Has anyone priced a 3.8 conversion lately?
11-25-2021, 12:34 PM
#1
Rennlist Member
Thread Starter
Has anyone priced a 3.8 conversion lately?
A few very old threads out there on this topic
Just curious what a realistic budget should be nowadays.
Just curious what a realistic budget should be nowadays.
Last edited by nowata; 11-25-2021 at 01:01 PM.
11-25-2021, 09:43 PM
#2
Not that it will do you any good, I did price a 3.8 rebuild, it is pricey but the real costs come with what you have to do to make it work. On its own, a 3.8 (depending on geography and individual shop) ground up rebuild is approx. $38k. Your best source for this is Ninemeister in the UK but you will need all sorts of exotic **** and Motec. Otherwise, the HP gains are fairly minimal and not worth the money. This is from my indy who is a crew chief for Porsche IMSA. My regular 3.6 rebuild came to just under $25k and I am VERY happy with it. I have a fair bit of track time and cannot squeeze the car to its fullest, more HP doesn't make you faster, it just makes you poorer; if that isn't a problem, have at it.
The following 3 users liked this post by misterbeverlyhills:
11-25-2021, 10:57 PM
#3
Rennlist Member
Thread Starter
Not that it will do you any good, I did price a 3.8 rebuild, it is pricey but the real costs come with what you have to do to make it work. On its own, a 3.8 (depending on geography and individual shop) ground up rebuild is approx. $38k. Your best source for this is Ninemeister in the UK but you will need all sorts of exotic **** and Motec. Otherwise, the HP gains are fairly minimal and not worth the money. This is from my indy who is a crew chief for Porsche IMSA. My regular 3.6 rebuild came to just under $25k and I am VERY happy with it. I have a fair bit of track time and cannot squeeze the car to its fullest, more HP doesn't make you faster, it just makes you poorer; if that isn't a problem, have at it.
https://bringatrailer.com/listing/1991-porsche-911-carrera-2-49/
Last edited by nowata; 11-25-2021 at 10:58 PM.
11-26-2021, 09:41 AM
#6
Rennlist Member
I guess I didn’t realize the complexity. The recent RoW 3.8 sale on BaT got me thinking about it. The HP gains posted there are significant.
https://bringatrailer.com/listing/19...-carrera-2-49/
https://bringatrailer.com/listing/19...-carrera-2-49/
11-26-2021, 10:33 AM
#7
Rennlist Member
I speak from some personal experience but also picking the brains of some people significantly smarter than me. I had a few lengthy conversations with Peter Dawe of Dawes Motorsports Development, Jeff Gamroth of Rothsport Racing, and a couple of other, perhaps lesser known engine builders and “experts”. @misterbeverlyhills nailed it when he said the added displacement alone doesn’t generate significant HP numbers. A properly built 3.8L with the right components will increase HP but in order to maximize the increased displacement you need the right intake, fuel system, ignition system, exhaust set up, and of course engine management system. As Jeff and Peter both said, the air cooled engine is just a big air pump so pumping the air efficiently creates the power and those bolt on pieces play a significant role in the performance.
You also have to decide the trade off between performance and every day drivability and reliability. The more you squeeze out in performance the more effort it will take to run at that peak performance. Generalization here but there is truth in this statement…..The more performance you pull out of the engine the more temperamental. Think of driving a race car versus its road going sibling, the HP difference may be nominal but everything that goes into the race car in terms of throttle response, braking, cornering, weight reduction, etc all take away from the reliability and longevity of a street car but significantly increase performance.
My grey 964 hot rod build was a stock 46k mile 964 C2. I purchased the car with work already performed by Autometrics (well known in racing circles) in Savanna GA. The PO had the car twin plug, coil on plug, ITB’s, and a competition version MoTec. The throttle response was ridiculous and it screamed in the upper revs but she was also temperamental. I took the car up to Dawe’s and when the car arrived it was pulling in the 250ish HP range at the wheels on a Mustang Dyno. Around 20% better performance than a stock C2. BY the time I got the car back it was pulling in the 270’s at the wheels or significantly more than a stock C2 and that was achieved by changing the air filter set up, removing a primary muffler and tuning. The engine was a Stock case with $35k of bolt ons, increased HP from roughly 220hp stock to 270hp with mods. Temps and elevation all mess with the performance of that car.
Just my humble opinion, a good solid 3.6 or 3.8 with the proper fuel, air, exhaust mixture and engine management system tuned properly. Keep in mind that very few shops regardless of what they tell you have expertise in tuning a MoTec, its a skill and art that is under appreciated and BTW the shops and techs who are excellent with air cooled MoTec are few and far between and they aren’t cheap. There is always the Wong chip option which is very good but the best air cooled shops will make their own chips specific to your car tuned by them. A short ratio gearbox with proper flywheel and clutch and cut 150-200 pounds with the right wheels, seats and removing a few unnecessary items and you will have a fantastic machine.
You also have to decide the trade off between performance and every day drivability and reliability. The more you squeeze out in performance the more effort it will take to run at that peak performance. Generalization here but there is truth in this statement…..The more performance you pull out of the engine the more temperamental. Think of driving a race car versus its road going sibling, the HP difference may be nominal but everything that goes into the race car in terms of throttle response, braking, cornering, weight reduction, etc all take away from the reliability and longevity of a street car but significantly increase performance.
My grey 964 hot rod build was a stock 46k mile 964 C2. I purchased the car with work already performed by Autometrics (well known in racing circles) in Savanna GA. The PO had the car twin plug, coil on plug, ITB’s, and a competition version MoTec. The throttle response was ridiculous and it screamed in the upper revs but she was also temperamental. I took the car up to Dawe’s and when the car arrived it was pulling in the 250ish HP range at the wheels on a Mustang Dyno. Around 20% better performance than a stock C2. BY the time I got the car back it was pulling in the 270’s at the wheels or significantly more than a stock C2 and that was achieved by changing the air filter set up, removing a primary muffler and tuning. The engine was a Stock case with $35k of bolt ons, increased HP from roughly 220hp stock to 270hp with mods. Temps and elevation all mess with the performance of that car.
Just my humble opinion, a good solid 3.6 or 3.8 with the proper fuel, air, exhaust mixture and engine management system tuned properly. Keep in mind that very few shops regardless of what they tell you have expertise in tuning a MoTec, its a skill and art that is under appreciated and BTW the shops and techs who are excellent with air cooled MoTec are few and far between and they aren’t cheap. There is always the Wong chip option which is very good but the best air cooled shops will make their own chips specific to your car tuned by them. A short ratio gearbox with proper flywheel and clutch and cut 150-200 pounds with the right wheels, seats and removing a few unnecessary items and you will have a fantastic machine.
The following 2 users liked this post by luv2race:
Blu RS (11-26-2021),
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11-26-2021, 05:11 PM
#8
Rennlist Member
It seems the most bang for your buck for an enjoyable street car is mid-weight flywheel (or lightweight with ECU programming change), trans re-gearing, and an intake system that is re-freshed or operating properly (vacuum lines, microswitch, resonance flap actuators, vacuum valves, etc). Assuming your compression and leak down numbers are ok
Last edited by RicardoD; 11-26-2021 at 05:12 PM.
The following users liked this post:
luv2race (11-26-2021)
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11-26-2021, 05:59 PM
#10
I speak from some personal experience but also picking the brains of some people significantly smarter than me. I had a few lengthy conversations with Peter Dawe of Dawes Motorsports Development, Jeff Gamroth of Rothsport Racing, and a couple of other, perhaps lesser known engine builders and “experts”. @misterbeverlyhills nailed it when he said the added displacement alone doesn’t generate significant HP numbers. A properly built 3.8L with the right components will increase HP but in order to maximize the increased displacement you need the right intake, fuel system, ignition system, exhaust set up, and of course engine management system. As Jeff and Peter both said, the air cooled engine is just a big air pump so pumping the air efficiently creates the power and those bolt on pieces play a significant role in the performance.
You also have to decide the trade off between performance and every day drivability and reliability. The more you squeeze out in performance the more effort it will take to run at that peak performance. Generalization here but there is truth in this statement…..The more performance you pull out of the engine the more temperamental. Think of driving a race car versus its road going sibling, the HP difference may be nominal but everything that goes into the race car in terms of throttle response, braking, cornering, weight reduction, etc all take away from the reliability and longevity of a street car but significantly increase performance.
My grey 964 hot rod build was a stock 46k mile 964 C2. I purchased the car with work already performed by Autometrics (well known in racing circles) in Savanna GA. The PO had the car twin plug, coil on plug, ITB’s, and a competition version MoTec. The throttle response was ridiculous and it screamed in the upper revs but she was also temperamental. I took the car up to Dawe’s and when the car arrived it was pulling in the 250ish HP range at the wheels on a Mustang Dyno. Around 20% better performance than a stock C2. BY the time I got the car back it was pulling in the 270’s at the wheels or significantly more than a stock C2 and that was achieved by changing the air filter set up, removing a primary muffler and tuning. The engine was a Stock case with $35k of bolt ons, increased HP from roughly 220hp stock to 270hp with mods. Temps and elevation all mess with the performance of that car.
Just my humble opinion, a good solid 3.6 or 3.8 with the proper fuel, air, exhaust mixture and engine management system tuned properly. Keep in mind that very few shops regardless of what they tell you have expertise in tuning a MoTec, its a skill and art that is under appreciated and BTW the shops and techs who are excellent with air cooled MoTec are few and far between and they aren’t cheap. There is always the Wong chip option which is very good but the best air cooled shops will make their own chips specific to your car tuned by them. A short ratio gearbox with proper flywheel and clutch and cut 150-200 pounds with the right wheels, seats and removing a few unnecessary items and you will have a fantastic machine.
You also have to decide the trade off between performance and every day drivability and reliability. The more you squeeze out in performance the more effort it will take to run at that peak performance. Generalization here but there is truth in this statement…..The more performance you pull out of the engine the more temperamental. Think of driving a race car versus its road going sibling, the HP difference may be nominal but everything that goes into the race car in terms of throttle response, braking, cornering, weight reduction, etc all take away from the reliability and longevity of a street car but significantly increase performance.
My grey 964 hot rod build was a stock 46k mile 964 C2. I purchased the car with work already performed by Autometrics (well known in racing circles) in Savanna GA. The PO had the car twin plug, coil on plug, ITB’s, and a competition version MoTec. The throttle response was ridiculous and it screamed in the upper revs but she was also temperamental. I took the car up to Dawe’s and when the car arrived it was pulling in the 250ish HP range at the wheels on a Mustang Dyno. Around 20% better performance than a stock C2. BY the time I got the car back it was pulling in the 270’s at the wheels or significantly more than a stock C2 and that was achieved by changing the air filter set up, removing a primary muffler and tuning. The engine was a Stock case with $35k of bolt ons, increased HP from roughly 220hp stock to 270hp with mods. Temps and elevation all mess with the performance of that car.
Just my humble opinion, a good solid 3.6 or 3.8 with the proper fuel, air, exhaust mixture and engine management system tuned properly. Keep in mind that very few shops regardless of what they tell you have expertise in tuning a MoTec, its a skill and art that is under appreciated and BTW the shops and techs who are excellent with air cooled MoTec are few and far between and they aren’t cheap. There is always the Wong chip option which is very good but the best air cooled shops will make their own chips specific to your car tuned by them. A short ratio gearbox with proper flywheel and clutch and cut 150-200 pounds with the right wheels, seats and removing a few unnecessary items and you will have a fantastic machine.
Indeed
365 at crank
2600 lbs wet
Dawes tuned/ jae lee designed
Custom regear
11-26-2021, 08:18 PM
#11
Rennlist Member
11-26-2021, 08:44 PM
#12
If you were to build a 3.8 using the same engine builders that Singer uses expect to pay $100k. That would give you around 375hp.
11-26-2021, 10:05 PM
#13
Rennlist Member
My 3.6 with RS pulley, SW 93 chip, cup airbox, LWFW, RS clutch, cup pipe, cat delete, FD secondary, CAE shifter, and 2800 lbs (cutting another 100 over the winter), makes for an incredibly fun car.
If I step it up, I’ll do an LSD and a regear. Personally, I don’t see the value in the 3.8 unless you just have money to spend and time to wait. That said, I haven’t driven a 3.8 so maybe I’m all wrong.
If I step it up, I’ll do an LSD and a regear. Personally, I don’t see the value in the 3.8 unless you just have money to spend and time to wait. That said, I haven’t driven a 3.8 so maybe I’m all wrong.
11-26-2021, 10:39 PM
#15
My 3.6 with RS pulley, SW 93 chip, cup airbox, LWFW, RS clutch, cup pipe, cat delete, FD secondary, CAE shifter, and 2800 lbs (cutting another 100 over the winter), makes for an incredibly fun car.
If I step it up, I’ll do an LSD and a regear. Personally, I don’t see the value in the 3.8 unless you just have money to spend and time to wait. That said, I haven’t driven a 3.8 so maybe I’m all wrong.
If I step it up, I’ll do an LSD and a regear. Personally, I don’t see the value in the 3.8 unless you just have money to spend and time to wait. That said, I haven’t driven a 3.8 so maybe I’m all wrong.
My 3.6
365 at crank
Regear
Lwf
Motec
2590 lbs wet