GM_Lover

Update:

Based on everyone's advice that these cars really love cold air, I took my car back to the same strip with literally no changes to the car except swapping out the 30k Bosch 010 pump for a new 010 pump. Still no split cooling though. Oh, the car also had an extra 5 gallons of gas in the tank this time (one tick over 3/4's full), but no big deal. Still 100% 93 octane, 100% full interior, spare, etc, etc)

New times (~100-500' DAs, ~60-65 F, ~30.35 inHg)
1st run -- 11.978 @ 121.01 (2.001 60') -- starting IAT 116 F, ending IAT 140 F
2nd run -- 12.047 @ 121.70 (2.086 60') -- starting IAT 104 F, ending IAT 135 F

Old times (~2200-2500' DA, ~80-82 F, 29.93 inHg)
1st run -- unknown
2nd run -- 12.894 @ 117.06 (2.453 60') -- starting IAT 125 F, ending IAT 165 F
3rd run -- 12.316 @ 118.00 (2.033 60') -- starting IAT 125 F, ending IAT 185 F

Excuse the horrendous 60 fts since I'm on China street tires @ 35 psi. This car will probably never see slicks or even DRs, but I do plan to get some quality summer tires next year.

So it seems there's almost no point in taking the car to the strip when the DA is up there. Based on traps (and I think at least one person mentioned this in this thread), I lost as much as 30-40 hp because of the weather/IATs. All of my previous strip experiences have been with turbo cars which quite frankly all ran pretty consistently unless it was obscenely hot and humid, so I was pretty shocked. Literally within the first few seconds of the 121.01 mph run, I could feel the car was waaaaaay up on power vs last time.

As for the impact the new Bosch 010 made (vs one with 30k miles on it), I don't know, but I definitely wouldn't discount that it was also responsible for the added power. After I replaced the pump, I logged cruising IATs for about a week, and they were consistently in the 12-15 F over ambient range (from ambients as low as mid-50 F to as high as 80+ F). On the 30k miles pump, my cruising IATs were almost always 20 F over ambient.




Original post:

Took my '05 to Cecil County Dragway in Rising Sun, MD this evening for a few 1/4-mile runs. This is a pretty fast strip, so was hoping to break 120 mph traps. Didn't happen.

Mods:

• UPD 83mm clutched pulley
• UPD belt wrap kit
• Eurocharged 30"x6" heat exchanger
• Eurocharged canned tune (Jerry really is awesome)
• OBX catted long tube headers
• 1 step colder NGK plugs

Everything else was bone stock right down to the OEM Mann paper air filters. NO split cooling. All season tires (some crappy brand I've never heard of). Full interior. Straight 93 octane gas with nothing else added. No pano roof.

Got 3 runs in but forgot to pick up my slip the first time.

Second run: 12.894 @ 117.06 (2.453 60')
Third run: 12.316 @ 118 (2.033 60')

Track elevation is 320 ft, but was 80 F and 75% humidity when I ran.

Picked up less than 26.5 mph on the back half of both runs, which seems a bit low based on other similar E55's I've seen. I'm wondering if it was because of my IATs which seemed to be through the roof! First run maxed out around 150 F; second run maxed out around 165 F; third run maxed out at 185 F! Is this what other people with similar mods see? 185 F seems obscene for a 0 to 120 mph run.

I feel like 120 mph traps are possible if I can get the cooling sorted out (assuming there's actually an issue there).

M5 LOL

yea, fix the cooling and your north of 120.

watch this

GM_Lover

Ha yeah I saw that. Not thrilled about installing 2 gallons of water over my accessory battery, but I'd do it if it actually works well.

I'm just confused why my IATs were so high when I only have an 83mm pulley, bigger heat exchanger, and long tubes. Or maybe they weren't, and those temps are normal? If these are normal temps for my mods, I can't imagine anyone running a 77mm or equivalent without a trunk tank and water-meth.

BTW you have a really cool car collection!

drothgeb

Seems a little high. I have a 77mm pulley, a bigger heat exchanger, and a CWA50 pump and I was hitting 160 peak, OA temps around 75. 185 seems a bit excessive for similar cooling mods and a bigger SC pulley. I'd figure the 77 would make much more heat than the 84 so with me having a little higher flowing pump temps should be similar. Might double check your pump or something? Or make sure the system is properly bled, did you change the heat exchanger recently?

GM_Lover

Thanks for the reply. Exactly the type of info I was looking for.

The heat exchanger came with the car, but I did drain 2 gallons of coolant a few weeks ago to R&R the alternator. I manually bled the circuit afterward though but it's possible I didn't get all the air out. The Bosch 010 in the car has 30k miles on it, so maybe I should just replace it and rebleed.

drothgeb

Np, good luck chasing it down After seeing how hot it still gets with my big *** heat exchanger, I decided to give up and plumb up some water injection. I have parts on order now. You'll probably not get temps your happy with and end up doing the same haha

shardul

iTrader: (1)

Replace the pump and add a rear tank. Fill it up with ice and then take it down the 1/4 mile. You MPH should be in the 120 to 123

Forrest Gump 9

And you need to split the cooling circuit. What's your 60' times? Anyway, the 55k loves cold ait

drothgeb

Maybe there is more of an affect if you are on stock HE and pump still but for me there was no discernible difference before and after split cooling. I can only use cruising temps as a reference due to a larger clutched pulley at the same time, but I was cruising at +15 before with larger HE and PUMP and I almost feel like after split it is on average, a little closer to +20 now.

new55

are the colder plugs necessary with the headers ? - they should reduce heat/boost - also if you add water to the mix you probably dont want colder plugs either correct ?

JoeJErnst

Given that your Density Altitude was probably around 3000' with those temp and humidity numbers, those times and MPH don't seem too bad.

Your IAT numbers don't seem too far off either. My car always picks up 60 degrees of IAT from the burnout box to the end of the 1/4 mile. A lot of people don't realize how damn hot the car gets while sitting in the staging lanes. Remember there's no air flowing over the heat exchanger so IATs will continue to rise while staging.

Do you know your *starting* IAT for each run? How much time was between each run?

drothgeb

That's a good point Joe, GM Lover just for reference my starting temps were pretty much always ~120 after burn out and usually always "caught" and held at 160 through the end of the run. Just for a point of reference.

trabots

Would there be an advantage to skipping the burn out so as to keep my Killer Chiller tank water at maximum cold?

JoeJErnst

I doubt it. I have a KC with a tank and the temps only go up about 3-4 degrees after a burnout, and then they always come back down to where they started by the time I'm fully staged.

atoms

I'm not sure how to interpret this. You mentioned unknown tires and I'm most suspicious of that. We have similar mods, but I have stock headers and plugs.

I run a very consistent 12.4X (2.09X 60') @115 on street tires (michelin ps2) in the temps you describe. I do have split cooling but all its allowed me to do is run more often, not faster. I do not do a burnout. Instead, I carefully roll into the throttle. I also don't bother to bring the revs to ~1500 before launch. These are things I need practice doing, hence, I know I'm part of the problem.

I feel that my driving skills and lack of drag radials are holding my car back. Do you think that could be part of what's holding yours back?

Your third run looks decent to me. With your setup, it seems that you ought to be able to get sub 2 second 60'. I am willing to bet that when you do, you'll also trap 120. I'm just can't say how much coolant temps have to do with it.

BTW, it's the 12.8 at 117 that's throwing me off. Were I to run a 12.8, I'm pretty sure I'd be LUCKY to hit 112. And, I've never gone faster than 115. Heck, I don't even think I've gone much slower than 12.8 and that's while trying to figure how well the car sticks on launch (e.g. I spun the wheels and had to back off)

drothgeb

He has a pulley, a tune, and long tube headers. If you are running stock and wondering why you don't have as high as trap speeds as him that's why. His 12.8 run was a bad launch, he still has much more power than you to pick up the trap speed on the back end.

atoms

Thanks drothgeb, we're actually on the same page here in that the 12.8 pull probably wasn't worth mentioning.

The point I was trying to make, was that a 12.3 at 118 is in fact FASTER than my car which has fewer performance mods. I.e. it's not unreasonable. The OP mentioned unknown tires, I was attempting to emphasize considering those as one of the primary causes of not meeting the expectations (while also suggesting as tactfully as possible driver ability).

TLDR: Possibly launching slower than capable, but pulling well.

T9ja

When I ran my car with just 83mm, HE and tune from EC, best time was 12.1@116mph. This was in a 60ish degree weather. Added LT headers, and ran 12.3 @ ~122mph in a 50ish degree weather. The temp. plays a major role on the track.

C3Duece

Split that cooling system and IATs will drop 80*

GM_Lover

Thanks all! In response to some of the things that were mentioned:

Not a fan of the trunk tank since it'd require me to lose the donut. Not my daily driver but would like to keep the car as practical as stock. Even the LT's were a compromise because of the extra noise (although this car sounds absolutely amazing with them). Will definitely address the pump and split cooling though this weekend.

My 60' was 2.453 on the 12.894 @ 117.06 run, and 2.033 on the 12.316 @ 118 run. This was my first time out with the car, and I was very afraid of snapping a rear subframe bolt (or worse) since the car has 113k miles on it, and the bolts and bushings are probably the originals.

The colder plugs came with the car (uninstalled), so I just threw them in since the originals had 113k miles. Regardless I've always adopted the notion that going 1 step colder when you start to mod on any platform is a good move. They came with 0.030 gap (slightly less than stock), and I threw them in as-is.

My starting IATs were in the 120-125 F range on the last 2 runs. Time between runs was about 5 minutes just waiting in the lanes because other cars kept breaking down (haha). Unfortunately I have no idea what my starting IAT/ET/trap were for my first run, but at the end of the run I was right around 140 F. I thought, "Sweet, not too bad", but the max IATs just kept going up on subsequent runs. Based on what you guys are saying though, there might not be much room for improvement for me without adding a serious cooling mod. I didn't realize the DA was so bad though, so that's good news. It's just been unseasonably warm and humid here.

The tires on the car are some brand I've never heard of. They're either all seasons or summer. I looked them up when I got the car, and they were sub-$100 tires. haha. All 4 corners were literally brand new though. As for my driving skill, I'd be the first to label them pure amateur. Over the years, I've probably made 50+ passes in various cars at various strips, but nothing in what anyone would consider fast. If I could drive my car home at the end of the night, I always considered it a success. That didn't happen once though.

122 mph is an awesome trap with your (my) mods. I'll be sure to hit the strip in late Oct before they close.

Will definitely do the split cooling!

Thanks, all.

JoeJErnst

If you do a lot of racing at the track, you should consider mounting two or three small fans to the heat exchanger and wire them (and the pump) to run continuously when the key is on. Your starting IATs will be a lot cooler and more consistent.

Here's the setup I had before going to the Killer Chiller:

GM_Lover

Thanks, JoeJErnst. That seems like a pretty good idea. Will have to see if I can set that up before my next dragstrip visit. For a long while, I was under the assumption that pre-run IATs didn't really matter in cars that get as hot as ours. With a good cooling system, I figured they'd plateau and hold, regardless of starting temp. Plus they spike very quickly at WOT. Obviously I was wrong.

For the long term though, I think I'm going drothgeb's route with water-meth. I'm a big believer in wm in general, but it didn't seem ideal on our cars since we're so limited in nozzle placement. But hard to overlook 80-100 F temps during sustained WOT.

oneslow55

No offense but how you expect to run good times one in warm weather still aMD two high iat .Your loosing around 60 whp with those temps ,get a new bosch pump and go back in the late fall .e55 and warm weather is a slow turd fyi.when modded there winter cars not summer!

SMed08

You lost 0.2s and gained 6mph by adding headers? If the ET difference is not a typo, is the slower time because of much worse launch due to increased wheelspin?

drothgeb

I have all my stuff getting here next week, I'm doing a shurflo 100psi pump I got on eBay for $80, and then a 3 pre SC and a 7 after the IC on the flat pad(furthest from iat possible). I have my set up pieced together and ordered except the solinoid I'm going to run and grab from summit and a Hobbs pressure switch I'll get from Napa. I realllllyyyyy wanted to do a pre IC nozzle for the extra pressure and slightly SC cooling, but I also wanted to run a 10 post ic. I'm in dry *** nv so I don't think I'd have triuble but every one recoments 7 and 3 so that's what I went with. I'll let you know how it works out for me hopefully some time this week.