Boosting 3.2L output during top end rebuild
10-08-2004, 04:36 AM
#1
Racer
Thread Starter
Join Date: Jun 2004
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
Boosting 3.2L output during top end rebuild
1984 3.2L.
What is the most practical means of improving engine output during a top end rebuild? I have heard of replacing the heads with 930's. Is that cost effective or even reasonable? I am not trying to outrun cup cars just get quicker acceleration off the line and passing. (aren't we all!)
At the track I am definitely horsepower limited on the straightaways.
Who has the better and more reliable rebuild kits?
Reg
What is the most practical means of improving engine output during a top end rebuild? I have heard of replacing the heads with 930's. Is that cost effective or even reasonable? I am not trying to outrun cup cars just get quicker acceleration off the line and passing. (aren't we all!)
At the track I am definitely horsepower limited on the straightaways.
Who has the better and more reliable rebuild kits?
Reg
10-08-2004, 11:15 AM
#2
Addict
Rennlist Member
Rennlist Member
Join Date: Jun 2001
Location: Jefferson City, Missouri
Posts: 256
Likes: 0
Received 0 Likes
on
0 Posts
If you can get 93 octane gas then switch out the pistons and cylinders for the euro 10.3:1 setup. Then go with SSI's with a Dansk sport muffler and a Steve W chip.
10-08-2004, 12:32 PM
#3
Technical Specialist
Rennlist
Lifetime Member
Rennlist
Lifetime Member
In considering what you can do, be sure and replace your piston rod bolts with ARP or Raceware bolts. Porsche reduced the size from the 3.0L to the 3.2L and 3.6L engines. This could become important with more HP or revs at the track. I believe that Bruce Anderson talks about engine options in his "Porsche 911 Performance Handbook".
10-08-2004, 01:10 PM
#4
Racer
Join Date: Jan 2004
Location: Surrey, UK
Posts: 466
Likes: 0
Received 0 Likes
on
0 Posts
I am in the same situation and I am considering going to 3.5 or 3.7L. With a 3.7L I am hoping to get 275hp at the wheels and a much better torque curve.
Obviously brakes, suspension and possibly an extra oil cooler are to be taken into consideration.
I don't have any $$$ amount yet. Andial quoted me $22-24k for a 3.7L rebuild.
Obviously brakes, suspension and possibly an extra oil cooler are to be taken into consideration.
I don't have any $$$ amount yet. Andial quoted me $22-24k for a 3.7L rebuild.
10-08-2004, 09:39 PM
#5
RL Technical Advisor
Reg:
There are some relatively simple things you can do that to enhance performance on your Carrera. Here are a few:
1) Install a GOOD performance chip; they are not all the same.
2) Regrind your cams to the 964 profile.
3) Extrude-hone your intake manifolds. Leave your heads alone as they have plenty of airflow up to 340 HP. (930 heads are nowhere near as good as your Carrera ones)
4) SSI Heat exchangers & Monty Sport muffler. This may affect smog compliance if thats an issue in your area.
5) 3.4 litre (98mm) pistons & cylinders. You'll need twin-ignition for compression ratios over 9.7:1 using pump gasolines.
As you can see, there are lots of options. A properly done twin-plug 3.4 with all these mods can make 270 HP with lots of torque.
There are some relatively simple things you can do that to enhance performance on your Carrera. Here are a few:
1) Install a GOOD performance chip; they are not all the same.
2) Regrind your cams to the 964 profile.
3) Extrude-hone your intake manifolds. Leave your heads alone as they have plenty of airflow up to 340 HP. (930 heads are nowhere near as good as your Carrera ones)
4) SSI Heat exchangers & Monty Sport muffler. This may affect smog compliance if thats an issue in your area.
5) 3.4 litre (98mm) pistons & cylinders. You'll need twin-ignition for compression ratios over 9.7:1 using pump gasolines.
As you can see, there are lots of options. A properly done twin-plug 3.4 with all these mods can make 270 HP with lots of torque.
Last edited by Steve Weiner-Rennsport Systems; 10-08-2004 at 10:03 PM.
10-09-2004, 01:38 AM
#6
The Ancient One
Rennlist Lifetime Member
Rennlist Lifetime Member
Join Date: Dec 1969
Location: Los Angeles, CA
Posts: 1,407
Likes: 0
Received 0 Likes
on
0 Posts
[QUOTE=Steve Weiner-Rennsport Systems]Reg:
1) Install a GOOD performance chip; they are not all the same.
What are some differences in the performance chips that are considered "good", and which chips are simply not worth the effort?
Do you need to do anything besides installing the chip and increasing air flow with a good filter and exhaust setup to receive any benefits? If thes alone will provide more HP & torque, how much of each is a realistic expectation?
Thanks.
1) Install a GOOD performance chip; they are not all the same.
What are some differences in the performance chips that are considered "good", and which chips are simply not worth the effort?
Do you need to do anything besides installing the chip and increasing air flow with a good filter and exhaust setup to receive any benefits? If thes alone will provide more HP & torque, how much of each is a realistic expectation?
Thanks.
10-09-2004, 04:19 AM
#7
RL Technical Advisor
Dan:
The differences are in the execution of the changes in the fuel & ignition maps.
A good chip will make a noticable difference & improvement in throttle response, mid-range torque and mid-range power. Its all about drivability and enhanced acceleration, NOT absolute HP.
Some chips offer such modest improvements as not to be worthwhile at all. Some chips have much too aggressive ignition mapping and will trigger detonation with marginal fuels and under hot conditions. These products are VERY dangerous and carry severe consequences to your bank account.
A good chip should be tuned for any modifications to the car and with the local grades of fuel. Some modifications certainly do not merit changes in mapping since their gains are very small.
A good chip should NOT change the rev limiter unless internal engine modifications have been done. This is another issue that carries severe consequences to your bank account, as well.
I cannot comment on what chips are good and which ones are not good, however some basic research on your part will provide that information.
The differences are in the execution of the changes in the fuel & ignition maps.
A good chip will make a noticable difference & improvement in throttle response, mid-range torque and mid-range power. Its all about drivability and enhanced acceleration, NOT absolute HP.
Some chips offer such modest improvements as not to be worthwhile at all. Some chips have much too aggressive ignition mapping and will trigger detonation with marginal fuels and under hot conditions. These products are VERY dangerous and carry severe consequences to your bank account.
A good chip should be tuned for any modifications to the car and with the local grades of fuel. Some modifications certainly do not merit changes in mapping since their gains are very small.
A good chip should NOT change the rev limiter unless internal engine modifications have been done. This is another issue that carries severe consequences to your bank account, as well.
I cannot comment on what chips are good and which ones are not good, however some basic research on your part will provide that information.
Trending Topics
10-09-2004, 06:16 AM
#8
Racer
Thread Starter
Join Date: Jun 2004
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
Kurt: Yes, I can get 93 octane.
Steve: Is item #5 of your response the sames as what Kurt suggests? Have you heard of the chip (Steve W) that he mentions? Is the order of your list a suggestion on how to appoarch the job? Regrind cams? Are there any out there that have the correct profile that will fit and that I can buy ? I am concerned about finding a good machine shop.
Steve and Kurt: Monty or Dansk sport muffler?
Bill: I'll have to look for the Performance handbook.
Mamo: 22-24K?????????!!!!!!!!
Anyone: What are the pros and cons of just buying a rebuilt engine the way you want vice redoing your own? Costs obviously if you pay another instead of doing it on your own. I mean final product.
Can any of the modifications be done alone or must some include others. For example if remapping will increase exhaust gas temperature should it be tied with the exhaust changout?
Which mod will give the biggest improvement?
I know I have alot of questions but I would rather ask up front than assume anything.
Thanks for all the excellent suggestions,
Reg
Steve: Is item #5 of your response the sames as what Kurt suggests? Have you heard of the chip (Steve W) that he mentions? Is the order of your list a suggestion on how to appoarch the job? Regrind cams? Are there any out there that have the correct profile that will fit and that I can buy ? I am concerned about finding a good machine shop.
Steve and Kurt: Monty or Dansk sport muffler?
Bill: I'll have to look for the Performance handbook.
Mamo: 22-24K?????????!!!!!!!!
Anyone: What are the pros and cons of just buying a rebuilt engine the way you want vice redoing your own? Costs obviously if you pay another instead of doing it on your own. I mean final product.
Can any of the modifications be done alone or must some include others. For example if remapping will increase exhaust gas temperature should it be tied with the exhaust changout?
Which mod will give the biggest improvement?
I know I have alot of questions but I would rather ask up front than assume anything.
Thanks for all the excellent suggestions,
Reg
Last edited by afinepoint; 10-09-2004 at 06:39 AM.
10-09-2004, 11:23 PM
#9
RL Technical Advisor
Reg:
There are a few good chips out there and once again, I'll encourage you to do your homework,....
My list was not in any order since everything depends on one's budget and situation. Rebuild time is when these decisions should be addressed as its much more expensive to do some of these mods later on.
Your cams can be reprofiled by a few companies; We use Webcam. If you retain the Motronic system, stick with 964 cams.
FWIW, I use Monty mufflers as they are superior to Dansk in terms of build construction and performance. They also carry a lifetime guarantee and I prefer their sound (subjective).
Before you decide about buying a rebuilt enegine, I would strongly suggest that you first read this; http://www.rennsportsystems.com/1.html since the word "rebuilt" means many things to many people. Doing it yourself (if you do not do these for a living) might not be the best solution and one should honestly assess how much risk you wish to accept given the consequences of a mistake.
Hope this helps,
There are a few good chips out there and once again, I'll encourage you to do your homework,....
My list was not in any order since everything depends on one's budget and situation. Rebuild time is when these decisions should be addressed as its much more expensive to do some of these mods later on.
Your cams can be reprofiled by a few companies; We use Webcam. If you retain the Motronic system, stick with 964 cams.
FWIW, I use Monty mufflers as they are superior to Dansk in terms of build construction and performance. They also carry a lifetime guarantee and I prefer their sound (subjective).
Before you decide about buying a rebuilt enegine, I would strongly suggest that you first read this; http://www.rennsportsystems.com/1.html since the word "rebuilt" means many things to many people. Doing it yourself (if you do not do these for a living) might not be the best solution and one should honestly assess how much risk you wish to accept given the consequences of a mistake.
Hope this helps,
10-10-2004, 05:32 AM
#10
Racer
Thread Starter
Join Date: Jun 2004
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
Steve,
Thanks, I did a top rebuild of my truck engine which went well. A big difference is that it was done with the engine in place. Pulling an engine is more involved and will/may require a stand and such. Plus the "special" tools.
I am have been wondering if a top and bottom rebuild should be considered.
The engine only has 100,000 miles, leaks little oil with Mobil 1 and runs well.
I need to carefully consider what to change and what to "leave alone".
Reg
Thanks, I did a top rebuild of my truck engine which went well. A big difference is that it was done with the engine in place. Pulling an engine is more involved and will/may require a stand and such. Plus the "special" tools.
I am have been wondering if a top and bottom rebuild should be considered.
The engine only has 100,000 miles, leaks little oil with Mobil 1 and runs well.
I need to carefully consider what to change and what to "leave alone".
Reg
10-10-2004, 08:49 AM
#11
Reg,
I suspect that Steve doesn't feel comfortable making a specific brand recommendation regarding the chip, but his description fits Steve Wong's chip perfectly. Go to www.911chips.com for complete info.
I agree with Steve and Kurt -
1. Install a Steve Wong chip. Hands-down the best thing out there. You won't be disappointed.
2. Change the exhaust - I use a Dansk euro pre-muffler in place of the catalyst, and a Dansk sport muffler.
3. You can change the air filter to a K&N if you want but the increase is small or nonexistant. However the intake sound is great and the access to that side of the engine is much improved.
I suspect that Steve doesn't feel comfortable making a specific brand recommendation regarding the chip, but his description fits Steve Wong's chip perfectly. Go to www.911chips.com for complete info.
I agree with Steve and Kurt -
1. Install a Steve Wong chip. Hands-down the best thing out there. You won't be disappointed.
2. Change the exhaust - I use a Dansk euro pre-muffler in place of the catalyst, and a Dansk sport muffler.
3. You can change the air filter to a K&N if you want but the increase is small or nonexistant. However the intake sound is great and the access to that side of the engine is much improved.
10-10-2004, 10:21 AM
#12
Racer
Join Date: May 2001
Location: Monroe, La
Posts: 382
Likes: 0
Received 0 Likes
on
0 Posts
I agree with what Steve and Dave have said, also you may want to check out
www.pelicanparts.com under 911bbs and do a search on 3.2 mods
Motors are basically air pumps.... more air in, more air out, better air flow
more horsepower.
Good luck
Chuck
www.pelicanparts.com under 911bbs and do a search on 3.2 mods
Motors are basically air pumps.... more air in, more air out, better air flow
more horsepower.
Good luck
Chuck
10-10-2004, 01:43 PM
#13
For a discussion of chips, check out this web site ( www.andial.com ) on the FAQ
page under Question 2. Most of the comments about chips and one's experience
are mostly based on "feelings". Few if any have really fully evaluated their engines
in a "before & after" chip test using a dyno. Most/all chips require increasing the
octane limit or pinging results under load and hot weather conditions.
Bottomline: Only when intake and/or exhaust changes are made will
chip mods really benefit an engine. In these cases, the chip mod
must be tweaked using a dyno for the overall engine mods to achieve
realistic results.
page under Question 2. Most of the comments about chips and one's experience
are mostly based on "feelings". Few if any have really fully evaluated their engines
in a "before & after" chip test using a dyno. Most/all chips require increasing the
octane limit or pinging results under load and hot weather conditions.
Bottomline: Only when intake and/or exhaust changes are made will
chip mods really benefit an engine. In these cases, the chip mod
must be tweaked using a dyno for the overall engine mods to achieve
realistic results.
10-10-2004, 10:35 PM
#15
Racer
Reg, if you were considering the money replacing your heads, then considering instead spending on 3.4 p/cs, cams, polished intakes, a good exhaust, and matching chip. Steve Weiner provides very good advice and each of his recommendations are not a waste of money for incremental gains. You easily can output 270 hp, and the displacement increase will bring the broad range torque up similar to that of a 3.6 motor. If you decide to forgo the 3.4 p/c upgrade, then the other mods will still bring a nice power boost to a 3.2. We recently dynoed about 226 rwhp on a Dynojet with 3.2L Euro 10.3:1 p/cs, Extrudehoned intakes, Webcam 20/21s, SSIs with a GHL muffler, and a matching chip. With a 15% transmission loss factor, this approximates to 266 at the engine.
For an 84 Carrera 3.2, the difference is quite significant in both throttle response, low/midrange torque, and top end hp. Note that Porsche speced the 84-86 Carreras at 207 hp and to run on 87 CLC unleaded octane fuel and to pass U.S. emissions. Being that this was their first time with programmable fuel injection, tuning for Federal emissions, the part throttle mapping was so lean and conservative, much of the response and torque that the engine is capable of is constrained. Porsche or Bosch realized this about the U.S. cars and on the 87-89 Carreras, rewrote the chip software to improve the acceleration fuel enrichment code. This requred a larger eprom memory, from 2k to 4k, or 8k in the case of the 28 pin chips to store the code. The good news is that on any early 2k DMEs, a simple modification is all that is needed to upgrade to the 4k programming. The right chip will release much of this power equally on both bone stock motors and heavily modified ones - it makes no difference.
For an 84 Carrera 3.2, the difference is quite significant in both throttle response, low/midrange torque, and top end hp. Note that Porsche speced the 84-86 Carreras at 207 hp and to run on 87 CLC unleaded octane fuel and to pass U.S. emissions. Being that this was their first time with programmable fuel injection, tuning for Federal emissions, the part throttle mapping was so lean and conservative, much of the response and torque that the engine is capable of is constrained. Porsche or Bosch realized this about the U.S. cars and on the 87-89 Carreras, rewrote the chip software to improve the acceleration fuel enrichment code. This requred a larger eprom memory, from 2k to 4k, or 8k in the case of the 28 pin chips to store the code. The good news is that on any early 2k DMEs, a simple modification is all that is needed to upgrade to the 4k programming. The right chip will release much of this power equally on both bone stock motors and heavily modified ones - it makes no difference.