Performance of 400hp
Performance of 400hp
Author
Discussion

Mjpmark

Original Poster:

746 posts

213 months

Monday 23rd March 2009
quotequote all
Guys,

Never have i been so torn between decisions.
Does anyone have any idea what the performance is like with a 400hp Audi V8 engine, or other engine with 400hp.

Is it pointless should i be looking at larger figures.
Will i be left standing by porsches etc. I dont want to invest. Sorry i mean spend all this money only to find the car not quite upto the level i expect!

I have been told that over 450hp there are traction issues, but lets not beat around the bush. Do i need more than 400HP.

Ive had M3's, M5's etc so i know what 400hp is like i just cant imagine it with the lesser weight.

Advise would be appreciated.

Cheers

mark

Stig

11,823 posts

313 months

Monday 23rd March 2009
quotequote all
All I can say, from experience of having a 630hp and 400hp Ultima, is that for most mere mortals, they will both outpace most things.

It's the 'package' that makes the performance, not just the engine. The main benefit is that the Ultima is so light (relatively speaking) compared to mainstream cars.

Nothing wrong with either approach, but on a track, other than outright vmax on a straight, there's not a lot between them.

Gulf -LS7

1,922 posts

233 months

Monday 23rd March 2009
quotequote all
hi Mark

what do you want to use the car for???

ive driven a 400bhp car and it was not enough for me!!! but we are all different!!!i think 600bhp is where i want to be.

400bhp would not be enough on trackdays imo but im sure someone will think it is, i think the the Audi is a lovely motor but again imo the LS range beats it in everyway apart from revs...... im sure some people will disagree but we are talking in an Ultima application not in general.

Mjpmark

Original Poster:

746 posts

213 months

Monday 23rd March 2009
quotequote all
Guys,

Im afriad due to my commitments, track days will be more of special occasion rather than the norm. So its street setup for me.

Any idea of 0 - 60 times etc?

Cheers

mark

GreenV8S

31,014 posts

313 months

Monday 23rd March 2009
quotequote all
Stig said:
The main benefit is that the Ultima is so light (relatively speaking) compared to mainstream cars.
Just out of curiosity, how much do they weigh?

738 driver

1,202 posts

222 months

Monday 23rd March 2009
quotequote all
Mark, I would also consider future plans too. 400 multi-valve, hi-tech horses might be good for you now but in twelve/eighteen months time when you want a bit/lot more how do-able is it? Would it be like starting from scratch, new engine, box ,adapter plate, clutch, starter, headers etc,etc,etc?.....could be quite scary and costly unless you are an engine/engineering enthusiast!
At least the SBC/LS motors have room for improvement/development later on....their parts are still relatively cheap and tons of tuning experience out there.
Can-Am Dave's is an excellent example of possible bolt-on performance and could be done without many of the above hassles!


Around 950-1000KG AUW.

Edited by 738 driver on Monday 23 March 23:44

Wilder

1,509 posts

238 months

Tuesday 24th March 2009
quotequote all
For road use the Audi engine i think would be a good proposition and be very road friendly.
It should also be quite rapid at around 1,000kg. ( around 3.5 secs to 60 & perhaps 8.5 secs to 100mph
You can go totally bonkers (like a lot of us have) with over 600 bhp, but if you dont need that level of performance (and cost!), why bother?

ROWDYRENAULT

1,294 posts

243 months

Tuesday 24th March 2009
quotequote all
I have a 565hp LS1 the car is faster than I am. I will attempt over time to do the package justice but it ain't happenin yet. I think that the fellow who suggested a LS and than add power as you are on pace with the car makes a lot of sense. Car and Driver did a article here in the states several years ago on a smog legal LS1 in a GTR with about 350 hp and they turned a SUB 4 SEC 0-60. you can buy 400hp LS3s for $5k. Run it on the factory computor fly by wire with traction control and away you go. Lee

LuckyP

6,243 posts

254 months

Tuesday 24th March 2009
quotequote all
Depends which Porsches you want to play with.

My 550 SBC on drag events is a good match to the 650bhp AWD moded turbos. I've had plenty of fun with a good buddy of mine on here with each of us having a fair share of the spoils.

Traction is what you make of it. Feather it in and plant it when you have grip - not rocket science.

I just couldn't imagine turning up to an event with any less power, wouldn't do the car justice.

However, if as you say your think is road use, 400bhp will see you matching a std Turbo. But IMHO leave you forever thinking, what if?

HTH

Pete

Mjpmark

Original Poster:

746 posts

213 months

Tuesday 24th March 2009
quotequote all
Thanks Guys.

Your input is appreciated, i will let you know how i get on.




Stig

11,823 posts

313 months

Tuesday 24th March 2009
quotequote all
LuckyP said:
Depends which Porsches you want to play with.

My 550 SBC on drag events is a good match to the 650bhp AWD moded turbos. I've had plenty of fun with a good buddy of mine on here with each of us having a fair share of the spoils.

Traction is what you make of it. Feather it in and plant it when you have grip - not rocket science.

I just couldn't imagine turning up to an event with any less power, wouldn't do the car justice.

However, if as you say your think is road use, 400bhp will see you matching a std Turbo. But IMHO leave you forever thinking, what if?

HTH

Pete
Agree for drag events, but my comparison was for circuits. A well pedalled 400hp car will keep up with more powerful stuff without issue.

But, it depends on what you want. More power will help mask the inadequacies of the driver of course hehewink

LuckyP

6,243 posts

254 months

Tuesday 24th March 2009
quotequote all
Stig said:
LuckyP said:
Depends which Porsches you want to play with.

My 550 SBC on drag events is a good match to the 650bhp AWD moded turbos. I've had plenty of fun with a good buddy of mine on here with each of us having a fair share of the spoils.

Traction is what you make of it. Feather it in and plant it when you have grip - not rocket science.

I just couldn't imagine turning up to an event with any less power, wouldn't do the car justice.

However, if as you say your think is road use, 400bhp will see you matching a std Turbo. But IMHO leave you forever thinking, what if?

HTH

Pete
Agree for drag events, but my comparison was for circuits. A well pedalled 400hp car will keep up with more powerful stuff without issue.

But, it depends on what you want. More power will help mask the inadequacies of the driver of course hehewink
Totally agree Stig. On track you are then relying on low COG, grip and weight advantages over heavier more powerful cars.

In fact it might be slightly easier to drive a lower power car closer to it's limits on track coz you aren't constantly stuggling for traction on the exits?

deadscoob

2,265 posts

289 months

Tuesday 24th March 2009
quotequote all
But a well pedalled 400hp Ultima won't keep up with a well pedalled 600hp Ultima will it. As soon as there is a straight, it pulls away, next corner there's no difference, next straight it pulls away further etc.

Steve_D

13,802 posts

287 months

Tuesday 24th March 2009
quotequote all
Mark
It has been suggested that the Audi may not be the best route as it leaves little scope for adding power but you have not responded to this.

I too feel you will be limiting yourself and making it very difficult to add power later. One of the LS series engines would offer more.

I will not ponder on the issues of resale value.

Steve

qwick

530 posts

296 months

Tuesday 24th March 2009
quotequote all
Why not put the Audi engine in and turbo charge it if and when you want more power? After all isn't there a factory bolt on twin turbo option from Audi pushing 450bhp as standard? You can map it and install bigger injectors for more power thereafter.

Here's a good thread showing a 650bhp Audi lump, Audi is nice and light and a good box for it is the 2.7 diesel transaxle, apparently it bolts straight on to the 4.2 (worth checking - speak to scottyboy).

http://www.pistonheads.com/gassing/topic.asp?f=20&...

These guys look like they know what they're on about too.

http://www.technocars.de/index-engl.htm

Cheers, Rich

Stig

11,823 posts

313 months

Tuesday 24th March 2009
quotequote all
LuckyP said:
Stig said:
LuckyP said:
Depends which Porsches you want to play with.

My 550 SBC on drag events is a good match to the 650bhp AWD moded turbos. I've had plenty of fun with a good buddy of mine on here with each of us having a fair share of the spoils.

Traction is what you make of it. Feather it in and plant it when you have grip - not rocket science.

I just couldn't imagine turning up to an event with any less power, wouldn't do the car justice.

However, if as you say your think is road use, 400bhp will see you matching a std Turbo. But IMHO leave you forever thinking, what if?

HTH

Pete
Agree for drag events, but my comparison was for circuits. A well pedalled 400hp car will keep up with more powerful stuff without issue.

But, it depends on what you want. More power will help mask the inadequacies of the driver of course hehewink
Totally agree Stig. On track you are then relying on low COG, grip and weight advantages over heavier more powerful cars.

In fact it might be slightly easier to drive a lower power car closer to it's limits on track coz you aren't constantly stuggling for traction on the exits?
Absolutely Pete. There's nothing worse than to drive a car that you know (if you're honest with yourself) is a lot more capable than you are - not to mention the constant niggle of 'what if I stuff it?' which tends to slow you down a fair bit.

I've said it before and I'll say it again (yawn wink ), try to rationalise why you're building the car and what you'll use it for.

Ultimately, the higher the state of tune, the more 'attention' it will need. A milder, more reliable motor may suit you better - or you may opt for a more ballistic but possibly fragile setup?

The nice thing is, you can always lob in a nice mild unit (SBC) and then upgrade as time/needs/funds permit?

Stig

11,823 posts

313 months

Tuesday 24th March 2009
quotequote all
deadscoob said:
But a well pedalled 400hp Ultima won't keep up with a well pedalled 600hp Ultima will it. As soon as there is a straight, it pulls away, next corner there's no difference, next straight it pulls away further etc.
Fair point - but in reality, how often does that happen? wink

As long as you can dust most trackday cars, who cares?

smile

Mjpmark

Original Poster:

746 posts

213 months

Tuesday 24th March 2009
quotequote all
Right heres my plan.

Stick with the audi at approx 400bhp, then with the help of a few friends in the know. Install an after market Supercharger.

Then were talking anything from 500 - 600hp that should be enough to keep me happy from what i can gather.

Decisions decisions, and im guessing thats a fairly easy one to make!

738 driver

1,202 posts

222 months

Tuesday 24th March 2009
quotequote all
Sounds like a plan and different too!..... it will hopefully be a very nice end product.
As you are in business yourself Mark, I'm sure you have researched the number of suppliers who can support your planned R&D and offer ongoing tech/running support within the UK.
Good luck ......it will be interesting and certainly enhances your cars' individuality.

spatz

1,783 posts

215 months

Tuesday 24th March 2009
quotequote all
not sure if the audi engine can be easily brought to 500-600hp engine. My R8 FSI is 420hp stock
and MTM is bringing it to 550hp (35k EURO) with a charger, but they do usually more
powerful setups in RS6 and RS4 that are turbocharged.
I think the LS7 route is maybe smarter which will give you 550hp
aspirated with much room on top for the approx same price. And I do not know your skills but the Audi setup
will require a lot of custom parts whereas with the LS7 you can find almost anything from the shelf.

Edited by spatz on Tuesday 24th March 14:04


Edited by spatz on Tuesday 24th March 14:04