turbo techies knowledge wanted????????

[coxie]

also i have been looking into the exhaust wrap for the tubular manifold and my elbow/down pipe to the first flange under the car.. 8) :twisted:

it claims to reduce temps by upto 70 percent and also more efficent turbo system heat transfer. :shock:

is it worth it to do all three items for a cost of approx £30 :?:

 

[Nad]

Heat wrap to the manifold will reduce temps but causes uneven heat distribution and will cause the manifold to crack faster. This isnt as great an issue on the standard log manifold. They recommend a heat shield about 20mm away from the manifold which will keep temps down but not allow heat spotting and as much cracking. Rally cars have massive box section heat shield for their manifold, then ceramic coated the rest of the way. After the turbo u should be alright to wrap it as the temps arent as high.

Nad

 

[coxie]

thanks for your valuable input

 

[Odin]

thanks for your valuable input

That's gotta be the first time anybody said that about nad :shock: :lol:



rob

 

[Nad]

thanks for your valuable input

That's gotta be the first time anybody said that about nad :shock: :lol:



rob

Yeah well I started a decent degree now so am getting all brainy 8) :lol:

Nad

 

[coxie]

NAD:when you say it causes cracking is this on a daily used r or a spare time car as in the last 14 months i have only clocked up 1079 miles and for the next 4-5 years its off road for a complete restoration inside and out :shock: 8) .when this is complete i will use it at weekends only so am wondering wether it will be a major issue lagging it all :?:

CHEERS STU

 

[Anonymous]

think the theorists have got it wrong again somehow with their conclusions about equal length manifolds.

i've got both my "accurate" printouts in front of me and my engine gives approx 45bhp @ 1800rpm up to 380bhp @ 5370rpm.the torque is 110lb/ft @ 1800rpm up to 407lb/ft @ 4790rpm.

the other one is 40bhp @ 1800rpm up to 350bhp @ 4900rpm.the torque is 110lb/ft @ 1800rpm up to 385lb/ft @ 4560rpm.

i'd call both of these results a broad spread of power and torque over quite a normal rev range compared to the std rev range and certainly not what would be expected after reading both of nad's posts re equal length headers and their varying diameters :?

there are some clear photo's of my manifold on the DP web site,or if someone could host a couple of photo's for me,i have 3-4 that i could send them

 

[GINGA]

there are some clear photo's of my manifold on the DP web site,or if someone could host a couple of photo's for me,i have 3-4 that i could send them

Or you couldlook here http://www.gti-r.com/misc4/BruceSpence/index.htm for loads of pics and even the dyno graphs

 

[Nad]

think the theorists have got it wrong again somehow with their conclusions about equal length manifolds.

i've got both my "accurate" printouts in front of me and my engine gives approx 45bhp @ 1800rpm up to 380bhp @ 5370rpm.the torque is 110lb/ft @ 1800rpm up to 407lb/ft @ 4790rpm.

the other one is 40bhp @ 1800rpm up to 350bhp @ 4900rpm.the torque is 110lb/ft @ 1800rpm up to 385lb/ft @ 4560rpm.

i'd call both of these results a broad spread of power and torque over quite a normal rev range compared to the std rev range and certainly not what would be expected after reading both of nad's posts re equal length headers and their varying diameters :?

there are some clear photo's of my manifold on the DP web site,or if someone could host a couple of photo's for me,i have 3-4 that i could send them

One thing I would like to point out is that my posts contains the opinions not of myself but of others. I can find where the links come from, one of which is a race car outfit and u can talk to them direct if u wish. THe problem is with ur engine is that those two graphs you are comparing are not of a standard engine with the manifold just swapped over. This would be a more accurate way to show the improvement dont u think?

Also if u had read it properly, I said that alot of these examples are not relevant to turbocharged engines as the air is forced in and out

Just adding in that peak torque on a rally car is around 4000rpm but at around 500lb/ft, and 300bhp at around 5000rpm, this is what narrow tubes and long uneven headers do.

Nad

 

[Nad]

NAD:when you say it causes cracking is this on a daily used r or a spare time car as in the last 14 months i have only clocked up 1079 miles and for the next 4-5 years its off road for a complete restoration inside and out :shock: 8) .when this is complete i will use it at weekends only so am wondering wether it will be a major issue lagging it all :?:

CHEERS STU

Well in 4-5yrs I'm sure they may have solved the problem!!! :lol: Mainly its the cooling down process. If it cools down too fast it will crack. Heat shield allow air to circulate around both side of the tube hence equalising the temps better. On the mileage ur doing I doubt it would be a problem, but if the problem can be solved with a heat shield, that may be the best route. I am undecided what to do with mine atm.

Nad

 

[Edd]

Don't mean to be picky Bruce but are you sure you have a 4 inch exhaust from turbo back?
I've heard that you cannot fit much bigger than 3 inch over the rear axle. Also looking at the pictures of yuor car the turbo elbow definitelity isn't 4 inch. I presume your turbo has 4 inch inlet, so if you look as that, then look at the turbo elbow, that is 3 inch maybe a bit smaller
Maybe you just have a full 3 inch system.
It wouldn't be the first time DP had told you a porky

 

[Anonymous]

think the theorists have got it wrong again somehow with their conclusions about equal length manifolds.

One thing I would like to point out is that my posts contains the opinions not of myself but of others. I can find where the links come from, one of which is a race car outfit and u can talk to them direct if u wish. THe problem is with ur engine is that those two graphs you are comparing are not of a standard engine with the manifold just swapped over. This would be a more accurate way to show the improvement dont u think?

as per above nad,this was not meant as a personal attack on you but,i do question the judgement of all these theories and conclusions that you tend to quote from your books.also,is swapping the manifold on it's own not another tuning method used on n/a engines rather than ours :?: usually,our lot tend to change their manifolds at the same time as their turbo's.

Also if u had read it properly, I said that alot of these examples are not relevant to turbocharged engines as the air is forced in and out

i did read it properly.what is the point of quoting from books that are of no relevance to us :?: i've yet to see a n/a gti-r :!:

Just adding in that peak torque on a rally car is around 4000rpm but at around 500lb/ft, and 300bhp at around 5000rpm, this is what narrow tubes and long uneven headers do.

again,what relevance is there in comparing rally cars to our cars :?: .might i suggest that there are very few people on here that can afford the necessary to create an engine the equal of a rally car's :!:
when sam is finished mapping my car to HIS satisfaction,i would expect to achieve at least the torque figures you've quoted above if not the power figures.granted it will probably be at slightly different revs but not that far away.as for the power,i know i'll def have a little bit more than just 300bhp :twisted:

 

[Fast Guy]

Just adding in that peak torque on a rally car is around 4000rpm but at around 500lb/ft, and 300bhp at around 5000rpm, this is what narrow tubes and long uneven headers do.

Nad

I think that'll be down to alot more than the manifolds. Aren't rally cars restricted to 300bhp? so they want that figure as soon as possible. High boost and high compression ratios will help them get there. Obviously they want the best exhaust for power too, but it is only one of many factors involved.

 

[Nad]

think the theorists have got it wrong again somehow with their conclusions about equal length manifolds.

One thing I would like to point out is that my posts contains the opinions not of myself but of others. I can find where the links come from, one of which is a race car outfit and u can talk to them direct if u wish. THe problem is with ur engine is that those two graphs you are comparing are not of a standard engine with the manifold just swapped over. This would be a more accurate way to show the improvement dont u think?

as per above nad,this was not meant as a personal attack on you but,i do question the judgement of all these theories and conclusions that you tend to quote from your books.also,is swapping the manifold on it's own not another tuning method used on n/a engines rather than ours :?: usually,our lot tend to change their manifolds at the same time as their turbo's.

The reason I was on about just swapping the manifold was to be able to see the flow change. Comparing it on ur engine would not show this due to different boost levels and other changes. It would not clearly show the affect different manifolds have on the power band position.

Also if u had read it properly, I said that alot of these examples are not relevant to turbocharged engines as the air is forced in and out

i did read it properly.what is the point of quoting from books that are of no relevance to us :?: i've yet to see a n/a gti-r :!:

Because I was just showing what difference they can have and it is clearly shown and easier to understand with NA cars. As with most turbo cars u should treat them as NA first, get as much power out of them like that then strap the turbo on. This was exactly the same route of thinking that Norris took with his Evo. No bit of info can be seen as irrelevant as its another bit of info for the mind.

Just adding in that peak torque on a rally car is around 4000rpm but at around 500lb/ft, and 300bhp at around 5000rpm, this is what narrow tubes and long uneven headers do.

again,what relevance is there in comparing rally cars to our cars :?: .might i suggest that there are very few people on here that can afford the necessary to create an engine the equal of a rally car's :!:
when sam is finished mapping my car to HIS satisfaction,i would expect to achieve at least the torque figures you've quoted above if not the power figures.granted it will probably be at slightly different revs but not that far away.as for the power,i know i'll def have a little bit more than just 300bhp :twisted:

Once again I was making a point about what manifold designs can do to the engine. U may have the same figures but strap a 34mm restirictor on ur turbo like rally cars do and u will lose it all. The point was about matching ur manifold to what u want. Even so it is not as important on a turbo car every little helps so once again this is why I put the NA stuff in here. A turbo'd engines manifold will still roughly work along the same principles.

Nad

 

[Nad]

Just adding in that peak torque on a rally car is around 4000rpm but at around 500lb/ft, and 300bhp at around 5000rpm, this is what narrow tubes and long uneven headers do.

Nad

I think that'll be down to alot more than the manifolds. Aren't rally cars restricted to 300bhp? so they want that figure as soon as possible. High boost and high compression ratios will help them get there. Obviously they want the best exhaust for power too, but it is only one of many factors involved.

Sorry that was really worded right. I meant it along the lines of matching the manifold to where u want the power band. Rally cars run a 34mm resrictor which suffocates the engine over 4000rpm or so. Trying to get more torque with less air doesnt work so it is designed to make the maximum use of what it can breathe in.

Nad

 

[coxie]

:shock: christ some more good info...anyone else.

thanks to all who have answered my q's 8)

 

[Anonymous]

Because I was just showing what difference they can have and it is clearly shown and easier to understand with NA cars. As with most turbo cars u should treat them as NA first, get as much power out of them like that then strap the turbo on. This was exactly the same route of thinking that Norris took with his Evo. No bit of info can be seen as irrelevant as its another bit of info for the mind.

who cares about what happens with n/a cars :?: unless i'm mistaken,none of us are taking our engines back to the start of the tuning process.we all have turbo'd engines and i can't see the point of "muddying the waters" with n/a tuning methods :? oh come on nad,be reasonable ffs.i hardly think that any of us,no matter how anal retentive we are ,are in the same league or have the same tuning budget as simon.

you,as well as several others on here,seem hell bent on reinventing the wheel just because you've read a few books,studying for a degree or because somebody labels you as a guru.

Once again I was making a point about what manifold designs can do to the engine. U may have the same figures but strap a 34mm restirictor on ur turbo like rally cars do and u will lose it all. The point was about matching ur manifold to what u want. Even so it is not as important on a turbo car every little helps so once again this is why I put the NA stuff in here. A turbo'd engines manifold will still roughly work along the same principles.

wtf has restrictors got to do with us :?: we all seem to be trying to increase power/torque levels not limit them :? the rally teams also have various ways and means of increasing the power/torque levels that we don't have access to.quoting n/a techniques to a forum of turbo nutters just confuses the issues we are dealing with.

if someone on here asks questions about getting the most out of their cars engines,it's up to us as a group to give info that we know works,is reasonably practical and doesn't cost the earth.we shouldn't be quoting from text books and filling their heads with impractical,uneconomical bollox.

 

[Edd]

Don't mean to be picky Bruce but are you sure you have a 4 inch exhaust from turbo back?
I've heard that you cannot fit much bigger than 3 inch over the rear axle. Also looking at the pictures of yuor car the turbo elbow definitelity isn't 4 inch. I presume your turbo has 4 inch inlet, so if you look as that, then look at the turbo elbow, that is 3 inch maybe a bit smaller
Maybe you just have a full 3 inch system.
It wouldn't be the first time DP had told you a porky

you going to answer me when you stop your love affair with nad

 

[Anonymous]

Don't mean to be picky Bruce but are you sure you have a 4 inch exhaust from turbo back?
I've heard that you cannot fit much bigger than 3 inch over the rear axle. Also looking at the pictures of yuor car the turbo elbow definitelity isn't 4 inch. I presume your turbo has 4 inch inlet, so if you look as that, then look at the turbo elbow, that is 3 inch maybe a bit smaller
Maybe you just have a full 3 inch system.
It wouldn't be the first time DP had told you a porky

trust me i'm a doctor :twisted: it is 4" or 100mm and so is the elbow
are you looking at the correct photo's :?:

be nice edd :twisted: :lol:

i was getting round to you,get it :?: round :!: :twisted: :lol: :lol: :lol:

 

[Edd]

i looked at ones with ur engine on the stand with the turbo fitted and just the turbo elbow on..
is ur turbo 4 inch inlet?