turbo bhp

[geordie_racer]

hi read the sticky post bout carb turboing a 1.6 engine. could ne1 tell me a rough bhp figure for a 1.6 16v runnin a twin carb turbo? with the rest of the engine standard?

chris

[Chip_RB]

ZERO bhp if yuo run much boost on such a high compression engine, as it would detonate.

TURBO'S ARE NOT BOLT ON MODS, the whole engine needs to be specced to make use of it or you end up either resitricted to running tiny amounts of boost (pointless) or you blow it up.


Chip

[Ben]

thank god someone understands that :!:

Have explained that very same thing to 3 different people this week.

I belive its true that 95% of turbo owners only have them so they can fit dump valves.

If your going to fit a turbo go for the C20 LET, you would be MUCH better off both financially and power wise by fitting TB's to a 1600 16v than a turbo.

[geordie_racer]

i no and understand both your points ive built a 1.6 crx turbo so i no there certainly not bolt on jobs. i no fittin a c20let would b easier but im taken by the idea of runnin a decnet powered 1.6 16v in a nova and save the big stuff 4 me astra

i was hopint to run about 1 bar boost with the required compression jobs and was wonderin if ne1 could give me a rough bhp figure

i no i prob phrased the question badly but come on sum1 must b able to help

cheers
chris

[Chip_RB]

1 bar of boost on an appropriately built 1600 16v engine would yield APPROX (and i mean very approx) 200-220 bhp i should think.


Chip

[Ben]

210BHP is achevable off a 1600 16v with the use of TB's and a good load of other parts too.

How much you looking at to build a 1600 16v to a spec capable of withstanding a decent turbo?

[Chip_RB]

Not a lot to be perfectly honest, forged lower cr pistons, arp rod and head bolts, an MLS gasket, and thats about it, the blocks and cranks etc are actually pretty good.


Chip

[geordie_racer]

on;y other prob with this is i don't want the car bein awful off boost. my mates rs turbo is great when its boosting but really sluggish off boost. ideally id like to see 130bhp standard then 170-200bhp ish under boost ne1 got ne ideas on the best way to achieve this without givin mr bank a heart attack

chris

[Stuart]

a good engine build and a shit hot ECU (DTA, Motec, Wolf etc, NOT Omex/Lumenition)

[geordie_racer]

was lookin at runnin a carb turbo tho so unless im missin sumthin an ecu wouldn't b much use would it?

chris

[Ben]

carb turbo as in the same style as a Renault 5 GTT- Go careful we all know what there like.

if you want to run about 130bhp as standard and then upto 200 on boost why not consider a Mantzel powerbox and a decent exhaust etc- will reach 130BHP quite cheaply then put 60-70 BHP of NOS on a decent setup.

[geordie_racer]

yeah it'd b similer 2 the 5gtt setup but im not just gona whack the boost up n leave the rest like the renault boys do. the mantzel box is an option but im ditchin the ecu so not sure wot effects it would then have, nos isn't an option 2 expensive to refill all the time and i want a turbo really

any more suggestions?

[Chip_RB]

Sorry but what you are saying doesnt make ANY sense at all.

If you turbo it then every time you get past a couple of thousand revs with the throttle any more than very slightly open it will be "on boost" so how the hell do you expect to get 130bhp from it when its not boosting?

Turbo cars dont have an on boost and off boost figure like that, thats just a nonsense.


The thing you dont like is called lag, and the more power you want from any given cc engine the more lag you will get generally.

Lag is caused by:
turbo spinning up
low compression


The more power you want then the bigger the turbo you need and the lower the compression you need.

There are ways of minimising lag a bit, like ball bearing turbos, but you are looking at a lot of expense indeed.


TBH i dont see why you dont tune it to about 140bhp and then fit a nitrous kit, that way you get instant throttle response, zero lag and your 200+bhp when you want it.



Chip

[Chip_RB]

Also the money you save by having better fuel economy the 99% of the time you arent using nitrous will pay for the gas you use the 1% of the time when you are.


Chip

[Ben]

If you want to build a Turbo go ahead and do so, i am not digging about that, the questions i think you need to answer first is..

Why do you need a turbo?

What are you hoping to acheive from it?

How much you looking at spending?

So far what you have told us does not warrant having a turbo, you admit yourself you dont want and lag.

With a 2-220BHP 1600 16v turbo'd engine you will be looking at a large amount of lag on this.

[adam-s]

I think he wants a dump valve

[geordie_racer]

im lookin at runnin 170bhp and i want to do it with a turbo, not sure why but turbo is the way i want to go to achieve it.

1stly i want the engine running 130bhp b4 i add a turbo so what do i need for this 1st?

then what extra will i need to add the turbo?

im running this on carbs so no suggestions of chips and remaps please

chris

[Paul]

How about twin 45's or 40's, Very good cam piper 285 or above.

Or TB's.

Properly set up should be hitting approx 120ish BHP for the forties, 130BHP for the fortyfives, 150BHP fo the TB's. Im roughly guessing here, then with the cam, BIG exhaust manifold and sytsem, good air flow in, i.e carbon air box, should be hittin at least 160 on 40's and then bit more on 45's and even more on TB's.

Superchargers dont get lag.

[Ben]

If you want a turbo you will need to build it on at the same time as building the whole engine as you will need to build it as a low compression, whereas if you want to acheive 130BHP before adding the turbo then you will need a high compression.

[adam-s]

What about a supercharger and a turbo it been done hasn't it, used in rally cars as an early anti-lag system obviously out of most peoples price range though! would solve the lag problem though.

[geordie_racer]

been thinkin bout usin a nos setup to cure the lag but still not sure.
buildin a low compression carb setup to b 130bhp isn't too hard then it's just a case of settin the turbo up properly. only problem on top of this is traction.

any more ideas?
chris

[Chip_RB]

For gods sake would you just pay bloody attention to what people are saying to you!
None of it seems to be sinking in at all.


TURBO ENGINES NEEDS LOWER CR

If you want to run 170bhp from a 1.6 then i would estimate to do so safely you are going to need 9:1 compression or less.

You are not going to be able to tune it to 130bhp with 9:1 compression.

Well, not in a way that is condusive to turboing it.

You would need lairy cams, which would INCREASE lag etc


You cant tune an engine for with and without a turbo at the same time, the requirements of a turbo charged engine are different than an N/A one, some things are common, but they are few and far between, head mods, cams, fueling etc are ALL going to have a different optimum values for with and without a turbo.

You need to stop trying to achieve everything all in one go because you are pulling in two different directions.

Also, what is your budget?

This is VERY important, there is no point us giving us advice if its for things you cant afford.


Chip

[Aragorn]

also seems strange why u want to run some shitty old carb

theres a perfectly good injection system on there and all u'd need to do is add a 5th injector and ECU to handle boost fuelling and you'd be sorted

novaneil was getting a claimed 180ish bhp from a 1.6 8v using full dta management and a properly built block with low comp pistons etc

so maybe if u spoke to him nd applied what he's used to do the 8v to the 16v you'll be a few steps forward than u are now

[NovaNeil]

novaneil was getting a claimed 180ish bhp from a 1.6 8v using full dta management and a properly built block with low comp pistons etc

Not CLAIMED me boy, I now have a slip of paper that showed on Monday night it kicked out 191bhp and 195lb's ft Torque at one stage but the ignition was quite advanced so we backed it off to be safe and it now runs 181bhp and 185lb's ft Torque (Will Post dyno graphs soon). Im now running an electronic boost controller with a button on the steering wheel to allow me to swop between high and low boost (7 & 14PSi).

As for running a Turbo on Carbs I have no experience in that at all, so sorry I won't be able to help. But if you want to run it on injection I will try to answer any questions you might have, as i've been there, tried it and blown the dam thing up 3 times!!! :twisted:

[geordie_racer]

so neil what are you running in your turbo system and how? whay was the rough cost?

cost isn't really an issue as the project isn't startin till after xmas just need to know whats involved so i can start scouting the parts. obviously i don't want to break the bank.

as for usin a carb i just like the idea of usin a carb and i no there not that difficult to set up and get running properly

chris

[Chip_RB]

Far easier to map an ECU than to mess around with carbs to be honest, especially as that way you can easily map the timing as well.

Chip

[NovaNeil]

You want to listen to Chip_RB mate, what he says is very true.

I've spent ?1000's on mine! Literally. Have a look at my feature car for the full spec, but it is very much a one off as lots of it has been custom made and fabricated. If you wanted to build a replica your looking at least ?5000-?6000! if not more, with all the mapping it had to have.
I think if you know what you were doing you could comfortabley be able to do a standard conversion for under ?2000 and even less if you buy as much as poss 2nd hand.

[geordie_racer]

so basin this on a 1.6 16v engine. is there a head change that can be done to lower the compression?

chris

[Aragorn]

nope its the largest small block engine unfortunately so your talking about either low comp pistons or a bodge like gasket spacers

[geordie_racer]

are low comp pistons gona b enuff? wouldn't really say gasket spacing is a bodge but there are better ways to do it yes.

[Chip_RB]

Gasket spacers or even thicker top quality gasket like the multi layer steel one ive fitted to my own turbo ARE a bodge if you add more than a tiny amount, as it totally wrecks the squish bands of the engine, a GOOD low compression piston can lower the CR and still maintain squish as well, so its a far better option, on an 8v you can gain a lot of CFR by reworking the chamber but this is often less possible on a pentroof design, and it certainly isnt much of an option on the vauxhall ones TBH.

Chip

[geordie_racer]

so will low comp pistons lower the cr enuff for me to be runnin 170bhp thru a turbo conversion? if so how much am i lookin at for the pistons?

chris

[Chip_RB]

yes they will, although i would probably use an MLS gasket thats slightly thicker than the original as well to get it down too.

500 is a very ish price for the pistons, based on what they cost for other engines, but i dont know of anyone who actually sells low compression pistsons off the shelf for a 16xe


Chip

[Phil GTE]

SBD (http://www.sbdev.co.uk/Main.htm)


Pistons 1.6L XE
Part No. Description
PIST-OM79.00SLS 79.00mm Omega/SBD H.T. slipper piston set (4) 1.6L XE
PIST-OM79.05SLS 79.05mm Omega/SBD H.T. slipper piston set (4) 1.6L XE
PIST-OM79.05XS 79.05mm Omega/SBD H.T. piston set (4) 1.6L XE
PIST-OM79.05XSS 79.05mm Omega/SBD H.T. piston single 1.6L XE
PIST-OM79.50XS 79.50mm Omega/SBD H.T. piston set (4) 1.6L XE
PIST-OM79.50XSS 79.50mm Omega/SBD H.T. piston single 1.6L XE
PIST-OM80.00XS 80.00mm Omega/SBD H.T. piston set (4) 1.6L XE
PIST-OM80.00XSS 80.00mm Omega/SBD H.T. piston single 1.6L XE
PIST-OM80.50SLS 80.50mm Omega/SBD H.T. slipper piston set (4) 1.6L XE
PIST-OM81.50SLS 81.50mm Omega/SBD H.T. slipper piston set (4) 1.6L XE




Also, in the GTE turbo thread;



I would think that somewhere in the world, GM does a 1.6 OHC (small block) with low compression for use with cheap fuel (South America would be about right). This would be a cheap mod for turboing.

Also, Has anyone tried using bits off the Isuzu 1.7td as fitted in the Astra/Vectras? Outwardly it looks very similar to the 1.6 petrol lump.

South American Pistons? A bit like using a SA thermostat

[Chip_RB]

not sure about the diesel idea though, they run ridiculously high compression ratios

[Aragorn]

the cavvy 1.6 spi engine c16Nz is 9.x:1 compression but thats 8v

might be an option to use the pstons from that but you'd really need to calculate it out with the properly measured volumes

dunno if this is possible - just thinking up random ideas - but i know there was summat a while back where if u fitted a 1300crank and rods to a 1200 u'd achieve a 1401cc engine

is there any way to do this in reverse? since even dropping cc to 1550 would provide a huge decrease in CR - on a very quick calculation if u get the cc down to 1550 (and assuming the piston no longer stops flush with the block face - ie its stopping short due to the shorter crank etc) then u'd see a CR of about 7.8

[Chip_RB]

You can short stroke an engine to drop the CR, but you end up wrecking the squish again the same as if you were to use a very thick headgasket, and a custom crank is big bucks, although you could achieve a small result along the same lines for pennies by offset grinding the crank and using oversize bearings.

[Ben]

Speed ex race pistons manufacture Omega pistons for the C16 XE so would be able to make you a set for a low compression setr up, they make them for SBD.