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Re: 4.8L Performance upgrade options

Posted: 19 Jun 2018 19:49
by David M
CarloG wrote: 19 Jun 2018 15:21
Kagiso II wrote: 19 Jun 2018 11:52 My School reckons:
Freeflow manifold by VIPER and NB NB NB NB!!! ceramic coat inner and outer [that will bring the under-hood temp to lower than current.
Also the freeflow decat exhozt 76 mm [ceramic first section]
Then let Graham freeflow the head - bigger valves AND THE CAM TIMING
no chip needed.. maybe, if you can get them, performance injector tips for the fuel injection ?
Then you have well into 200's KW in oomph.
Will it cost you? ja magtag, klomp geld
Thanks - have contacted Viper - is this the Graham from Gtech?
Yep

Re: 4.8L Performance upgrade options

Posted: 19 Jun 2018 20:01
by Kagiso II
Yes for Graham .. I would trust him with "flowing" the heads on my car .. [else I would use VANDERLINDE Performance [at twice the price]

Re: 4.8L Performance upgrade options

Posted: 20 Jun 2018 05:49
by Tinus lotz
I really think you are barking up the wrong tree here .....keep the filter keep the head ...you were looking for more towing power and you are going to be building a race car here?
Just put a turbo on and do the pipe you will be happy ....or buy wilkies motor and fit that ...race car mods dont really give more pulling power hey :mytwocents:

Re: 4.8L Performance upgrade options

Posted: 20 Jun 2018 13:49
by CarloG
Tinus lotz wrote: 20 Jun 2018 05:49 I really think you are barking up the wrong tree here .....keep the filter keep the head ...you were looking for more towing power and you are going to be building a race car here?
Just put a turbo on and do the pipe you will be happy ....or buy wilkies motor and fit that ...race car mods dont really give more pulling power hey :mytwocents:
You've got the same car as me - have you done anything to it to improve performance: exhaust/ chip/ branches/ filter are you the mystery perdon Graham is testing his Turbo with?

Re: 4.8L Performance upgrade options

Posted: 20 Jun 2018 14:37
by davejones
Carlo - definitely try Viper - the exhaust note alone is worth it :mytwocents:

Re: 4.8L Performance upgrade options

Posted: 20 Jun 2018 18:26
by Tinus lotz
A chip is a waist of time but doing a descent exhaust can work . Doing heads ect is a waste of time and effort if you want to use it for towing . Lets have a chat sometime pm me your no

Re: 4.8L Performance upgrade options

Posted: 20 Jun 2018 20:37
by CarloG
davejones wrote: 20 Jun 2018 14:37 Carlo - definitely try Viper - the exhaust note alone is worth it :mytwocents:
Drove down to Kempton today to see Abel - seems like a top class guy and makes the pipes rights there. Still a little more advice gathering and then i'll pull the trigger next week on what i want to do.

Re: 4.8L Performance upgrade options

Posted: 21 Jun 2018 05:19
by Peter Connan
Tinus makes a good point:

All "breathing modifications" (exhaust, gas flow, air filter) are MUCH more effective at high revs. In fact, normally most of these mods will actually reduce torque at lower revs, which is what you are actually complaining about.

There are only three effective ways to significantly improve bottom end torque:
1) Increase the compression ratio (very expensive and you will need to run higher-octane fuel, which is also expensive and difficult logistically).
2) Increase the engine capacity (back to buying that Y62)
3) Forced induction (turbo or supercharger, but turbo also tends to be better at high revs, so supercharger mostly).

But this is a petrol engine. As such, you should not be scared of using the revs. And once you start managing the gearbox to use the revs, you will probably find the need for modification goes away...

Re: 4.8L Performance upgrade options

Posted: 21 Jun 2018 06:41
by CarloG
Thanks Peter - I agree with your and Tinus' point on the difficulty with getting torque gains low down in the rev range simply by improving the air characteristics.
It appears from my research (I have a lot time on my hands :blonde: ) that the supercharger option version is the most effective from obtaining torque evenly through the rev range. I have attached a dyno stat from one of the companies that apparently was from a real life car they did. +-R125k quote to do that. (I'm sure it can be done for about 80k but I don't have the data to back this assumption up.)

Given the varying views on what could be done and the gains achievable/not I'll try and measure the modifications as objectively and independently as possible so that, if nothing else, the next guy that wants to do this will have yet another data point to work from. :oldtimer: My suggested process is as follows - please add to it:

1. Test the car as current on a dyno that isn't the dyno of the company doing the work. When testing record air temp, time, tyre pressures, car setup (weight)
2. Record on a GPS a 0-100km/h run on a straight flat road, three runs. Record same data as above.
3. Record on a GPS a 0-80km/h run on a straight flat road, three runs, this time with my Caravan in tow. Record same data as above
4. I have been recording fuel consumption in varying conditions for years now so i have a good data on that.
(this is the standard car - original air filter, exhaust, nothing ever done to the engine it, except serviced by Gtech 5k km ago.)

5. Take car to have a 63mm stainless steel free flow exhaust fitted + steel branches (ceramic coated) + UniChipQ4 - hard wired in, one map only, with a bridge plug
- they will do their own Dyno test before and after.

6. As there are no K&N air filters in the country at the moment (arriving mid July according to K&N.) I will replace this myself and then repeat steps 1,2,3.
7. I am going to Mozambique in August for three weeks so will have good fuel consumption data (point 4) as I'm towing again.

This is not a massively expensive exercise but the data would be fun to know, for acceptable financial risk (given that i probably could just drive more aggressively with the revs - per Peters comment.

My conclusion on the filter is that I will give it a try (for 15 years I used washable oil filter on my motorbikes (BMC) - lots of dirt), including a planned 5 week to Botswana in Dec. I will take a replacement OEM paper air filter.

Happy to share the quotes I've received and who from but would prefer on a PM out of respect to those companies.

Re: 4.8L Performance upgrade options

Posted: 21 Jun 2018 06:43
by CarloG
And these are the actual results from: free flow exhaust (no branches); Unichip; K&N air filter,