firepinch

I have the Stu mod and I saw the words "Icebox mod" at some instances. Do you use ice cubes into the reservoir or you just use ice cold water??? At the dragstrip yesterday, I had 8 liters of ice cold water and this wasnt even enough (REALLY not enough) to bring down my IAT2s from 135-140 to 90-100F!!!

Damn, how do you get those IAT2 low and how do you trap 108 mph for those who have a 2.7-2.8" pulley? I have:

The 2.7" pulley, an OTTP heat exchanger, the GM dual pass endplate, the stu mod, intake, header, 3" downpipe, trans mounts.

Normally on the road, if I do a pull, my IAT2s start from like 90 up to 120-125 maximum. On the dragstrip, because the waiting line was too long, I started to do my pass at 135F of IAT2 and 160F at the end.

The best time I did with all my mods was 14.05 @ 102 mph!!! DO YOU SEE THOSE MPH??? HOLLY COW!!! I mean... I never saw that kind of number from someone with a 2.7-2.8" pulley! Not even trapping 104 mph... 102!!! Jesus!!!

However, as an important note, yes my clutch was slipping from 1 to 2nd during SOME PASSES and this can explain partially why I couldnt do better than 14... In some passes, I was shifting like... granny shifting but not that slow and I still wasnt able to brake 14s. But DAMN, why trapping this low, 102 mph!! I see that the heat is the reason but even that... Higher IAT2s around 150F can be that bad?? Im not talking about IAT2s of 200F!!!

I saw some posts where people can trap around 108 mph with a 2.7" pulley! My timing was 15.5-16 degrees instead of 18 at WOT because of my IAT2s during those passes.

Maybe I have all the reasons why Im doing that poor and that I can't accept that those facts are enough for such poor times? Am I too much requiring? To me 135 to 160F of IAT2, this is warm, but not HOT like some people can do when they hit 175F of IAT2s, no?

Tell me what you think guys, I'm despaired and really unsure of what you experience with a similar setup

Here is the video of that 14.05 pass: http://www.youtube.com/watch?v=wVTiAkEDU_s

Thanx in advance!!!

Cigar Hero

This is off topic but here is a modified ice boxhttps://www.cobaltss.net/forums/general-cobalt-68/cooling-mods-188402/

Zach06CobaltSC

As you know when your iat2's get higher you pull timing. I recommend getting methanol injection to combat this. Not only will your iat2's be lower with methanol injection but you can also advance the timing quite a bit. Instead of running your 16 degrees of timing you can run 25 degrees of timing *depending on your methanol mixture, tune, setup, etc* and gain some more power and get some better times.

What are you using for tires and what tire pressure are you running? How are your 60ft times doing? I have seen people run worse, are you getting any wheel hop? Do you have any traction mods? Have you kept up with general maintenance? Have you tried running a compression test to make sure you don't have any internal damage? What is your redline at? What gear are you trapping in, I would hope 3rd?

Get back to me/us on these things and hopefully we will be able to help you further. You wouldn't happen to have a log from any of the passes would you? I really think methanol injection would help you get into the mid 13s in all honesty.

ralliartist

you need to do opt b so that the air is constantly bled out of the system, but I think the reason you are trapping so low is probably because of your tune.

that small of a pulley and the bolt-ons you have, you should be hitting anywhere from 105-110 on street tires. but like I said, depends on your tune.

Doc

I took a few CO2 fire extinguishers to the track with me, they worked great at cooling the car down.

hatrickstu

iTrader: (1)

1st thing is to check the pump

firepinch

Thanx for your replies! I'm gonna answer all the questions.

Questions from Zach06CobaltSC:

1. What are you using for tires and what tire pressure are you running? Nitto INVO 235/35/R18 @ 22 PSI front, 32 PSI rear. I used as well football balloon into the rear springs. They was used as "drag bags", they were at 30 PSI. Maybe not enough?

2. How are your 60ft times doing? Between 2.3 and 2.4s average.

3. I have seen people run worse, are you getting any wheel hop? No wheel hops at all.

4. Do you have any traction mods? OTTP rotated trans mounts stage 2 only.

5. Have you kept up with general maintenance? I think that yes. Im doing my synthetic oil change each 5000 km (3000 miles). I did brake maintenances. This is pretty all what I did but I'm gonna change my oil filter soon. I have 28000 miles done. And of course, at the same time I installed my OTTP Stage 1 with the 2.7" pulley, I installed the new supplied spark plugs. Gapped at 0.34. Are they well gapped? I'm still getting misfires at idle and occasional POP at the end of second gear when I'm doing a pull. I didnt experienced that thought when I was at the dragstrip.

6. Have you tried running a compression test to make sure you don't have any internal damage? Nop. I can say however that I'm not burning or loosing oil. Oil is full at each oil change.

7. What is your redline at? 7400 RPM. Hitting often 7300-7400 in first, but shifting at 7200 from 2nd to 3rd, and from 3rd to 4th, at 7000.

8. What gear are you trapping in, I would hope 3rd? 3rd yes

9. You wouldn't happen to have a log from any of the passes would you? Yes, the best pass is this one:

Reaction: 0.896 s
60ft: 2.259 s
MPH1: 79.90 mph
1/8: 9.177 s
MPH2: 102.12 mph
1/4: 14.054 s

To answer hatrickstu, yes the pump is correct. Because normally when I cruise, my IAT2s are around 85-90F. Doing some pulls will results the IAT2 to go from 85-90 to 120-125. Doing another pulls again in again after the first one will increase the IAT2s to not more than 130-135. The reason why my IAT2s were that high at the dragstrip was that I waited often 10 to 15 minutes before doing a pass. The waiting line was long so this made my IAT2s increasing quite a lot. So my passes started from like 135 to 160-165 of IAT2 at the end of 3rd. Odly, turning my fans on by turning the AC on during 20-30 sec and then turning it off didnt help for the IAT2. This only helped for the motor coolant temperature. I was aware before going to the dragstrip that this could happen so I brang with me 8 liters of distilled ice cold water. I guess that this wasnt enough because when I emptied a 4 liters (draining the heat exchanger at the same time), the IAT2s went from like 135 to 130 lol! I did that while the car was on, so the pump was on too and I turned AC on in order to turn on the fans at the same time.

This is why I'm wondering how do people use the icebox mod to really REDUCE significantly IAT2s.

To conclude my answer, I know that my time can be really improved with better 60'. But you know, my REAL concern is my traps. I'm trapping really too much low for the mods I have, 102 mph is just not right at all. That is my main concern!

Rodimus_Prime

iTrader: (3)

I have very much the same kinda issues

hatrickstu

iTrader: (1)

that makes sense then. you need to wait until you can get right in line to race, or push the car while in line. no airflow = hot temps

ralliartist

or get a killer chiller.

Rodimus_Prime

iTrader: (3)

^^im starting to think thats the only way im ever going to get respectable times in the summer

firepinch

Do any people have installed the killer chiller kit in their cobalt ss/sc? There is certainly also a "how to"? I'm gonna look at this...

sput

iTrader: (3)

I'm tellin' ya running the fans at 100% while the car is off works well also. Depending on ambient temps, it should only take maybe 15 mins to cool down between passes and you don't have to spend any money.

Another cheap way to cool down is to buy a 5lb bag of ice at the track and stick it on top of the supercharger while you cool down.

And the most obvious, don't sit in line with the car running! Either push it or turn it on, move it up, turn it off again.

hatrickstu

iTrader: (1)

hmmmm i went 10.72 (1000' time) a couple weeks ago in the heat of summer....

hatrickstu

iTrader: (1)

yep. all of the above. just be careful not to kill the battery with the fans. i managed that a couple weeks ago

sput

iTrader: (3)

At least at the track I go to, they'll kick you out for dripping water on the track which would happen if you're running your AC on a hot day..

Even if it's in the staging lanes, you'll still drip water. I suppose you could install a catch pan or something though. Sounds like a lot of added weight to me.

firepinch

hatrickstu,

if you don't do what you do normally at the track (like turning on the fans etc etc) do you think that you would trap like me (102 mph) in the quarter mile instead of 108 mph? Heat can affect that much how much we are trapping?

hatrickstu

iTrader: (1)

nope, i still go 97-98 heatsoaked in the 1000. so id still go 105-106 or so

firepinch

So my heatsoak is not the only reason why I'm trapping this low... sure, a better clutch would be recommanded for me. I cannot shift as fast as I would like, if I do, the clutch just slip between 1st and 2nd gear. I tried once the wot box and this was even more horrible!

So as it is now, I'm trapping like a Gm stage 2 car without any supporting mods. LOL wow... what a performance for an SS/SC with a 2.7" pulley! The best time I did when I was justly stage 2 was 13.9 @ 102 mph! Go figure...

06cobalt racer

iTrader: (11)

next time you go to the track take some ice with you. and before you go to the staging lanes put ice in the res.

Zooomer

iTrader: (1)

W/o getting all techie, ice boxes in FMHE IC'd cars don't work.

The cooling doesn't offset the weight disadvantages.

firepinch

So what do you suggest to me Zoomer if I would like to trap around 106 to 108 mph like other people who have a 2.7" pulley without meth? It seems like I'm far away from this with my 102 mph! My clutch is slipped during my 14.0 @ 102 mph pass, but I dont think that my clutch slip would reduce that much my mph!

rollingboostedss

when I went to track I was running a 2.6 with no updated H/e and just a bag of ice sitting on the s/c and waited 15 min between runs and I ran a 13.90 at 109mph. but that is besides the point but make sure you give your car enough cool down time between runs.

hatrickstu

iTrader: (1)

this is wrong. i know what you are getting at, and it doesnt apply the same way in drag racing. for short bursts, it is beneficial. you would have to be either ignorant or in denial to argue introducing completely new MUCH colder fluid into a water/air system. the weight negligible and the fact intake temps are only rising say 11-13* across a full pass is proof it doesnt heak soak as bad.

now, in a road course application a large enough system to keep the system chilled would be a bad choice.

firepinch

For every people, here is the video of that famous 14.05 pass against a 350Z. You will hear my clutch slip and you will better judge by yourself. http://www.youtube.com/watch?v=wVTiAkEDU_s