Tuning turbo time!

[arc]

even if RR showed increase, i still need to know why

 

[craigb244]

haha ill fit the bigen then. guess i can try them both sometime in the future.
Ii was kinda hoping someone would so it would be useless on a turbo so i can sell it and get the 80ish i paid for it about 4weeks ago back lol also dads moaning about my HUGE stash of spares im gathering.

 

[craigb244]

even if RR showed increase, i still need to know why

I wonder if it increases power at all or just moves it around? everyone knows smaller tbs are better at lower rpms but chock at high rpm

 

[allanhelen]

I will say it again there is little point forcing more air in if you can't use it


I use a 40mm TB which is 10mm over stock on a 1108 but.......

I also have a ported Uno 45 manifold, flowed and ported head, custom pistons, fuelling as good as you can get for an SPI, turbo with electronic wategate and dump valve and a custom fully free flowing exhaust

 

[fordcosworth]

I will say it again there is little point forcing more air in if you can't use it


I use a 40mm TB which is 10mm over stock on a 1108 but.......

I also have a ported Uno 45 manifold, flowed and ported head, custom pistons, fuelling as good as you can get for an SPI, turbo with electronic wategate and dump valve and a custom fully free flowing exhaust

totaly agree with this if the engine can consume the air and has the capablitiy of flowing large amounts of air then the big throttle body is good thing

jason

 

[fordcosworth]

I wonder if it increases power at all or just moves it around? everyone knows smaller tbs are better at lower rpms but chock at high rpm

i would bet top end increased, mid range torque increased, low end power and torque down a little, makes sence if you think about the science involved right??

jason

 

[craigb244]

totaly agree with this if the engine can consume the air and has the capablitiy of flowing large amounts of air then the big throttle body is good thing

jason

true.... guess the only way to find out is to try it:idea:

i would bet top end increased, mid range torque increased, low end power and torque down a little, makes sence if you think about the science involved right??

jason

yeh the the car dont really have all that much but when you get to about 2.5k the engine tone changes and it really gets going

 

[allanhelen]

true.... guess the only way to find out is to try it:idea:

err no if you have too much air too little fuel with a turbo you have seconds before std pistons could melt.

start conservative and work up, ignore this if you want but most turbo owners past and present can show you the pics to prove it

if you really think you are that lucky can you PM me some numbers for this Fridays Euro millions draw

 

[craigb244]

quite right!

just reminded me I have the 16valve pistons to drop in before i remove the engine tomorrow.
Ive read the guide on turbo charging with megasquirt. and been given AFR maps and a few ignition maps for fire engine running different compression ratios.

I think as long as i take my time creeping down onto the right mixtures my pistons just stay intact (not going to even attempt the highest boost portion of the map. leave that to the dyno guys)

 

[gazzaman2k]

on my turbo when it was a spi it had a normal 30mm tb on and it chocked it i found, once i got a tricker 40mm tb lower revs and pull of was way more responsive went like **** of a shovel, i got a 43MPI TB now thats the largest it can go on a p75 TB as the hole in the top of the inlet manifold is 43 so any bigger and it will just be compressing it again into a 43mm hole, dunno what its like as i still havent got mine mapped but it spools up hell of alot faster but that may just be coz im running a GT15/20 hybrid

 

[craigb244]

is that trickers mpi tb? if so thats prob what i have and am mixing numbers up as usual

i just remembered it was HELLLLL of a lot bigger then standard punto 75 tb.

 

[gazzaman2k]

yes its a tricker mpi p75 43mm carb, i traded a silly ammount of normal 30mm ones + bit of cash for it lol

 

[craigb244]

ahhhh my bad. duh now i look at the p75 tb sitting on my desk its 37mm :bang:

 

[gazzaman2k]

err no if you have too much air too little fuel with a turbo you have seconds before std pistons could melt.

start conservative and work up, ignore this if you want but most turbo owners past and present can show you the pics to prove it

if you really think you are that lucky can you PM me some numbers for this Fridays Euro millions draw

mostly that is due to people being tight and not spending money on a propper remap that is needed

 

[AlexF]

ITB's really shine on turbo's and forced induction. and they have a MUCH bigger surface area in comparison to one large TB, so I'd say, the bigger the better. It must make some kind of difference.

Get it RR'd with both and put the debate to bed

Only one car I can think of uses this setup as std - Pulsar GTiR!

Its not necessary and VERY hard to balance the flows through each butterfly.

You only need enough surface area to support the flow rate that your turbo is providing.... and then thats only a consideration IF your valves are allowing enough flow as well!

Alex

 

[randomizered]

Only one car I can think of uses this setup as std - Pulsar GTiR!

Its not necessary and VERY hard to balance the flows through each butterfly.

You only need enough surface area to support the flow rate that your turbo is providing.... and then thats only a consideration IF your valves are allowing enough flow as well!

Alex

Nissan Skyline GT-R R32
Nissan Skyline GT-R R33
Nissan Skyline GT-R R34
Nissan Stagea 260RS

Most BMW M series cars

Sure there are plenty of other that I don't know about

Never heard about them being hard to balance Sure with carbs it can be a nightmare, but with EFI I can't see any problems.

Kristian

 

[AlexF]

I thought we were talking about turbo cars...

And balance is always an issue - different openings mean different air - thus fueling per cylinder would be wrong.

On BMWs they are factory set and if they are taken apart BMW have to fit a whole new setup!

This is why lots of after market ECUs for Jap cars include injector trim to blance out fuel delivery to each cylinder.

 

[craigb244]

half the 16valve pistons (thanks dave:worship are in. Decided to debur them and polish the tops before hand. this then led to cleaning out the ring lands to (full of carbon)

the rods are WAY better then the 8valve rods. they are much lighter and made using the newer method where the big in is cast as one piece and then cracked so when refitted it will always go in EXACTLY the same position is was machined in. I defiantly cant see them been at all weaker then the 8valve rods

the rings and shells are identical which is great as the car has had them replaced recently.

I have the bores a quick hone to deglaze and make sure everything seats in. it also showed up no defects in the bore. no low spots. out of round. tapered bore. :slayer:

pistons are a very good tight fit in the bores so definatly not much wear (i recall rallycinq mentioning pistons dropping thru the bores due to wear)


btw is that the oil squirter im told only punto 75 engines have???


edit - weighed the pistons/rods just out of interest.
16v - 633g
8v - 735g

with piston on table with big end on scale

16v - 315g
8v - 391g

16valve rods are way lighter

 

[dave]

they not supposed to be tight, or they get stuck when they hot

 

[Munkul]

tight as in piston-ring tightness?