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| why can i only run 8.2 psi without pinging? |
| Posted @ 18 Dec 2007, 8:48pm |
Member
Posts: | ok so the story goes the vl was over due for a dyno tune after fitting an interceptor to control fuel mixtures and was given a road tune. while i thought i was getting around running wat i thought was 6psi (was only 4.5 on dyno). anyway the final tune resulted in 200.6wrwhp @8.2psi..
while i was relatively happy with the power figure i want more boost!!! i'm aware i need more fuel... but what im wondering is if the turbos are only rated to about 300hp then will more boost do anything but create more hot air and decrease turbo life? these are the only mods that would have an effect on power... any feed back would be awesome!
KN filter
blaster coil
fuel reg
digital fuel adjuster (airflow meter intercept)
600x300x75 front mount 3" piping
throttle moved to front of plenum
3" exhaust hi flow cat single cannon muffler (all stainless)
rebuilt auto with heavy duty and apparently extra clutch and fricton plates(don't quote me on that one), kevlar bands modified valve body, 2500 stall
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| #690 |
| makka84 | Posted @ 18 Dec 2007, 10:01pm |
Member
Posts: 191 | Fuck man,you should be happy with that power!
You probably know that turbo's generate heat regardless,
if your chasing more boost then lower the compression (dish top pistons)or decompression plate.
Have you got an N/A engine thats been turboed?if so,keep in mind the compression ratio on the N/A engines is 9.0:1,more compression.
Standard VL Turbo compression ratio is 7.8:1,normally when you have more compression its gonna ping.so there again lower compression allows more boost.
Are you running a standard turbo(TO3)?you can get them rebuilt for around $1500 to how you want,i normally use GCG or MTQ turbo's through work and there great.
When i built my engine,i managed to crack 480Kw at the treads on 18psi with a chipped ECU and forged rods and pistons and alot of other mods,the last one i owned cracked 315Kw at the treads on standard internals(barring pistons).
You can try that or get a bigger turbo then retune it n see how she goes,hope this helps 
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| #691 |
| Posted @ 19 Dec 2007, 4:57pm |
Member
Posts: | hey thanks for the reply makka, they are some awesome power figures man... i'm still talking horsepower haha not rollin with the big boys yet...
anyway as far as i know it is a factory turbo car. how would i tell if it had been swapped for n/a bottom end though? i'm 90% sure that isn't the case but it would explain a lot.
Turbo is standard T3 except for hi flowed wastegate. at the moment i'm not going to commit to an engine rebuild.. paint job comes first.... driveline is all very sound anyway..... the police gave me 6 months to look and save for an even better vl turbo than the one i had at the time, aren't they kind  i know a bigger turbo will instantly make more power more efficiently( cooler charge) BUt would u really recommend changing the turbo if it's making that power on that boost? it was actually making 168hp on 4.5 psi so if i can up the boost from 8 to 12psi then i should actually have 230hp at the wheels. or am i missing something?
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| #693 |
| makka84 | Posted @ 19 Dec 2007, 8:27pm |
Member
Posts: 191 | Ok mate,the way to check if the bottom end is N/A or turboed
is to do a compression test,or find out if your head has been moded(shaved,80 to 100 thou)which adds compression.
But first,obtain the compression test figures from a workshop manual EG:150 to 180 psi per cylinder,thats an example for a standard NA engine.
if yours is well above factory figures you got higher compression figures than you should have to run a turbo
High compression=pinging under load,more boost more ping
Note 1:make sure you stick with premium fuel,never standard unleaded or 95
Note 2:Find someone who can tune your interceptor and get the timing to retard at higher boosts
Note 3:make sure your KNOCK SENSOR is working
Note 4:if all else fails,get a water mist injection system.
These are just examples and some reasons of what to check and how to fix.
any probs let me know
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| #694 |
| steven | Posted @ 19 Dec 2007, 9:53pm |
Member
Posts: 59 | hey the way to tell if the bottom end is a factory turbo job the engine number will have a 8 to the top right corner of the number if it has a 6 it's a factory n/a unless some one has changed the pistons by the way it's the engine number on the intake side of the block
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| #695 |
| steven | Posted @ 19 Dec 2007, 9:56pm |
Member
Posts: 59 | hey the way to tell if the bottom end is a factory turbo job the engine number will have a 8 to the top right corner of the number if it has a 6 it's a factory n/a unless some one has changed the pistons by the way it's the engine number on the intake side of the block
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| #702 |
| makka84 | Posted @ 20 Dec 2007, 3:57pm |
Member
Posts: 191 | Yeah that too,gota be carefull though coz as you sed someone could have changed slugs for all you know but yeah.
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| #703 |
| Posted @ 20 Dec 2007, 4:39pm |
Member
Posts: | thanks for the feedback guys appreciate it! um i checked eninge numbers yesterday but didn't know wat to make of them so that is awesome it is has the 8.
and as for compression i did a compression test about 2 months ago just out of curiousity and they were all about 160 with no.1 cylinder varying very slightly.
also the head was reconditioned prior to me buying the car so there is a good chance it's been shaved but just for a reco it would be very marginal wouldn't it?????? what do u guys make of all of this?
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| #704 |
| Posted @ 20 Dec 2007, 4:39pm |
Member
Posts: | thanks for the feedback guys appreciate it! um i checked eninge numbers yesterday but didn't know wat to make of them so that is awesome it is has the 8.
and as for compression i did a compression test about 2 months ago just out of curiousity and they were all about 160 with no.1 cylinder varying very slightly.
also the head was reconditioned prior to me buying the car so there is a good chance it's been shaved but just for a reco it would be very marginal wouldn't it?????? what do u guys make of all of this?
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| #706 |
| MICHAEL | Posted @ 20 Dec 2007, 7:23pm |
Member
Posts: 241 | 2 bottles of octane booster in fuel 
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| #707 |
| MICHAEL | Posted @ 20 Dec 2007, 7:26pm |
Member
Posts: 241 | does it ping or cut the engine out
if it pings then she aint got no knock sensor non turbo motor.
if the motor cuts out and jerks an shit then you know it will be too much boost   
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| #708 |
| Posted @ 20 Dec 2007, 9:04pm |
Member
Posts: | mmmm i dunno about that dude, it is a turbo motor for one..2 the knock sensor works as it was tuned with 100 octane and then i had to use 95 one time and it would lose power eg revs wouldn't go up under the hardest loads. i was under the impression that if it stops and jerks like your talking about that is a lean misfire?
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| #709 |
| makka84 | Posted @ 20 Dec 2007, 9:26pm |
Member
Posts: 191 | if the heads been done then it would deffinetly have been milled or shaved mate,adds compression like i said earlier.
Comp test sounds about rite,most importantly you need a competant tuner as it sounds like you aint knockn homeruns out.try a different tuner man.
Put a litre of metho in your tank coz that gets moisture and water n shit out of your tank.
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| #710 |
| MICHAEL | Posted @ 20 Dec 2007, 9:29pm |
Member
Posts: 241 | im just pissin in the wind mate
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| #712 |
| makka84 | Posted @ 20 Dec 2007, 9:33pm |
Member
Posts: 191 | lol
what does the splash back feel like?
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| #713 |
| MICHAEL | Posted @ 20 Dec 2007, 9:36pm |
Member
Posts: 241 | nice and warm mate
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