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NA Build


adamc

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I will be shortly starting my NA build. Before we go any further I am fully aware the reward, £ per hp isn’t anywhere near FI however, I am not trying to build a 400-500hp car. I already have a fast, fun, turbo car and very much enjoy the NA drivability of the 350z on track so have decided to go the NA route. 300whp would be perfect IMO.

 

My plan is the following, built from a stock vq35de engine:

vq37 crank

vq37 forged rods

cosworth high compression pistons (11:1)

cams (unsure which yet) 

Uprated valve springs 

plus all the usual bolt on mods including exhaust manifolds oil cooler etc.

not sure on sump options yet (any advise?)

 

 

One of my questions is what cams would people recommend, Tomei 272 (high/low?) or some JWT or something else?

 

I have done a fair amount of searching and reading however can’t find many people doing the ‘poor mans stroker’ option to make it a 3.7L, any reasons behind this other than cost?

 

Thanks

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Ah sorry, I didn't see you were new to the forum !
Use this area to check out what people are up to:
https://www.350z-uk.com/forum/156-member-build-projects/

 

And this is his build specifically (starting with an HR as his base, where as I'm a DE):

 

 

I don't have a build thread as I mentioned, I tend to just post bits here and there (car isn't finished of course):

 

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On 06/06/2019 at 17:39, adamc said:

I will be shortly starting my NA build. Before we go any further I am fully aware the reward, £ per hp isn’t anywhere near FI however, I am not trying to build a 400-500hp car. I already have a fast, fun, turbo car and very much enjoy the NA drivability of the 350z on track so have decided to go the NA route. 300whp would be perfect IMO.

 

My plan is the following, built from a stock vq35de engine:

vq37 crank

vq37 forged rods

cosworth high compression pistons (11:1)

cams (unsure which yet) 

Uprated valve springs 

plus all the usual bolt on mods including exhaust manifolds oil cooler etc.

not sure on sump options yet (any advise?)

 

 

One of my questions is what cams would people recommend, Tomei 272 (high/low?) or some JWT or something else?

 

I have done a fair amount of searching and reading however can’t find many people doing the ‘poor mans stroker’ option to make it a 3.7L, any reasons behind this other than cost?

 

Thanks

 

Firstly good luck with your build, as you say £ to Hp the trades not good but £ to driving pleasure I think n/a tuning is the way to go!

Like you I think 400hp is the dream target however don't get too obsessed with the numbers as their is so much rubbish written about hp gains especially from the states, just accept you'll be making huge gains over stock otherwise you could be very disappointed!

 

The plan you've listed above wont work as the blocks are completely different. The journals on the VQ37 crank are larger than the DE uses, you could get the block line bored to enlarge them however I think you'd may well hit issues with running the oil pump etc

The VQ37 block's deck height was also increased over the DE's so you'd have to work out rod lengths and piston pin heights to work with that. It can all be done but you're not going down an easy route there.

 

The later 350z HR engines use the same block as the VQ37 so it makes the conversion easier. (assuming you'd then use the very good VQ35HR heads) The crank is a drop in and you could use the VQ37 rods but the pistons don't offer the valve clearances you'd need so a custom piston would be required. Using a HR engine in a DE can be done but that itself would require a few modifications to the car itself and obviously the ecu loom......think Mark at Abbey carried this out on his car so could fill you in with what's required there but overall I'd say a 3.7lt HR engine conversion is the way you wanna go.

 

Re cams I went with the Tomei 272 10.8 cams purely as they are the maximum you can run for piston/valve clearance, they are still a mild cam although a great upgrade over standard specs. If you're doing a build you'd go with the 282 11/11.3 Tomei offer or as you say try and speak with JWT

 

Not so poor man stroker kit after all!!

Edited by 350Butcher
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Wow - thank you for your replies, much more detail than I was expecting. I have had a good read of your both your projects and have certainly learnt a thing or two. 

It looks like I am going to have to tweak my plan slightly and move away from the 3.7Loption.

 

350butcher - as you say I am not too hung up on numbers, my main plan is to make the car a bit more lively and exciting.

I plan to keep the de motor but thinking of going high compression pistons to help with the power and give me more camshaft options, some nice exhaust manifolds and either forged rods or arp rod bolts to help future proof the engine. 

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53 minutes ago, adamc said:

Wow - thank you for your replies, much more detail than I was expecting. I have had a good read of your both your projects and have certainly learnt a thing or two. 

It looks like I am going to have to tweak my plan slightly and move away from the 3.7Loption.

 

350butcher - as you say I am not too hung up on numbers, my main plan is to make the car a bit more lively and exciting.

I plan to keep the de motor but thinking of going high compression pistons to help with the power and give me more camshaft options, some nice exhaust manifolds and either forged rods or arp rod bolts to help future proof the engine. 

 

Sticking with the DE engine, you want to follow what Rob's doing with his car as he's putting up some genuinely good and truthful info about his modifications and the gains on offer in both terms on numbers and subjectively changing the driving of the car.

 

I'd definitely swap out the rods and not just change bolts as the rod itself is weak and will be your limiting factor.......there's weight savings to be had as well as the strength benefits.

 

Look forward to following your progress with it when you've got your plan and ready to get building

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  • 4 weeks later...

I found for HR that exhaust manifolds, long tube cai, custom exhaust & hfc gave a really nice gain bhp wise...But from a drivers perspective, the cams (also Tomei’s 10mm lift) helped the power curve, paired with the JWT light weight clutch upgrade it now drives amazing and I’d say that they (and poly bushes) have been the best mods I’ve done so far as have made the car so much nicer to drive.. also just upgraded suspension which has made it feel awesome!

 

Completely agree with 350Butcher on the numbers side of things. I’ve spent ££££ on it now, especially as I don’t have a garage and have to rely on my mechanic more than I’d like... if you can do the engine work yourself you’ll save loads!

 

By now I’d of paid most of FI build off but I wanted to keep NA for now at least. if you want 400bhp you will have to FI.. I got 347 but will need to throw loads more at it to increase it now.

 

Also, if you’re doing the cams you should replace the other acillarys & (gallery) gaskets too.

 

Edited by Foo56
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  • 2 weeks later...

Considering the huge restriction and gain on these engines has been proved to be the intake side (hence why the HR with dual TBs and better plenum makes so much more power, higher in the rev range and responds even better to basic breathing mods like decat, exhaust, intake)

 

...why not put the money into a ITB setup with standalone ECU instead? I would think there's at least one well know tuner in the UK that's done a ITB install with ECU on one of these...

 

Add the biggest cams you can with stock internals and you would be looking at between 315-340 whp depending on other mods.

 

Heck, Sasha Anis made 326 whp with an open DE plenum and custom 300° cams on stock DE internals: http://www.superstreetonline.com/how-to/engine/modp-1303-nissan-350z-vq35de-engine-build

 

...before it got sick with built engine and ITBs doing 370+ whp.

Edited by msitpro
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  • 4 months later...

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