Torque about TFI and MPFI

[petah from oz]

A freind and myself are tring to work out why the 1.6 throtle body injected engine has more low torque than the 1.6 multi point injected engine.
Are there cam differances, computer and or injectors or a combination of all of them.
Ive got a MPFI and want to get more low torque or is that Power.
seem to loose too much with bigger tyres, yet my friends TFI runs 31s with out problems. Both geared the same.
Thanks heaps

[mud4b]

A freind and myself are tring to work out why the 1.6 throtle body injected engine has more low torque than the 1.6 multi point injected engine.
Are there cam differances, computer and or injectors or a combination of all of them.
Ive got a MPFI and want to get more low torque or is that Power.
seem to loose too much with bigger tyres, yet my friends TFI runs 31s with out problems. Both geared the same.
Thanks heaps

for starters the spi is 8 valve. the cam, puters,valve size,pisons, ect is totally different.

i dont know the 2 different zooks but many things can vary to make the difference.

[alien]

you motor could even just be more "tired" than his...

Karmic off these forums just went from a clapped out 1.3l carby motor which took 1km to reach 100km/hr to a 1.6SPI which takes 100m... nothings changed gearing or tyre wise either... HUGE difference.

[cj]

If you mean why does his motor has more torque than yours then as has been said his may be in better condition than yours but if you mean TBI motors compared to MPFI motors then you might want check your information beacause although the 16v MPFI motor makes its peak torque at 4000rpm instead of 3000rpm for the 8v TBI or carby, at 3000rpm it is making about the same or a touch more torque if you have ever seen the graph.

[flyinwall]

is this anything like the debate as to why a twin cam motor has less torque than a single cam motor
but back to your question from what i can understand a Throttle Body Injection (TBI not TFI) allows the fuel to mix better and the design of the manifold will also affect the amount of torque (if my memory serves me right longer intake manifold runners are better for more torque, someone please correct me if i am wrong) Multi Point Fuel Injection (MPFI) is for increased fuel ecconomy

[mud4b]

not sure if i read this wrong but the spi has the same manifold as a carby..

[petah from oz]

Thanks all
Flyinwall i think your on the right track, need to look into it.
Yes i ment TBI
my 93 MPFI 16v motor has only got 130k on it, havnt done a compression test on ti yet, extractors, 2" exhaust , not sure if this has effect a busted cat (no guts) got rocked.
ive made a vernier cam pully and tryed advancing 4deg and it helped a little at low revs but lost a bit at higher revs, now trying retarding the same amount and found the opposite efect. Could be the fuel mix?
Also thinking of rapping the aluminium tube between the air flow meter and throttle body to try and keep it a bit cooler, ive also made my own snorkle.
What about Jaycars Digital Fuel Adjuster Kit, has anyone tryed it. Im thinking of giving it a go.

cj where can i get graphs, my friends 1.6 8v TBI motors got over 180k and similar exhaust.

[cj]

Thanks all
Flyinwall i think your on the right track, need to look into it.
Yes i ment TBI
my 93 MPFI 16v motor has only got 130k on it, havnt done a compression test on ti yet, extractors, 2" exhaust , not sure if this has effect a busted cat (no guts) got rocked.
ive made a vernier cam pully and tryed advancing 4deg and it helped a little at low revs but lost a bit at higher revs, now trying retarding the same amount and found the opposite efect. Could be the fuel mix?
Also thinking of rapping the aluminium tube between the air flow meter and throttle body to try and keep it a bit cooler, ive also made my own snorkle.
What about Jaycars Digital Fuel Adjuster Kit, has anyone tryed it. Im thinking of giving it a go.

cj where can i get graphs, my friends 1.6 8v TBI motors got over 180k and similar exhaust.

Yes, a busted cat can hurt you performance wise. How about you send me details on your swaybar disconnect and I send you some graphs My cam timing is advanced about 6deg and with tri-y headers and a higher flowing cat, muffler and 2" pipe it revs all the way to the redline fine but then again I do have a little cam work too

[petah from oz]

Wared ya hear about my swaybar disconnect ? its been working for over 12 months now, should be tooling up soon to sell em.
Hows your rig go with 2 adults, 2 teens, roof pod and camper trailer. I did a 2 week 4600km flat out trip to Tazzy and got avg 11lt/100.
I want to improve power beteen 3 and 4k which is my highway range what can i do.
Whats the differance between a busted cat and a high flow if the exhaust and headers are the same.

So many questions, so many answers, i just need some.
Go Zooks

[nicbeer]

Get a Cam. did a good difference to my 1.3 between that ranges.

cheers

[oozuk]

A freind and myself are tring to work out why the 1.6 throtle body injected engine has more low torque than the 1.6 multi point injected engine.
Are there cam differances, computer and or injectors or a combination of all of them.
Ive got a MPFI and want to get more low torque or is that Power.
seem to loose too much with bigger tyres, yet my friends TFI runs 31s with out problems. Both geared the same.
Thanks heaps

for starters the spi is 8 valve. the cam, puters,valve size,pisons, ect is totally different.

i dont know the 2 different zooks but many things can vary to make the difference.

hate to correct you mark but your wrong....

infact the 1600 was released in SPI and 16V think back to the SF swift sedan 1.6L both 1600's and 16v's but the MPFI and the SPI in 16v heads do differ as the MPFI heads have i cutaway for the injectors in the inlet port

[ZOOK60]

not sure if i read this wrong but the spi has the same manifold as a carby..

sorry mark but i have owned two spi swift sedans both of which are now at sims metal. They had a small run of 16v spi engines in the sedans only. It is a totaly diferent setup to the 8v manifolds

[Santos]

it just sunk in, you mounted a swift sedan with the sierra?

Sedans are higly sought out by the swifter as something different to 'GTi-erfy'

still it's cool to see a tbi 16v didn't know about that... still would say MPi would have more torque as it's closer to an IR set up, unless the newer engine has different fuel maps or/and cam setting to pass tighter emmisions

[Santos]

scrap the emmisions comment... went on the old car info for Suzuki Japan and the later model MPi 16v Sohc have a 8nm increase on the TBi