handling with a 20b in a fd...
02-23-05, 11:06 PM
#26
Originally Posted by FD3SR1
I was just wondering how well an fd handles with a 20b in it?
I think keeping the stock subframe and depending on your suspension set up, wheels, brakes, tire size and compound, you will have a car that can handle better than stock FD..
Also, depend on how you want to set up your car, weight could be about the same as stock fd.. maybe 50lb extra
02-25-05, 10:57 AM
#27
Originally Posted by herblenny
FD w/ 20B?.. well, depend on what you are comparing with.. stock fd to stock fd with 20B?? I mean, the question like this make me wonder what your idea of good handling car is?
I think keeping the stock subframe and depending on your suspension set up, wheels, brakes, tire size and compound, you will have a car that can handle better than stock FD..
Also, depend on how you want to set up your car, weight could be about the same as stock fd.. maybe 50lb extra
I think keeping the stock subframe and depending on your suspension set up, wheels, brakes, tire size and compound, you will have a car that can handle better than stock FD..
Also, depend on how you want to set up your car, weight could be about the same as stock fd.. maybe 50lb extra
I concur. My car now handles much better than a stock FD. This has everything to do, however, with my upgraded suspension/brakes/tire components, not the 20B swap.
The Pettit subframe does not cause understeer. Pettit modifies the front spindles to "reset" the car back to stock geometry. I've driven the car now enough to verify this. Cam from Pettit will also argue that the car now has better weight distribution (battery relocation, etc.) but I'm not sure of this. All I know is the car drives like a beast (can't match the torque band of a 3 rotor with a turbo swap in a 2 rotor) and is extremely "sticky" in the corners.
I also note that a 20B conversion is much more intensive than a turbo swap and, if someone else does it for you, expect $35K+. I'm sure you can get it done for less but I'd double ensure that however is doing the conversion knows what the hell they're doing. For more info on this, check out my posting on the Pettit 20B conversion. I took my car to Pettit last summer to begin the conversion and I'm just now wrapping it up.
02-25-05, 01:06 PM
#29
The 20b swap is def. not a easy swap by any means. I am 1 year and about at least $18,000 in to mine and still need about $10k-$15k to finish it, haha.
Ok, back to your question, I haven't driven mine yet, because its still not done. The way I'm installing mine is by using a pettit style subframe and a bumpsteer correction kit (both made by a forum member) I think by lowering engine bay weight (relocating battery, getting rid of the stock twins and upgrading with a lighter single turbo, etc) that it should handle close to stock. The 3 rotor engine is a lot heavier than I thought it would be. I was able to drag the 2 rotor by myself, and lift it with another person, but the 3 rotor is nearly impossible to drag by myself and I couldn't lift it with another person. Sorry if I wasn't much help.
Ok, back to your question, I haven't driven mine yet, because its still not done. The way I'm installing mine is by using a pettit style subframe and a bumpsteer correction kit (both made by a forum member) I think by lowering engine bay weight (relocating battery, getting rid of the stock twins and upgrading with a lighter single turbo, etc) that it should handle close to stock. The 3 rotor engine is a lot heavier than I thought it would be. I was able to drag the 2 rotor by myself, and lift it with another person, but the 3 rotor is nearly impossible to drag by myself and I couldn't lift it with another person. Sorry if I wasn't much help.
02-25-05, 03:00 PM
#31
From my earlier post (only like 10 posts ago!) in this thread:
The VERY FIRST post in that thread says the following:
Originally Posted by FDNewbie
Regarding weight distribution, I found this thread to be most helpful: https://www.rx7club.com/20b-forum-95/just-scaled-20b-fd-265222/
Originally Posted by howard coleman
a friend, Dick Lambert, recently acquired a nicely built 1995 fd 3 rotor and i am in the initial stages of taking a good look at it from an engineering perspective.
my background is 22 seasons of SCCA Nat roadracing, the last 6 in a tube frame mazda rx3. i am a suspension guy, i own a shock dyno and a high tech spring rater as well as a bunch of cool laser based alignment tools... (after having plotted the entire fd geometry i can tell you why the fd drives like a racecar... it is because it has a true racecar suspension complete w negative camber gain etc.)
i was concerned, firstly, w how much front weight the 20b added... so onto my scales it went. i was positively impressed.
dick's '95 3 rotor weighed 2694 with no gasoline on board. dick has another 95 fd w an rx6 single turbo w very light wheels, exhaust etc. i weighed it at the same time and it weighed in at 2517 with no gasoline.
the 3 rotor frontweight was 1395 versus the 2 rotor at 1285. both cars unfortunately still retain the xxxxx power steering and a/c so you could remove at least another 60 pounds of nose weight. (the 3 rotor did benefit from the battery relocated to the right place whereas the 2 rotor had a smaller battery in the stock location.)
considering the major improvement in torque and hp w the 3 rotor i was very impressed w the modest increase in front weight. if it was my car the power steering and a/c would be gone leaving just 1335 (51%) on the front tires.
i drove the car briefly and being in Door County (just north of Green Bay Wis) and dealing w 35 degrees ambient w a poorly tuned temperature-corrected Haltech E11 and not having time to do some tuning... boost cut etc... i was initially impressed w my reading of the handling and front end geometry. the car has either a Pettit subframe or something similar w a relocated steering rack and lengthened steering arms. in the next few weeks i am going to do a bump steer evaluation to see what the real story is re the steering relocation and will report back.
my background is 22 seasons of SCCA Nat roadracing, the last 6 in a tube frame mazda rx3. i am a suspension guy, i own a shock dyno and a high tech spring rater as well as a bunch of cool laser based alignment tools... (after having plotted the entire fd geometry i can tell you why the fd drives like a racecar... it is because it has a true racecar suspension complete w negative camber gain etc.)
i was concerned, firstly, w how much front weight the 20b added... so onto my scales it went. i was positively impressed.
dick's '95 3 rotor weighed 2694 with no gasoline on board. dick has another 95 fd w an rx6 single turbo w very light wheels, exhaust etc. i weighed it at the same time and it weighed in at 2517 with no gasoline.
the 3 rotor frontweight was 1395 versus the 2 rotor at 1285. both cars unfortunately still retain the xxxxx power steering and a/c so you could remove at least another 60 pounds of nose weight. (the 3 rotor did benefit from the battery relocated to the right place whereas the 2 rotor had a smaller battery in the stock location.)
considering the major improvement in torque and hp w the 3 rotor i was very impressed w the modest increase in front weight. if it was my car the power steering and a/c would be gone leaving just 1335 (51%) on the front tires.
i drove the car briefly and being in Door County (just north of Green Bay Wis) and dealing w 35 degrees ambient w a poorly tuned temperature-corrected Haltech E11 and not having time to do some tuning... boost cut etc... i was initially impressed w my reading of the handling and front end geometry. the car has either a Pettit subframe or something similar w a relocated steering rack and lengthened steering arms. in the next few weeks i am going to do a bump steer evaluation to see what the real story is re the steering relocation and will report back.
Last edited by FDNewbie; 02-25-05 at 03:02 PM.
02-25-05, 03:24 PM
#32
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The last time I had my 13B FD corner weighed it actually had more weight over the rear than it did the front. With proper placement of ancilliaries, suspension setup specifically for the 20B, etc...you should be just fine.
02-25-05, 04:13 PM
#35
Yea I was sure you saw that thread because you posted in it 
And it's only 110 lbs more, and that's for the long block. That ain't bad at all. As Howard showed, getting rid of power steering and the AC removes about 60lbs, then relocate the battery to the trunk, and you're practically there. Throw in a sub and two amps w/ custom enclosures in the hatch, and you're pretty much set 
A roll bar that goes down into the hatch floor will help as well.
And it's only 110 lbs more, and that's for the long block. That ain't bad at all. As Howard showed, getting rid of power steering and the AC removes about 60lbs, then relocate the battery to the trunk, and you're practically there. Throw in a sub and two amps w/ custom enclosures in the hatch, and you're pretty much set A roll bar that goes down into the hatch floor will help as well.
Last edited by FDNewbie; 02-25-05 at 04:15 PM.
02-25-05, 06:10 PM
#36
Originally Posted by FDNewbie
David, last summer?? Has it really been that long?! Wow...time flies.
