Although I am still along way off finishing the body on my track sprint I started thinking about the engine. Whilst I know it will be hard and pricy I was thinking about aiming for one of the following targets.
(A) I wanted 200bhp at the fly
(B) I wanted 200bhp at the wheels
I intend to TBI with Vems ecu & tubular exhaust manifold.
Presumably I would also need to to dowl the head - block and manifolds, run a block brace, balanced crank, lightened flywheel, cams and ported head I would also like to go dry sump and electric water pump. But what else would I need to do do.
Neil.
Engine advice needed.
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SPRINTPARTS
200BHP
Simple answer,
(A). A LOT OF MONEY
(B). A LOT MORE MONEY and I don't know if this figure is GENUINELY achievable.
To have 200bhp at rear wheels you would be looking at 240-250bhp flywheel, and although there might be some people say they can achieve this I don't believe them. If this is the HP that really want look at another type of motor, ie Toyota, Honda etc.
Mark
(A). A LOT OF MONEY
(B). A LOT MORE MONEY and I don't know if this figure is GENUINELY achievable.
To have 200bhp at rear wheels you would be looking at 240-250bhp flywheel, and although there might be some people say they can achieve this I don't believe them. If this is the HP that really want look at another type of motor, ie Toyota, Honda etc.
Mark
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Neil907
Re: 200BHP
thought that might be the answer.SPRINTPARTS wrote: (B). A LOT MORE MONEY and I don't know if this figure is GENUINELY achievable.
If i was going to do an engine swap it would be for a rotary turbo with an easy 350+ bhp but I would rather just get the most I can from a sprint.
Im a good 9 months of touching the engine at the the minute just want some ideas to ponder upon so I can make the right decision.
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SPRINTPARTS
Weight Reduction
Something else that I should add.
If we are talking a race car or track car, look at weight reduction rather than spending a s##t load of money on a motor for it to go bang when it is being run in.
If the rules that you run under allow weight reduction then this will be more cost effective improvement in performance than a big buck motor. A standard Sprint with roll cage will weigh around 1000kg, depending on type of cage, then bigger brakes and wheels all ADD weight.
Remove everything that is not required, use minimum length bolts where possible. Make a new wiring harness with just what you require, carbon fibre bonnet, boot and maybe even door skins. Remove glass and replace with Lexan. Pick light weight wheels, alloy brake caliper, light weight brake rotors. Small fuel cell and minimum fuel load for each run.
The list can go on, alloy radiator, light weight exhaust and alloy muffler, alloy shock adsorders with small springs.
It all comes down to cost (budget). A weight reduction to say 900kg will be better than 10% power gain, because you have the added benefit of less weight to stop and to throw into a corner.
Mark
If we are talking a race car or track car, look at weight reduction rather than spending a s##t load of money on a motor for it to go bang when it is being run in.
If the rules that you run under allow weight reduction then this will be more cost effective improvement in performance than a big buck motor. A standard Sprint with roll cage will weigh around 1000kg, depending on type of cage, then bigger brakes and wheels all ADD weight.
Remove everything that is not required, use minimum length bolts where possible. Make a new wiring harness with just what you require, carbon fibre bonnet, boot and maybe even door skins. Remove glass and replace with Lexan. Pick light weight wheels, alloy brake caliper, light weight brake rotors. Small fuel cell and minimum fuel load for each run.
The list can go on, alloy radiator, light weight exhaust and alloy muffler, alloy shock adsorders with small springs.
It all comes down to cost (budget). A weight reduction to say 900kg will be better than 10% power gain, because you have the added benefit of less weight to stop and to throw into a corner.
Mark
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Neil907
Funny you should metion that that my goal is 900Kg. Its a weld in multi point cage so will be quite heavy. I intend to use it use for track days and hill climbsand autotests so rules will not be an issue. Lexan windows and lightweight panels are all on the list.
So what in your eyes would be a sensible amount of power to aim for.
cheers for all the advice.
So what in your eyes would be a sensible amount of power to aim for.
cheers for all the advice.
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SPRINTPARTS
Budget
Horsepower and reliabilty will both be dependant on the budget you have for the motor.
If you build the motor yourself, you may not get the same output that a "professional" engine builder will get, or "say that they will get", but you will save heaps of money, or will have more money to spend on other goodies.
I would be considering parts that will increase reliability as the first priority, because it is not point building a high HP motor that goes bang the first time you push it. Baffled sump, nitrided crank, etc. If you run a high lift camshaft, make sure that the valve springs that you use are suitable for the cam lift. ARP conrod bolts, and ideally forged pistons if you wish to rev the motor hard. If you intended to run 7000+rpm consider fitting a girdle plate to the block.
180+BHP should be achievable without to much pain, but it does depend on MONEY, BHP=MONEY
Mark[/list]
If you build the motor yourself, you may not get the same output that a "professional" engine builder will get, or "say that they will get", but you will save heaps of money, or will have more money to spend on other goodies.
I would be considering parts that will increase reliability as the first priority, because it is not point building a high HP motor that goes bang the first time you push it. Baffled sump, nitrided crank, etc. If you run a high lift camshaft, make sure that the valve springs that you use are suitable for the cam lift. ARP conrod bolts, and ideally forged pistons if you wish to rev the motor hard. If you intended to run 7000+rpm consider fitting a girdle plate to the block.
180+BHP should be achievable without to much pain, but it does depend on MONEY, BHP=MONEY
Mark[/list]
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Dollyboy
just a suggestion, all this hardcore engineering is over my head but for some guidelines i reckon its worth talking to the jedi master (dolly racer 33), i think his race sprint makes about 190+ at the wheels. if you asked him really nicely he could also build you a sprint engine which will achieve the 240 odd hp needed to give you that at the wheels, but mark is of course and as usual correct, its all about how much you can afford to throw at it. jedi race spec engine will set you back some serious ££££.
my jigsaw fast road spec should make 180-190hp at the flywheel, its a similar spec to marts track car, i.e. mahle pistons, 45DCOE's, DMS1 cam, ported, aldon dizzy, lumention ign, nitrided crank, lightened, balanced etc etc. that cost me over 2k (using my old engine, my cam, my webers etc that are not included in the 2k).
i did get my sump mod'd included in that money, it's got a little 'box' on each side with one-way flaps in it which in theory will keep the oil pickup immersed under very hard cornering. oil capacity is nearly doubled, and thats more weight. downside is that i'll need to lift the lump off the subframe to remove the starter motor. as far as i know jigsaw are the only folk in the uk with the pattern for that sump, but baffles will probably do almost as well
mines just a road car (well it will be one day) that may get treated to the odd track day, i really dont intend to drive her hard all the time, for the money ive spent i want some reliability and some enjoyment out of her!!
my jigsaw fast road spec should make 180-190hp at the flywheel, its a similar spec to marts track car, i.e. mahle pistons, 45DCOE's, DMS1 cam, ported, aldon dizzy, lumention ign, nitrided crank, lightened, balanced etc etc. that cost me over 2k (using my old engine, my cam, my webers etc that are not included in the 2k).
i did get my sump mod'd included in that money, it's got a little 'box' on each side with one-way flaps in it which in theory will keep the oil pickup immersed under very hard cornering. oil capacity is nearly doubled, and thats more weight. downside is that i'll need to lift the lump off the subframe to remove the starter motor. as far as i know jigsaw are the only folk in the uk with the pattern for that sump, but baffles will probably do almost as well
mines just a road car (well it will be one day) that may get treated to the odd track day, i really dont intend to drive her hard all the time, for the money ive spent i want some reliability and some enjoyment out of her!!
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Neil907
As I said above I intend to look into dry sumping it. I had planned to to talk to him some point in the future, Right now Im just trying to get an idea of what is possible and just how much that will cost. As far as money goes 4k is around the figure I currently have bugeted in my head but that could easily change in either direction and I intend to do a large percentage of the work myself.
Again cheers for the sound advice.
Again cheers for the sound advice.
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trackerjack
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