jpindy3
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| posted on 10/5/09 at 04:17 PM |
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turboing [happy]
if you turbo an already tuned engine,will you have more hp,than a turbod std engine.
or dose it not make any odds as you are forceing air in????
i know its a silly queston,i hope you can undersand it
jamie.
[Edited on 10/5/09 by jpindy3]
[Edited on 10/5/09 by jpindy3]
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fesycresy
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| posted on 10/5/09 at 04:20 PM |
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Depends on the tuning.
If the tuning included lowering the CR then you'll be in trouble.
Turbos normally requires a higher CR.
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The sooner you fall behind, the more time you'll have to catch up.
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gazza285
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| posted on 10/5/09 at 04:23 PM |
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quote:
Originally posted by fesycresy
Depends on the tuning.
If the tuning included lowering the CR then you'll be in trouble.
Turbos normally requires a higher CR.
T'other way round.
DO NOT PUT ON KNOB OR BOLLOCKS!
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fesycresy
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| posted on 10/5/09 at 04:43 PM |
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Just re read what I typed. Doh !
Normally asperated tuning sometimes includes skimming the head, pocketing pistons etc, raising the CR.
Turbo's do indeed need a lower CR i.e. a thicker head or base gasket.
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The sooner you fall behind, the more time you'll have to catch up.
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mr henderson
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| posted on 10/5/09 at 05:02 PM |
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You might get more interest if you make your thread title more infomative.
I rarely look at threads with 'teaser' titles, and I expect a lot of other don't either
John
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iank
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| posted on 10/5/09 at 05:03 PM |
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Tuning that improves strength of the bottom end is also helpful for turbos and will allow higher boost before the con-rods try to escape from the
block.
Cams and CR will be wrong for the turbo engine and should/must be changed.
I think, though I'm not a turbo expert that any mods which improve gas flow (head porting, inlet manifold improvements, exhaust system - not
including manifold as that will be changed for a turbo) will help a turbo engine by allowing you to use a smaller less laggy turbo for the same power
- won't change a thing on the max power but will make the car much faster and easier to drive (and less dangerous) when being driven anywhere
but a drag strip.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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jpindy3
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| posted on 10/5/09 at 05:51 PM |
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it tuned to a fast road spec,big valve head fr32,21cc, ground crank,hepolite pistons,runing zx9r carbs,luminition spark.
im using a decomp plate with 2 gaskets,and a t3 and few other bit to make it go together?
but what i wanted to know is if you had a tuned engine are you gona be at an advartige over a std engine,whan you turbo them??
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mr henderson
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| posted on 10/5/09 at 06:06 PM |
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quote:
Originally posted by jpindy3
but what i wanted to know is if you had a tuned engine are you gona be at an advartige over a std engine,whan you turbo them??
As Iank says, it all depends on what sort of tuning has been carried out. It's not possible to give a definitive answer. although the car will
probably be wrong for turbocharging
John
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jambojeef
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| posted on 10/5/09 at 06:52 PM |
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Get a good book and have a read - "forced induction performance tuning" isnt a bad place to start (albeit a pretty dry read)
In essence all tuning is done to achieve the same result i.e. to make the engine more efficient at flowing air.
So if you've tuned your N/A engine by gas flowing the head or something similar then obviously it will be at an advantage regardless of whether
it be atmospheric fed or positive pressure fed.
Probably the only clear waste of money would be if you'd paid for an exhaust designed for a N/A engine since its matched lengths aint gonna do
much behind a turbo - let alone fit!
This talk of compression ratios is unhelpful in isolation. Its one of a range of considerations when turboing an engine but there is no cut-off point
where the C/R prohibits forced induction.
Fuel octane rating, temperature of intake charge, VE, stroke:bore ratio etc etc all factor in engine efficiency.
Its an interesting topic and thers lots of reading to be done, I have just found today an IMechE paper on the design of the Jag V12 engine - my bed
time reading!
Geoff
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ss1turbo
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| posted on 10/5/09 at 07:17 PM |
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If the engine has been tuned to N/A principles, then it's not ready for a turbo - overlap on the cam will make it laggy as all hell (if it
boosts at all) and your off-boost performance will be terrible.
N/A tuning invloves making the best of cylinder scavenging whereas thats exactly the opposite of what you want with a turbo lump.
Gas flowing will aid either type of induction - just if it was a turbo lump you'd pay more attention to the exhaust side than the inlet.
A high(er) compression ratio will kill your engine if you force induct it. Saab are one of the few who got a high compression engine to run with a
turbo but it involves using a knock sensor controlling the boost (in effect). Taking a stock engine and bolting a turbo on takes a lot of development
(as well as large cahooners) - doing it to a tuned N/A engine is a great way to make the pistons melt and the conrods meet fresh air via the
block..plus it'll most likely drive like a pig. Go one way or the other...
Long live RWD...
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jpindy3
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| posted on 10/5/09 at 08:31 PM |
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quote:
Originally posted by ss1turbo
If the engine has been tuned to N/A principles, then it's not ready for a turbo - overlap on the cam will make it laggy as all hell (if it
boosts at all) and your off-boost performance will be terrible.
N/A tuning invloves making the best of cylinder scavenging whereas thats exactly the opposite of what you want with a turbo lump.
Gas flowing will aid either type of induction - just if it was a turbo lump you'd pay more attention to the exhaust side than the inlet.
A high(er) compression ratio will kill your engine if you force induct it. Saab are one of the few who got a high compression engine to run with a
turbo but it involves using a knock sensor controlling the boost (in effect). Taking a stock engine and bolting a turbo on takes a lot of development
(as well as large cahooners) - doing it to a tuned N/A engine is a great way to make the pistons melt and the conrods meet fresh air via the
block..plus it'll most likely drive like a pig. Go one way or the other...
sorry mate you dont have a scoby doo,about turbo pintos,you can turbo a pinto with second hand bits for 400quid,
i know what your gona say its gona drive like sh*t,take a look at turbosport furom serch pinto turbo.
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flibble
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| posted on 10/5/09 at 10:05 PM |
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From the very little I picked up supercharging my mx6, turboing my fireblade and sorting out my Saab motor, I'd say SS1 was fairly close, he
just answered the question asked.
All he said was basically that performance cams for a NA engine are not perfectly suited for a turbo motor, you can still use 'em though.. (they
do what it says on the tin!), - high compression is also not ideal in most cases, you know that.
He didn't say you can't do it, many have, me included and it worked fine, just nowhere near as well as if it'd been done with the
right bits first.
He didnt say it was expensive either unless I missed something? (I did my mx for about £400).
[Edited on 10/5/09 by flibble]
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ss1turbo
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| posted on 10/5/09 at 10:53 PM |
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quote:
sorry mate you dont have a scoby doo,about turbo pintos,you can turbo a pinto with second hand bits for 400quid,
i know what your gona say its gona drive like sh*t,take a look at turbosport furom serch pinto turbo.
No, I don't have a scooby - but do own three turbo charged cars (with a total of 5 engines in stock - 2 of which i've built from scratch
and 2 of the others i've rebuilt) so know a bit about turbo engines.
The Pinto is a big old boat anchor and will take a fair amount of abuse - but depends if you're intending this engine to last more than a few
thousand miles. I build mine to last a projected 50k or so. I also like my cars to have good road manners, so that means quick spool times and good
mid-range.
You make anything a turbo engine for £400 - some will last a good while and have good road manners. Others will make a good dyno bhp figure and that
will be it. I've spent 3 years so far on a zetec turbo engine - not because i'm slow, but keep finding a better or stronger way to do
something. My build will come in not much more than £400, but if I wanted any more than my projected 230-250bhp target then i'm looking at
double that just in pistons and rods
Hell, if you want, slap the turbo from a Scania onto a 100k Pinto lump go for it.
If using a "high" compression engine (over say 9:1 - depending on the engine) then you have to be either conservative with the boost (half
a bar), make the sure the charge cooling is up to scratch or be very clever with your mapping..or all 3. Unless you are lucky, then some work will be
needed in the bowels of the engine.
There's doing a job, and doing a job properly.
Sorry but last time I went on the turbosport forum I went there for a laugh. I know there are some knowledgable people of there but....there are a
lot of jokers. Almost the same as Pistonheads sometime..
If I wanted serious power from my Saab turbo, then I can get 300+bhp from it - but I doubt it would get me the 400 miles a week to work and back for
long without more than a chuffing big turbo and some oversized injectors.
If you wanted a turbo pinto engine, buy a YB lump instead - the prices for bits aren't higher "just" because they are for as
Cosworth - there's a reason for it.
Long live RWD...
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cd.thomson
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| posted on 11/5/09 at 08:02 AM |
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quote:
Originally posted by jpindy3
it tuned to a fast road spec,big valve head fr32,21cc, ground crank,hepolite pistons,runing zx9r carbs,luminition spark.
im using a decomp plate with 2 gaskets,and a t3 and few other bit to make it go together?
but what i wanted to know is if you had a tuned engine are you gona be at an advartige over a std engine,whan you turbo them??
I think this topic has been dealt with well by the other locosters like SS1 but specifically to your pinto I think you may find you have to change out
your camshafts, they may have too much overlap even though they are only the basic fast roaders.
Secondly I'd be wary of the ground crank as this may represent a weak point, I know one of the first things to be changed when converting a
pinto to a YB is to fit some steel bottom end parts.
Nobodys saying it cant be done, in fact people are being constructive.. if you were going to ignore well educated advice then why did you even ask?
[Edited on 11/5/09 by cd.thomson]
Craig
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Volvorsport
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| posted on 13/5/09 at 05:10 PM |
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rods and bolts would be the first thing to change , and maybe if your CR is 11:1 then the pistons aswell .
volvo use 9.3:1 for their turbo motors - its how you tune it that makes the difference and for £400 itll most likely blow up if you want to run silly
boost .
An NA cam is not necessarily a bad thing - as long as the exhaust manifold is properly designed itll make some decent power , individual runners need
to be about 400mm long , but you can of course , have a turbo cam reground to suit your needs for about £170 , this would include a wide LCA to
prevent overlap but still get a pretty good duration/lift aswell .
Also if your on turboford isnt that mostly American based ? If so the lima engine can take all sorts of abuse , but isnt really anything like the
pinto except in looks .
www.dbsmotorsport.co.uk
getting dirty under a bus
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