Chasing More Power........

[Dr H]

Some on here will know what I'm like in my spending on the car and messing about. Many moons ago I bought a 70mm TB for the Honda from Clockwise. I then spent a lot of effort (and money) having some custom supercharger inlets machined up. Much bigger and straighter than the normal one on the JRSC setup.

 

Today I spent a day at TDI South seeing if these bits made any difference......

 

About 3 years ago the car (in it's current spec) was mapped by Scuffers. 318 HP and 203 torques at the hubs.

 

Since then the changes have been a 100 cell sports cat and recently changed the ECU to a PRB version with k-pro. I booked a day on a dyno to see what the car now makes and what the new SC inlet and TB makes.

 

Arrived this morning, set it up on the dyno and Sam (the mapping chappy) did his stuff.

 

He mapped the car from scratch and the base map on car with current inlet and normal TB gave 326 HP and 200 torques.

 

All was OK so I fitted the new SC inlet and kept the normal TB. Sam ran the car checked the figures, tweaked the map and we got 323 hp and 201 torques.

 

We were all a bit confused as everyone at TDI was expecting the inlet to give a power increase. The laws of physics and basics of gas flow mean it should. So we accepted the figures (what else can you do!) and fitted the bigger TB.

 

Once again a run, a few tweaks and a power run. This time we got 333hp and 204 torques.

 

Sam then gave the car a good test at part and full throttle simulating driving round a track and made a few more very small mods to make sure it ran perfect throughout the rev range.

 

So it seems that when the new inlet it on the car (mine at least) it's the TB that is the restriction. Still not sure why this is. Jamie's car showed the exact opposite with gains from his straight inlet and nothing from the TB. But Jamie's car has a much less restrictive exhaust than mine.

 

So 3.25hours of mapping time at £125 / hours has led to the conclusion that:

 

Sam's base map was more powerful than Scuffer's map.

 

On my car the inlet needs a bigger TB to get the most out of it

 

The gains from the inlet alone seem to depend on the car it is fitted to.

 

Graphs of all three runs:

 

 

Impressively linear for both HP and Torque. The inlet +TB after 6500rpm gives gains. The other thing that was commented on, is that there is no drop off in HP at all. Sam said he could easily get a higher figure if we revved it to 9k but we both agreed that was a bad idea.

 

333 at the hubs isn't bad I guess and Sam said it was probably the highest figure for this type of setup with a CAT as most others run without one. Who knows what the engine figures is but it must be somewhere between 370 and 380 and I ain't gonna argue with that

 

TDI were brilliant. Sam is atop bloke (as are they all). He explains everything and is incredibly knowledgeable when it comes to mapping cars. They lent me tools to swap things over and helped when stuff got a bit difficult. They even cut down an alloy pipe and re-swaged it for me.

 

Also a big thanks to Dave (Numbnutz) for wiring up my new ECU. If he hadn't of helped with this the mapping couldn't have happened.

[mambosasa]

Good work Leigh. Did you notice the difference in sound post inlet swap? Your engine really keeps on giving. Must be epic to drive.

[Dr H]

Bis - was trying to listen to the engine tonight on the way back but constant traffic and really bad rain meant I couldn't really push it. But I don't think it's made that much of a difference TBH.

 

Took 4.5 hrs to do a 2 hr 10 min journey................

[Steve J]

If you're not seeing the gains with the better flowing inlet and TB that others are then maybe something else is restricting. Possibly post engine I.e. manifold cat exhaust ?

What filter are you running?

 

 

[scatty]

Lovely...

 

Time to chuck those pesky cats in the bin....;-)

[Dr H]

If you're not seeing the gains with the better flowing inlet and TB that others are then maybe something else is restricting. Possibly post engine I.e. manifold cat exhaust ?

What filter are you running?

 

There was another car there that had a straight inlet, same manifold ex man, same back box. It had no cat, JDM cams (as opposed to my A3s) a standard throttle body and also some porting of the charger bit of the inlet manifold. It made 329 and 214. So a good 5% up on torque and 8hp up on mine with a straight inlet and standard TB.

 

So it really does seem that different engines just like different setups. I doubt the lack of a CAT would give so much more torque. Mine is a 100 cell race CAT. Maybe it's just a stronger engine!

 

As Sam said himself, you can't tell the car what power to make. You run it, listen to it (figuratively) and then give it what it wants/needs. Then it will make the best power it can and nothing more.

[Steve J]

Dont the JDM cams give better torque anyway?

[Phil S1]

However you look at it, that's still an impressive graph Leigh................I'm hoping for something similar from mine on Tuesday at Area 52

[jonnyfox]

OO nice Leigh!

[Dr H]

After looking a my results and 3 other cars all running JDM cams I really think that JDM cams are better in the real world.

 

They give more torque from about 4-8k than the A3s. The A3s gives slightly more power and just don't drop off towards the rev limit (where the JDMs do). Who drives their car at 8K+ revs all the time....?

 

If you want to rebuild your Honda to rev to 10k then get A3 cams as they will keep on delivering the power to those levels. If not just get JDMs, Cheaper and better for the vast majority of situations I'd swap my 4 extra hp for 5% extra torque across a big chunk of the rev range. Why did I have to spend shit loads to work this out!