lq4 with maggie high iat pulling timing
lq4 with maggie high iat pulling timing I have a stock lq4 with an mp122 maggie on 8 pounds . It is intercooled with a heat exchanger out front with 2, 7 inch fans. I can drive down the highway and temps stay low ,about 115 degrees and can run the car hard without pulling timing. At the strip it is a different story. I spray methanol also but it does not help my intake air temps like I think it should or the iat sensor just is not picking it up. It was pulling timing at 102 degrees but i changed it so it would pull timing at 135 degrees.On a 70 degree day It heats up to about 147 going down the track and pulls timing. I dont see any knock yet either.
Where is everyone else pulling time to be safe on this setup?
I run 93 octane most of the time also. What is too hot. I run a bout 13 degrees of timing but it pulls it back to 9 or 10 on a run. Im thinking of going e85 but I would like to try to stay with 93 pump on methanol.
Where is everyone else pulling time to be safe on this setup?
I run 93 octane most of the time also. What is too hot. I run a bout 13 degrees of timing but it pulls it back to 9 or 10 on a run. Im thinking of going e85 but I would like to try to stay with 93 pump on methanol.
160 on a magnacharger? Those types of blowers heat soak and are more prone to preignition/detonation than a turbo app due to the early torque peak. 160 seems awfully brave.
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Joined: Mar 2014
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From: Ohio
Not to mention, IATs are more of a cause for concern at higher boost than he's running.
I usually don't differentiate IATs between blower/turbo setups. Air temp is air temp. You absolutely HAVE to adjust your timing curve between blower and turbo for the low RPM detonation issues, though.
A lot of the CTS-V blower swapped cars I've tuned have ran 140-160 IATs at double the boost he is running. Getting the main timing table right is most important.
I usually wait until 160 to pull timing, and then pull aggressively from there.
Depends on where his IAT is honestly. If his IATs are with the meth hitting the sensor, then there is absolutely cause for concern.
Not to mention, IATs are more of a cause for concern at higher boost than he's running.
I usually don't differentiate IATs between blower/turbo setups. Air temp is air temp. You absolutely HAVE to adjust your timing curve between blower and turbo for the low RPM detonation issues, though.
A lot of the CTS-V blower swapped cars I've tuned have ran 140-160 IATs at double the boost he is running. Getting the main timing table right is most important.
I usually wait until 160 to pull timing, and then pull aggressively from there.
Not to mention, IATs are more of a cause for concern at higher boost than he's running.
I usually don't differentiate IATs between blower/turbo setups. Air temp is air temp. You absolutely HAVE to adjust your timing curve between blower and turbo for the low RPM detonation issues, though.
A lot of the CTS-V blower swapped cars I've tuned have ran 140-160 IATs at double the boost he is running. Getting the main timing table right is most important.
I usually wait until 160 to pull timing, and then pull aggressively from there.
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I had an MP112 and experienced the same delema.
One option is to spray a small 75 shot of N2O. This will cool the initial charge substantially which will translate into combustion chamber temps being reduced enough to keep from yanking timing. Part of the systemic problem is that the IAT sensor gets saturated & we lose accurate readings. The other downside to this was that my tune was dumbed down all the time. We needed to reduce timing to accommodate the N2O. At that time I didnt have a method of having multiple tunes ( one for the track, one for daily street use). So out of boost & 1/2 throttle street stuff suffered.
Later I ditched the N2O & morphed into meth/water. It kept things under control. The water helped cooling the charge more than straight meth & it substantially cools the combustion chamber ( which is where devil lives).
Same saturated IAT sensor issues here as well. If you can monitor EGT you can dial this in.
This stuff can take you down a rabbit hole ! Larger heat exchanger, ice rsevoir yada yada
Back then many people had advised me to go E85 and my worries would go away. I can’t speak to that but maybe others here can chime in.
PS: lots of information re: these older Maggie’s on the GTO forums.
One option is to spray a small 75 shot of N2O. This will cool the initial charge substantially which will translate into combustion chamber temps being reduced enough to keep from yanking timing. Part of the systemic problem is that the IAT sensor gets saturated & we lose accurate readings. The other downside to this was that my tune was dumbed down all the time. We needed to reduce timing to accommodate the N2O. At that time I didnt have a method of having multiple tunes ( one for the track, one for daily street use). So out of boost & 1/2 throttle street stuff suffered.
Later I ditched the N2O & morphed into meth/water. It kept things under control. The water helped cooling the charge more than straight meth & it substantially cools the combustion chamber ( which is where devil lives).
Same saturated IAT sensor issues here as well. If you can monitor EGT you can dial this in.
This stuff can take you down a rabbit hole ! Larger heat exchanger, ice rsevoir yada yada
Back then many people had advised me to go E85 and my worries would go away. I can’t speak to that but maybe others here can chime in.
PS: lots of information re: these older Maggie’s on the GTO forums.
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Verdad Gallardo Thanks for the input. I may just go e85 or ice tank for race day. I did install a thermocouple under the intercooler and it is reading 8 to 10 degrees cooler than the sensor under boost so I may just use this also to dial it in instead of using the iat sensor. I will look into the exhaust temps also.
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Joined: Mar 2014
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From: Ohio
Others will set the main timing table as their 'well rounded' table and then use the IATs to compensate for the blower down low since the IAT table rows are in KPA.
Either way works.
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Joined: Nov 2005
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You can look into an Interchiller setup, do some research on the company and see if they can actually deliver or not. I ordered one up from one guy that was waiting on a part and expected to ship in 4 - 6 weeks. Almost 6 months later had to file a dispute just to get my money back via paypal because he was unresponsive to calls, texts and emails. I went with one on my LSA G8 and would consistently see below 20 below ambient temps and no real change in cabin A/C.
The other thing you can do is check the routing. In my experience I've seen best results with the pump pushing straight into the blower cooling brick. I believe the Maggy routing has it push through the HX and then that same fluid attempt to push into the brick and flow is drastically reduced. The one upside to it from what I've noticed is temps don't climb as fast but take longer to come back down.
Everyone approaches the tuning a little differently but I always went on the side of caution and would start pulling out timing in the 125-130ish mark. At about 12 lbs I could typically hit 145ish on a 70* day on a long pull.
The other thing you can do is check the routing. In my experience I've seen best results with the pump pushing straight into the blower cooling brick. I believe the Maggy routing has it push through the HX and then that same fluid attempt to push into the brick and flow is drastically reduced. The one upside to it from what I've noticed is temps don't climb as fast but take longer to come back down.
Everyone approaches the tuning a little differently but I always went on the side of caution and would start pulling out timing in the 125-130ish mark. At about 12 lbs I could typically hit 145ish on a 70* day on a long pull.
Depends on where his IAT is honestly. If his IATs are with the meth hitting the sensor, then there is absolutely cause for concern.
Not to mention, IATs are more of a cause for concern at higher boost than he's running.
I usually don't differentiate IATs between blower/turbo setups. Air temp is air temp. You absolutely HAVE to adjust your timing curve between blower and turbo for the low RPM detonation issues, though.
A lot of the CTS-V blower swapped cars I've tuned have ran 140-160 IATs at double the boost he is running. Getting the main timing table right is most important.
I usually wait until 160 to pull timing, and then pull aggressively from there.
Not to mention, IATs are more of a cause for concern at higher boost than he's running.
I usually don't differentiate IATs between blower/turbo setups. Air temp is air temp. You absolutely HAVE to adjust your timing curve between blower and turbo for the low RPM detonation issues, though.
A lot of the CTS-V blower swapped cars I've tuned have ran 140-160 IATs at double the boost he is running. Getting the main timing table right is most important.
I usually wait until 160 to pull timing, and then pull aggressively from there.
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Joined: Mar 2014
Posts: 7,192
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From: Ohio
Interesting. I usually go with aggressive timing, but also pull it aggressively. On my very first trip to Ohio is where I learned how much difference IAT can make. I had been tuning the GTO in high 80* air in Georgia, and it was low 30* temps in Akron. The car went from fun to OH **** when I added a few degrees in the main timing table on your cold roads. When I got back, I had to pull the timing back out to eliminate KR. Now I use around 120*F as a baseline. Anything under I add timing, and anything over I pull it. Your regional temps may lead to a different strategy, of course. My baseline will also be completely skewed when tuning a car with an actual MAT instead of IAT sensor. My previous tuning has always been with an IAT, but discussions have led me to believe that I may obtain better results using a MAT sensor.