Did you ever do a dyno run with the functioning stock cam timing map versus one that you tinkered with to increase HP? I am trying to get an idea how much power you were able to gain with cam timing when compared to a normal codeless stock ECU.

Car looks awesome on the track. Did you ever get a feel for the car in the turns?

I added a tiny spacer in the stock Tstat so that it opens sooner. My coolant temp usually stays right at 180 degrees while I'm hotlapping on the drag strip. But if your fans were on the entire time, 210 does sound a tad higher than normal unless it was 90+ degrees outside.

It sucks that the engine was fine on the dyno, but gave you problems on the the track. Hope you can get it sorted out soon.

 

Looking good man, do you have a stock fwd 3.5 tstat? I have a 350z lower temp tstat and my temps are always in the 180's, even when beating on it on high boost. You being n/a will greatly benefit from it. Also use mostly water vs. coolant. put like 90% water, the rest coolant, and water wetter ontop of that. You will see your temps drop big time

 

I run zero coolant, pure water and no Tstat. I started with a 350Z one, ran hot. Then removed the springs and wired it open all the time. Still ran hot. Then filled a funnel with water and stuck it on the top of the rad while it idled. That pushed out some air. Ran it again.. still hot. Then remove the entire Tstat - still hot.

It was 93' at Roebling, and temps would creep up to 210 after 6 laps.. at 20% throttle. I dunno if I still have air trapped in the motor or what. What you use to bleed the system? I've heard the 3.0's were hard to bleed, but nothing about the 3.5s

FYI, dont need fans on at track speeds.

 

Yeah, something is up. You shouldn't be that hot without a Tstat. 100% water is better than an antifreeze/water mix. I run a small amount of coolant just for corrosion purposes.

You're right, fans shouldn't be needed for a road racing car. Forgot.

I jack the front of the car up so that the radiator cap is higher than the highest coolant passage on the engine. Then keep letting it idle until all the bubbles pop out of the top of the radiator.

If you are still running that hot on the track, I have had GREAT results using "40 Below" "Stops Overheating" made by "Pro Blend". Pep Boys may still stock it. I know Advance Auto does not. I have thoroughly tested Water Wetter on several occasions with only a 1 degree drop in temperature in 115 degree Las Vegas heat. But with 40 Below, it was a very noticeable drop in temperature.

I'm not even sure if you're allowed to use anything besides 100% water with NASA. But just a suggestions.

 

Shiate! I totally forgot about 40 Below. I'll try that. NASA says no A/F but water wetter, etc is probably ok.

 

So you've heard of 40 Below? I first heard about it from the hardcore bracket racers in Las Vegas. You're allowed to use that stuff according to the NHRA rules I believe. When I conducted my tests, I was amazed that it actually worked. I tested Water Wetter first and couldn't see any noticeable gains after hours of testing.

I've also had GREAT results using the Pro Blend product called Trans Cool. My transmission temperatures are perfectly fine right now and they never exceed 160 degrees. I guess my style of driving and tranny cooler work just fine. But when I lived in Las Vegas and drove with the AC on full blast with it being 115 degrees outside, the tranny fluid would easily get way hotter than 160. When I put the Trans Cool stuff in, it actually lowered the temperature TOO much. So I did a drain and fill and diluted things and it worked fine ever since.

Right now, I only use straight conventional trans fluid. But with my 4K+ stall converter about to be installed, I may have to revisit Trans Cool.

And I just realized you're not an automatic. lol

 

210 on a tracked VQ is fine according to Kojima

 

Maybe, but it tops 230 on cool down.

 

Yeah but with no tstat, dosnt make sense. Should be so much lower, in my car i just let the car idle for as long as there is no bubbles coming up. pretty much all I do to burp it.

my temps dont ever go above 190 when cruising or driving hard, at 15psi of boost. only gets in the 200 when in traffic, with a/c off, and fans set to stock activation, I do have a bypass that activates the fans much sooner. never really looked at a sentra upclose, but do you have good airflow going into the radiator?

 

you have 1 tiny fan that only cools 1/2 the radiator, lol

 

damn.. you got any close up pics of the front end of the car? is the hood vented?

nevermind. just saw it, damn even with vented hood and still getting hot! somethings up.

 

Water wetter, etc will help if there are air bubbles sticking to the aluminum. I'll try that and burp it one more time. I run my fast lap by 3-4 anyway, so its not a huge issue if I only have 6 laps before running hot.

 

Joe.. I use some very high capacity 12" SPAL pusher fans on cars that I know will see high temps/heavy use.

 

what's funny is, even limping the car around teh track, it was still good enough for 3rd palce, lol.

 

Did you ever think about trying a restrictor vs removing the thermostat. My understanding behind this is to try and restrict the "free flow" of the hot water so that there is more pressure in the system thereby increasing boiling point and also to prevent the coolant from cavitating in the water pump due to the lack of pressure, which according to one site as I understand is both undesirable and may damage the water pump. Also the restrictor apparently collapses the air bubbles and prevents air pockets from forming.

I've been using a 5/8" restrictor for 3 years now and rarely have to use the fans while drag racing and when I do the temp drops to around 160 deg even on really hot days.

 

If you are having cooling problems on the track but everything seems good and no problems anywhere, something to check is if your radiator is shrouded... Make sure that the air from the front of the car going into the radiator can ONLY go through your radiator and not around it. Make sure as best you can that it is sealed up. This will usually make or break a car on the track ( a higher HP car that is)

 

great thread.... just read all 5 pages and glad to see the vq world always moving forward

 

Road Atlanta this upcoming weekend

 

We had about 8pts to spare in our class, so we added a JSP wing similar to the BTCC-style. This should give the car much needed rear downforce without adding excessive drag. Also changing to a bumper with more surface area to help keep the nose planted. That will happen for VIR in July.

Now that the new control arm bushings are in place, we're going back to -3.2 camber and zero toe. The tramlining is all but gone. Timing is going back to 17, new (revised) crank sensor installed, second fan was added to the radiator and the shocks were firmed up. We're going against a host of M3s, a very fast S2000 and an unkown RSR porsche at Road Atlanta.

We'll have pictures/video of the NWP/BC Racing Sentra. And if all goes well, maybe get on the podium. Realistically, I'm thinking 5th.

4Merryman, Skip 2002 Honda S2000 Gray
Oseroff, Jonathan 1993 Bmw 325 IS Blue
St John, Kevin 1990 Ford Mustang grey
Hill, Clyde 1995 BMW M3 purple
Agostini, Sean 1998 BMW M3 Green
Miller, Robert 1998 Ford Mustang White
Parson, Everette 1986 BMW 535 white
Hedberg, Eric 2001 BMW M3 Carbon
Ippolito, Joe 2002 Nissan Sentra Silver
Crace, David 1973 Porsch 911RSR White
Kilgore, Larry 1985 Ford Mustang Black

 

Good luck Joe!

 

when I went SSIM and then TS with z33 vtc map, I picked up as much as 20+wtq from 3000-5500 comparing stock vtc map to the new vtc map

 

1991-1999 M3 seem to dyno kinda low..... 210-240ishWHP with very few hitting the 260whp range w/o a euro spec motor.

The 2001 M3 on the other hand probably has us on power, but we should have them on weight.

Mustangs....... weak

I can't find anything out about the S2000 or driver.... mo lap times in the South East

The Porsche, the RSR model is a limited production model to meet 500 production cars to race rule...... so IDK.

I'll bring the espresso maker........

 

Water is better at taking heat away but it also has a MUCH lower boiling temperature. This needs to be taken into consideration. This is why cooling systems are pressurized in the first place; to work around this inherent issue with water, regardless of its proportion to coolant.

 

it's fine, the temps stabilize.

 

I should have added the fact that I was just speaking in general terms.


I'm just not a huge fan of 100% water.

 

Skip's S2000 used to run in TTA. The Vette's killed him. Eric Wong's M3 isnt registered, he holds the records.

Oil changed, hoosiers mounted, shocks/camber set.. Bring on the cafe ole. Sean will have a HD camera in the car.

 

I think this is the Eric's car. He's running a 1:37-1:39. http://vimeo.com/10193513

Joe's old track record was a 1:46.xx, after some suspension tweaking and 0 power increase, the record was reset to 1:43.xx, almost 4 seconds on the old record. This was with the 180whp 4 cyl. The car has crazy grip now, a little more body roll because we lowered it more and still haven't corrected the roll centers. I think any more spring to correct roll and the car will get slide happy. I think the rear is at that point where it might be snap happy. It needs downforce, roll center correction, and another degree of camber.

The car used to be (with the 180whp 4 cyl) drag limited at the end of the back straight to about 135-140. 0-80mph the car was pretty quick, but 90-140 it was a dog. The car as it sits is geared to run 170+ and all areas of acceleration, except for maybe 1st and 2nd due to wheel spin, but also never get used on a road course, have improved dramatically. Joe knows the track well, it's the home track. I might end up bumping the rev limiter up to 7400 from 7100, it just gets there so quick and is still pulling pretty good, but just for some overrun to hold a corner or pull a little longer to pass. Joe is pretty good about not killing the motor, but he'll use it if it's there.

The new poly bushing we did 2 weeks ago should have been done a long time ago. The car just feels planted and responds so much better to steering input. If we ever correct the roll centers, the car will improve just as much all over again. Once I'm/we're not gaining from anymore suspension work, then it's time to address aero... I think it's pretty close to time now because the car is going to be spending more time at 100+.

For the Ultimate Track Car Challenge we can do whatever we want to the car because it's a non-restricted format...... and we'll need it. The track looks pretty tight on video in sections, so, top speed and high HP shouldn't have any edge in those sections or in braking at the end of the straights. Videos show most Vettes and vipers hitting 135-140 at VIR. Even before all the changes the Sentra would already whoop most cars in the corners.

 

could an oil cooler (or two),help to keep temps down???dont know if the issue was resolved

 

Watching only 2mins of Eric's video its very easy to spot the mistakes. Maybe he got better throughout the race, but early turn in for Turn 7 which caused a early track out, very late on the gas. You should be rolling on the throttle before the apex. And downshifting after the backstraight through all the gears into 10A? Thats just wasting time. Full brake, slide your heel and go from 5th to 3rd.

What are the Honda Challenge cars turning at RA?

In comparison, here is our last run at Road Atlanta, with the 180hp 4banger and crap suspension (notice the skipping). I think the car has more motor now than aero. Which will require a delicate throttle.

http://www.youtube.com/watch?v=HP1c32x7cno

 

Honda Challenge cars are getting BIG backing from Honda now. Lots of contingency, parts support, and coverage........

 

at the nationals the HC1 cars were running between 2:10.x to 2:15.x and the HC2 cars were running 2:15.x to 2:30.x

 

2:10 is brutally fast at Miller. We'd be lucky to crack 2:12.

Last night after the rain (70 something degrees), the motor ran very cool, b/w 175-185. Driving around within the limit and a couple full throttle runs. The twin fans come on around 205.

I think the bump steer kit has too much pos bump. I'm going to raise up the tierod slightly.

Details..details..

 

ok, overheating problems are still plaguing us.


We are running no thermostat, water wetter, the bypass is blocked off, the front of the car is sealed around the 2' core aluminum radiator.

2-3 hot laps and the temps creep up to top 230+*, down the straights the temps will drop some. I'm to the point now where I'm suspecting something more than just an air flow or coolant flow issue, oil temps are fine.

The deviations from a standard VQ35DE are:

VQ35DE "RevUp" camshafts......... early exhaust cam opening timing might be an issue....... this is where I'm leaning now. Yeah, I know, I need an EGT set up. The RevUp cams have an exhaust opening of 70* vs 52* for a standard DE. Looking at cam timing maps, the HR motor in the upper RPM ranges is holding 15* on the exhaust cam, putting the cam center line and opening and closing events in a range more comparable to a DE motor. I doubt setting the exhaust cams off by a tooth would get me close, either way the motor has to come out to do it, so it might be time to call Clark @ JWT for some advice and cams.

VQ35HR headgaskets with a revised coolant routing, This could be an issue.... but there are plenty of tracked 350s w/o problems.

11:1 compression.......... not an issue

Need to look over data logs to see if ignition timing could be playing a roll, but I tuned the maps pretty well.

Oil temps stay fine, oil cooler is getting moved to the fender to expose more of the radiator.

 

We are having coolant issues on Deckout2s car as well, we want to keep his temps in the 170s but it doesn't hold there very long before it goes up to the 190s. Hopefully that is only because of the crazy 90-100 degree weather we've been having for a few weeks straight. From what I have been able to determine it is a fan or radiator issue. We swapped out his 5/8" A33 radiator for a 1" A32 radiator, it did appear to help some but not as much as i hoped. I believe the next logical step is something along the lines of what you mentioned. However I was thinking about getting two 14" pullers and using them to replace the OE fans.

 

Why not use the aluminum radiators?

 

im hitting 190 and my motor is stock. thats normal i though in 93 deg weather?

 

everything got moved to the back of the radiator........ oil cooler got moved to the fender well......

if that doesn't do it, it'll be time to build some real racecar ducting.

 

This overheating is odd.

I run on the road course and it doesn't see temps exceeding 205 F. That 205 F happened in 100 degree ambient air temps in Texas at Maxus '06. Usually the car runs around 190 ~ 200 F degrees with 70 ~ 90 F ambient temps. I have the data logger plots that show that. The only time it shot to 220 ~ 230 F was when I was in Texas at Maxus '05 with the old crusty stock radiator and this damaged the old engine's head gaskets.

I now run a VQ30DEK engine, header wrap on the y pipe, Griffin aluminum radiator, 60% water / 40 % coolant, and the two stock thermostats that came with the DEK engine. Still have AC in the car and the front bumper/hood hasn't been modified for any aero. So I would think there is more air flow restriction on my radiator and the engine output on both cars isn't that different.

I wonder if not having a thermostat is causing some turbulence & cavitation in your coolant system?

 

Have you tried running a Tstat or a restrictor as Jime mentioned?

 

J.. have you guys performed a leakdown test? You might have a slight head gasket issue. I've seen head gasket leaks under heavy load, where you get just a little bit of combustion gas into the cooling system. This hits the temperature sensor, and makes it read higher. It also can create localized hot spots in the block..

Just something to look into.. I've seen it happen a few times with big HP turbo QR's. It could be something as simple as a tiny piece of trash, or a ding in either seating surface.

Travis