Throttle Bodies Or Supercharger? - Fast Road, Occasional Track, Toy

[Malc 45]

That is the million pound question, you need to choose the ecu your mapper is most comfortable with, I chose Omex, mainly for the aftercare etc

I ran K6 emerald on my last kit car, wiring was a nightmare but when it was mapped what a peach, guy who mapped it made it run smoother than a babies butt, can it not be run on standard ecu, rotrex seems to run on this?

[stef205 92 1 Cars]

You'd have to visits chipwizards, he does all the rotrex mapping on standard ecu's. although I'm told he's very busy. My omex wiring was a breeze, although sandy told me the mapping software is a little over complicated.

[Sandy 191]

It's not that hard to make OMEX or Emerald run smoothly, but true map refinement, for economical and clean running, over the range of conditions, is harder to achieve I find. The main reason I favour DTA. Alot of mappers like the fact that you can get it 80-90% nice quite easily on OMEX/Emerald and to the customer it'll feel fine. I map those systems almost as much as DTA, but I won't allow them on my own engines, because of the difficulty in nailing that last 10-15%, that makes a crisper feel, better economy and helps to maintain engine perfomance longer term, because less unwanted deposits occur and bore washing is reduced. It's a key difference between just mapping engines and refining whole engine packages.

 

Going back to the OT question and speaking personally, I've sampled alot of SC cars, from bolted on Eatons to full race 250bhp/litre Rotrex K20s and Hayabusas; it's an undeniably effective power delivery done right and I would argue the case for SC over Turbocharging in almost every scenario, but I can't really love them either way. The power/torque you can expect to achieve from Throttle Bodies is obviously less, but the way a small french hatch drives with a nicely rounded TB engine' really enhances the character for me. The thing I love most about it, is the subtle low noise gargle, wisp and sucking noises that seem so instantly and perfectly connected to throttle movement and engine speed; something you can enjoy all the time and doesn't require the increasingly elusive wide open, smoothly surfaced road that you need to nail hard a SC engine and get the benefit of it! Then there's the bridges/walls/tunnels of course, from time to time. There are alot of issues around using high performance on the road and I think a well done TB engine gives you alot more value in that respect.

[Spiky 37]

For me it's a no brainer

 

I went from tb's to supercharger

 

Secondhand charge setup is abou 2k

 

So 200 Bhp or 260? You choose

[John_B 11]

It's not that hard to make OMEX or Emerald run smoothly, but true map refinement, for economical and clean running, over the range of conditions, is harder to achieve I find. The main reason I favour DTA. Alot of mappers like the fact that you can get it 80-90% nice quite easily on OMEX/Emerald and to the customer it'll feel fine. I map those systems almost as much as DTA, but I won't allow them on my own engines, because of the difficulty in nailing that last 10-15%, that makes a crisper feel, better economy and helps to maintain engine perfomance longer term, because less unwanted deposits occur and bore washing is reduced. It's a key difference between just mapping engines and refining whole engine packages.

 

That's interesting Sandy. What is it that the DTA does over the other ECUs that allows you to reduce unwanted deposits and bore washing more easily?

[Sandy 191]

It's not easy to define, I'd have to write a massive piece to even attempt to explain it, but essentially it's being able to get a feel for what works well for the engine, the balance of fuellng and ignition advance through the range of speeds/loads/conditions. Most mapping is simply done by numbers, the mapper will have a preconceived AFR target for each area of the map, that they will work to and set the ignition the same way and maybe vary it a little to see what gives the best tractive effort/torque (known as MBT); many mappers will only actually alter a base ignition map if they think there's a problem (I have numerous examples of this where I've got copies of the before and after maps and they have literally not touched the ignition, we're talking well known mappers and system recommended agents here).

You can achieve a great deal more if you're prepared to search and test what the engine wants. It's really hard, mostly impossible to do with key tapping adjustment. Knob control of the main map values gives alot more feel as you swing it, but since it requires some variation of areas of the map, rather than working on a single site in a table; easy manipulation of the map graphs is incredibly helpful. Having a clear indication of the compensations that are effective at the same time too, means problem solving and taking a wide view of what the ECU outputs are doing relates readily to what the engine is doing.

Beyond that, the environment has a big impact too, the ventilation needs to be good enough to make it relate to road conditions, but noisy fans and rollers can make you feel out of touch with what the engine's doing; so you end up mapping "on instruments", which isn't going to produce a well honed result.

 

I see the numbers Steve and I know we all want different things from it, but for me 200bhp that I enjoy all the time is worth alot more than 260bhp for a few glancing moments!

[Spiky 37]

But I find the sc cars better than tb'd smooth and always power on tap

 

Mines a track car so I'm always ring it's neck lol

 

But I enjoy it on the road too

[Spiky 37]

It's all personal choice

 

Don't get me wrong i loved the tb setup, and the noise was intense

[Sandy 191]

Yeah, I do lean on it being my personal preference, I'm not trying to define one way being better. For what you want from the car SC is clearly a better choice, but I couldn't justify spending my money that way, for what I want from it.

[petert 586]

I'm with Sandy. I'll take the N/A engine. I'd be disappointed with only 200hp however. A well mapped N/A 2L engine, with TPS and MAP blending and sequential fuel, should see 220hp and have impeccable road manners. You can easily see if you've been short changed on the ignition mapping. If the values are still at whole values and not to 0.1 of a degree, the mapper has spent zero time there.

Edited September 8, 2013 by petert

[DC2T 51]

It sounds like you want to boost it tbh, id say why not both?

 

Get a set of bike throttle bodies, fabricate a mounting system and plenum to contain the boost and fit the supercharger

 

Gtir bodies were relatively cheap too around a hundred quid, same as bike bodies.

[Malc 45]

For me it's a no brainer

I went from tb's to supercharger

Secondhand charge setup is abou 2k

So 200 Bhp or 260? You choose

Decision is made definitely SC, I take in Sandy's points, I do love a properly set up N/A motor on bodies, my last kit car (tiger Avon with zetec, gsxr bodies, emerald k6) was fantastic, the throttle response, noise and delivery of power was fantastic, however I just fancy the challenge of building a supercharged motor for the grunt it will offer.

[camgti 56]

Send your head to sandy, get him to fit bodies, tweak the head, matched with some cams and management. Will be nicer, last longer and be more enjoyable on the road and track. 260+ hp in a 205 needs work on the front end. Youll be spinning while the other is 'using' the power.

 

My 2 cents.

[Sandy 191]

You can easily see if you've been short changed on the ignition mapping. If the values are still at whole values and not to 0.1 of a degree, the mapper has spent zero time there.

 

OMEX saves round values as decimals (input 24 and it'll save as 23.9 or 24.1 automatically, strange quirk of all GEMS based systems). Emerald only has round ignition values in the table, no decimal places. So won't really tell you anything on those systems.

[welshpug 1,657]

Another induction junkie signing in!

 

Sat on the ferry on the way back from a 2.5k mile blast in a V6 205, kept up with the other cars where power and not utter lunacy counted! What a bloody noise.

 

Made 8v turbos look silly pulling out of 2nd gear hairpins

 

 

AND, clocked nigh on 40mpg on a few tanks cruising at 130kph.

[petert 586]

 

. Emerald only has round ignition values in the table, no decimal places. So won't really tell you anything on those systems.

 

So you'd have trouble mapping the ignition on Emerald to any degree of accuracy? One degree is a huge jump when you start getting serious on high compression or blown engines.

[Sandy 191]

Afraid so and I find the interpolation steppy too, but it's not that apparent when you just drive it.

[chipstick 382 1 Cars]

Some want bigger numbers with a certain delivery.

 

Others want reasonable power with a noisey throttle response.

 

The majority who want the former don't often care about anything else than saying they've got 250+

 

Having felt the delivery in a low boost rotrex 306, I personally prefer the rawness of bodies in a 205.

[Spiky 37]

Send your head to sandy, get him to fit bodies, tweak the head, matched with some cams and management. Will be nicer, last longer and be more enjoyable on the road and track. 260+ hp in a 205 needs work on the front end. Youll be spinning while the other is 'using' the power.

 

My 2 cents.

 

but the cost is going to be higher than a charged setup

 

and less torque

[Spiky 37]

Some want bigger numbers with a certain delivery.

 

Others want reasonable power with a noisey throttle response.

 

The majority who want the former don't often care about anything else than saying they've got 250+

 

Having felt the delivery in a low boost rotrex 306, I personally prefer the rawness of bodies in a 205.

 

 

not been in 306, but mine has such a linear feel, it's no different on track than my TB setup

 

there's no surge of power, and can play with throttle mid corner (if needed)

 

come out in mine, i'll convert you ..lol

Edited September 9, 2013 by Spiky

[allye 530 3 Cars]

Another induction junkie signing in!

 

Sat on the ferry on the way back from a 2.5k mile blast in a V6 205, kept up with the other cars where power and not utter lunacy counted! What a bloody noise.

 

Made 8v turbos look silly pulling out of 2nd gear hairpins

 

 

AND, clocked nigh on 40mpg on a few tanks cruising at 130kph.

 

George has his all sorted then? Mines parked up for the winter now

[welshpug 1,657]

We just did the austrian and italian alps, so you could say so

 

currently in bloody traffic on the m25, our road network/driving culture and standards suck!

Edited September 9, 2013 by welshpug