Needed a new project... LS3 soon!

[ILLSMOQ]

Originally Posted by kask2_6.0

Got it on the dyno this weekend for tuning and it went surprisingly smoothly. You always run into something unexpected with a new build but I only had a couple of minor issues. The throttle body was occasionally going into limp mode due to a mismatch of throttle command an throttle position. The throttle position sensor in the throttle body is the issue. I’m thinking the throttle body I bought on eBay is actually a counterfeit so I ordered a new one. That should hopefully solve the issue. ]

Check your throttle travel/calibration

I ran into throttle issues in the beginning as well with my motec build. I discovered as I went to WOT, if I pushed the pedal harder, the floor board (where the throttle stop is) would flex allowing the throttle to pass 100% which resulted in a throttle fault. I recalibrated the throttle swing, pushing the pedal really hard at true 100% and modified the calibration so that the last 10% of pedal travel equaled 100% to the M130. If I floor it lightly I see 100% and if I try to put my foot through the floor I don’t go past 100%

Something for you to check before changing parts.

[kask2_6.0]

Originally Posted by ILLSMOQ

Check your throttle travel/calibration

I ran into throttle issues in the beginning as well with my motec build. I discovered as I went to WOT, if I pushed the pedal harder, the floor board (where the throttle stop is) would flex allowing the throttle to pass 100% which resulted in a throttle fault. I recalibrated the throttle swing, pushing the pedal really hard at true 100% and modified the calibration so that the last 10% of pedal travel equaled 100% to the M130. If I floor it lightly I see 100% and if I try to put my foot through the floor I don’t go past 100%

Something for you to check before changing parts.

While looking at the data you could see that the TB was entering a fault state from an aim tracking fault that would occur when releasing the throttle quickly. Basically the throttle position sensor wasn’t tracking well with the requested position on a fast decel. Any discrepancy over 2% would cause the TB to return to an unresponsive “safe” position of 20% open. A throttle blip would reset after a few seconds but it wasn’t right. I got the “OEM” throttle body for a too good price which is also why I was kind of thinking it might not be a legit part. Turns out it was a knockoff. See the pic for different between a legit part and the fake. New throttle body solved the problem I was having.


Added some header wrap and heat shielding for the fuel and brake lines too.






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[ILLSMOQ]

[QUOTE=kask2_6.0;3429097]While looking at the data you could see that the TB was entering a fault state from an aim tracking fault that would occur when releasing the throttle quickly. Basically the throttle position sensor wasn’t tracking well with the requested position on a fast decel. Any discrepancy over 2% would cause the TB to return to an unresponsive “safe” position of 20% open. A throttle blip would reset after a few seconds but it wasn’t right. I got the “OEM” throttle body for a too good price which is also why I was kind of thinking it might not be a legit part. Turns out it was a knockoff. See the pic for different between a legit part and the fake. New throttle body solved the problem I was having.
]



Great to hear

[kask2_6.0]

I haven’t had any overheating problems but just preparing for sitting in traffic in 90+ degree temps. Made some new mounts and swapped out my slim fans for high output units. With the fans being larger I had to use a 12” fan on the drivers side and an 11” on the passenger side. You can see in the pic below the 12” slim fans were a slightly smaller width due to the flat spots on the side. The 11” fan also had to be biased towards the bottom of the radiator to clear the thermostat housing/fitting. The new fans pull almost double the amount of air as the old fans.

[ILLSMOQ]

Nice job on the fans👌🏼 What radiator hoses are you using. I’d like to try a set like that

[kask2_6.0]

Originally Posted by ILLSMOQ

Nice job on the fans What radiator hoses are you using. I’d like to try a set like that

The hose clamps are gates power grip heat shrink clamps: https://www.summitracing.com/parts/aaf-all30257 They work pretty well as they have very wide clamping area and uniform clamping forces. Can also grow/shrink a bit with the silicone hose so they don’t loosen up.

Hoses are silicone elbows from Pegasus. You can see there is a union in the upper hose joining two elbows together.
https://www.pegasusautoracing.com/gr...upID=COOL38MMK
https://www.pegasusautoracing.com/pr...sp?RecID=25712

[ILLSMOQ]

Thanks, I’ll give them a try.

[TRS]

Originally Posted by kask2_6.0

The hose clamps are gates power grip heat shrink clamps: https://www.summitracing.com/parts/aaf-all30257 They work pretty well as they have very wide clamping area and uniform clamping forces. Can also grow/shrink a bit with the silicone hose so they don’t loosen up.

Hoses are silicone elbows from Pegasus. You can see there is a union in the upper hose joining two elbows together.
https://www.pegasusautoracing.com/gr...upID=COOL38MMK
https://www.pegasusautoracing.com/pr...sp?RecID=25712

@ILLSMOQ: I used the gates clamps too and they work great since thousands of miles. Very OEM style looking Hoses can be build with those clamps. The by far Best aspect is the low space consumption compared to traditional clamps. But you should realy order them at rockauto. The price is less then 1/3 there.
@kask2_6.0: Concerning the radiator and fans: If you dont use a full shroud and seal the radiator properly to the frame, the high output fans will be not change much, at least not as much as they could. What they will do is raising the pressure inside the compartment, what will cause more hot air from inside the compartment to flow back through and arround the radiator and will then be sucked through it again. So you get only more hot air cycling through the radiator again and again. And this will obviously not improve cooling very effectively.

If you are doing this to help cooling at low speed it might help a little better, especially since you have well positioned louvres in the hood. But for more cooling while car is stopped (as I understand your post), the effect of more power full fans will be much smaller than it could be with a full shroud and well sealed radiator.

To use no or a open shroud is a racing style design. There the car is meant to be moved fast most of the time and definetaly not sitting in traffic jam. The disadavantage of low cooling efficiency is intensonally accepted for that purpose. More airflow through the radiator at high speeds, where a full shroud could be limiting, is the gain of this design. But at full stop, ideling and maybe with A/C running, a full shroud is very important to get proper cooling efficiency.
A well sealed gap between frame/airscoop and radiator is very important for both appliacations. This should definately be done.

[ILLSMOQ]

Originally Posted by TRS

@ILLSMOQ: I used the gates clamps too and they work great since thousands of miles. Very OEM style looking Hoses can be build with those clamps. The by far Best aspect is the low space consumption compared to traditional clamps. But you should realy order them at rockauto. The price is less then 1/3 there.
@kask2_6.0: Concerning the radiator and fans: If you dont use a full shroud and seal the radiator properly to the frame, the high output fans will be not change much, at least not as much as they could. What they will do is raising the pressure inside the compartment, what will cause more hot air from inside the compartment to flow back through and arround the radiator and will then be sucked through it again. So you get only more hot air cycling through the radiator again and again. And this will obviously not improve cooling very effectively.

If you are doing this to help cooling at low speed it might help a little better, especially since you have well positioned louvres in the hood. But for more cooling while car is stopped (as I understand your post), the effect of more power full fans will be much smaller than it could be with a full shroud and well sealed radiator.

To use no or a open shroud is a racing style design. There the car is meant to be moved fast most of the time and definetaly not sitting in traffic jam. The disadavantage of low cooling efficiency is intensonally accepted for that purpose. More airflow through the radiator at high speeds, where a full shroud could be limiting, is the gain of this design. But at full stop, ideling and maybe with A/C running, a full shroud is very important to get proper cooling efficiency.
A well sealed gap between frame/airscoop and radiator is very important for both appliacations. This should definately be done.

A sealed shroud would be ideal for sitting in traffic but a hinderance at speed. Flaps could be a good compromise but there isn’t “that” much area to make it worth while to fabricate a shroud with flaps.

I’ll bet this fan upgrade does the job just fine. They are a huge step up from the slim fans.

[TRS]

Sure, the fans will help. Especially with the louvers in the hood. Without them the heat soak in a LS swaped 86 Chassis with full underbody is extream. But the Fans could do better when the radiator is sealed to the frame. This also under speed. And at stop also the shroud will Improve the cooling. Since I expoerienced heat issues with my LS swap ONLY at stop, even under heavy load and A/C on, and never at speeds constantly over ~30mph, a shroud would be my clear recommendation, since cooling when the car is moving has proofen to be suitable.

And sure, under speed the shroud is not optimal. Flaps are a great idea. But again, I never expoerienced heat issues as long as I keep moving with more then 30mph. So I would say that openening the shroud or working with Flaps is not necessary, even for track use. Also on the track, you usually dont want to have more air moving through the car then absolutely necessary, since this always means negativ aerodynamic effects.

Other builds for sure might behave different, especially as yours with pretty extrem modified LS engine. For my part I have full underbody, full catalyst system stuffed in the tunnel, A/C condenser + oil cooler infront of the radiator and no louvers in the hood (yet), but still I have no heat issues when moving at speed.

On the other hand, the heat management when stopped at hot 100+degree days and with A/C running is critical. Temps go pretty high within 10-20min. Without A/C also this works out, but you can pretty much die inside the car during a 30min traffic jam. I wasnt able to test this entirely on my swap after I changed the radiator, since we didnt had even nearly 90degree since nearly a year. But if the outside temp is realy high and stop long enough, I would guess that there still will be some issues.

[kask2_6.0]

Originally Posted by TRS

Sure, the fans will help. Especially with the louvers in the hood. Without them the heat soak in a LS swaped 86 Chassis with full underbody is extream. But the Fans could do better when the radiator is sealed to the frame. This also under speed. And at stop also the shroud will Improve the cooling. Since I expoerienced heat issues with my LS swap ONLY at stop, even under heavy load and A/C on, and never at speeds constantly over ~30mph, a shroud would be my clear recommendation, since cooling when the car is moving has proofen to be suitable.

And sure, under speed the shroud is not optimal. Flaps are a great idea. But again, I never expoerienced heat issues as long as I keep moving with more then 30mph. So I would say that openening the shroud or working with Flaps is not necessary, even for track use. Also on the track, you usually dont want to have more air moving through the car then absolutely necessary, since this always means negativ aerodynamic effects.

Other builds for sure might behave different, especially as yours with pretty extrem modified LS engine. For my part I have full underbody, full catalyst system stuffed in the tunnel, A/C condenser + oil cooler infront of the radiator and no louvers in the hood (yet), but still I have no heat issues when moving at speed.

On the other hand, the heat management when stopped at hot 100+degree days and with A/C running is critical. Temps go pretty high within 10-20min. Without A/C also this works out, but you can pretty much die inside the car during a 30min traffic jam. I wasnt able to test this entirely on my swap after I changed the radiator, since we didnt had even nearly 90degree since nearly a year. But if the outside temp is realy high and stop long enough, I would guess that there still will be some issues.

I agree that a fully shrouded setup would be a bit better in traffic but I'm hoping this setup will work well enough as without the shrouding it will be better for track duty. It's hard to tell from my pictures but the fan mounts are actually sealed to the radiator with a foam strip. So essentially about 70% of the radiator surface is shrouded within the fans. I also do not have an AC condenser so that will help out a bit more too. I guess I'll find out soon enough as it starts heating up around here.

Your build is looking really nice BTW

[TRS]

Thats a big difference for sure! If you dont have AC and therefore also no condenser and no added heat you should be in pretty good shape, especially with the Verus radiator and your hood louvers.

Let us now if it truly works out, but I would say it should.

[Razorlor]

What intake are you using on this? I did some driving around town this weekend and my intake temps are just way too high (around 150 degrees), looks like a much better setup. @kask2_6.0

[kask2_6.0]

Originally Posted by Razorlor

What intake are you using on this? I did some driving around town this weekend and my intake temps are just way too high (around 150 degrees), looks like a much better setup. @kask2_6.0

It's a modified corvette intake. They are pretty expensive but keep an eye out on ebay and sometimes you can come across a used one at decent price that just needs cleaning. Picked that one up for $250.

https://www.knfilters.com/chevrolet/...l-v8-gas/2008/