the NA tuning discussion thred

[lumoxs 0]

Hey guys, I'm wanting to dig deeper into NA tuning and of course the bhp gains etc

Now of course the best thing to go is ITB, now I don't really wanna go that far, so what I am looking at is schrik inlet and cams 6 branch manifold 2.5" exhhaust system air filter and possibly port n polished head. What sort of gains with these mods do you think I could see? Of course please also discuss the route of ITB's and the route to go down and if there is an off the shelf kit you can buy!

Thanks for anyones advice likes and input Ash

[oldmandon 1]

I don't have the Schrik inlet manifold, but I have the rest of your mods and I have dyno charts ranging from 199 bhp and 200ftlb torque to 210 bhp and 206ftlb torque. Not sure that the Schrik would add that much more, probably smooth it out a bit better. Don't forget you will need to de-cat it and re,map it, otherwise it's a waste. If your serious about ITB's, when you've got the head off for porting, why not increase the valve sizes as well, maybe look into flowing the throttle body also (but some say you need some sort of turbulence, so don't go too mad).

ITB's will they add more power?? not sure, they will be more responsive and smoother, but I would guess a real PAIN to set up.........

So what do others think??!!

[Daverse 175]

I think it is grant motorsport, they do a itb set up, but their in america.. sounds amazing on itb's theres a couple of vids on youtube. thought about carbs? easier to tune e.t.c.

[VR6Pete 1,455]

My last vr6 was 221bhp;

Shrick VGI

2.9 wossner pistons rebuilt stealth racing engine

Schrick big valve head

Stock cams

Race land 6 branch

Bmc cda

Miltek exhaust

Decat

Stealth racing remap

Your looking at about 4 - 5k easy!

Head was a grand, schrick was a grand, pistons were nearly 900 quid and that's without labour! If your going down the NA route consider a 3.68 final drive. Cheaper and produces excellent results!

Pete

[oldmandon 1]

I agree, sound would be Awesome, but oh soooooooo expensive for the returns you'd get.

[oldmandon 1]

So .1ltr extra capacity, fancy pistons and big valves equals an extra 10 to 11 bhp over my car!!!....Hmmmm AND SOOOOO expensive...get a supercharger, forget N/A, it's the way I'm going...eventually.....

Just thought, supercharger and IBT's with an exhaust...wonder what THAT would sound like!!!!!!!!!!! If it could be done!!!! Now where PARKY when you need him!??lol

[lumoxs 0]

the problem is everyone goes ahh why spen 5k when i can just throw 1.5k and super dooper it....

i'd be pretty keen to throttle boddy it,

never knew you could carb and vr6... any more info on doing this?

[FishWick 21]

ITBs can give huge gains. Look at all the BMW M engines. They all use them to get high hp. Take the E46 CSL for instance. 350hp from 3.2 litres. Compare that to 280ish after a remap of VW's 3.2 R32 engine. The R32's inlet manifold holds it back. Dump it and fit 268 cams and you'll get close to 100hp/litre.

ITBs with a proper enclosed plenum the way BMW do it is something I've wanted to try on both 12 and 24 valve VR6s but the cost is prohibitive and it would have to be fully custom and a standalone management.

If you can find an E34 M5 at a breakers, that's a good place to start.

Incidentally, in terms of actual norm' asp hp flow the VR heads can support is ~ 300hp for the 12V and ~450hp for the R32.

Historically, not many people have exceeded 250hp from a 12V and it costs £1000s. IMO, if you want high n'asp power with a VW engine, stick the R32 in.

[ashmk3 0]

I'm not sure on hp but Gareth spillers vento is built buy grant Motorsport I think using the tt 3.2 and sounds absolutely evil. Personal opinion of mine is yes forced induction gives great numbers and a quick car but sure an itbd vr6 would be more usable.

[Daverse 175]

the problem is everyone goes ahh why spen 5k when i can just throw 1.5k and super dooper it....

i'd be pretty keen to throttle boddy it' date='

never knew you could carb and vr6... any more info on doing this?

[/quote']

on the other hand, every mod you do for NA will help get every last hp for a turbo so you don't need so much boost.

So in conclusion, get a turbo

regarding carbs, you can do it to any car if you know your way around them, i would look into twin webers and go from there, would sound lush!

[FishWick 21]

I think Gareth's is over 300hp and runs a DTA standalone.

Yep, the more power you get out of a nasp engine, the more power you get when you boost it. It's why Honda VTECs make so much power from low boost. Honda turbos get into the 10s easily.

[lumoxs 0]

Super tempted to give it a whirl and then boost it best of both

Deffinitly true what fishwick is sayin a boosted vtec engine on say eight psi your looking at two hundred ish bhp with the right mods

[sharky_70 0]

often wondered why n/a tuning is a bit neglected compared to an equivalent bmw engine. when you consider you can get of the shelf carbon inlets and tuned plenums for old e30's, 328's and m3s etc.

maybe just cos theyre flat 6 and long mounted youve got more room so it gives you more scope! certainly aint cheap though

[FishWick 21]

Because the gains are a lot smaller per £ than forced induction but there's more to it than that really. Some people prefer the power band of normally aspirated. Certainly in the M3, the power feels like it's never going to run out, just keeps pulling and pulling.... and no lag :-)