4350 replies to this topic

[JG]

which exhaust?

[chris_uk]

Ots a custom one he had made.

[chris_uk]

Aslong as there are no probs with the injectors etc and the engine is safe and healthy, id be quite happy with that outcome. Nearly an extra 40ft/lb will deffinatly not go un-noticed.

[Nev]

G-Bob wins the car sticker.

348 BHP and 301 lbft

Very happy with the hike in torque, I only wish the BHP could have matched it. The only thing we can pinpoint as a possible restriction is the exhaust system otherwise we should have matched the Harrop'd 370 they have seen before.

A nice step in the right direction

How much are your inlet valves lifting Mike and what's their open duration? Also what's the I/D of your exhaust primaries and the rest of the exhaust as a matter of interest?

[Mike (Cliffie)]

Aslong as there are no probs with the injectors etc and the engine is safe and healthy, id be quite happy with that outcome.

Nearly an extra 40ft/lb will deffinatly not go un-noticed.

I am happy with it to be honest Chris and it is plenty fast enough for me, it is just that others have made more and you can't help wanting the same power level as them.

[chris_uk]

It will only start to cause problems having any more power imo better to stick with what is 100% safe plus you having confidence in the car not having underlying issues is worth that little drop in power. Come up to mine on sat 4th and we can have a good day sunday going over the car, spanner check, good wash and clean etc etc.

[Exmantaa]

And the results are in; anybody fancy a sweepstake?

The before figures were 333 BHP and 264 Lbft.

Two changes were 2.9 pulley to 2.75 and the addition of the Bosch 044 pump.

Did they look to the boost pressure and intake temps with that small pulley?? Ultimate had very high IAT temps with his 75mm (2.95) pulley and my mate with a 80mm Harrop already tips the 50*C with spirited road driving. (1.45bar boost though due to a restrictive exhaust.) Both on 2.0 engines though.

Hope the engine is still within safe limits for race use...

[G-Bob]

G-Bob wins the car sticker.

348 BHP and 301 lbft

Very happy with the hike in torque, I only wish the BHP could have matched it. The only thing we can pinpoint as a possible restriction is the exhaust system otherwise we should have matched the Harrop'd 370 they have seen before.

Sooooooo close! I won something?

The torque in the midrange will help you inbetween the corners when not at full revs, so it all helps.

[Mike (Cliffie)]

And the results are in; anybody fancy a sweepstake?

The before figures were 333 BHP and 264 Lbft.

Two changes were 2.9 pulley to 2.75 and the addition of the Bosch 044 pump.

Did they look to the boost pressure and intake temps with that small pulley?? Ultimate had very high IAT temps with his 75mm (2.95) pulley and my mate with a 80mm Harrop already tips the 50*C with spirited road driving. (1.45bar boost though due to a restrictive exhaust.) Both on 2.0 engines though.

Hope the engine is still within safe limits for race use...

It is mapped on the safe side.

IETs will always be the enemy but I can take cool down laps in Time Attack so not all is lost.

Edited by Cliffie, 18 April 2013 - 01:19 PM.

[vocky]

348 BHP and 301 lbft

Very happy with the hike in torque, I only wish the BHP could have matched it. The only thing we can pinpoint as a possible restriction is the exhaust system otherwise we should have matched the Harrop'd 370 they have seen before.

that is a nice result

I have to agree that the exhaust manifold is perhaps a little too small for a Harrop

But at least you are well below the limit of the liners

[Mike (Cliffie)]

G-Bob wins the car sticker.

348 BHP and 301 lbft

Very happy with the hike in torque, I only wish the BHP could have matched it. The only thing we can pinpoint as a possible restriction is the exhaust system otherwise we should have matched the Harrop'd 370 they have seen before.

A nice step in the right direction

How much are your inlet valves lifting Mike and what's their open duration? Also what's the I/D of your exhaust primaries and the rest of the exhaust as a matter of interest?

No idea Nev, Cocky timed the cams and may know. They are blower cams.

Primaries are 1.75 I believe.

[Aerodynamic]

Which size of exhaust do you run? Regards, Per

[Mike (Cliffie)]

Which size of exhaust do you run?

Regards, Per

3" system with 1.75 primaries.

[Nev]

Primaries are 1.75 I believe.

1.75" primaries are quite large IMO (assuming that's the I/D), I don't think your restriction will be from that. Nippers are considerably smaller than that for instance. The 3" pipework might be a mild restriction at a guess. I did some calcs on nipper using gas laws to calculate the thermal expansion of gasses and thence the flow speeds to be expected in a 3" pipe. You could do the same - the results will scare you most likely! LOL

As a matter of interest, at what power level and torque level would you consider "enough" for the kind of tracks you are on? ie at what point is any more power useless (assuming a dry and warm day and semi-sticky tyres).

Edited by Nev, 18 April 2013 - 09:06 PM.

[jameso]

I think tracks have a way of always leaving you wanting for more power. Cars can feel very fast on road but as soon as you come out of a corner onto the back straight I can never have enough power I think

[Bumblebee]

I think tracks have a way of always leaving you wanting for more power. Cars can feel very fast on road but as soon as you come out of a corner onto the back straight I can never have enough power I think

Sounds like it could be Garrett time

[jameso]

Sadly £££ means stopping at stage 4 really. Anything else should be money saved towards an Atom

Edited by jameso, 18 April 2013 - 09:30 PM.

[Bumblebee]

Think it would have to be an ultima for me that's if I wanted to track

[NickB787]

G-Bob wins the car sticker.

348 BHP and 301 lbft

Very happy with the hike in torque, I only wish the BHP could have matched it. The only thing we can pinpoint as a possible restriction is the exhaust system otherwise we should have matched the Harrop'd 370 they have seen before.

Which size of exhaust do you run?

Regards, Per

3" system with 1.75 primaries.

with a 2.75 pulley I would have said 380+ bhp

Both on a 3"system, think my primaries are the same size also, your comp blower cams aren't you? one thing which may be different is Jim put a really BIG cat on mine, unless there is a difference in back box?

Edited by NickB777, 19 April 2013 - 07:27 AM.

[Scuffers]

Mikes is not helped by being a miss-match port wise... his is a 4-2-1 where they have paired 1&2 and 3&4, quite what they were thinking I don't understand... (if you're going down the 4-2-1 route, it's 1&4 and 2&3). Also, looking at them, I don't think his primaries are 1.75", they look smaller than that (that said, I have not measured them). Realistically, 3" is plenty big enough for 400+ hp, as with most things, it's the detail in the design and construction that are key. All that said, it's making decent power and to be blunt, it's not lack of power that's holding Mike back (when he gets to the point that the logging shows 70%+ of the lap time on WOT, that's the time to chase more power)