Does 90/90 combo require tuning?
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From: Paxs River, MD
Originally Posted by brad8266
Not really but it would help to get the fuel trims at a good area.
Here is some good info from J-rod:
Originally Posted by J-Rod
Good threads here... Most of this is realted to idle. Also, the stock TB can get a bit better with some porting. I've also noticed when you dial the tables especially throttel cracker, the thing sometimes gets "sloppy" and you have to give it more throttle.
Just keep in mind a lot of values are going to increase or decrease about 48% based on the new Tb's effective area. But, if its based on airflow, then what you will need to do is log desired air, etc... to make sure things like desired air matches.
Also, you need to look at Idle airflow vs ect
log airflow data vs coolant temp and re-do that table.
Also, you may need to look at things like:
Throttle Cracker Airflow
Throttle Follower Airflow
Throttle Follower Airflow vs TPS
Throttle Follower Decay Gear vs Speed
C5 - ETC Scaler on 90mm TB, question
https://ls1tech.com/forums/pcm-diagnostics-tuning/434267-c5-etc-scaler-90mm-tb-question.html
Update 90mm TB + 48% Effective table
https://ls1tech.com/forums/pcm-diagnostics-tuning/335186-update-90mm-tb-48-effective-table.html
Is there anyone who has a big cam with no surging?
https://ls1tech.com/forums/pcm-diagnostics-tuning/404894-there-anyone-big-cam-who-doesn-t-have-low-rpm-surging.html
Throttle follower, throttle cracker, running airflow. (see the tables that were posted, and look at them)
https://ls1tech.com/forums/pcm-diagnostics-tuning/400278-issue-raf-table-stit-ltit.html
Simple facts are:
75mm Throttle Body and 90 Throttle Body. 48% is not related to airflow, it is the percentage of step that the 90mm uses to mimic the 75mm Area. So.....
Hypothetically
IF a 75mm TB @ 40 steps has 1 cu/inch of area
Than
a 90mm TB would need 19.2 steps to have the same 1 cubic inch of area
So you need to....
Multiply the 40 steps by .48 to get 19.2
40 x .48 = 19.2
There is alot more to the calculation but this is the jist. Rather than using steps since the step is going to be linear and equally sized, I used 0 to 90degrees and calculated area based on .25 degree. Calculated area when open - area closed to find total area gained, divided that by my 360 steps(360 - 1/4 or .25 degree increments) to find total area for each 1/4 degree of throttle movement. I used that to make a chart to map area of the 75mm TB as the butterfly opens from 0 to 90 degrees or WOT. I made another chart based on the area as it gained and reversed solved the 90mm TB to find the required step to mimic the exact area that the 75 shows. The steps were 48% less in each calculation. So reguardless of what unit that the ECU uses this calculates the same thing.
Just keep in mind a lot of values are going to increase or decrease about 48% based on the new Tb's effective area. But, if its based on airflow, then what you will need to do is log desired air, etc... to make sure things like desired air matches.
Also, you need to look at Idle airflow vs ect
log airflow data vs coolant temp and re-do that table.
Also, you may need to look at things like:
Throttle Cracker Airflow
Throttle Follower Airflow
Throttle Follower Airflow vs TPS
Throttle Follower Decay Gear vs Speed
C5 - ETC Scaler on 90mm TB, question
https://ls1tech.com/forums/pcm-diagnostics-tuning/434267-c5-etc-scaler-90mm-tb-question.html
Update 90mm TB + 48% Effective table
https://ls1tech.com/forums/pcm-diagnostics-tuning/335186-update-90mm-tb-48-effective-table.html
Is there anyone who has a big cam with no surging?
https://ls1tech.com/forums/pcm-diagnostics-tuning/404894-there-anyone-big-cam-who-doesn-t-have-low-rpm-surging.html
Throttle follower, throttle cracker, running airflow. (see the tables that were posted, and look at them)
https://ls1tech.com/forums/pcm-diagnostics-tuning/400278-issue-raf-table-stit-ltit.html
Simple facts are:
75mm Throttle Body and 90 Throttle Body. 48% is not related to airflow, it is the percentage of step that the 90mm uses to mimic the 75mm Area. So.....
Hypothetically
IF a 75mm TB @ 40 steps has 1 cu/inch of area
Than
a 90mm TB would need 19.2 steps to have the same 1 cubic inch of area
So you need to....
Multiply the 40 steps by .48 to get 19.2
40 x .48 = 19.2
There is alot more to the calculation but this is the jist. Rather than using steps since the step is going to be linear and equally sized, I used 0 to 90degrees and calculated area based on .25 degree. Calculated area when open - area closed to find total area gained, divided that by my 360 steps(360 - 1/4 or .25 degree increments) to find total area for each 1/4 degree of throttle movement. I used that to make a chart to map area of the 75mm TB as the butterfly opens from 0 to 90 degrees or WOT. I made another chart based on the area as it gained and reversed solved the 90mm TB to find the required step to mimic the exact area that the 75 shows. The steps were 48% less in each calculation. So reguardless of what unit that the ECU uses this calculates the same thing.
Originally Posted by cantdrv65
Yes. Remember you are changing the effective area of the Tb by +48%....
Fine to drive it without changing the tune but in my case drivablity suffered a little.
Fine to drive it without changing the tune but in my case drivablity suffered a little.
Originally Posted by brad8266
The FAST 90/90 is like a 20HP gain, it does not need a tune. And it is known that a stock unported FAST90/90 combo will hurt low end drivability anyway. It has nothing to do with the tune, the fuel trims will fix any fueling issues that arise and you wont even ever notice it.
On this one I don't agree with you, tuning has a lot to do with drivability issues on a 90/90 set-up modification.
I am so close from really good with my 16° of overlap, specially at low speed, fuel spark for sure plus adjustments on some tables related to 90TB...
Streetability video:
http://www.youtube.com/watch?v=PL7h3QvOUFs
Christian
Trending Topics
Originally Posted by miami993c297
Hi brad8266,
On this one I don't agree with you, tuning has a lot to do with drivability issues on a 90/90 set-up modification.
I am so close from really good with my 16° of overlap, specially at low speed, fuel spark for sure plus adjustments on some tables related to 90TB...
Streetability video:
http://www.youtube.com/watch?v=PL7h3QvOUFs
Christian
On this one I don't agree with you, tuning has a lot to do with drivability issues on a 90/90 set-up modification.
I am so close from really good with my 16° of overlap, specially at low speed, fuel spark for sure plus adjustments on some tables related to 90TB...
Streetability video:
http://www.youtube.com/watch?v=PL7h3QvOUFs
Christian
Thats great that your big cam is streetable but thats not what we are talking about here.
To the OP, dont waste your money on a tune for a FAST 90 alone if you are going to have a bit more mods in the near future. If my head/cam car could run fine untuned with a FAST then your bolton car will be just fine. Will it run optimum will a tune, yes, will you even notice a difference driving it around on the street whether it is tuned or untuned, probably not.
Last edited by brad8266; Apr 5, 2007 at 06:43 AM.
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Originally Posted by brad8266
LOL, a tune is not needed for a FAST on a bolt on car. It can wait until he gets whatever mods he wants to get. You are mentioning all this overlap and such but we are talking about a bolt on car I believe. You dont have to tune it for it to run ok. Thats what the GM gods invented fuel trims for. And there are idle trims that make up for any variances in the TB.
Thats great that your big cam is streetable but thats not what we are talking about here.
To the OP, dont waste your money on a tune for a FAST 90 alone if you are going to have a bit more modfs in the near future. If my head/cam car could run fine untuned with a FAST then your bolton car will be just fine.
Thats great that your big cam is streetable but thats not what we are talking about here.
To the OP, dont waste your money on a tune for a FAST 90 alone if you are going to have a bit more modfs in the near future. If my head/cam car could run fine untuned with a FAST then your bolton car will be just fine.
That is what I want to express here, it seems in line with the question.
YES you have to consider also the parameters related to the increase of the TB Area (as well as only bolts on...)
Fuel and spark will not be enough.
O2 sensors are just bringing your stoich in line.
Drivability is simply more than this.
YES you need a tune related to the 90mm TB...
Hope that helps.
Christian
Well I am so tired of arguing on the internet with people so i am not even going to argue anymore about this because it is a waste. If you want to get a tune for a FAST then go right ahead and waste some of your $$.
The OP didnt say he wants perfect drivability he just wants to know if it will drive OK, which it will.
The funny part is I actually drove a FAST90/90 without a tune so i can give first hand experience driving one untuned, can you? I would bet you put one on when you did your head/cam swap and had it tuned all at once so now you think becasue you had good results with it tuned that it means that everyones FAST90/90 wont run good unless its tuned. That is false logic. You can sit here and cite tables, fuel, and sprark until you turn blue in the face, but have you ever driven a FAST90/90 bolton car without a tune? If you havent then you are talking in theory.
Any amount of common sense will tell you that that combo will work best with a tune, that goes for every single engine mod. That doesnt mean that it is required to have it tuned for it to drive around decently at all.
The OP didnt say he wants perfect drivability he just wants to know if it will drive OK, which it will.
The funny part is I actually drove a FAST90/90 without a tune so i can give first hand experience driving one untuned, can you? I would bet you put one on when you did your head/cam swap and had it tuned all at once so now you think becasue you had good results with it tuned that it means that everyones FAST90/90 wont run good unless its tuned. That is false logic. You can sit here and cite tables, fuel, and sprark until you turn blue in the face, but have you ever driven a FAST90/90 bolton car without a tune? If you havent then you are talking in theory.
Any amount of common sense will tell you that that combo will work best with a tune, that goes for every single engine mod. That doesnt mean that it is required to have it tuned for it to drive around decently at all.
Last edited by brad8266; Apr 5, 2007 at 07:03 AM.
Hi cantdrv65,
Thank you very much to bring back all those very informative threads from Forum Members that have tested a lot and reported with accuracy for our pleasure...
I already learned a lot from some of those experienced persons in term of drivability / streetability / idling / leaving a stop smoothly / stopping at a light normally !!!!
There is a lot more inside the threads mentionned in J-Rod post that simply waiting about the O2 sensors doing the job they are build for.
Christian
Thank you very much to bring back all those very informative threads from Forum Members that have tested a lot and reported with accuracy for our pleasure...
I already learned a lot from some of those experienced persons in term of drivability / streetability / idling / leaving a stop smoothly / stopping at a light normally !!!!
There is a lot more inside the threads mentionned in J-Rod post that simply waiting about the O2 sensors doing the job they are build for.
Christian
Originally Posted by brad8266
Well I am so tired of arguing on the internet with people so i am not even going to argue anymore about this because it is a waste. If you want to get a tune for a FAST then go right ahead and waste some of your $$.
The OP didnt say he wants perfect drivability he just wants to know if it will drive OK, which it will.
The funny part is I actually drove a FAST90/90 without a tune so i can give first hand experience driving one untuned, can you? I would bet you put one on when you did your head/cam swap and had it tuned all at once so now you think becasue you had good results with it tuned that it means that everyones FAST90/90 wont run good unless its tuned. That is false logic. You can sit here and cite tables, fuel, and sprark until you turn blue in the face, but have you ever driven a FAST90/90 bolton car without a tune? If you havent then you are talking in theory.
The OP didnt say he wants perfect drivability he just wants to know if it will drive OK, which it will.
The funny part is I actually drove a FAST90/90 without a tune so i can give first hand experience driving one untuned, can you? I would bet you put one on when you did your head/cam swap and had it tuned all at once so now you think becasue you had good results with it tuned that it means that everyones FAST90/90 wont run good unless its tuned. That is false logic. You can sit here and cite tables, fuel, and sprark until you turn blue in the face, but have you ever driven a FAST90/90 bolton car without a tune? If you havent then you are talking in theory.
I am not arguing with you and will not do, I don't see any reason why.
Reread my post above...I am tuning my car myself (HP Tuners) and describe the process about the 90mm TB item improvement.
Is it necessary to retune after a change like the 90mm TB to have the car running???
No because the GM Engineers have imagined so many cases where something could go bad in your car that your PCM will always find a way to make it drive home (or dealer!!!)
Just changing the ETC Area Scalar under Idle / Idle Airflow / General will bring back in line with all the algorithms that GM Engineers have created for us and will make the PCM calculations accurate again.
That will help as well the O2 sensor making them less busy fitting with contradictory informations (but they can do it...)
Not changing this ETC Scalar Area parameter and you send a wrong information to your PCM and all the calculations and algorythms related to the TB Area (and there are some!!!) are simply faulse.
Then to stay in the way of thinking of all the GM Engineers that have work so smartly to make the C5 customers happy, after the 90mm TB change yes you need a tune to make your PCM as valid as it was before the change.
Christian
Yeah i agree with you when you say that tuning will bring it all back together like it came from the factory. That is all true. My point was that a tune is not required to drive your car when you install a FAST. That is the subject of this topic, not whether or not it will make your car the most driveable or make the most power. The FAST90/90 will drive just fine with no tune at all.
I know how to tune for the TB I do all my own tuning, the OP didnt ask for how to tune for it, he just wanted to know if it will be OK untuned. I have driven a FAST90 untuned so i know first hand it will be fine. Lets keep it on topic, we dont need a bunch of technical crap in such a simple thread. If you havent ever driven a FAST setup untuned then you dont know if you it needs a tune or not. I have driven it untuned and it will drive just fine.
I know how to tune for the TB I do all my own tuning, the OP didnt ask for how to tune for it, he just wanted to know if it will be OK untuned. I have driven a FAST90 untuned so i know first hand it will be fine. Lets keep it on topic, we dont need a bunch of technical crap in such a simple thread. If you havent ever driven a FAST setup untuned then you dont know if you it needs a tune or not. I have driven it untuned and it will drive just fine.
Originally Posted by miami993c297
Is it necessary to retune after a change like the 90mm TB to have the car running???
No because the GM Engineers have imagined so many cases where something could go bad in your car that your PCM will always find a way to make it drive home (or dealer!!!)
Then to stay in the way of thinking of all the GM Engineers that have work so smartly to make the C5 customers happy, after the 90mm TB change yes you need a tune to make your PCM as valid as it was before the change.
Christian
Sorry that's ethic and has nothing to do with this thread...
Shooter, you know the two faces of the story, build your own truth!!!
Trying to help as I was on this board, just making the info going on.
Christian
Thread Starter
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From: Paxs River, MD
Guys first off thank-you very much for take time to write up so what info. It made for very good reading. I going to wait on the tune, I'm going with a stall next month most likely a 3200 Vigilante and get a tune for my shifting points, then I'll be saving for all summer and fall for a head/cam package form mostly Texas speed. And tune everything in the winter and looking for 450-475 that is what my goals are.
Thank-you again and GOD bless, LS1tech is the **** because of guys like you that take the time to help out others.
Thank-you again and GOD bless, LS1tech is the **** because of guys like you that take the time to help out others.
Originally Posted by brad8266
Yeah i agree with you when you say that tuning will bring it all back together like it came from the factory. That is all true. My point was that a tune is not required to drive your car when you install a FAST. That is the subject of this topic, not whether or not it will make your car the most driveable or make the most power. The FAST90/90 will drive just fine with no tune at all.
I'd recommend ponying up for EFIlive and a wideband in conjunction with your future planned mods. It is an invaluable tool and much better than paying someone else to make three dyno runs on your car and call it "tuned"....
Since the person asking the question has a non-etc car the only real reason to get a tune is to lower the throttle position vs PE to make it kick into PE sooner with the extra air a bigger TB provides at a given throttle position. Required? Not really, but it is nice. The ETC scalar doesn't affect him. On an ETC car the scaler helps the most on a heads/cam car where correct calculated airflow per throttle position % is paramount to a good idling/driving car. A stock car or bolt on car can adjust on it's own just fine in that respect and will not drive bad at all.
If you guys are going to go off on a tangent at least make sure it's applicable.
If you guys are going to go off on a tangent at least make sure it's applicable.
Originally Posted by NicD
Since the person asking the question has a non-etc car the only real reason to get a tune is to lower the throttle position vs PE to make it kick into PE sooner with the extra air a bigger TB provides at a given throttle position. Required? Not really, but it is nice. The ETC scalar doesn't affect him. On an ETC car the scaler helps the most on a heads/cam car where correct calculated airflow per throttle position % is paramount to a good idling/driving car. A stock car or bolt on car can adjust on it's own just fine in that respect and will not drive bad at all.
If you guys are going to go off on a tangent at least make sure it's applicable.
If you guys are going to go off on a tangent at least make sure it's applicable.
Lol, no concern with the ETC....Shooter is not ETC
Christian
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From: Paxs River, MD
Originally Posted by NicD
Since the person asking the question has a non-etc car the only real reason to get a tune is to lower the throttle position vs PE to make it kick into PE sooner with the extra air a bigger TB provides at a given throttle position. Required? Not really, but it is nice. The ETC scalar doesn't affect him. On an ETC car the scaler helps the most on a heads/cam car where correct calculated airflow per throttle position % is paramount to a good idling/driving car. A stock car or bolt on car can adjust on it's own just fine in that respect and will not drive bad at all.
If you guys are going to go off on a tangent at least make sure it's applicable.
If you guys are going to go off on a tangent at least make sure it's applicable.
