when is it time to upgrade the IC
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Phoneguy
Cometic HG stress tester
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The TSA cars were running bottom 11's and dipped into the 10's
Bryan
Bryan
highboostgn
Well-Known Member
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"when is it time to upgrade the intercooler?"
-as soon as you buy it
-as soon as you buy it
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You could probably run 7s on a stock intercooler if you put it on 6 second car, but that is besides the point.
I think what your are asking is at what point the stock intercooler is a restriction.
With alky you can compensate for the temperature reduction limitations of the stock intercooler.
However with that being said you will still have pressure drop across the core.
In my opinion if you have an upgraded turbo you would benefit from an aftermarket intercooler.
That does not mean that you would need it, but in just that you would be receiving an improvement.
In my old car "Super Junk" with a stock long block and a stage II turbo, I needed to add fuel after adding a PTE front mount.
My boost went up and the AITs went down and were faster to recover.
With that being said I still have a stock intercooler on my driver.
I am waiting for Alradco to ask me to test something. =)
I think what your are asking is at what point the stock intercooler is a restriction.
With alky you can compensate for the temperature reduction limitations of the stock intercooler.
However with that being said you will still have pressure drop across the core.
In my opinion if you have an upgraded turbo you would benefit from an aftermarket intercooler.
That does not mean that you would need it, but in just that you would be receiving an improvement.
In my old car "Super Junk" with a stock long block and a stage II turbo, I needed to add fuel after adding a PTE front mount.
My boost went up and the AITs went down and were faster to recover.
With that being said I still have a stock intercooler on my driver.
I am waiting for Alradco to ask me to test something. =)
I think it is sort-of a loaded question........
Will your car be quicker with a FMIC..... could be a little.... the difference is not near as noticable at lower boost/power levels.... as John alluded to....alky can cover up alot of sins the stock intercooler has. I'd say a bottom 11 sec car could possibly benefit from a good FMIC..... but it comes with a price...... the cars in the hot parts of the country that drive them on the street with air conditioning have a harder time keeping the engine cool with a large FMIC up there getting first shot at incoming air.
If I had alky.... and only wanted to go high 10's and drove my car often in hot weather with the a/c.... I'd look elsewhere....... there have been plenty of people with a SLIC get into the 9's..... either a stretched stock IC or just a dutt neck installed on a stock IC.
One place where a front mount has a clear advantage is back-to-back passes at the strip..... the FMIC is not near as prone to heat soak IMHO.
HTH
Will your car be quicker with a FMIC..... could be a little.... the difference is not near as noticable at lower boost/power levels.... as John alluded to....alky can cover up alot of sins the stock intercooler has. I'd say a bottom 11 sec car could possibly benefit from a good FMIC..... but it comes with a price...... the cars in the hot parts of the country that drive them on the street with air conditioning have a harder time keeping the engine cool with a large FMIC up there getting first shot at incoming air.
If I had alky.... and only wanted to go high 10's and drove my car often in hot weather with the a/c.... I'd look elsewhere....... there have been plenty of people with a SLIC get into the 9's..... either a stretched stock IC or just a dutt neck installed on a stock IC.
One place where a front mount has a clear advantage is back-to-back passes at the strip..... the FMIC is not near as prone to heat soak IMHO.
HTH
84BuickGNYorkPA
Daily Driving Buick V-6 Turbo's 1979 - Present
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Well if you get/got a decent set of heads and cam, intercooler upgrade would be on the short list.
Chuck
Chuck
Would you say the pressure drop on...say a stock IC with the Dutt neck, affect how quickly the engine spools up? If so how by how much?
I received some info from Red Armstrong a LOONG while ago when I bought some chips from him. This compares the StockIC to his Stretched/large neck, stockIC. This info could be up to 15 years old.
Description:
100% of stock and 70% of another and big neck.
He says that it is worth approx. 5mph and 3/10's in the 1/4 mile.
Stock IC: Pressure drop across a stockIC at 20 psi at the intake manifold is approx. 4 1/2 psi. In other words the turbo has to make 24 1/2 psi of boost to get 20 psi at the manifold.
Stretched IC (big neck):
Pressure drop across stretched IC at 20 psi at the intake manifold is approx. 1 1/4 psi. In other words the turbo has to make 21 1/4 psi of boost to get 20 psi at the manifold.
quote: "I found that for each additional pound of boost the turbo charger had to make, the air temperature was incresed 12 to 15 degrees F. My intercooler has 70% more cooling cabability than a stock intercooler, this coupled with the fact that there is less pressure drop across it, means that the turbo doesn't have to make as much boost, reducing the air temperature from the turbocharger..."
Thanks Red Armstrong.
Description:
100% of stock and 70% of another and big neck.
He says that it is worth approx. 5mph and 3/10's in the 1/4 mile.
Stock IC: Pressure drop across a stockIC at 20 psi at the intake manifold is approx. 4 1/2 psi. In other words the turbo has to make 24 1/2 psi of boost to get 20 psi at the manifold.
Stretched IC (big neck):
Pressure drop across stretched IC at 20 psi at the intake manifold is approx. 1 1/4 psi. In other words the turbo has to make 21 1/4 psi of boost to get 20 psi at the manifold.
quote: "I found that for each additional pound of boost the turbo charger had to make, the air temperature was incresed 12 to 15 degrees F. My intercooler has 70% more cooling cabability than a stock intercooler, this coupled with the fact that there is less pressure drop across it, means that the turbo doesn't have to make as much boost, reducing the air temperature from the turbocharger..."
Thanks Red Armstrong.
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Kevin,
Thanks for these numbers.
I would imagine the drop over a front mount would be even less.
An extra boost gauge and a one way check valve would help get this data.
Yea, I think it's good data for a stock IC and it certainly shows the restriction it has. One thing to remember is that there are people who have used it succesfully beyond it's capabilities but as always it's always good to see data.
ks
ks
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- May 28, 2001
- Messages
- 2,530
On a stock GN such as yours, it is a good idea. Look at the numbers posted above. The stock intercooler has a natural restriction once you go over stock boost levels. The Duttweiler neck was meant to address that problem. You will see better response from the turbo, especially when you turn up the boost, which we all do.
The good news is that you wont need to buy another one later down the road when you spring for that bigger turbo or alky set up or both. It is nice when you can build on top of parts you already bought.
If your car is bone stock the first thing you really, really need to do is get a good fuel pump, hotwire kit and volt booster for that car before anything else. A stock pump is the shortest path to becoming a master at changing head gaskets......
The good news is that you wont need to buy another one later down the road when you spring for that bigger turbo or alky set up or both. It is nice when you can build on top of parts you already bought.
If your car is bone stock the first thing you really, really need to do is get a good fuel pump, hotwire kit and volt booster for that car before anything else. A stock pump is the shortest path to becoming a master at changing head gaskets......
This article has been out since 2003. A lot of new members have probably not seen it. Very good data on intercoolers.
http://www.vortexbuicks-etc.com/bob_dick.htm
Table 3 and Table 4 TB Inlet temperatures are probably the most interesting (and easier to read than the graphs). Note that in Table 4, the "TB Inlet" and "Turbo Outlet" data appears to have been accidentally switched. Chart 4 is also very interesting - note how much less pressure drop all of the intercoolers offer compared to stock. Even installing a Dutt neck onto a stock intercooler lowers its pressure drop by 40%.
Use the data, judge for yourself.
http://www.vortexbuicks-etc.com/bob_dick.htm
Table 3 and Table 4 TB Inlet temperatures are probably the most interesting (and easier to read than the graphs). Note that in Table 4, the "TB Inlet" and "Turbo Outlet" data appears to have been accidentally switched. Chart 4 is also very interesting - note how much less pressure drop all of the intercoolers offer compared to stock. Even installing a Dutt neck onto a stock intercooler lowers its pressure drop by 40%.
Use the data, judge for yourself.
True. Proves that even somewhat reliable sources can screw up the data a bit.
I hate getting involved in these types of give and take. The only correct answer is..... will it help? YES. Do you need the help? ????. Can you afford the help? ????.
Of course you'll always hear the stories of how so and so ran 9's on a stock IC!! Means absolutely nothing as far as I'm concerned! Likely took and 8 second motor to do it.
All I know is, when I upgraded to my CAS V4 many, many years ago, even on my somewhat stock build, it allowed me to run much more boost than I could with a stock IC., next best would be streched stock, and best would be a good FM.
Are there trade-off's? some. You'll have to have a cooling system that's up to snuff, and a good cooling fan capacity! (these I have, so overheating is not a concern on mine). Such a good front mount is a bonus for me because I refuse to run alky.
I burn straight 93 octane pump with no other help.
My wot timing is set to 21.8 in 1st and 2nd gears, and 19 in 3rd.
My boost is set to 21# in 1st and 2nd, and 19 in 3rd.
I do all this with no knock or knock retard. My tune has been perfected over quite a bit of time and is very close. If I push the early boost to 23 ish, it's start tickling the knock sensor, so I have a bit of a safety margin.
Max temps I have ever seen (this past summer), during a long hard wot pull, was 99°
So, is it time to upgrade to a front mount. It's a question you can only answer yourself. According to your goals/aspirations.
Not to hijack the thread, but I'm interested in this. Like you, I'm a member of alcoholics anonymous, and I partially make up for it with my large FMIC. If you don't mind sharing, what F/A ratio are you running in 1st, 2nd, and 3rd gears? My 93-octane "street tune" runs similar timing to you, but I'm not able to get to those boost levels without some knock.
Thanks,
I'm running 11.3:1 in all gears (wot). Have you tried pulling your timing back just a bit at a time? To be a little extra safe as of late, I've pulled the boost back to an even 20# in 1st and 2nd, and 19# in 3rd.
