after installing 69mmTB
the car is driving different. vt I v6
its changing gears at much a lower rpm then before installation when the same amount of throttle is given.
for example: leaving lights normally it would change gear 2700rpm give or take. but now with the same amount of throttle its chaging at 2000rpm.
also i need to almost flat foot it to get the thing to downshift for decent excelleration.
im not complaining to much its saving me heaps more fuel, but sometimes i do want it to downshift easier for better exceleration. will i need to get a tune? i thought a tune was not nessacary for this mod?
i did reset the computer, altho how precise do you have to be.
i disconected the bat for about 50seconds, and held the car at 2100rpm for about 1min
It's because the ratio between the tps and the amount of air in the engine has changed
Did you install the the restrictor as per the fitting instructions? As it does help in regards to shifting characteristicsOriginally Posted by bigneilsen
We normally have the fitting instructions online for some of our products (including this one) but it's being updated at the moment. Should be back online tomorrow but will still be subject to a few revisions over the coming weeks months etc.
This aside though and assuming that everything has been installed correctly, and you're still not comfortable with the shifting characteristics, then you can install a shift kit (preferably one of these 4L60e Single Stage Shift Kit - $70.00 : Shiftkits Australia, Performance Shift Kits and Vehicle Electronics as you can switch it on or off) or we can supply you with a memcal to suit. Having said this though even the manifold insulators and plenum spacers help out in this regard as well.
There are more technical detail about these throttle bodies here V6 Peformance Parts but just to give you a snap shot as to what happens when installing a larger throttle on a v6
on holiday
like greenfoam said your making power with less throttle which makes it change early due to the TPS % controlling shifts will be down on trans pressure as well with it reading to low simple fix get a tune all sorted
I tune the oldschool way fear on the passengers face and knuckle colour cant go wrong
tabbacco is still my favorite vegetable
thanks for response.
already have stage 2 shift kit with corvette servo
yes i installed the restirctor. (that was such a bitch to get in without dropping it haha)
what would this memcal do? like how does it change the computer?
how do the insulaters help out? cos they were on the cards for next couple of mods.(which one would you recomend)
is what greenfoam and delco... said correct MACE? i thought that only the vs had problems with the computer.
It's not a problem, its just obvious, you are opening the throttle more but the tps is staying the same
Krabbyball Champion!
Hey bignielsen, It is thought that the VN to VR would escape problems with a bigger throttle body... which isnt the case. I had the same issues with my VR when i installed the 70mm T/B... I ended up putting the standard T/B back on ..... you will need a tune to suit. I havent got a tune yet but one day i may persist in a mod that is currently unnessasary for my car as it is and ask the expert tuners on here for a tuned memcal and whack the 70mm back on.
“thanks for response.
already have stage 2 shift kit with corvette servo
yes i installed the restirctor. (that was such a bitch to get in without dropping it haha)”
Has the general line pressure been increased though? They can easily do this by adjusting the force motors in the valve body when the oil pan is off. In saying this though I much prefer this mod 4L60e Single Stage Shift Kit - $70.00 : Shiftkits Australia, Performance Shift Kits and Vehicle Electronics as you have the option of being able to switch it off or on.
“what would this memcal do? like how does it change the computer?”
Would change the line pressure and shift points
“how do the insulaters help out? cos they were on the cards for next couple of mods.(which one would you recomend)”
The plenum spacer does dull the response of the throttle body (as it requires more time to fill up the plenum) similar to what the factory humps in the throttle body do, dull the response throttle body. In saying this though it still does improve overall performance
“is what greenfoam and delco... said correct MACE?
What they are saying is accurate but, I’ve gone into that into greater detailed in the quoted text a few posts back (which can be found here V6 Peformance Parts)
i thought that only the vs had problems with the computer.”
The VS computers are more inclined to require a tune given the computing power they have (compared to a VT-on computer), making them less adaptable to larger throttle bodies etc.
On the note of the better fuel economy it would also be reflected by overall power increase (contrary to what some people may speculate) as reflected by a slightly higher air fuel ratio. Meaning more air is entering the engine even at wide open throttle.
Last edited by MACE; 11-12-2009 at 09:31 AM.
You just need a more aggressive tuneFoamy did one for me. Good Value. I have the same gearbox mods and it's a sweet drive now.
The shifting characteristics on the VN-VR V6's DON'T change when running a larger throttle body as the flow characteristics don't significantly change per throttle position, unlike a ported ecotec one. Problems like this will most often arise if you have an engine fault code or an aftermarket memcal which has not been calibrated to suit the larger throttle body. The factory memcal in this case is perfectly fine. So did you have a fault code come up when running our larger throttle body or are you running a different memcal from factory?
on holiday
ive fixed many vr's with 69mm with sloppy early changes now ive lost count .fitting the v8 stock TB messes with the shifts pretty badly the amount of air getting round the butterfly at low opening % is where it all stems from its set to change at X speed at X TPS% and with the lower throttle % needed to do the same speed it just makes them sloppy as or you need to get on the throttle more its when just cruising around like a nana that is a problem driving with a little aggression they dont do it much at all and WOT is fine of course.also fixed many vs and vt both charged and none charged which both have the same issue
I tune the oldschool way fear on the passengers face and knuckle colour cant go wrong
tabbacco is still my favorite vegetable
righto makes sence.
so what are my options memcal/tune wise?
what prices am i looking at?
will i need additional tunes if i do any more mods further down the track(rockers/spacers)?
Krabbyball Champion!
I am running a different memcal from factory ... but i did swap the factory memcal in and took the car for a run. I just found that the benifits of running the remapped memcal with the standard T\B outweighed running the 70mm T\B with the standard memcal, ie - I prefered how the car drove with standard T\B and tuned memcal.
Car went great at higher revs with your T/B but cruiseing around slowly was a pain in the butt, with both the remapped memcal and the standard memcal, I just havn't got a tune to suit the larger T\B and increased air flow ( was a definate increase in air flow cause my exhaust note had changed quite a bit ) ..... when i get a tune it should all be sweet.
Cammed & Eventualy Blown!
i got one of delco's tune to suit my 69mm Tb and its sweet so much more responsive then standard
Krabbyball Champion!
I should get one to put the T\B to good use, mine is on a VR though. At the time i put it on i started a thread about it, and both greenfoam and delcowizzid said they could sort something out ... but delcowizzid was off on holiday and greenfoam would of had to spend a fair bit of time out of his busy schedual to sort a tune out as he hadnt done one for a VR yet i think (he said he would do it if i really wanted it, even though he is of the opinion that a larger TB is not nesesarry on the V6 --- GOOD Bloke)
I just haven't persued it since then and just put the standard throttle back on.
Do you know anyone with a VR that has the 70mm T/B with a delco or foam tune?
If I seen a 70 mm throttle body gain more than 1rwkw on a V6 on a legit dyno I would just about eat a throttle body
Krabbyball Champion!
^^If I seen a 70 mm throttle body gain more than 1rwkw on a V6 on a legit dyno I would just about eat a throttle body^^..lol.. This comment cracked me up ..lol..
Well, i did test the 70mm throttle body on the dyno and guess what ..... no gain. Used the same dyno, about a year ago got 110.x rwkw with standard TB and just recently got 110.x rwkw with the 70mm TB.
I was going to test again with the 70mm TB and tune to suit but as you know i havnt enquired about getting one as yet .... if i do and get 112rwkw i will remember this comment .. hehe
I remember Cobez gained 1rwkw with a 70mm on his 5 litre but they can suck down alot more air than the V6's
I still find it extremely difficult to believe that our throttle body (bare in mind that not all throttle bodies on the market are the same!) on a VR V6 will significantly change the shifts on a factory tune.
I can tell you from personal experience that the VR computer is very good at adapting to change. For instance we’ve done an ecotec engine conversion into a VR running the standard VR V6 loom and computer. Changing things like the injectors and temp sensors in the process over to the ecotec engine in the process the car started first time and idled quite well.
The only problem we initially had was that it caused the shifts to be a bit delayed, at the time though we were still running the standard ecotec throttle body which differs significantly to the “buick” throttle body as mentioned previously. To solve this problem all we did was ran one of our ported ecotec throttle bodies bringing the shift quality back to about 95% of that of standard. Not a 100% perfect but considering we undertook a significant mod such as an engine swap without a tune it goes to show how adaptable these computers are
There are a few suppliers of memcals on the market, ourselves included. If you let the company know of your requires (including future mods) they’ll best be able to advise you on what exactly they can supply
In regards to how the car drove down low was that because it was a bit too responsive then you would have liked? If so they a tune can definitely dull down the responsiveness a little, however in quoting WogBoyz below some people really like the way these throttle bodies can wake up the V6
Would you like a side of salad or chips with your 70mm throttle bodyIf I seen a 70 mm throttle body gain more than 1rwkw on a V6 on a legit dyno I would just about eat a throttle body
In all fairness not a lot was gained with the memcal when testing was done either, despite the apparent real world gains from the seat of the pants meter :P Let alone improvements in drivability and responsiveness, which can’t really be measured on a dyno^^
Well, i did test the 70mm throttle body on the dyno and guess what ..... no gain. Used the same dyno, about a year ago got 110.x rwkw with standard TB and just recently got 110.x rwkw with the 70mm TB.
I was going to test again with the 70mm TB and tune to suit but as you know i havnt enquired about getting one as yet .... if i do and get 112rwkw i will remember this comment .. hehe
Dyno results of an Ebay 'performance' chip!
Now I’m not saying that these items don’t work, as from experience they certainly do, however the fact that the testing was done a year apart leaves open way too many variables that would compromise the accuracy of the results. For arguments sake, car may have experienced more wear, different tires, different oil, strapped down differently, different operator etc.
True, but the main restriction in the 5L’s is mainly the manifold around the elbow where the throttle body bolts up to. In the case of the V6’s the main restriction is the throttle body as they fortunately have much more of an open free flowing manifold designI remember Cobez gained 1rwkw with a 70mm on his 5 litre but they can suck down alot more air than the V6's
I am have got a larger air flow meter and getting a larger throttle body
What kind of tune is needed ?? how much?
I know mace do supply retuned memcals to suit for vt's for $110 so all you do take out the factory one and plug in the new mace one
is $110 a flat rate for any retuned memcal or does the price get higher if you have more mods that require a more precise tuned memcal? just asking because $110 memcal tune sounds alot better than a dyno/mafless tune that i have head will cost more than $500-$800
The retuned Mace memcals I would say are a basic tune eg increased line pressure,fuel maps and auto shifts adjusted to suit minor mods
Give delcowizzid or greenform a pm cos them two would know alot more than i would regarding memcal retunes
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