goofygrin

iTrader: (5)

Brian, although I shudder to think about the results (because who the heck knows really), if you wanted a 15 click asian shock to dyno, I wouldn't mind putting mine out there for you to test (although you'd have to put the car up on a jack to take it out and then put it back together, no matter the results


Stance GR+Pro SSD

Spool4Fun

iTrader: (9)

Sorry to move away from the suspension discussion for a second...

I have been kicking around the idea of going with a ported exhaust manifold and o2 housing this year. Sounds like you recommend these mods for STU. Would they be worth the time/material cost for someone who still considers themselves an amateur autocrosser? Some info is listed below just in case this affects your recommendation.

Supporting power mods: drop-in, TBE/HFC
Supporting suspension mods: Ohlin DFVs and Dunlop Z1s

EVOlutionary

iTrader: (38)

I would recommend the ported stock exhaust manifold and aftermarket 02 housing to nearly every evo owner. There really are no downsides. . . more power everywhere with no drawbacks.

If you do it, get them ceramic coated (preferrably Swain coating) if allowed in ST rules. . . it really cleans up your engine bay and reduced heat. . .

EVOLutionary

spool_sample

iTrader: (3)

Is it just the pics, or are the Kumhos noticably narrower than the Dunlops? That sort of sucks, but we'll see what your data says.... the XS might be the surprise tire this year.

In other tire news, a guy I race with who works for Bridgestone got the chance to try the RE11s out a week or so ago. He said they were "very good" and "much better than the RE01Rs", but I don't think he's allowed to say more than that. No real data, unfortunately, but the RE11s are supposed to be going on sale on March 1st. I'm going to start saving my pennies now...

Spool4Fun

iTrader: (9)

Thanks, EVOLutionary. I think I'll be placing a few orders soon. I appreciate the advice.

evo8dad

iTrader: (15)

I highly recommend a tubular exhaust manifold (JM Fabrications manifold) and a good O2 housing (JM Fabrications O2 housing). I've seen power gains on numerous customer Evos switching from ported stock manifolds to the JMF manifold. Its nearly a equal length manifold and you'll see peak post figures are 22 to 23 psi with their O2 housing and a TBE/HFC. With just the O2 housing I found peak boost numbers around 21psi. Spool is also improved a few hundred rpm with the JMF manifold vs. the ported stocker.

One cool new feature JMF has developed is they are now making their O2 housing (the site hasn't been updated with new pictures) with a velocity stack style wastegate pipe in the O2 housing.

The JMF manifold is slightly heavier than the stock manifold but, the additional power is a good trade off given how power restrictive our class is.

EVOlutionary

iTrader: (38)

Do you have, or have you seen any back to back tests of a BR or PPI ported stock manifold vs. the JMF unit - something that supports the claim that it spools faster than a ported stock unit. That would pretty remarkable if it did. I know I haven't seen ever dyno thread out there, but of the ones I have seen I don't recall ANY tubular manifold spooling faster than a stocker.

I had a 5 pound $1700 ASpec titanium exhaust manifold on my car for a while. After going back to the PPI ported stock unit I could feel a clear difference in boost response as well as see it on the dyno. With the PPI unit boost came up smoother and faster. . . I chose the better boost response vs. the 10# weight savings off the front of the car. . .

If the JMF performs as you said it would be a good candidate, but for the price and weight it would have to be significantly better than a ported stock exhaust manifold. . .

*edit* - of course my setup is much different than an STU setup . . . so results can not be correlated too much . . .

evo8dad

iTrader: (15)

I have plenty of logs from stock, ported and tubular manifolds from customer Evos and I've found that the JMF one spools the fastest. Seat of the pants the JMF feels the fastest as well but, I've yet to get any dyno testing down to back it up. I've had plenty of my customers get dyno pulls done with all sorts of different manifolds but, they were always done after doing other mods as well.

Caffeine Slug

iTrader: (3)

Has anybody had a chance to test shaved vs full tread Dunlops back-to-back?

I'm guessing most here either read or heard about the test Sportscar did last year where full tread Bridgestones were faster than the shaved version, but that tread design doesn't seem to benefit as much from shaving as the Dunlop does.

Pics for reference:



It's pretty evident that the Dunlop is putting more rubber down at low tread depths, but what kind of time difference this might make, I have no idea. I'm interested to hear what others think. Any kind of speed difference eventually leads into the value discussion as well. At a cost of $100/set plus reduced tire life I might do it just for nationals if I'm only gaining a tenth, but 3-4 tenths and I'd consider doing it for every set.

Caffeine Slug

iTrader: (3)

Registration for more National Tours opened today (well, it opened over the weekend, but they finally fixed the website today). Here is the link for San Diego, you can get to the others from your membership home page.

Evo_Someday

Getting ready.. season starts next month here! I've been fixing things up...

delongedoug

iTrader: (20)

Is that a CF lip hanging on the wall?

Evo_Someday

Yes - but it's broken. Carbon fiber shatters very easily. Cracked on a curb, then tore it off on a cone at 50+ MPH.



It was attached to the bumper at one edge and dragging the concrete at the other edge until the road ate it up.



Now it has a big old hole in it and just needs to hit the trash can.

I may get a replacement lip in polyeurethane or maybe just get an OEM to o back stock. Still undecided.

I do wonder if the lip might stick out and topple cones... It does kind of stick out past the bumper a bit. what do you all think? Probably not.

delongedoug

iTrader: (20)

I ran mine for about 2 years before it broke. It took a lot of scrapes, bottoming outs and cone hits in its time.







I glued it up a bit but I expect one good hit to break it loose.

Evo_Someday

^^ That's the exact same place where mine broke (see top picture). And I actually did glue it back together with gorilla glue.

But yeah.. one cone hit and it broke apart again. The glue held fine for a few days of driving around but it can't hold up to a cone hit.

So for me it's polyurethane next or back to OEM.