The dreaded part throttle surge after front mount install.

INEEDAGN

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Joined
Feb 28, 2003
Anything that can be done about it? I either need to fix it or become a better driver. If I lift for vehicle control/tire spin, it surges badly, knock sensor goes through the roof, have to get completely out of the throttle and take a second stab at it. Also moderate throttle acceleration will do it sometimes.

Mild engine build, don't know exactly whats in it but receipts show a 194/204 cam, 3 angle valve job, maybe mild head porting but don't know. Built 2 owners ago circa 1995.
PTE front mount
Te44 with garrett .63 housing
Atr ext. gate downpipe with the dump open
restalled d5
Big mouth cold air/3.5" maf pipe
mototron 60's/trans plus/extender/hotwired mystery pump in the tank

This is a pump gas only build, front mount helped a ton with stretching the boost level, but it'll never see 25+ psi so I figured I haven't outgrown the 44 yet. I am happy with the current performance of the car and don't want to throw a bunch more money at it. Is there anything else I can do? Spoolup is bad enough as it is, I don't want to have to get a bigger turbo or go with a better converter. Need to play with spool fuel and launch assist in the extender chip but i'll openly admit I dont have a clue which way to swing the spool fuel. With stock intercooler I had to have it at +6 or +8% wot fuel, I had to max the wot fuel at +14% to keep the thing from knocking after the fm. Probably looking at a chip reburn but not until winter.
 
Change the maf to blow through. Or go speed density.


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Blow through MAF is possible but would suck to rig up with the FM pipes, they are discontinued now and I can't modify them cause they are apparently worth their weight in gold. Speed density ain't happenin'. I had heard about the tornado thing before but never knew if someone was just trying to blow smoke up my ass. I have a tornado on the shelf at work that I got out of a trade in, it's too small of diameter but its cut so that it can be stretched. Maybe I will try it.
 
The info on Speed Density is correct. Fixed my surge issue. I must say after the Speed Density change I will never go back to MAF. Period.
 
there are 2 issues with surge.

First is the surge itself, its not real good for the turbo, but at part throttle its probably not going to hurt anything.

Second is how it makes the car drive. Depending on the MAF the air rushing in and out makes the MAF read a ton of air that the engine is not using, so the fuel delivery surges, and this is what you feel, the car "chugging".

Switching to speed density takes away the chug, the car runs smoothly during these events. But it does not "fix" the surge. Fixing the surge is tougher. In some instances it can be fixed with some clever chip programming, I have heard of success with the tornado (apparently breaks up the mechanical resonance.)

B
 
Why don't you like the idea of speed density??


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There was a long technical discussion about this a little while ago. The bottom line is that some have seen elimination of part-throttle surge by installing a Tornado right in front of the compressor inlet. The Tornado acts like a set of inlet guide vanes, moving the surge line of the compressor to the left. Those running the Tornado say there is no performance loss either.

http://www.turbobuick.com/forums/index.php?posts/3060068

Note that the Tornado will not do anything about the surge that happens when you close the throttle.

My car gets a little part throttle surge with my TA49 and FMIC, but it's easy to drive around. If it was worse, I might consider installing one.

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Why don't you like the idea of speed density??

Mostly because I don't want to have to throw more money at it after doing the trans plus/extender/ls1 maf setup. It works great and I love it. If I were to start from stock again on my second car, I'd consider it. I'm going to try the tornado. I know theres nothing that can be done about the sneeze when the throttle is slammed shut except a bov. I just hate having an area in the throttle that I can't use.
 
Mostly because I don't want to have to throw more money at it after doing the trans plus/extender/ls1 maf setup. It works great and I love it. If I were to start from stock again on my second car, I'd consider it. I'm going to try the tornado. I know theres nothing that can be done about the sneeze when the throttle is slammed shut except a bov. I just hate having an area in the throttle that I can't use.

I sold my MAF and Translator for more than the cost of the TT SD chip.

My turbo has snorted a lot in it's lifetime and it's still going strong. You'll probably upgrade to a bigger turbo before you damage the one you have.
 
I had your same issue. Don't kid yourself about the tornado directing the air better or anything. If it directed air better, the surge would be worse! It's a cork but it will solve your problem. My 44 still surges a bit but you don't need to drive around it anymore. It's audible but the bad bucking and kr is gone. Without alky, I don't have it, but with alky spraying, the compressor is just too damn efficient to not get surge. As far as my cork comment, I leave my tornado in at that track and still trap 120+mph so it isn't holding max flow back; the exhaust housing still does that for me! Simple fix though and you'll forget it's even in there but the car will drive much better.

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Wot surge is the only surge to be concerned about but my car would buck and run poorly at part throttle from the surge/turbulent air through the maf. This all occurred between 8-12psi. Anything below or above and it was fine; still is fine.

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I had a surge with a TA-49 and front mount. Put the Tornado back about 6-7 years ago and have not had any issues DD or at the track.

Dannyo


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Don't mean to hijack, but where do guys get the tornado from? Will a cheapie off E-bay do the trick or do I have to get the real deal? I've had compressor surge around 10psi(part throttle) since I installed my TE-44 and PTE slic. I'm not getting any kr or bucking, but it doesn't sound or feel like it's good for the turbo at all. It sounds like it's 'cycling' at 60 hz or something.
 
Don't mean to hijack, but where do guys get the tornado from? Will a cheapie off E-bay do the trick or do I have to get the real deal? I've had compressor surge around 10psi(part throttle) since I installed my TE-44 and PTE slic. I'm not getting any kr or bucking, but it doesn't sound or feel like it's good for the turbo at all. It sounds like it's 'cycling' at 60 hz or something.


How big is the inner diameter of your intake? I'll post a link if you tell me the size.
 
For S&G, I might try this. I have a 3 inch MAF pipe. I'm not totally sold on this yet, but I don't drag race the car any more, so all out performance isn't as important to me.

Which Tornado would I need?

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You want a KI-75 for your 3" application, but most stores appear to be out of them right now. And as far as performance, my tornado hasn't stopped me from maxxing out my te44.
 
You want a KI-75 for your 3" application, but most stores appear to be out of them right now. And as far as performance, my tornado hasn't stopped me from maxxing out my te44.
Thanks. I found some in stock on ebay.
 
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