Inlet manifold

[SR-Rally]

Thinking of replacing my down draft weber for a single 45 so can still compete in road rallys, does anyone no where I could get inlet manifold to run dingle 45 or to run split 40's?

[let_nova]

bogg brothers?

[Aragorn]

why bother?

EFI FTW!

[SR-Rally]

My car is beating all the 1.4injections out at the moment ;) and it's 1.3 carb. Il try bog brothers thanks

[Aragorn]

Well EFI WILL make more power, thats been proved time and time again!

[GRUNT 16V]

im thinking about making inlet manifolds ! put my new TIG welder to use !

[SR-Rally]

Yeah but you can only run standard injection and throttle body for road rallying, my last 1.3 made just over 100 hp at wheels that's plenty for lil nova. :)

[garyc]

Why not run a weber IDA down draught (like a dcoe but down draught) on something like a MK1 astra inlet manifold?

[SR-Rally]

Do you mean down draft? That's what I'm running now,

[garyc]

IDA are proper racing down draughts, what are you running now? what spec engine?

[Aragorn]

Carbs are like a bucket with a hole in the bottom.

You can polish the bucket, finely craft the hole or even add more than one hole, but at the end of the day its still a bucket with a hole in the bottom.

Nail a GTE/GSI inlet manifold on there and some megasquirt and i would put money on getting a better end result compared with what you have now.

[Angus Closier]

Carbs are like a bucket with a hole in the bottom.

You can polish the bucket, finely craft the hole or even add more than one hole, but at the end of the day its still a bucket with a hole in the bottom.

Nail a GTE/GSI inlet manifold on there and some megasquirt and i would put money on getting a better end result compared with what you have now.



I really don't believe this is true??? Iv seen a few with twin 40s running far more power than injection....at the end of the day injection is better but not because it runs more power, but due to the better fuel economy, mapping,etc etc BUT its been proven time and time again that carbs make good power!

To be honest I would go carb over standard injection any day....even with megapoo....

[SR-Rally]

To put twin forties on my car Inc rolling road cost me £500 there abouts, to run throttle bodys i'd be looking closer to 1000 or more? I agree injection is a better design but at a price. I can only run standard injection systems for road rallying but I can run upgraded carbs which do produce more bhp then standard injection, if I was track or stage with no ristrictions jenvey throttle bodys all the way. But I'm not :D thanks for imput though guys

[Spudly]

Err mr nova16vxe (http://www.pngclub.com/forum/member.php?u=35774) i would listen to Aragorn, he is a clever boy and knows his stuffs :p lol

[Aragorn]

You cant really compare a set of twin 40's with a standard EFI inlet manifold. One has a single butterfly and the other has four butterflys with a much greater throttle area.

Saying that though, Bruce's old GTE had a worked cylinder head (standard valves though), full on camhaft and a standard GTE inlet manifold and throttle body fitted with C20XE injectors and DTA management. It made 150hp peak at 7100rpm (power was still climbing but he didnt want to rev it any higher) and it had a mostly flat torque output of 110lbft across the rev range.

More could have been had from ITB's but it would have meant a higher rev limit and more changes to the internals to handle it.

[SR-Rally]

I agree injection is far superior but isn't upgraded carbs going to be better then standard injection, like split 40's will be running 2 butterflies? May be able to run 40's apparently because were fitted to nova standard (sport) waiting for msa scrutineer to get back to me tomorrow.

[George g]

40's can only be run on a genuine nova sport with homologation papers, like mk2 escort rs2000 can run 45's as they came with them, otherwise you are not allowed to run more than one choke per 2 cylinders.

Bogg brothers are the best for manifolds mate. They seem to be able to do anything...

What kinda budget you got for the upgrade? And howmuch do you want for your old carb? And will it fit on an Sr inlet manifold? Lol.

[Angus Closier]

Err mr nova16vxe (http://www.pngclub.com/forum/member.php?u=35774) i would listen to Aragorn, he is a clever boy and knows his stuffs :p lol


Im never saying he does not! I'm not somone to slag off other people;)

Just if he is not allowed to run anything other than the injection which is standard ie not even mappable management, then surely the carbs have it over??? I want to run throttle bodies on my xe and would choose them over carbs anyday but what I was saying is unlike me he has restrictions? would carbs not be better in this circumstance?
(BTW I'm only just 17 and in no way do I think im right but at the same time I should be able to voice my word! in doing so I will learn allot more from corrections than just not saying anything. so don't think im a person who thinks they know everything as I dont and I dont pretend you know)

[SR-Rally]

Homologation papers? Heard of these not to sure what they are, you can get them from msa etc or would they be suplied with the car from new? A local scrutaneer said to me if it says sport on the v5 then youl be aloud to run forties? Don't want to break rules but would like to learn :)

[Aragorn]

Obviously if you compare multithrottles with a single throttle inlet, be it carbs or EFI, the multi throttle will flow more air for a given engine spec, and therefore should make more power.

So if you take a standard GTE engine, and fit twin 40's, you'll gain power. However if you fit some ITB's instead of the 40's you'll gain even more power.

The fact that bruces engine made 150hp on the standard inlet manifold just goes to show what efi can do. There arent many twin carbed 1600's making more than 150hp, yet he managed that on the standard inlet.

SR-Rally: Obviously your working to a set of rules, and as i dont know what the rules are its hard to say wether in this case the carbs are the better choice, however i would say if your comparing a single weber carb with an EFI inlet manifold, more power can be had from the EFI setup.

There are a number of reasons this is the case. One is the accuracy of the fuelling, with EFI you get it spot on, with a carb its a close-enough ballpark. The second is a carburettor by its very nature is a restrictive device. You need a restriction in the airflow (the choke) to allow the carb to work. If you fit a larger less restrictive choke to gain power at the top end, you lose power everywhere else because the fuelling goes to hell, so its a compromise. With EFI you have no restrictions, and because your injecting the fuel, you dont have to worry about low air speeds stopping the carb working correctly, so it runs properly everywhere. EFI also gives you complete control over the ignition timing, rather than relying on a dizzy designed for a 1.4 engine making 70hp.

It can be more pricey if you go out and buy some shiney jenveys and a DTA ecu, however there are other options, such as bike throttle bodies and megasquirt, and used equipment does pop up now and then too.

[saloon3]

Are you allowed to use bike carbs?..cheaper option ?

[SR-Rally]

Nope, I've got twin forties at home all set up but only allowed to run them if car is a sport.

[George g]

The basic rules for road rallying are that injection system must be standard with freedom on the ecu, so megasquirt is acceptable, and carbs must not have more than 2 chokes per bank of 4 cylinders, so bike carbs are out...

I think the question here is what's the budget? If its large then efi and mappable ecu is the way forward, however if its tight then a carb is a tried and tested way.