induction upgrades
Discussion
My griffs engine is standard apart from an mildly upgraded cam /chain chip rockers and followers .Iam looking for 300bhp but retaing as much driveability as possible .The question is whether to procced with additional mechanical upgrades or go down the induction route ie bosh AFM /injectors Act Plenun and chipping.THe cam upgrade is causing some shunting at low speeds which I would like smoothed out (Perhaps MA chip will help.) but otherwise Iam happy with the extra power.Accordingly I would welcome comments from owners who have had induction mods.... put cost aside, just tell me if you got the power/ driveability you expected and were you happy at the end
Standard plenum will only flow around 310bhp, so you shouldn't need to change this yet. Likewise the injectors are good for at least theat and both ar eexpensive to replace.
If you're still running on a standard map, I would suggest the Mark Adams Tornado chip and roling road set up. This will make the most of what you've got. Take Mark's advice on what to do after that.
The ACT smoothbore silicone inlet pipe is worth around 10bhp and is a very cheap upgrade.
If you cam's very lumpy, could be you'd benefit from an OMEX 100 which gives you control over your ignition advance, allowing lots of advance at low revs when it's runnign rivh, and leaning off to prevent pinking at the top end.
If you're still running on a standard map, I would suggest the Mark Adams Tornado chip and roling road set up. This will make the most of what you've got. Take Mark's advice on what to do after that.
The ACT smoothbore silicone inlet pipe is worth around 10bhp and is a very cheap upgrade.
If you cam's very lumpy, could be you'd benefit from an OMEX 100 which gives you control over your ignition advance, allowing lots of advance at low revs when it's runnign rivh, and leaning off to prevent pinking at the top end.
What Griff do you have? It must be a 4.x something.
The factory bhp outputs were 400 240 bhp, 400 gas flowed 250 bhp, 400 HC 275 bhp, 430 280 bhp, 430 BV 300 bhp, 450 285 bhp, 450 BV 320 bhp, 500 340/320 bhp (pre-serpentine, post serpentine with Cats).
So, I guess you have a pre-cat which rules out removing the cats for hp increase.
From what I understand by reading around, the best hp increase is to do head work - bigger valves if you can stretch that far and gas flowing the ports. If you do that then an intake gas increase with twin plenum chanbers makes sense. Then you can change the cam for something a bit hotter - but you seem to have that already. Any changes will need proper mapping on a rolling road to get the best out of them as the engine fuel mapping will be wrong with a standard chip. If you have lumpy running with the current cam it might be worth just doing the rolling road mapping ans see what you have at present. The engineers will advise you, expertly, of further upgrades when they do the mapping.
Phil T
The factory bhp outputs were 400 240 bhp, 400 gas flowed 250 bhp, 400 HC 275 bhp, 430 280 bhp, 430 BV 300 bhp, 450 285 bhp, 450 BV 320 bhp, 500 340/320 bhp (pre-serpentine, post serpentine with Cats).
So, I guess you have a pre-cat which rules out removing the cats for hp increase.
From what I understand by reading around, the best hp increase is to do head work - bigger valves if you can stretch that far and gas flowing the ports. If you do that then an intake gas increase with twin plenum chanbers makes sense. Then you can change the cam for something a bit hotter - but you seem to have that already. Any changes will need proper mapping on a rolling road to get the best out of them as the engine fuel mapping will be wrong with a standard chip. If you have lumpy running with the current cam it might be worth just doing the rolling road mapping ans see what you have at present. The engineers will advise you, expertly, of further upgrades when they do the mapping.
Phil T
Last year I did the Bosh injectors, flaired trumpets, smooth bore air pipes, bosh air flow meter, silicone hoses and a Mark Adams session including the special chip. The net result was an extra 10mph down the main straight at kirkistown race track. Fellow 500 owner could ONLY get 120mph down the straight. The car does run a lot smoother but in town I still need to keep it in 4th gear. The real power gain is in the 30mph to 80mph range. It is just incredible and does take a bit getting used to. 320lbs of Torque can't be bad. It does put a Very big smile on your face time and time again.
thanks for all your comments
I should have mentioned that I have the griff 500 1998 ,just 19000 on the clock.
I did speak at some length with paul of Austic during the recent show at the NEC and came away convinced ( he sells himself and his products very well and I was impressed by what he said in support of the induction upgrade)that the induction route was the best for me.I then spoke to another TVR tuner who rubbished induction ( although conceded that the bosh injectors would make a difference)and talked about rebuilds new heads balancing of the engine and said induction was simply awaste of money; hence this plea for someone to comment on their experience.
Its disappointing that we the customer are in a war of sorts between these tuners .I do however intend to go for the induction perhaps after a MA chip and rolling road session and then see about plenums injectors ect
I should have mentioned that I have the griff 500 1998 ,just 19000 on the clock.
I did speak at some length with paul of Austic during the recent show at the NEC and came away convinced ( he sells himself and his products very well and I was impressed by what he said in support of the induction upgrade)that the induction route was the best for me.I then spoke to another TVR tuner who rubbished induction ( although conceded that the bosh injectors would make a difference)and talked about rebuilds new heads balancing of the engine and said induction was simply awaste of money; hence this plea for someone to comment on their experience.
Its disappointing that we the customer are in a war of sorts between these tuners .I do however intend to go for the induction perhaps after a MA chip and rolling road session and then see about plenums injectors ect
I have alloy 45mm Alloy Trumpets fitted and V8D Plenum with enlarged throttle 71mm. along with the Silicon Air Hoses, not done the AFM or Bosh Injectors......Yet 
along with MA chip and RRS esion with MA and Austecs pulling around 280BHP, was a very poorly 230ish before. Although I am led to believe the original AFM is good to 300bhp.
BB
along with MA chip and RRS esion with MA and Austecs pulling around 280BHP, was a very poorly 230ish before. Although I am led to believe the original AFM is good to 300bhp. BB
You run a dastek unichip .. erm the clue is where I said dastek unichip, lol .. it's the industry standard piggyback ecu .. it modifies the airflow meter signal to foll your own ecu into giving you the fuelling you require .. and intercepts the signal from the dizzy to give you mapped ignition too .. best bit is the price is fixed by dastek so you know exactly how much yuo're going to pay inadvance, and plus because you only have to splice a few wires it's very easily reversible and there's a full no quiblle money back guarantee.
Short of chamging the existing ecu for a fully mappable version it's the best route in my opinion.
Short of chamging the existing ecu for a fully mappable version it's the best route in my opinion.
howardm said:
thanks for all your comments
I should have mentioned that I have the griff 500 1998 ,just 19000 on the clock.
I did speak at some length with paul of Austic during the recent show at the NEC and came away convinced ( he sells himself and his products very well and I was impressed by what he said in support of the induction upgrade)that the induction route was the best for me.I then spoke to another TVR tuner who rubbished induction ( although conceded that the bosh injectors would make a difference)and talked about rebuilds new heads balancing of the engine and said induction was simply awaste of money; hence this plea for someone to comment on their experience.
Its disappointing that we the customer are in a war of sorts between these tuners .I do however intend to go for the induction perhaps after a MA chip and rolling road session and then see about plenums injectors ect
hmm .. don't know why anyone would rubbish induction changes .. I made great gains on my V8S for a few hours with the grinder and TIG welder on the bigger butterfly and on my trumpet base putting generous radiused entries on there .. once the fuelling was sorted out it made 198bhp which was about 10bhp up on the previous highest figure i'd seen using a non tvr plenum and twin throttle body arrangement. Interestingly HarryW mentions elsewhere about when he made his plenum bigger and it lost hp but i have no direct evidence to support that myself, but i think everyone is agreed that radiused trumpet entries are worth hp on the RV8, especially teh larger 5 litre cars with their non-radiused exhaust pipes for inlets. In fact I'm trying to get a company to make me some trumpets for my own conversions on the RV8s.
What it also shows though is that different people have different ideas about where to spend their money and how much to spend on each area, that's something you'll never change .. also you'll never change people pushing their own kits ahead of anyone else's .. all you can do is ask a lot of people and spend your money with whoever you feel comfortable with.
there is lots of good information allready in this post allready but just to add to it, the 2 main factors that affect poor driveabilty are low air speed into the cylinder's and holding the valves open too long, both these will kill low down torque, more cubic inches always improves torque regardless how small the inlet flow is and more cubes means a car can accelarte faster, it doesnt mean you will get more hp but the car will still be faster! also the dynamic compresion ratio is very important, by fitting a long duration cam you are lowering the compresion ratio and in effect reducing your engine from a 5ltr to a 4.8, basically because the valves are open longer you lose your ability to totaly fill the cylinder as some is lost out of the exhaust, valve size is one way to significantly improve bhp, you can not over valve a rover engine, the optimum valve size for a 5ltr is 1.9 inch they are fitted with 1.690, so upping the inlet valves to 1.8 which is the max you can go to is well worth it, the exhaust is allready to big but that you just have to live with, port size is also too big as you are losing gas speed through the ports which kills driveabillity and doesnt increase bhp, plenum top is too small, lets face it this was designed for a 3.5 ltr!!
As always it comes down to how deep your pockets are for the increase you are looking for? if you are only looking for 300 bhp you should be looking at the act range to be honest, a twin plenum with what you already have should crack this, sorry this post is a bit long winded but i was just trying to show the gains and losses of what could happen.
As always it comes down to how deep your pockets are for the increase you are looking for? if you are only looking for 300 bhp you should be looking at the act range to be honest, a twin plenum with what you already have should crack this, sorry this post is a bit long winded but i was just trying to show the gains and losses of what could happen.
Having fitted induction upgrades (listed below) I can confirm they definantly make a noticable difference to the car (no idea of bhp gain though)
I've fitted the ACT carbon fibre trumpets, ACT induction kit, new fuel injectors (Rob Robertson)...
The trouble I have now is:
is starting it, it used first time all the time, now it cranks over lots before firing up
its eratic at tick over as well despite cleaned stepper motor.
It chucks flames out the back (not a problem
) but only out one exhaust pipe....guess something aint right there then
So I guess it needs a fettle around of the management system to balance evrything up and to cope with the extra air its breathing........
So options Dastec chip, MA tornado chip any others ?????????? ups n downs of them
I've fitted the ACT carbon fibre trumpets, ACT induction kit, new fuel injectors (Rob Robertson)...
The trouble I have now is:
is starting it, it used first time all the time, now it cranks over lots before firing up
its eratic at tick over as well despite cleaned stepper motor.
It chucks flames out the back (not a problem
) but only out one exhaust pipe....guess something aint right there then So I guess it needs a fettle around of the management system to balance evrything up and to cope with the extra air its breathing........
So options Dastec chip, MA tornado chip any others ?????????? ups n downs of them
Sounds like you have changed lots of hardware, and some of these changes could require significant changes to the map for it to work properly. Until you correct the map it's no surprise that the engine is badly behaved. If you have a cat you might find you aren't doing that any favours either.
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