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RHD engineering Itb's

Posted: Sat Apr 19, 2014 1:13 pm
by si.
Does anyone have any experience with the company or the parts??

Looking at building an itb setup for my m20 using bike tb's but then came across these and overall the cost of building it myself from what ever i buy off ebay any RHD's setup wont be all that different

So just wondering if anyone had any experience with RHD the company and/or their kit

Aussie company so hoping one of you guys from down under might know a bit



Cheers
Si.

Re: RHD engineering Itb's

Posted: Wed Apr 23, 2014 5:40 pm
by Bullet Ride

Re: RHD engineering Itb's

Posted: Wed Apr 23, 2014 6:12 pm
by e21-Mark
They do look pretty sweet. There are some cracking pics in that link.

Are you going to ditch the stock MAF and go standalone?

Re: RHD engineering Itb's

Posted: Wed Apr 23, 2014 11:26 pm
by si.
They do look good its just if they 'are' any good

Yeh definatly stand alone best way in my opinion ive converted honda twin cam engines to use tb's before although they dont use maf's it still gives you much better better maps, plus i can then run open trumpets when i want to :driving

Re: RHD engineering Itb's

Posted: Thu Apr 24, 2014 11:48 am
by si.
Having read that thread on e30 tech it seems they are pretty good

Time to start trying to find a new head to get worked and rebuilt and hopefully by the end of the year have a setup ready to bolt on

Re: RHD engineering Itb's

Posted: Thu Apr 24, 2014 12:32 pm
by croma_man
i read differently on other topics regarding ITB's and M20...the M20B25 intake manifold is designed very well, by deleting the restrictive bosch AFM, fitting a bigger diameter inlet, the difference between dbilas ITB's and B25 intake (with a regular AFM not the restrictive Bosch) was only 4-5 HP and 15-20Nm of torque. Both times the engine was tuned, not just parts bolted on. Yes the ITB's sound like all hell breaks loose, but for the money difference, I rather get myself new tyres, brakes, jada-jada...

Re: RHD engineering Itb's

Posted: Thu Apr 24, 2014 7:30 pm
by Bullet Ride
croma_man wrote:i read differently on other topics regarding ITB's and M20...the M20B25 intake manifold is designed very well, by deleting the restrictive bosch AFM, fitting a bigger diameter inlet, the difference between dbilas ITB's and B25 intake (with a regular AFM not the restrictive Bosch) was only 4-5 HP and 15-20Nm of torque. Both times the engine was tuned, not just parts bolted on. Yes the ITB's sound like all hell breaks loose, but for the money difference, I rather get myself new tyres, brakes, jada-jada...
If you look at the E30tech thread they took a stock 325i dynoed it at 150hp, then installed their 40mm ITB kit and re-tuned the fuel map, with no other mods the car made 174hp on the same dyno.

24whp is significant... The power is pretty close to what an average 2.8L stroker build makes.

dbilas is a bad example for the ITB bench mark, it's pretty well agreed that their throttle bodies are too big and the plenum/runner design kills the air velocity, which is why the kit performs so poorly.

Re: RHD engineering Itb's

Posted: Fri Apr 25, 2014 12:01 am
by si.
Agreed,

having built itb setups before (on honda engines) i learnt that runner length and size are very important, which has been taking into consideration by RHD and seemingly slightly overlooked/miscalculated by others

Also, even if the gains are small my car has been nut and bolt rebuilt with everything uprated in the past year the only thing i dont have is an lsd which i will be sorting soon so engine mods are next on my list

I also have a very agressive 300deg Newman cam already so with a nicely rebuilt head with a mild port and polish my cam and these itb's i should see some decent power and of course lots of noise!!!!

Re: RHD engineering Itb's

Posted: Fri Apr 25, 2014 12:13 am
by e21-Mark
Seem to recall Dave Walker spending ages flowing M20 heads and not making any noticeable gains. Will see if I can find the issues of PPC it was in. Might have been Car and Car Conversion then?

Re: RHD engineering Itb's

Posted: Fri Apr 25, 2014 11:04 am
by si.
I think ive read the same thing mark but i figured if the head is going to be rebuilt then i may aswell get a port and polish job done on it, you never know with all the other mods it may yield some small gains

Re: RHD engineering Itb's

Posted: Fri Apr 25, 2014 11:31 am
by croma_man
I did only port matching on both sides (intake/exhaust), and on the valve guides a bit of rounding, otherwise just minor polishing without porting.