Normal street driving and auto-x dip in and out of the boost so often that you don't put such a load on the cooling system. 20 minutes of track time at high load is like auto-x with continuous runs for an hour. Your turbos are under continuous load for that long ... think about how hot they get. Especially the twins.

I also did not have any ECU-related power loss with my coolant temps that high. I noticed the retarded timing with my intake temps at > 50C. It didn't pull as hard ... as I was chasing down that spec racer Porsche. (dammit ... ) I felt the same way at the end of the day ... third fastest lap time and my cooling issues were holding me back!

 

If its not running hot at autocrosses and daily driving then most likely just adding some duct work will help a great deal. The shark mouth mod for the front opening is a good idea along with cutting some sheet metal to fit securely on the sides of the rad to force some more air through it. Some dual coolers or one big single should make a huge difference too. Piper Perfomance did some really nice duct and oil cooler work on my car and they are close to you in Manassas.

Again good luck,
Fritz

 

Carl,
Nothing but love. I'm raising the back of my hood today
Thanks,
Fritz

 

Currently there's a waiting list...I've emailed Dave Nugent to see how deep the waiting list is...

 

Looks like I have some duct work to do ASAP. Mitch is near me, but I'll probably try to handle this one myself first as I probably need to patch some gaps rather than fab up a whole duct setup.

Will see how this works before going with the expense of the dual coolers, although I'm not against it if it will make a big difference in overall temps. However, I've heard it is only a marginal improvement.

As for the shark mouth thing, again I'd rather see how the improved ducting works before drilling holes in my front end. I'll do some research on this though, as I seem to recall someone saying this mod did bring down temps at Sebring... which is hotter than anyplace I'll likely go. I'm stuck with the OEM nose AFAIK because I live in the city, so I refuse to get a fibreglass bumper, and I hate the license plate holder on the 99+ nose.

 

Older threads:
1) on cooling a FD on the track: https://www.rx7club.com/forum/showth...5&pagenumber=1

2) on the shark mouth mod: https://www.rx7club.com/forum/showth...h&pagenumber=1

 

I've got a set of CWRs in the mail, scot, and i'm just completing some alluminum ducting for the rad, so i'll let you know how it goes at WGI in three weeks.

 

another good idea is to make sure none of the hoses or fittings is leaking. a small leak will bleed off pressure causing the water temp to rise. this small leak might not show up during street driving. if you have the tools pressurize the system do it yourself or have a shop do it and see if it is tight. you may only have a heater hose leaking slightly. I found my radiator cap has a slight leak this weekend. I have not had any recent temp problems but this could bite me on the track during a race. good to do a yearly check of the entire system whether it is a race car or not.

 

BEFORE change to AWR CORSS FLOW radiator. I was using KOYO. in the hot day(95 F). the temp will went straight up to 205 at 3 laps. this scary me off. so I install AWR's radiator( still need to make a better ducting since the location is different than KOYO) with rebuild oil cooler, accusump. so right now My peak temp after 30 min of track time is . water temp 220( usually is in 190 but will rise up to 220 at very last part of session..) my oil temp is 240-250.( bit hight ). I will try to make a new ducting for my radiator

 

Scott,

Those are some hot temps, buddy. They can cause damage if they continue.

I suggest you get a shark nose opener for your stock nose from N-tech Engineering. And the investment in an additional oil cooler from CWC would make a lot of sense, too.

Good advice on having Mitch Piper make some side covers to seal the leaks where you undertray meets the frame rails.

When at the track, I used to put duct tape around all the holes and gaps to seal it for the weekend. The stuff will stay put until it rains and really helps.

Also make sure your oil cooler fins are all straight and the cooler isn't clogged with road grime.

Hope that helps...

 

some have recomended lifting the rear of the hood with shims. if your goal is to vent hot air out of the enging bay, consider that the bottom of the windshield is a high pressure area aerodynamically so it is theoretically possible to lessen the flow out of the engine bay by opening the hood this way.

any thoughts on this?

i was at buttonwillow this weekend....HOT as HELL!!! over 100F ambient. 220F water and oil temp was typical....after hard driving for 20-25 minutes, water temp of 230F would bring me in for some cool down laps. i don't know if there is any damage done by this, but the car seemingly tolerates it without complaint.

today i went down to look at how many gaps there might be in my ducting....there's quite a bit!! if i still have the car, that's my next little project.

btw....the yellow beast is for sale still. one of you guys has to buy it!!! i don't want to sell it to a bozo!!!! i'm considering offers

 

A bunch of us tried removing the rubber strip at the rear of our FD's engine compartments many years ago. Nothing happened. I decided to run a session with a strip of masking tape at the center rear edge of my hood one session. The tape was pulled into the gap. All I know of now run with the rubber seal installed.

You can make your own decision about that.

 

Love the car...hope someone like Fritz Flynn gets it! Wish I had the money to pitch an offer to ya

 

Hey, I thought Fritz was 'buying' my car!

 

On the hood lift question, you need to create a greater positive pressure under the hood than the one off the windshield for it to work. This is why the front bumper of my car has an added opening(almost from turn signal to turn signal 2.5" high. In addition raising the hood also moves the high pressure zone on the windshield up(IMHO). I know it works on my FC, It dropped my temps nearly 30* both oil and water, AND THAT"S A TRIED AND TRUE FACT!
As Fritz said nothing but love for you guys. Carl Byck

 

One other thing, All thes high temps may not cause an outright failure that day, but they are prematurely aging the O rings (shortening the total life of the engine).

 

score another one for TMIC

 

I'd trade slightly higher coolant temps, which can be rectified with some shrouding, over a completely inefficient cooling of the intake charge...

 

A little second-hand knowledge here, by virtue of the car I own, but...

On my FD (Peter Farrell's ex-IMSA #77), there are a few washers added onto the hood hinge mount bolts, to bring the rear of the hood up about 1/8". And of course, the rubber strip is removed. This was proven (several years ago, I might add) to create a positive pressure difference in favor of the engine bay (more importantly, it was proven to actually lower coolant and underhood temps in real track-driving conditions). Now I have not reverted this mod to actually check the difference in temps at the track, but the car's previous owner claimed that it dropped coolant temps significantly on hotter days (which is any day at VIR or Summit during the summer). Coming from who I bought the car from, I figured it to be believable...

So has anybody else done this sort of mod to their FD?

I don't know enough about FCs to determine whether that comparison is even worthwhile...

Oh, and I see 220-230F water temps on hot days at the track regularly. Not a single problem yet.

 

Hey, when you guys are talking about coming to VIR this fall to "run with the Porsches and BMWs", are you talking about the G&W weekend Nov 29-30? I'll be there this year, as I was last year (best track time I've ever had, period! I am not joking). Guaranteed 3.5 hours of track time over the weekend, and last year, my group got an hour and twenty minute session on both days! There were multiple sessions each day for each group, obviously, but on both days, one of the sessions was very long. I find that kind of track time hard to find, whether I run with NASA, BMWCCA, PCA, or any of the other groups I have run with in the past.

If you're interested in coming this year, go sign up now at www.gandwmotorsports.com - it's called the "Fall Fling", and this is the fourth year they have hosted it. It's pretty cool getting out on track (VIR full, I might add) with the Oreca Vipers, G&W GT3R's, and maybe we'll see the G&W DP car this year... Last year, it wasn't on the track, but G&W (whose headquarters/shop are on site at VIR) had an open house going through the weekend.

 

This is the way you, Fritz, and I are thinking LOL, thus we have bad-boy FMICs on our Rx7s--plus all the street racers think twice before engaging us at a stoplight race, when the see the "teeth" showing

 

Thanks Brad. You and Crispy talked me into the CWR setup - ordered it yesterday. Not sure I'm going to do the Shark's mouth yet. I'm going to ask my bodyshop (which is across the street from Mitch) first if there less ghetto way to open up the nose.
Yep - his Piper Motorsports logos were all over the place at SP this weekend. Looks like he is doing well since he left Peter's.
I thought there were some tapes that were more waterproof?
I'll be sure to check that when I throw my stock oil cooler in the trash.

 

really??

i'm of the opposite mind...assuming you've tuned the A/F conservatively enough to tolerate the higher intake charge temps, i don't think i'd sacrifice engine cooling for horsepower.

if i had an unlimited race budget and absolutely needed the results ....i'd change my opinion. but for now, reliability rules the game.

regards
fabian

 

I agree with foko - assuming you're supplying enough fuel. If you have a rotary (especially turbo), you should have addressed the fuel delivery issue before even thinking about charge temps.

 

I agree 100% and was also there last year

Manny you should consider this event for sure.

Dig Dug what were you driving last year. I have a blue montego base model and I think at that time I had some sweet fm10's on her