is peanuts in the grand scheme of vehicle setup?

Bob Tunnell's E36 took 2nd this year in EM at scca solo nationals with a supercharged cast iron inline 6, half of which is in front of the axle. thats all kinds of weight in the wrong place. EM is the fastest door slammer class, for those that arent into parking lot racing lol.

GodSquadMandrake

This is getting way off topic. Please don't get the thread locked or deleted. I'm actually looking to buy the Pettit Trak Pro coilovers so I'm interested in the discussion regarding the suspension.

There are entire websites to debate the V8 vs Rotary thing so please don't waste your time here. People have been debating this for 20 years now.

ALPSTA

iTrader: (3)

Doug I thought you were getting Iasata N1 or are you calling both trak pro?

GodSquadMandrake

I was referring to the Iasati N1 as the Trak Pro Competition series just because this whole thread started off with Pettit's line of products. I think we have established already that they are identical products even if there is a difference in opinion on where to buy them. But as long as we're talking about the same stuff.

ALPSTA

iTrader: (3)

Ok np, got it now.

Rice Hata

iTrader: (24)

The Stage IIs work very well on my LS1 swapped FD. I mostly drive on the street and will finally take the car to the track next year to see what it can do. I've never driven a stock FD, but on the softest setting, my car would lean too much in the turns and was not to my liking. I keep the settings in the middle for all 4 corners, but need more time to test out whether I should go slightly stiffer in the front or rear. Overall, the Pettits are a great coilover at a fair price.

t-von

iTrader: (8)

Exactly!

t-von

iTrader: (8)

Damn you were almost the one. I'm waiting for someone who had stock suspension and then purchased the Pettit's to see actually the difference. Right now my suspension is 100% stock. The ride with coilovers really scared me ever since I road in my buddy's 93 Fd w/Tein SS coil over set-up. I could not stand the ride quality. Now I don't know if those are adjustable for not? Too me it felt like the car was riding on the frame.

Brent Dalton

iTrader: (31)

Not butt hurt at all. I do get annoyed with people spouting ridiculous nonsense based off something they have no experience with. I'm sure you are a smart guy and have done great things with your 20b. Doesn't mean you know anything about LS1 swaps or suspension other than what you have read.

So I'll take that as a no for my call out to you. Continue to virtually test your suspension and I'll continue to really test mine. I held my own at Road Atlanta today. BTW, funny you bring up the RX-8... I had one on the skid pad today. The guys I hang out with are the GA RX-8 club and have been out on track in an RX-8 many of times. While the handling is similar, I don't think it holds a candle to the FD. You read it on the internet though and rode in one on the street so it must be true.

On topic, Cam Sr. doesn't do forums. I saw these coilovers on his car at Road Atlanta in August when he was working on developing them and I'm sure he will stand behind his product just like he always has.

Rice Hata

iTrader: (24)

I went in the opposite direction from Stock, as I bought the car with 16kg f/r Tein Circuit Master coilovers already installed. With 235/265 Nitto 555s (crappy tire) on 18" wheels, the car was better suited for drifting than holding the road. Those coilovers require big slicks and heavy aero to keep the car planted, however, that wasn't the direction I was heading.

I've been gradually getting the car set up properly for street/track-- 18x10" on all 4 corners with 285s and the Pettit Stage II coilovers. I did my research before buying and even spoke to Cam, which made up my mind. Even though he's busy, he'll take time out to give you his insight.

Aftermarket parts can be a crap shoot unless you can test them out on your car beforehand. Being that our cars are over 15 years old, each one has different wear/mods/alignment, etc. so there is no 1 size fits all answer to the right coilover for each person/car's needs. I say do your research (online and behind the wheel of a comparable car if possible) and choose the product that you feel most comfortable with. We sometimes spend more time arguing than driving and enjoying our cars, which is the most important thing.

ArmenMAxx

iTrader: (21)

the million dollar question for me:

For someone who already has koni's, is the price difference of buying track pro stage 3 vs Ground controls worth it?

t-von

iTrader: (8)

I'm not gonna waste my time to set up a useless challenge to compare my car with yours. That's an apples to oranges challenge because of the differences is suspension set-up and drive train mods. I know for a fact that any vehicle that does not properly have it's suspension set-up, can handle very poorly when compared to the exact same car that has a suspension turned by an expert. The only way to properly test the two would be to do the engine swap and NOT change any of the suspension to compensate for the changes in weight distribution and see which vehicle handles better. You willing to do that and your on. I'm not dumb as I know that when weights are being moved around a vehicles chassis, proper suspension tuning can compensate for those changes but only to a point. Bottom line is a perfectly balanced chassis foundation gives you the best possible chance of having a vehicle that performs at it's best under all conditions. Then again, an out of balance chassis can't always be saved my perfect suspension tuning because you can't always over come weight transfer/ineria.

Now as far as the Rx8. The street is the REAL world and a place that 98% of Rx7 owners drive their cars my friend, maybe you should try it sometime. I don't need to drive at the limits of adhesion to know that I actually enjoyed driving that rx8 more than my stock Fd. Aside from the lack of power, I couldn't believe that I enjoyed it that much.

GodSquadMandrake

Good point Rice Hata.


At this point what you are comparing is the quality of the shocks.

<track>7

iTrader: (2)

Now back to the original Topic of this thread.

Spent a COLD day yesterday at MSR Cresson flogging my mule. Had to increase tire pressure 5lb per corner just to get enough heat in the tires to work at all. Coilovers performed flawlessly as they did the 3 events before this one.

When you guys trying to save a few dollars need some help just ask yourself who you'll call. I've called Cam 3 times about setup and general FD questions and he answered everytime. His answers were spot on btw.

Howard Coleman

iTrader: (6)

Cam called last night and we talked for close to a couple of hours. it is always a pleasure and i never fail to pick something up from him.

he had just run another track event.

the FD is AMAZING!

on a 2.03 mile track he was two tenths off a full built turbo'd 911 variant and second fastest in the field. both cars on the same tires. and Cam is running the factory turbos!

that sort of underscores my experience at my Ferrrari Club of North America events at wide open Brainerd. i was on factory turbos and racegas and never beaten in 4 events.

which gets back to how amazing the FD is on a roadcourse.

he said he had a bit of a push and elected to re-attach the rear bar which helped a bit but didn't cure it. while he mentioned that others were encountering the same thing. my view is that it was probably the track temp.

his tires were at 180 and were in the lower half of the suggested operating temp band. cold tracks push. lower air pressure and spring rates would have built a bit more air pressure and then you could do a bit of camber tuning.

one of the items that always separates the men from the boys is the mod sequence tree...

you have your FD. you want to do "X" w it. you have 100 potential options to elect mod-wise.

what do you do First, Last?

i see alot of stock stuff on Cam's car. and yet it seems to always be near first in class. and yet something jumps out at me...



you don't see many fuel cells in track FDs. you see lots of fancy stuff but few cells. you can't get on the track in a real race (SCCA for instance) without a fuel cell. sure there are the showroom stockers but we are talking about running 1:25s on a 2.5 mile track here. a properly setup FD is a fast car and can get into alot of trouble. have you ever seen what just one gallon of gas can do? granted the Time Attack format reduces the fender to fender stuff a bit but there is a reason the cell is in Cam's car.

here are a couple of Cam Nuggets:

Magnecore (10 MM) plug wires are close to the ultimate. i run them on my FD. they are a semi bear to attach as they grip the plug so tightly. Cam uses a small tie wrap when he slips them over the coil output fitting. the tie wrap provides an air channel to bleed the air out so that when the coil warms the air doesn't expand and tend to push the wire away from the fitting.

crush washers on plugs.... Cam says he sees alot of FDs come in w un-crushed washers. un-crushed washers do not allow the plug to transfer heat away from the rotor housing resulting in warped ($700+) housings. of course we all knew this, right?

aside from the fact that Cam and i go back to the 80s when we raced at the Road Atlanta Runoffs for Mazda and Cam is a great guy, it is always fun to shoot the breeze w him as i always end up learning something.

howard

Brent Dalton

iTrader: (31)

Howard, great information as always. However, I'm pretty sure you are not required to run a fuel cell in SCCA or NASA racing in the majority of classes(none that I know of at a grassroots level... could be wrong, but I have friends that run several different classes and most don't have cells). Of course, classes like the muscle milk trans am series require them, but that is by no means a grass roots level series. I agree that a fuel cell is a must(as well as the other safety items) as I have one in my FD.

Time Trials aren't any different than a qualifying session for a club race. This last weekend at Road Atlanta for example, 60 cars on track at the same time trying to get clean track for a fast lap. Prime example from this weekend:
http://vimeo.com/17505640

Brent Dalton

iTrader: (31)

Howard, what 2.5 mile track are you referencing btw? 1:25's are smoking at any of the 2.5 milers I know of in the area. That'd have to be a really fast track.

t-von

iTrader: (8)

That couldn't be more true. Customer service is very important. I'm actually getting ready to bite the bullet on the stage 2's in the next month or so. Cam WILL be getting my money on these. This will give me time to upgrade my differential as it's currently going out.

Howard Coleman

iTrader: (6)

"Howard, what 2.5 mile track are you referencing btw? 1:25's are smoking at any of the 2.5 milers I know of in the area. That'd have to be a really fast track."

Hey Brent,

really enjoyed your VIR videos... thanks for sharing. i believe Cam said he was at Palm Beach which is 2.03 miles. i may have mis-heard Cam re the length.

http://www.racepbir.com/road.html