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Thoughts & comments on my DIY weldless TGV delete solution before I fit them?
Hi all. One of my next upgrades is a DIY TGV delete. My car is a daily commuter so it can’t be off the road for long so I bought some parts off ebay to work on at my leasure.
I wanted to completely gut the ports, but don’t have welding equipment (or any experience!), and I’ve not found a ‘friendly mechanic’ who can weld for beer money yet so I’ve gone for a weldless option. As many posts have suggested I threaded and fitted bolts in the outer holes and used a healthy amount of threadlock. I also reused the rubber seals around the threads of the bolts and made an end plate from copper sheet to support a liquid silicon gasket to seal it - pretty belt and braces I reckon!
I also wanted to isolate each port and didn’t fancy using epoxy or similar as it could work loose and be drawn into the engine, so I put a piece of bar in the centre holes. The bar ground to fit is actually just short enough that it could potentially work it’s way out and fall down into the engine, so I wanted a solution that is mechanically fail safe, or as best as. I bought some 8mm mild steel bar off ebay, cut it to roughly the correct length, drilled and tapped an M5 hole in the middle, then drilled a 5.5mm hole vertically into the ‘tunnel’ between the 2 ports, created a recess for the bolt head, tightened in an M5 machine bolt, and filled the recess with super steel (hard epoxy). I’ve used a healthy amount of thread lock on the bar and M5 bolt for a seal and good measure. The epoxy is there for 2 reason: firstly to a create a seal to stop air leakage (also the manifold gasket covers it to), and then to act as a mechanical backstop for the bolt in the unlikely event it loosens.
Before I fit these to the car, I wanted to see what peoples’ thoughts were on this solution, any concerns, comments?
from various forums I've been reading they are there for cold start emissions control (much like the secondary air pump is for Hawks onwards), so they are active (closed) for a short time at cold startup then the rest of the time just a sizeable physical restriction in the intake system!
I'm quiet interested in DIY (relatively cheap) ways to reduce intake and exhaust loses, as these don't necessarily make the engine more powerful, but rather, just more efficient. I've bought a Tactrix Openport 2.0 to be able to turn of the DTCs as well...
good stuff - you'll be hard pushed to notice the mighty increase in torque from this mod alone but at least with the openport you will be able to extract a few more ponies from it if your feeling brave.
If you've not got one already then get a wideband o2 sensor on your shopping list so you can see what the AFR is up too following all your changes. I take it your signed up to romraider as well?
yeah, I've registered with romraider and ecuflash forums, in the process of reading through their (many) helpful posts on the subject. I understand the basics having worked in a warranty dep't for an OEM and dealing with customer warranty concerns for all aspects of the vehicle (inc. engine issues), but never got into the specifics of engine mapping - always good to learn a new skill though!
I'm fitting a sports cat soon and getting the car mapped by a scooby specialist, so I've read the current map, and will get it after, so I have a before and after that's specific to my car for reference.
Not got a wideband sensor yet, but will look into it. Can you recommend one, or where to buy? Perhaps I can get it fitted before it's mapped...
also double check with your mapper that they won't lock them map on you - otherwise your opensource software won't be able to read the car once it's been tinkered.
For wideband Zeitronix, Innovate or AEM seem to be the most popular. The AEM i've heard tales of it being a little odd in it's readings but no personal experience of the unit. Innovate I'm currently using with a plan to upgrade to the Zeitronix having seen one in a car recently.
for the wideband sensor is that something you fit instead of the stock 02 sensor, or additional to? it looks like you fit additional to, but how do you mount it, and where is the best place on a Hawk sti?
it's in addition to the stock sensor. You can disable the rear o2 sensor and put it in there or you can mount it in on the backbox with a temporary clamp. Using the backbox will give you a *slightly* delayed reading and your idle figures will be messed up. But sticking it permanently in the rear o2 spot makes it tricky to remove if you need to. Don't forget to calibrate the sensor before installing too.
If your in as far as the TGV deletes I take it your binning the secondary air pumps as well? On a 2.5 you'd be as handy picking up a set of det cans as well as the stock pistons won't take any abuse. I use the Phormula KSPro: http://www.phormula.com/KnockAnalyserPro.aspx
Yes it's another expense to fork out on but if it saves you popping the engine then it's well worth it. They do a KS4 as well which you can leave in the car all the time and it will beep/flash etc. if it hears anything dodgy.
Thanks for good info! When I bought the car I didn’t realise the head gaskets were going (doh!), so I ended up shelling out for a full engine rebuild and fitted Mahle 4032 forged pistons, RCM 11mm head bolts and 0.78mm head gaskets and other parts (oil pump pickup, main bearings etc), as well as the air pump delete; so that lump of dead weight is gone already
I think with the forged pistons the engine will be more robust, but I’ll take a look at the AFR and knock equipment. I think mounting the AFR sensor in the post cat O2 sensor bung would be sensible, since I guess it’s only for monitoring the condition of the cat anyway, and with the DTCs disabled it will not affect the running of the car?
I like to have the proper tools for the job where possible and planning to make other mods, like ported headers, HS ‘trick’ up-pipe etc and I’d like to start understanding how they affect running and how to tune the map for them.
Due to time constraints though I’m not able to fit the TVG deletes before the car is mapped for the sports cat, but I plan to fit them and disable the DTCs myself after. Would you expect the AFR to alter significantly after fitting the deletes? So much so that the remapped ECU could not adjust for it?
As for my weldless solution, does it seem reasonable do you think?
you'll notice very little difference in removing the TGV's unless your pushing for 110% from the setup. Just again make sure the map won't be locked otherwise you won't be able to turn the codes off afterwards.
there's a few on romraider who've done TGV deletes this way and for the most part has been fine (i recall someone lost a nut/bolt something and it made love to a piston). So long as you've them well held on you should have no problems.
For the rear o2 - no not all ECU's will be happy to just turn off the rear o2 codes. You also have to zero out the AF#3 correction range otherwise you'll get some wonky fuel trims on cruise as the car attempts to get the cat up to temp.
Yes it's another expense to fork out on but if it saves you popping the engine then it's well worth it. They do a KS4 as well which you can leave in the car all the time and it will beep/flash etc. if it hears anything dodgy.
Would this be worthwhile buying if i want to keep my engine in one piece above 400bhp on stock internals ?
you'll notice very little difference in removing the TGV's unless your pushing for 110% from the setup. Just again make sure the map won't be locked otherwise you won't be able to turn the codes off afterwards.
there's a few on romraider who've done TGV deletes this way and for the most part has been fine (i recall someone lost a nut/bolt something and it made love to a piston). So long as you've them well held on you should have no problems.
For the rear o2 - no not all ECU's will be happy to just turn off the rear o2 codes. You also have to zero out the AF#3 correction range otherwise you'll get some wonky fuel trims on cruise as the car attempts to get the cat up to temp.
the mapper has confirmed he can offer various options, and I have asked for opensource - so that should be covered at least.
as for the AF #3 correction range, i've googled it and it seems you need to edit this in the ECM code with an app called IDA, is that right!? I've check it out and can not make head nor tale of it even with some forums posting about that very subject! It's pretty far down the rabbit hole....
will do, thanks for the advice. I'll speak to him about the AF
#3 zeroing also at the time. I think i'm going to spend some time logging a learning more before I do any changes after the remap.
26 July 2016, 06:02 PM
Thoughts & comments on my DIY weldless TGV delete solution before I fit them?
