my stock bushings...well lets just say they are 15years old

Delrin is harder than polyurethane so it controls the slop better.
Therefore it increases the noise, vibration, and harshness ...won’t deform overt time, soften when overexposed to the heat or bind when unload...Delrin is self-lubricating

More important for the street, delrin rebounds from impacts whereas poly tends to "dent"

polyurethane bushings also squeak and need to be lubed (pain in you know what) and deteriorates rather quickly

Delrin offers the performance of solid aluminum bushings without the harshness

i all ready decided i wanna go with delrin for the differential mounts
and i am thinking stock replacement mount for the engine

what should i do for the rest of the car go all delrin
or get some stock replacement bushings or is there any other options

track/street
still wanna be able to drive in street ,so firmer than stock, but nothing unbearable ,,tires 17 255 40 all around

 

From what I have read you should consider Derlin to be solid mounted. They will have like 0 give compared to any form of rubber mounts, oem, harder than oem rubber, or poly.

 

Stay away from delrin for the suspension. They clunk and become sloppy when they heat up. There are a bunch of posts on this if you search.

 

+1

 

I wouldn't run Delrin suspension bushings on an FD under any condition. Poly busings are far more common in the automotive world and for good reason.

 

I searched, can't find what you are talking about. Got any links?

 

Ok, that sounds just like vague marketing speak.

"Any condition"? Really, do you have some test results for all conditions that any FD may be used in?

"Poly bushings are far more common in the automotive world and for good reason"

How about some explanation rather than just 'good reason'?

What are some of the 'good reasons'?

 

really?

https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin
https://www.rx7club.com/showthread.p...ghlight=delrin

 

Delrin, from what I know. is also known to swell from moisture. Played paintball for a while and Delrin was pretty popular for misc. parts. IMO, its suspension- which means it should have some give to it. I just put in pettits bushings on my dif and they are great,

 

Yes, really.

The only thing I saw in those threads regarding the adverse affect of heat on Delrin was this:

Contrary to people saying the bushings made the steering and handling tighter, I found out that it was the opposite as the car heats up, in hot weather or if you're pounding on it. The steering got looser and less predictable and the noise, lord the noise, turn the steering wheel and your car groans as if you're on a sailing slave ship tacking into heavy winds.

Not terribly objective in regards to the heat. There are many things that can cause the car to become looser as it heats up, and there's nothing to show that the bushings were at fault.

When I searched, I was using more than just 'Delrin'.

 

Why is this not considered objective? Just because he isnt reporting back that they are great doesnt mean he is not being objective. I would also assume he would take the other potential variables into consideration. I am sure the author has driven his fd with and without these bushings so he would be used to how the car felt and would be able to narrow down the culprit rather easy.

 

I am not going to make assumptions.

If it is necessary to make assumptions about what the author may or may not have intended, the report is not objective.

 

i wouldnt use delrin on the suspension.. i just replaced all my suspension bushing with polyurethane ones and i couldnt be any happier

 

Almost all of those were for the FC. The one that wasnt... I posted in as the only "complaint".

Ive had the delrin's in since almost when the group buy of them came out. (i.e.: I was one of the first to get a set and install them)

After over a year they finally started creaking and squeeking. I put zerk's fittings into them, and shot some lube into the lube grooves. Not another sound from them since. Poly bushings would have needed the same thing.

They aren't "self lubricating" (at least enough to not need additional lube added periodically) but I would hardly call them troublesome. My wife and myself drove the FD about 10 hours 1 way on vacation this summer. Its not like the delrin make the car unlivable or anything. It does add what amounts to NVH like having super wide tires on your car though. The radio on, or the windows down drowns it out rather easily.

IF I were to do it again... Id go with new OEM or MS Rubbers. However, its not worth it to me to redo them as there arent really any negatives that affect me.

I read something about if you are racing with R comp's the non-give throws the alignment off. I cant speak of that particular poster, though I can say I run 275 wide v710's on all 4 corners at autox and my alignment didnt move anything noticably in the 2 years in between alignments.

OP, depending on your budget and what deals you can and cant get - The delrin arent *bad* in my experience. Just make SURE you put zerks in them and arent buying into the "self lubing" thing. They WILL need lube added periodically. The car will feel much more responsive to steering inputs. This is great on an autox track, a bit un-nerving on a road course. (or maybe thats the autox alignment ) OEM and MS's are pretty expensive, so if you cant afford either or want something stronger I wouldnt be turned off by the delrins. Of course, I also wouldnt be turned off by the poly. (which are apparently hard to get now)

In the end its up to you. I dont think there is a "bad" choice out there. I think youd have a hard time going wrong replacing your bushings with anything newer than 15 years old

 

i know that polyurethane is more common...

i was planing to use Delrin for rear differential only...as i dont like to feel to much movment in dif...so i would say it would mostly transfer vibration and not affect the ride to much

now for the rest of the suspension after reading on the forums and the links posted on this page...i would say delrin would be lil to hardcore for me....and i might use polyurethane for the car

so i am really looking for other options full hardend rubber bushings any one making this for fd

i came accros some cheap tricks to filling stock bushings with polyurethane i dont know how good that would work but people do it...not realy what i wnna do

stock stuff is to soft and the race stuff is to harsh
looking for some middle ground

 

MS Rubbers bushings....intrested ....dont know any thing about them

oem vs ms

 

Sounds like you want somebody to do your research for you. It also sounds like you have already made up your mind so buy whatever you want.

 

I'm not asking anyone to do research. I've already done it.

I had questions regarding a vague post, they weren't answered.

Delrin bushings already purchased, I just need to install them this winter.

As it isn't a street car, I'm not overly concerned about a rough ride.

 

After a couple years autocrossing on Delrin bushings, I thought an update was in order on this thread.

The setup: FD, single turbo, 350 WHP, splitter, dual element wing, lowered to about 25.5 at the fender lip, Koni yellows with Ground Control, 285/30/18 Kumho V710 on all four corners.

There are no misgivings about the noise (there isn't any noise), or the handling - turn in is crisp, and the car is very predictable.

The only downside I have found to the Delrin bushings is that front alignment does get messed up a bit - I've hard to mark the correct locations, reset a bit and tighten the bolts.

This is on the front lower control arms only.

 

So there's wear or just slop? I'm interested in the alignment issues...

 

From what I have read the alignment loosens up because there is no give from the derlin.

 

News to me - if anything they need more frequent greasing than polyurethane

 

mazdaspeed bushings are 40% stiffer than the stock ones.

 

Alignment loosens as far as what? Do you mean the eccentrics moving?

 

There isn't any wear or slop - the alignment changes because there is no give in the bushings. Hit a bump hard enough, and it moves the arm, regardless of how torqued down the bolts are.

Keep in mind this is autocross use. If I hit a bump in a corner, I'm likely hitting it harder than you would on the street.

Unless maybe you're running R comps on the street.