GranSport exhaust mods - picture heavy thread

Felonious Crud

Felonious Crud

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CatmanV2 said:
Does the Trofeo have a vent?
I'd have thought it's going to be sucking in hot air from that location as well.

C
Click to expand...

Yup - big one, looks like it feeds air straight to the air filter. 'nuf said - I don't think that mod would work well without a new bonnet. A better move would be one of Noor's direct replacement high-flow air filters, at least in the case of the GT.

Newton's work on the revised ducting for the 4200 / GS will yield better results, I think.
 
CatmanV2

CatmanV2

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Yeah, I would lean towards agreeing.
The vent will make things noisier (induction noise is going to be stepped up a lot I expect) and I wouldn't be surprised if it became something of a handful in situations where a delicacy of touch is required.

C
 
conaero

conaero

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They look so much better....I watch with interest.

Oh, what we were talking about the other night, if you can have them send to Benny he will get the jig made then drop them round Marios's when done.
 
conaero

conaero

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AdamN said:
It's not all in the exhaust. This is something to do with it. Not exactly sure what but as I understand it helps create that deeper rumble. You're welcome to have a poke round mine anytime.

View attachment 19926

PS - I may be wrong! Those of a stronger engineering and exhaustic-acoustics bent will have far more of a clue.
Click to expand...

My GTV had the same thing so I asked the question and was told that they cause the airflow to change and produce better induction flow....some sort of Venturi effect.
 
adam01

adam01

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Maf

Manifold wise yr moving from a 2 bolt flange to a 4 bolt

4 those (GS) owners that have invested in 2 bolt decats ie Larini etal, would need a some conversion plate for a connection

Any thoughts?
 
BennyD

BennyD

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Just take the manifold to an exhaust fabricator. These days a fair few will have access to water jet cutters and it would be a matter of some simplicity to make a 2 bolt flange and, after removing the 4 bolt flange, weld it on to the manifold.
 
M

MAF260

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adam01 said:
Maf

Manifold wise yr moving from a 2 bolt flange to a 4 bolt

4 those (GS) owners that have invested in 2 bolt decats ie Larini etal, would need a some conversion plate for a connection

Any thoughts?
Click to expand...
That depends on if they've fitted decat pipes or sports cats. If the former, the car will be left with no cats and will have emissions problems, CELs etc I would think. If they've fitted sports cats then it's a case of having something fabricated, although I think this would be a poor option due to the different positioning of the flange angles. Instead I would suggest selling the US-spec Larini pipes and fitting the correct version for the new manifolds.
 
philw696

philw696

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Need a forum friendly Mot tester with a common sense approach. If the car is healthy it will be close on the emissions test and the tester has discretion.
 
2b1ask1

2b1ask1

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Looking good Mark...

Adam; a K&nctype filter doesn't need to be a cone, just spend a happy few minutes looking at Opie Oils selection, I think for best results in a GTS you want to reach in front of the radiator to get cool air and not require any bonnet mod. You may need to consider loosing the 'beautification panels' that hide the lovely engine...
 
M

MAF260

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Progress update:

After a lot of research and conversations with many helpful folk I have ordered my new exhaust parts today. I've ordered Larini sports cat pipes which will fit my replacement manifolds and a h-pipe to replace the huge and cumbersome standard resonator/x-pipe. The h-pipe is less aggressive in noise than the unsilenced x-pipe; I will already be unleashing plenty of V8 music with the manifolds and sports cats!
I've decided to go the Larini route for a number of reasons:
1. quality of product
2. lifetime guarantee
3. proven product tested by many
4. I already have some Larini parts fitted
5. I can get back at least 50% of my outlay should I ever decide to fit standard parts back on
6. the dyno figures from Supersprint showed just a 6bhp and 6ft/lbs increase over standard, whereas the Larini sports cats release a claimed 18bhp alone
7. Supersprint were quoting up to 8 weeks before delivery and I'm too impatient to wait that long!

Noor from Torenno Performance has been a great help and has answered my many questions with great patience. He has sold me a very good deal (thank you!) but still relieved me of plenty of cash!

Delivery should be in the next couple of weeks and the car will be going up to Autoshield to have the parts fitted. I will be getting a reading from a rolling road (tbc) prior to the changes. Noor will also be helping with some mapping work after fitting to get the best from the mods. I will then follow up with a reading from the same rolling road to provide a direct comparison. There will be a warts and all report once it's all done so that anyone else considering doing the same work can see what the benefits are (or aren't!!!)
 
S

SimonCC

New Member
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690
Sounds good Mark am looking forward to your updates.

Do you currently have the Larini back boxes?
 
BennyD

BennyD

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15,006
MAF260 said:
Progress update:

After a lot of research and conversations with many helpful folk I have ordered my new exhaust parts today. I've ordered Larini sports cat pipes which will fit my replacement manifolds and a h-pipe to replace the huge and cumbersome standard resonator/x-pipe. The h-pipe is less aggressive in noise than the unsilenced x-pipe; I will already be unleashing plenty of V8 music with the manifolds and sports cats!
I've decided to go the Larini route for a number of reasons:
1. quality of product
2. lifetime guarantee
3. proven product tested by many
4. I already have some Larini parts fitted
5. I can get back at least 50% of my outlay should I ever decide to fit standard parts back on
6. the dyno figures from Supersprint showed just a 6bhp and 6ft/lbs increase over standard, whereas the Larini sports cats release a claimed 18bhp alone
7. Supersprint were quoting up to 8 weeks before delivery and I'm too impatient to wait that long!

Noor from Torenno Performance has been a great help and has answered my many questions with great patience. He has sold me a very good deal (thank you!) but still relieved me of plenty of cash!

Delivery should be in the next couple of weeks and the car will be going up to Autoshield to have the parts fitted. I will be getting a reading from a rolling road (tbc) prior to the changes. Noor will also be helping with some mapping work after fitting to get the best from the mods. I will then follow up with a reading from the same rolling road to provide a direct comparison. There will be a warts and all report once it's all done so that anyone else considering doing the same work can see what the benefits are (or aren't!!!)
Click to expand...

Getting rid of those crappy standard GS cats and headers will give a lot more than 6 bhp so you are onto a winner and Supersprint need to update their figures!
 
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